Merge branch 'maint' into tj/imap-send-remove-unused

* maint: (18123 commits)
  documentation fix: git difftool uses diff tools, not merge tools.
  Git 1.7.7.4
  Makefile: add missing header file dependencies
  notes merge: eliminate OUTPUT macro
  mailmap: xcalloc mailmap_info
  name-rev --all: do not even attempt to describe non-commit object
  Git 1.7.7.3
  docs: Update install-doc-quick
  docs: don't mention --quiet or --exit-code in git-log(1)
  Git 1.7.7.2
  t7511: avoid use of reserved filename on Windows.
  clone: Quote user supplied path in a single quote pair
  read-cache.c: fix index memory allocation
  make the sample pre-commit hook script reject names with newlines, too
  Reindent closing bracket using tab instead of spaces
  Git 1.7.7.1
  RelNotes/1.7.7.1: setgid bit patch is about fixing "git init" via Makefile setting
  gitweb: fix regression when filtering out forks
  Almost ready for 1.7.7.1
  pack-objects: don't traverse objects unnecessarily
  ...

Conflicts:
	imap-send.c

92 files changed, 46371 insertions, 0 deletions

diff --git a/builtin/add.c b/builtin/add.c
new file mode 100644
index 0000000..c59b0c9
--- /dev/null
+++ b/builtin/add.c
@@ -0,0 +1,474 @@
+/*
+ * "git add" builtin command
+ *
+ * Copyright (C) 2006 Linus Torvalds
+ */
+#include "cache.h"
+#include "builtin.h"
+#include "dir.h"
+#include "exec_cmd.h"
+#include "cache-tree.h"
+#include "run-command.h"
+#include "parse-options.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
+
+static const char * const builtin_add_usage[] = {
+	"git add [options] [--] <filepattern>...",
+	NULL
+};
+static int patch_interactive, add_interactive, edit_interactive;
+static int take_worktree_changes;
+
+struct update_callback_data {
+	int flags;
+	int add_errors;
+};
+
+static int fix_unmerged_status(struct diff_filepair *p,
+			       struct update_callback_data *data)
+{
+	if (p->status != DIFF_STATUS_UNMERGED)
+		return p->status;
+	if (!(data->flags & ADD_CACHE_IGNORE_REMOVAL) && !p->two->mode)
+		/*
+		 * This is not an explicit add request, and the
+		 * path is missing from the working tree (deleted)
+		 */
+		return DIFF_STATUS_DELETED;
+	else
+		/*
+		 * Either an explicit add request, or path exists
+		 * in the working tree.  An attempt to explicitly
+		 * add a path that does not exist in the working tree
+		 * will be caught as an error by the caller immediately.
+		 */
+		return DIFF_STATUS_MODIFIED;
+}
+
+static void update_callback(struct diff_queue_struct *q,
+			    struct diff_options *opt, void *cbdata)
+{
+	int i;
+	struct update_callback_data *data = cbdata;
+
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		const char *path = p->one->path;
+		switch (fix_unmerged_status(p, data)) {
+		default:
+			die(_("unexpected diff status %c"), p->status);
+		case DIFF_STATUS_MODIFIED:
+		case DIFF_STATUS_TYPE_CHANGED:
+			if (add_file_to_index(&the_index, path, data->flags)) {
+				if (!(data->flags & ADD_CACHE_IGNORE_ERRORS))
+					die(_("updating files failed"));
+				data->add_errors++;
+			}
+			break;
+		case DIFF_STATUS_DELETED:
+			if (data->flags & ADD_CACHE_IGNORE_REMOVAL)
+				break;
+			if (!(data->flags & ADD_CACHE_PRETEND))
+				remove_file_from_index(&the_index, path);
+			if (data->flags & (ADD_CACHE_PRETEND|ADD_CACHE_VERBOSE))
+				printf(_("remove '%s'\n"), path);
+			break;
+		}
+	}
+}
+
+int add_files_to_cache(const char *prefix, const char **pathspec, int flags)
+{
+	struct update_callback_data data;
+	struct rev_info rev;
+	init_revisions(&rev, prefix);
+	setup_revisions(0, NULL, &rev, NULL);
+	init_pathspec(&rev.prune_data, pathspec);
+	rev.diffopt.output_format = DIFF_FORMAT_CALLBACK;
+	rev.diffopt.format_callback = update_callback;
+	data.flags = flags;
+	data.add_errors = 0;
+	rev.diffopt.format_callback_data = &data;
+	rev.max_count = 0; /* do not compare unmerged paths with stage #2 */
+	run_diff_files(&rev, DIFF_RACY_IS_MODIFIED);
+	return !!data.add_errors;
+}
+
+static void fill_pathspec_matches(const char **pathspec, char *seen, int specs)
+{
+	int num_unmatched = 0, i;
+
+	/*
+	 * Since we are walking the index as if we were walking the directory,
+	 * we have to mark the matched pathspec as seen; otherwise we will
+	 * mistakenly think that the user gave a pathspec that did not match
+	 * anything.
+	 */
+	for (i = 0; i < specs; i++)
+		if (!seen[i])
+			num_unmatched++;
+	if (!num_unmatched)
+		return;
+	for (i = 0; i < active_nr; i++) {
+		struct cache_entry *ce = active_cache[i];
+		match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, seen);
+	}
+}
+
+static char *find_used_pathspec(const char **pathspec)
+{
+	char *seen;
+	int i;
+
+	for (i = 0; pathspec[i];  i++)
+		; /* just counting */
+	seen = xcalloc(i, 1);
+	fill_pathspec_matches(pathspec, seen, i);
+	return seen;
+}
+
+static char *prune_directory(struct dir_struct *dir, const char **pathspec, int prefix)
+{
+	char *seen;
+	int i, specs;
+	struct dir_entry **src, **dst;
+
+	for (specs = 0; pathspec[specs];  specs++)
+		/* nothing */;
+	seen = xcalloc(specs, 1);
+
+	src = dst = dir->entries;
+	i = dir->nr;
+	while (--i >= 0) {
+		struct dir_entry *entry = *src++;
+		if (match_pathspec(pathspec, entry->name, entry->len,
+				   prefix, seen))
+			*dst++ = entry;
+	}
+	dir->nr = dst - dir->entries;
+	fill_pathspec_matches(pathspec, seen, specs);
+	return seen;
+}
+
+static void treat_gitlinks(const char **pathspec)
+{
+	int i;
+
+	if (!pathspec || !*pathspec)
+		return;
+
+	for (i = 0; i < active_nr; i++) {
+		struct cache_entry *ce = active_cache[i];
+		if (S_ISGITLINK(ce->ce_mode)) {
+			int len = ce_namelen(ce), j;
+			for (j = 0; pathspec[j]; j++) {
+				int len2 = strlen(pathspec[j]);
+				if (len2 <= len || pathspec[j][len] != '/' ||
+				    memcmp(ce->name, pathspec[j], len))
+					continue;
+				if (len2 == len + 1)
+					/* strip trailing slash */
+					pathspec[j] = xstrndup(ce->name, len);
+				else
+					die (_("Path '%s' is in submodule '%.*s'"),
+						pathspec[j], len, ce->name);
+			}
+		}
+	}
+}
+
+static void refresh(int verbose, const char **pathspec)
+{
+	char *seen;
+	int i, specs;
+
+	for (specs = 0; pathspec[specs];  specs++)
+		/* nothing */;
+	seen = xcalloc(specs, 1);
+	refresh_index(&the_index, verbose ? REFRESH_IN_PORCELAIN : REFRESH_QUIET,
+		      pathspec, seen, _("Unstaged changes after refreshing the index:"));
+	for (i = 0; i < specs; i++) {
+		if (!seen[i])
+			die(_("pathspec '%s' did not match any files"), pathspec[i]);
+	}
+        free(seen);
+}
+
+static const char **validate_pathspec(int argc, const char **argv, const char *prefix)
+{
+	const char **pathspec = get_pathspec(prefix, argv);
+
+	if (pathspec) {
+		const char **p;
+		for (p = pathspec; *p; p++) {
+			if (has_symlink_leading_path(*p, strlen(*p))) {
+				int len = prefix ? strlen(prefix) : 0;
+				die(_("'%s' is beyond a symbolic link"), *p + len);
+			}
+		}
+	}
+
+	return pathspec;
+}
+
+int run_add_interactive(const char *revision, const char *patch_mode,
+			const char **pathspec)
+{
+	int status, ac, pc = 0;
+	const char **args;
+
+	if (pathspec)
+		while (pathspec[pc])
+			pc++;
+
+	args = xcalloc(sizeof(const char *), (pc + 5));
+	ac = 0;
+	args[ac++] = "add--interactive";
+	if (patch_mode)
+		args[ac++] = patch_mode;
+	if (revision)
+		args[ac++] = revision;
+	args[ac++] = "--";
+	if (pc) {
+		memcpy(&(args[ac]), pathspec, sizeof(const char *) * pc);
+		ac += pc;
+	}
+	args[ac] = NULL;
+
+	status = run_command_v_opt(args, RUN_GIT_CMD);
+	free(args);
+	return status;
+}
+
+int interactive_add(int argc, const char **argv, const char *prefix, int patch)
+{
+	const char **pathspec = NULL;
+
+	if (argc) {
+		pathspec = validate_pathspec(argc, argv, prefix);
+		if (!pathspec)
+			return -1;
+	}
+
+	return run_add_interactive(NULL,
+				   patch ? "--patch" : NULL,
+				   pathspec);
+}
+
+static int edit_patch(int argc, const char **argv, const char *prefix)
+{
+	char *file = xstrdup(git_path("ADD_EDIT.patch"));
+	const char *apply_argv[] = { "apply", "--recount", "--cached",
+		NULL, NULL };
+	struct child_process child;
+	struct rev_info rev;
+	int out;
+	struct stat st;
+
+	apply_argv[3] = file;
+
+	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
+
+	if (read_cache() < 0)
+		die (_("Could not read the index"));
+
+	init_revisions(&rev, prefix);
+	rev.diffopt.context = 7;
+
+	argc = setup_revisions(argc, argv, &rev, NULL);
+	rev.diffopt.output_format = DIFF_FORMAT_PATCH;
+	out = open(file, O_CREAT | O_WRONLY, 0644);
+	if (out < 0)
+		die (_("Could not open '%s' for writing."), file);
+	rev.diffopt.file = xfdopen(out, "w");
+	rev.diffopt.close_file = 1;
+	if (run_diff_files(&rev, 0))
+		die (_("Could not write patch"));
+
+	launch_editor(file, NULL, NULL);
+
+	if (stat(file, &st))
+		die_errno(_("Could not stat '%s'"), file);
+	if (!st.st_size)
+		die(_("Empty patch. Aborted."));
+
+	memset(&child, 0, sizeof(child));
+	child.git_cmd = 1;
+	child.argv = apply_argv;
+	if (run_command(&child))
+		die (_("Could not apply '%s'"), file);
+
+	unlink(file);
+	return 0;
+}
+
+static struct lock_file lock_file;
+
+static const char ignore_error[] =
+N_("The following paths are ignored by one of your .gitignore files:\n");
+
+static int verbose = 0, show_only = 0, ignored_too = 0, refresh_only = 0;
+static int ignore_add_errors, addremove, intent_to_add, ignore_missing = 0;
+
+static struct option builtin_add_options[] = {
+	OPT__DRY_RUN(&show_only, "dry run"),
+	OPT__VERBOSE(&verbose, "be verbose"),
+	OPT_GROUP(""),
+	OPT_BOOLEAN('i', "interactive", &add_interactive, "interactive picking"),
+	OPT_BOOLEAN('p', "patch", &patch_interactive, "select hunks interactively"),
+	OPT_BOOLEAN('e', "edit", &edit_interactive, "edit current diff and apply"),
+	OPT__FORCE(&ignored_too, "allow adding otherwise ignored files"),
+	OPT_BOOLEAN('u', "update", &take_worktree_changes, "update tracked files"),
+	OPT_BOOLEAN('N', "intent-to-add", &intent_to_add, "record only the fact that the path will be added later"),
+	OPT_BOOLEAN('A', "all", &addremove, "add changes from all tracked and untracked files"),
+	OPT_BOOLEAN( 0 , "refresh", &refresh_only, "don't add, only refresh the index"),
+	OPT_BOOLEAN( 0 , "ignore-errors", &ignore_add_errors, "just skip files which cannot be added because of errors"),
+	OPT_BOOLEAN( 0 , "ignore-missing", &ignore_missing, "check if - even missing - files are ignored in dry run"),
+	OPT_END(),
+};
+
+static int add_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "add.ignoreerrors") ||
+	    !strcmp(var, "add.ignore-errors")) {
+		ignore_add_errors = git_config_bool(var, value);
+		return 0;
+	}
+	return git_default_config(var, value, cb);
+}
+
+static int add_files(struct dir_struct *dir, int flags)
+{
+	int i, exit_status = 0;
+
+	if (dir->ignored_nr) {
+		fprintf(stderr, _(ignore_error));
+		for (i = 0; i < dir->ignored_nr; i++)
+			fprintf(stderr, "%s\n", dir->ignored[i]->name);
+		fprintf(stderr, _("Use -f if you really want to add them.\n"));
+		die(_("no files added"));
+	}
+
+	for (i = 0; i < dir->nr; i++)
+		if (add_file_to_cache(dir->entries[i]->name, flags)) {
+			if (!ignore_add_errors)
+				die(_("adding files failed"));
+			exit_status = 1;
+		}
+	return exit_status;
+}
+
+int cmd_add(int argc, const char **argv, const char *prefix)
+{
+	int exit_status = 0;
+	int newfd;
+	const char **pathspec;
+	struct dir_struct dir;
+	int flags;
+	int add_new_files;
+	int require_pathspec;
+	char *seen = NULL;
+
+	git_config(add_config, NULL);
+
+	argc = parse_options(argc, argv, prefix, builtin_add_options,
+			  builtin_add_usage, PARSE_OPT_KEEP_ARGV0);
+	if (patch_interactive)
+		add_interactive = 1;
+	if (add_interactive)
+		exit(interactive_add(argc - 1, argv + 1, prefix, patch_interactive));
+
+	if (edit_interactive)
+		return(edit_patch(argc, argv, prefix));
+	argc--;
+	argv++;
+
+	if (addremove && take_worktree_changes)
+		die(_("-A and -u are mutually incompatible"));
+	if (!show_only && ignore_missing)
+		die(_("Option --ignore-missing can only be used together with --dry-run"));
+	if ((addremove || take_worktree_changes) && !argc) {
+		static const char *here[2] = { ".", NULL };
+		argc = 1;
+		argv = here;
+	}
+
+	add_new_files = !take_worktree_changes && !refresh_only;
+	require_pathspec = !take_worktree_changes;
+
+	newfd = hold_locked_index(&lock_file, 1);
+
+	flags = ((verbose ? ADD_CACHE_VERBOSE : 0) |
+		 (show_only ? ADD_CACHE_PRETEND : 0) |
+		 (intent_to_add ? ADD_CACHE_INTENT : 0) |
+		 (ignore_add_errors ? ADD_CACHE_IGNORE_ERRORS : 0) |
+		 (!(addremove || take_worktree_changes)
+		  ? ADD_CACHE_IGNORE_REMOVAL : 0));
+
+	if (require_pathspec && argc == 0) {
+		fprintf(stderr, _("Nothing specified, nothing added.\n"));
+		fprintf(stderr, _("Maybe you wanted to say 'git add .'?\n"));
+		return 0;
+	}
+	pathspec = validate_pathspec(argc, argv, prefix);
+
+	if (read_cache() < 0)
+		die(_("index file corrupt"));
+	treat_gitlinks(pathspec);
+
+	if (add_new_files) {
+		int baselen;
+
+		/* Set up the default git porcelain excludes */
+		memset(&dir, 0, sizeof(dir));
+		if (!ignored_too) {
+			dir.flags |= DIR_COLLECT_IGNORED;
+			setup_standard_excludes(&dir);
+		}
+
+		/* This picks up the paths that are not tracked */
+		baselen = fill_directory(&dir, pathspec);
+		if (pathspec)
+			seen = prune_directory(&dir, pathspec, baselen);
+	}
+
+	if (refresh_only) {
+		refresh(verbose, pathspec);
+		goto finish;
+	}
+
+	if (pathspec) {
+		int i;
+		if (!seen)
+			seen = find_used_pathspec(pathspec);
+		for (i = 0; pathspec[i]; i++) {
+			if (!seen[i] && pathspec[i][0]
+			    && !file_exists(pathspec[i])) {
+				if (ignore_missing) {
+					int dtype = DT_UNKNOWN;
+					if (excluded(&dir, pathspec[i], &dtype))
+						dir_add_ignored(&dir, pathspec[i], strlen(pathspec[i]));
+				} else
+					die(_("pathspec '%s' did not match any files"),
+					    pathspec[i]);
+			}
+		}
+		free(seen);
+	}
+
+	exit_status |= add_files_to_cache(prefix, pathspec, flags);
+
+	if (add_new_files)
+		exit_status |= add_files(&dir, flags);
+
+ finish:
+	if (active_cache_changed) {
+		if (write_cache(newfd, active_cache, active_nr) ||
+		    commit_locked_index(&lock_file))
+			die(_("Unable to write new index file"));
+	}
+
+	return exit_status;
+}
diff --git a/builtin/annotate.c b/builtin/annotate.c
new file mode 100644
index 0000000..fc43eed
--- /dev/null
+++ b/builtin/annotate.c
@@ -0,0 +1,24 @@
+/*
+ * "git annotate" builtin alias
+ *
+ * Copyright (C) 2006 Ryan Anderson
+ */
+#include "git-compat-util.h"
+#include "builtin.h"
+
+int cmd_annotate(int argc, const char **argv, const char *prefix)
+{
+	const char **nargv;
+	int i;
+	nargv = xmalloc(sizeof(char *) * (argc + 2));
+
+	nargv[0] = "annotate";
+	nargv[1] = "-c";
+
+	for (i = 1; i < argc; i++) {
+		nargv[i+1] = argv[i];
+	}
+	nargv[argc + 1] = NULL;
+
+	return cmd_blame(argc + 1, nargv, prefix);
+}
diff --git a/builtin/apply.c b/builtin/apply.c
new file mode 100644
index 0000000..311a94e
--- /dev/null
+++ b/builtin/apply.c
@@ -0,0 +1,3996 @@
+/*
+ * apply.c
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ *
+ * This applies patches on top of some (arbitrary) version of the SCM.
+ *
+ */
+#include "cache.h"
+#include "cache-tree.h"
+#include "quote.h"
+#include "blob.h"
+#include "delta.h"
+#include "builtin.h"
+#include "string-list.h"
+#include "dir.h"
+#include "parse-options.h"
+
+/*
+ *  --check turns on checking that the working tree matches the
+ *    files that are being modified, but doesn't apply the patch
+ *  --stat does just a diffstat, and doesn't actually apply
+ *  --numstat does numeric diffstat, and doesn't actually apply
+ *  --index-info shows the old and new index info for paths if available.
+ *  --index updates the cache as well.
+ *  --cached updates only the cache without ever touching the working tree.
+ */
+static const char *prefix;
+static int prefix_length = -1;
+static int newfd = -1;
+
+static int unidiff_zero;
+static int p_value = 1;
+static int p_value_known;
+static int check_index;
+static int update_index;
+static int cached;
+static int diffstat;
+static int numstat;
+static int summary;
+static int check;
+static int apply = 1;
+static int apply_in_reverse;
+static int apply_with_reject;
+static int apply_verbosely;
+static int allow_overlap;
+static int no_add;
+static const char *fake_ancestor;
+static int line_termination = '\n';
+static unsigned int p_context = UINT_MAX;
+static const char * const apply_usage[] = {
+	"git apply [options] [<patch>...]",
+	NULL
+};
+
+static enum ws_error_action {
+	nowarn_ws_error,
+	warn_on_ws_error,
+	die_on_ws_error,
+	correct_ws_error
+} ws_error_action = warn_on_ws_error;
+static int whitespace_error;
+static int squelch_whitespace_errors = 5;
+static int applied_after_fixing_ws;
+
+static enum ws_ignore {
+	ignore_ws_none,
+	ignore_ws_change
+} ws_ignore_action = ignore_ws_none;
+
+
+static const char *patch_input_file;
+static const char *root;
+static int root_len;
+static int read_stdin = 1;
+static int options;
+
+static void parse_whitespace_option(const char *option)
+{
+	if (!option) {
+		ws_error_action = warn_on_ws_error;
+		return;
+	}
+	if (!strcmp(option, "warn")) {
+		ws_error_action = warn_on_ws_error;
+		return;
+	}
+	if (!strcmp(option, "nowarn")) {
+		ws_error_action = nowarn_ws_error;
+		return;
+	}
+	if (!strcmp(option, "error")) {
+		ws_error_action = die_on_ws_error;
+		return;
+	}
+	if (!strcmp(option, "error-all")) {
+		ws_error_action = die_on_ws_error;
+		squelch_whitespace_errors = 0;
+		return;
+	}
+	if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
+		ws_error_action = correct_ws_error;
+		return;
+	}
+	die("unrecognized whitespace option '%s'", option);
+}
+
+static void parse_ignorewhitespace_option(const char *option)
+{
+	if (!option || !strcmp(option, "no") ||
+	    !strcmp(option, "false") || !strcmp(option, "never") ||
+	    !strcmp(option, "none")) {
+		ws_ignore_action = ignore_ws_none;
+		return;
+	}
+	if (!strcmp(option, "change")) {
+		ws_ignore_action = ignore_ws_change;
+		return;
+	}
+	die("unrecognized whitespace ignore option '%s'", option);
+}
+
+static void set_default_whitespace_mode(const char *whitespace_option)
+{
+	if (!whitespace_option && !apply_default_whitespace)
+		ws_error_action = (apply ? warn_on_ws_error : nowarn_ws_error);
+}
+
+/*
+ * For "diff-stat" like behaviour, we keep track of the biggest change
+ * we've seen, and the longest filename. That allows us to do simple
+ * scaling.
+ */
+static int max_change, max_len;
+
+/*
+ * Various "current state", notably line numbers and what
+ * file (and how) we're patching right now.. The "is_xxxx"
+ * things are flags, where -1 means "don't know yet".
+ */
+static int linenr = 1;
+
+/*
+ * This represents one "hunk" from a patch, starting with
+ * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
+ * patch text is pointed at by patch, and its byte length
+ * is stored in size.  leading and trailing are the number
+ * of context lines.
+ */
+struct fragment {
+	unsigned long leading, trailing;
+	unsigned long oldpos, oldlines;
+	unsigned long newpos, newlines;
+	const char *patch;
+	int size;
+	int rejected;
+	int linenr;
+	struct fragment *next;
+};
+
+/*
+ * When dealing with a binary patch, we reuse "leading" field
+ * to store the type of the binary hunk, either deflated "delta"
+ * or deflated "literal".
+ */
+#define binary_patch_method leading
+#define BINARY_DELTA_DEFLATED	1
+#define BINARY_LITERAL_DEFLATED 2
+
+/*
+ * This represents a "patch" to a file, both metainfo changes
+ * such as creation/deletion, filemode and content changes represented
+ * as a series of fragments.
+ */
+struct patch {
+	char *new_name, *old_name, *def_name;
+	unsigned int old_mode, new_mode;
+	int is_new, is_delete;	/* -1 = unknown, 0 = false, 1 = true */
+	int rejected;
+	unsigned ws_rule;
+	unsigned long deflate_origlen;
+	int lines_added, lines_deleted;
+	int score;
+	unsigned int is_toplevel_relative:1;
+	unsigned int inaccurate_eof:1;
+	unsigned int is_binary:1;
+	unsigned int is_copy:1;
+	unsigned int is_rename:1;
+	unsigned int recount:1;
+	struct fragment *fragments;
+	char *result;
+	size_t resultsize;
+	char old_sha1_prefix[41];
+	char new_sha1_prefix[41];
+	struct patch *next;
+};
+
+/*
+ * A line in a file, len-bytes long (includes the terminating LF,
+ * except for an incomplete line at the end if the file ends with
+ * one), and its contents hashes to 'hash'.
+ */
+struct line {
+	size_t len;
+	unsigned hash : 24;
+	unsigned flag : 8;
+#define LINE_COMMON     1
+#define LINE_PATCHED	2
+};
+
+/*
+ * This represents a "file", which is an array of "lines".
+ */
+struct image {
+	char *buf;
+	size_t len;
+	size_t nr;
+	size_t alloc;
+	struct line *line_allocated;
+	struct line *line;
+};
+
+/*
+ * Records filenames that have been touched, in order to handle
+ * the case where more than one patches touch the same file.
+ */
+
+static struct string_list fn_table;
+
+static uint32_t hash_line(const char *cp, size_t len)
+{
+	size_t i;
+	uint32_t h;
+	for (i = 0, h = 0; i < len; i++) {
+		if (!isspace(cp[i])) {
+			h = h * 3 + (cp[i] & 0xff);
+		}
+	}
+	return h;
+}
+
+/*
+ * Compare lines s1 of length n1 and s2 of length n2, ignoring
+ * whitespace difference. Returns 1 if they match, 0 otherwise
+ */
+static int fuzzy_matchlines(const char *s1, size_t n1,
+			    const char *s2, size_t n2)
+{
+	const char *last1 = s1 + n1 - 1;
+	const char *last2 = s2 + n2 - 1;
+	int result = 0;
+
+	if (n1 < 0 || n2 < 0)
+		return 0;
+
+	/* ignore line endings */
+	while ((*last1 == '\r') || (*last1 == '\n'))
+		last1--;
+	while ((*last2 == '\r') || (*last2 == '\n'))
+		last2--;
+
+	/* skip leading whitespace */
+	while (isspace(*s1) && (s1 <= last1))
+		s1++;
+	while (isspace(*s2) && (s2 <= last2))
+		s2++;
+	/* early return if both lines are empty */
+	if ((s1 > last1) && (s2 > last2))
+		return 1;
+	while (!result) {
+		result = *s1++ - *s2++;
+		/*
+		 * Skip whitespace inside. We check for whitespace on
+		 * both buffers because we don't want "a b" to match
+		 * "ab"
+		 */
+		if (isspace(*s1) && isspace(*s2)) {
+			while (isspace(*s1) && s1 <= last1)
+				s1++;
+			while (isspace(*s2) && s2 <= last2)
+				s2++;
+		}
+		/*
+		 * If we reached the end on one side only,
+		 * lines don't match
+		 */
+		if (
+		    ((s2 > last2) && (s1 <= last1)) ||
+		    ((s1 > last1) && (s2 <= last2)))
+			return 0;
+		if ((s1 > last1) && (s2 > last2))
+			break;
+	}
+
+	return !result;
+}
+
+static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
+{
+	ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
+	img->line_allocated[img->nr].len = len;
+	img->line_allocated[img->nr].hash = hash_line(bol, len);
+	img->line_allocated[img->nr].flag = flag;
+	img->nr++;
+}
+
+static void prepare_image(struct image *image, char *buf, size_t len,
+			  int prepare_linetable)
+{
+	const char *cp, *ep;
+
+	memset(image, 0, sizeof(*image));
+	image->buf = buf;
+	image->len = len;
+
+	if (!prepare_linetable)
+		return;
+
+	ep = image->buf + image->len;
+	cp = image->buf;
+	while (cp < ep) {
+		const char *next;
+		for (next = cp; next < ep && *next != '\n'; next++)
+			;
+		if (next < ep)
+			next++;
+		add_line_info(image, cp, next - cp, 0);
+		cp = next;
+	}
+	image->line = image->line_allocated;
+}
+
+static void clear_image(struct image *image)
+{
+	free(image->buf);
+	image->buf = NULL;
+	image->len = 0;
+}
+
+static void say_patch_name(FILE *output, const char *pre,
+			   struct patch *patch, const char *post)
+{
+	fputs(pre, output);
+	if (patch->old_name && patch->new_name &&
+	    strcmp(patch->old_name, patch->new_name)) {
+		quote_c_style(patch->old_name, NULL, output, 0);
+		fputs(" => ", output);
+		quote_c_style(patch->new_name, NULL, output, 0);
+	} else {
+		const char *n = patch->new_name;
+		if (!n)
+			n = patch->old_name;
+		quote_c_style(n, NULL, output, 0);
+	}
+	fputs(post, output);
+}
+
+#define CHUNKSIZE (8192)
+#define SLOP (16)
+
+static void read_patch_file(struct strbuf *sb, int fd)
+{
+	if (strbuf_read(sb, fd, 0) < 0)
+		die_errno("git apply: failed to read");
+
+	/*
+	 * Make sure that we have some slop in the buffer
+	 * so that we can do speculative "memcmp" etc, and
+	 * see to it that it is NUL-filled.
+	 */
+	strbuf_grow(sb, SLOP);
+	memset(sb->buf + sb->len, 0, SLOP);
+}
+
+static unsigned long linelen(const char *buffer, unsigned long size)
+{
+	unsigned long len = 0;
+	while (size--) {
+		len++;
+		if (*buffer++ == '\n')
+			break;
+	}
+	return len;
+}
+
+static int is_dev_null(const char *str)
+{
+	return !memcmp("/dev/null", str, 9) && isspace(str[9]);
+}
+
+#define TERM_SPACE	1
+#define TERM_TAB	2
+
+static int name_terminate(const char *name, int namelen, int c, int terminate)
+{
+	if (c == ' ' && !(terminate & TERM_SPACE))
+		return 0;
+	if (c == '\t' && !(terminate & TERM_TAB))
+		return 0;
+
+	return 1;
+}
+
+/* remove double slashes to make --index work with such filenames */
+static char *squash_slash(char *name)
+{
+	int i = 0, j = 0;
+
+	if (!name)
+		return NULL;
+
+	while (name[i]) {
+		if ((name[j++] = name[i++]) == '/')
+			while (name[i] == '/')
+				i++;
+	}
+	name[j] = '\0';
+	return name;
+}
+
+static char *find_name_gnu(const char *line, char *def, int p_value)
+{
+	struct strbuf name = STRBUF_INIT;
+	char *cp;
+
+	/*
+	 * Proposed "new-style" GNU patch/diff format; see
+	 * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
+	 */
+	if (unquote_c_style(&name, line, NULL)) {
+		strbuf_release(&name);
+		return NULL;
+	}
+
+	for (cp = name.buf; p_value; p_value--) {
+		cp = strchr(cp, '/');
+		if (!cp) {
+			strbuf_release(&name);
+			return NULL;
+		}
+		cp++;
+	}
+
+	/* name can later be freed, so we need
+	 * to memmove, not just return cp
+	 */
+	strbuf_remove(&name, 0, cp - name.buf);
+	free(def);
+	if (root)
+		strbuf_insert(&name, 0, root, root_len);
+	return squash_slash(strbuf_detach(&name, NULL));
+}
+
+static size_t sane_tz_len(const char *line, size_t len)
+{
+	const char *tz, *p;
+
+	if (len < strlen(" +0500") || line[len-strlen(" +0500")] != ' ')
+		return 0;
+	tz = line + len - strlen(" +0500");
+
+	if (tz[1] != '+' && tz[1] != '-')
+		return 0;
+
+	for (p = tz + 2; p != line + len; p++)
+		if (!isdigit(*p))
+			return 0;
+
+	return line + len - tz;
+}
+
+static size_t tz_with_colon_len(const char *line, size_t len)
+{
+	const char *tz, *p;
+
+	if (len < strlen(" +08:00") || line[len - strlen(":00")] != ':')
+		return 0;
+	tz = line + len - strlen(" +08:00");
+
+	if (tz[0] != ' ' || (tz[1] != '+' && tz[1] != '-'))
+		return 0;
+	p = tz + 2;
+	if (!isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
+	    !isdigit(*p++) || !isdigit(*p++))
+		return 0;
+
+	return line + len - tz;
+}
+
+static size_t date_len(const char *line, size_t len)
+{
+	const char *date, *p;
+
+	if (len < strlen("72-02-05") || line[len-strlen("-05")] != '-')
+		return 0;
+	p = date = line + len - strlen("72-02-05");
+
+	if (!isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
+	    !isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
+	    !isdigit(*p++) || !isdigit(*p++))	/* Not a date. */
+		return 0;
+
+	if (date - line >= strlen("19") &&
+	    isdigit(date[-1]) && isdigit(date[-2]))	/* 4-digit year */
+		date -= strlen("19");
+
+	return line + len - date;
+}
+
+static size_t short_time_len(const char *line, size_t len)
+{
+	const char *time, *p;
+
+	if (len < strlen(" 07:01:32") || line[len-strlen(":32")] != ':')
+		return 0;
+	p = time = line + len - strlen(" 07:01:32");
+
+	/* Permit 1-digit hours? */
+	if (*p++ != ' ' ||
+	    !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
+	    !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
+	    !isdigit(*p++) || !isdigit(*p++))	/* Not a time. */
+		return 0;
+
+	return line + len - time;
+}
+
+static size_t fractional_time_len(const char *line, size_t len)
+{
+	const char *p;
+	size_t n;
+
+	/* Expected format: 19:41:17.620000023 */
+	if (!len || !isdigit(line[len - 1]))
+		return 0;
+	p = line + len - 1;
+
+	/* Fractional seconds. */
+	while (p > line && isdigit(*p))
+		p--;
+	if (*p != '.')
+		return 0;
+
+	/* Hours, minutes, and whole seconds. */
+	n = short_time_len(line, p - line);
+	if (!n)
+		return 0;
+
+	return line + len - p + n;
+}
+
+static size_t trailing_spaces_len(const char *line, size_t len)
+{
+	const char *p;
+
+	/* Expected format: ' ' x (1 or more)  */
+	if (!len || line[len - 1] != ' ')
+		return 0;
+
+	p = line + len;
+	while (p != line) {
+		p--;
+		if (*p != ' ')
+			return line + len - (p + 1);
+	}
+
+	/* All spaces! */
+	return len;
+}
+
+static size_t diff_timestamp_len(const char *line, size_t len)
+{
+	const char *end = line + len;
+	size_t n;
+
+	/*
+	 * Posix: 2010-07-05 19:41:17
+	 * GNU: 2010-07-05 19:41:17.620000023 -0500
+	 */
+
+	if (!isdigit(end[-1]))
+		return 0;
+
+	n = sane_tz_len(line, end - line);
+	if (!n)
+		n = tz_with_colon_len(line, end - line);
+	end -= n;
+
+	n = short_time_len(line, end - line);
+	if (!n)
+		n = fractional_time_len(line, end - line);
+	end -= n;
+
+	n = date_len(line, end - line);
+	if (!n)	/* No date.  Too bad. */
+		return 0;
+	end -= n;
+
+	if (end == line)	/* No space before date. */
+		return 0;
+	if (end[-1] == '\t') {	/* Success! */
+		end--;
+		return line + len - end;
+	}
+	if (end[-1] != ' ')	/* No space before date. */
+		return 0;
+
+	/* Whitespace damage. */
+	end -= trailing_spaces_len(line, end - line);
+	return line + len - end;
+}
+
+static char *find_name_common(const char *line, char *def, int p_value,
+				const char *end, int terminate)
+{
+	int len;
+	const char *start = NULL;
+
+	if (p_value == 0)
+		start = line;
+	while (line != end) {
+		char c = *line;
+
+		if (!end && isspace(c)) {
+			if (c == '\n')
+				break;
+			if (name_terminate(start, line-start, c, terminate))
+				break;
+		}
+		line++;
+		if (c == '/' && !--p_value)
+			start = line;
+	}
+	if (!start)
+		return squash_slash(def);
+	len = line - start;
+	if (!len)
+		return squash_slash(def);
+
+	/*
+	 * Generally we prefer the shorter name, especially
+	 * if the other one is just a variation of that with
+	 * something else tacked on to the end (ie "file.orig"
+	 * or "file~").
+	 */
+	if (def) {
+		int deflen = strlen(def);
+		if (deflen < len && !strncmp(start, def, deflen))
+			return squash_slash(def);
+		free(def);
+	}
+
+	if (root) {
+		char *ret = xmalloc(root_len + len + 1);
+		strcpy(ret, root);
+		memcpy(ret + root_len, start, len);
+		ret[root_len + len] = '\0';
+		return squash_slash(ret);
+	}
+
+	return squash_slash(xmemdupz(start, len));
+}
+
+static char *find_name(const char *line, char *def, int p_value, int terminate)
+{
+	if (*line == '"') {
+		char *name = find_name_gnu(line, def, p_value);
+		if (name)
+			return name;
+	}
+
+	return find_name_common(line, def, p_value, NULL, terminate);
+}
+
+static char *find_name_traditional(const char *line, char *def, int p_value)
+{
+	size_t len = strlen(line);
+	size_t date_len;
+
+	if (*line == '"') {
+		char *name = find_name_gnu(line, def, p_value);
+		if (name)
+			return name;
+	}
+
+	len = strchrnul(line, '\n') - line;
+	date_len = diff_timestamp_len(line, len);
+	if (!date_len)
+		return find_name_common(line, def, p_value, NULL, TERM_TAB);
+	len -= date_len;
+
+	return find_name_common(line, def, p_value, line + len, 0);
+}
+
+static int count_slashes(const char *cp)
+{
+	int cnt = 0;
+	char ch;
+
+	while ((ch = *cp++))
+		if (ch == '/')
+			cnt++;
+	return cnt;
+}
+
+/*
+ * Given the string after "--- " or "+++ ", guess the appropriate
+ * p_value for the given patch.
+ */
+static int guess_p_value(const char *nameline)
+{
+	char *name, *cp;
+	int val = -1;
+
+	if (is_dev_null(nameline))
+		return -1;
+	name = find_name_traditional(nameline, NULL, 0);
+	if (!name)
+		return -1;
+	cp = strchr(name, '/');
+	if (!cp)
+		val = 0;
+	else if (prefix) {
+		/*
+		 * Does it begin with "a/$our-prefix" and such?  Then this is
+		 * very likely to apply to our directory.
+		 */
+		if (!strncmp(name, prefix, prefix_length))
+			val = count_slashes(prefix);
+		else {
+			cp++;
+			if (!strncmp(cp, prefix, prefix_length))
+				val = count_slashes(prefix) + 1;
+		}
+	}
+	free(name);
+	return val;
+}
+
+/*
+ * Does the ---/+++ line has the POSIX timestamp after the last HT?
+ * GNU diff puts epoch there to signal a creation/deletion event.  Is
+ * this such a timestamp?
+ */
+static int has_epoch_timestamp(const char *nameline)
+{
+	/*
+	 * We are only interested in epoch timestamp; any non-zero
+	 * fraction cannot be one, hence "(\.0+)?" in the regexp below.
+	 * For the same reason, the date must be either 1969-12-31 or
+	 * 1970-01-01, and the seconds part must be "00".
+	 */
+	const char stamp_regexp[] =
+		"^(1969-12-31|1970-01-01)"
+		" "
+		"[0-2][0-9]:[0-5][0-9]:00(\\.0+)?"
+		" "
+		"([-+][0-2][0-9]:?[0-5][0-9])\n";
+	const char *timestamp = NULL, *cp, *colon;
+	static regex_t *stamp;
+	regmatch_t m[10];
+	int zoneoffset;
+	int hourminute;
+	int status;
+
+	for (cp = nameline; *cp != '\n'; cp++) {
+		if (*cp == '\t')
+			timestamp = cp + 1;
+	}
+	if (!timestamp)
+		return 0;
+	if (!stamp) {
+		stamp = xmalloc(sizeof(*stamp));
+		if (regcomp(stamp, stamp_regexp, REG_EXTENDED)) {
+			warning("Cannot prepare timestamp regexp %s",
+				stamp_regexp);
+			return 0;
+		}
+	}
+
+	status = regexec(stamp, timestamp, ARRAY_SIZE(m), m, 0);
+	if (status) {
+		if (status != REG_NOMATCH)
+			warning("regexec returned %d for input: %s",
+				status, timestamp);
+		return 0;
+	}
+
+	zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
+	if (*colon == ':')
+		zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
+	else
+		zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
+	if (timestamp[m[3].rm_so] == '-')
+		zoneoffset = -zoneoffset;
+
+	/*
+	 * YYYY-MM-DD hh:mm:ss must be from either 1969-12-31
+	 * (west of GMT) or 1970-01-01 (east of GMT)
+	 */
+	if ((zoneoffset < 0 && memcmp(timestamp, "1969-12-31", 10)) ||
+	    (0 <= zoneoffset && memcmp(timestamp, "1970-01-01", 10)))
+		return 0;
+
+	hourminute = (strtol(timestamp + 11, NULL, 10) * 60 +
+		      strtol(timestamp + 14, NULL, 10) -
+		      zoneoffset);
+
+	return ((zoneoffset < 0 && hourminute == 1440) ||
+		(0 <= zoneoffset && !hourminute));
+}
+
+/*
+ * Get the name etc info from the ---/+++ lines of a traditional patch header
+ *
+ * FIXME! The end-of-filename heuristics are kind of screwy. For existing
+ * files, we can happily check the index for a match, but for creating a
+ * new file we should try to match whatever "patch" does. I have no idea.
+ */
+static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
+{
+	char *name;
+
+	first += 4;	/* skip "--- " */
+	second += 4;	/* skip "+++ " */
+	if (!p_value_known) {
+		int p, q;
+		p = guess_p_value(first);
+		q = guess_p_value(second);
+		if (p < 0) p = q;
+		if (0 <= p && p == q) {
+			p_value = p;
+			p_value_known = 1;
+		}
+	}
+	if (is_dev_null(first)) {
+		patch->is_new = 1;
+		patch->is_delete = 0;
+		name = find_name_traditional(second, NULL, p_value);
+		patch->new_name = name;
+	} else if (is_dev_null(second)) {
+		patch->is_new = 0;
+		patch->is_delete = 1;
+		name = find_name_traditional(first, NULL, p_value);
+		patch->old_name = name;
+	} else {
+		name = find_name_traditional(first, NULL, p_value);
+		name = find_name_traditional(second, name, p_value);
+		if (has_epoch_timestamp(first)) {
+			patch->is_new = 1;
+			patch->is_delete = 0;
+			patch->new_name = name;
+		} else if (has_epoch_timestamp(second)) {
+			patch->is_new = 0;
+			patch->is_delete = 1;
+			patch->old_name = name;
+		} else {
+			patch->old_name = patch->new_name = name;
+		}
+	}
+	if (!name)
+		die("unable to find filename in patch at line %d", linenr);
+}
+
+static int gitdiff_hdrend(const char *line, struct patch *patch)
+{
+	return -1;
+}
+
+/*
+ * We're anal about diff header consistency, to make
+ * sure that we don't end up having strange ambiguous
+ * patches floating around.
+ *
+ * As a result, gitdiff_{old|new}name() will check
+ * their names against any previous information, just
+ * to make sure..
+ */
+static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
+{
+	if (!orig_name && !isnull)
+		return find_name(line, NULL, p_value, TERM_TAB);
+
+	if (orig_name) {
+		int len;
+		const char *name;
+		char *another;
+		name = orig_name;
+		len = strlen(name);
+		if (isnull)
+			die("git apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
+		another = find_name(line, NULL, p_value, TERM_TAB);
+		if (!another || memcmp(another, name, len + 1))
+			die("git apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
+		free(another);
+		return orig_name;
+	}
+	else {
+		/* expect "/dev/null" */
+		if (memcmp("/dev/null", line, 9) || line[9] != '\n')
+			die("git apply: bad git-diff - expected /dev/null on line %d", linenr);
+		return NULL;
+	}
+}
+
+static int gitdiff_oldname(const char *line, struct patch *patch)
+{
+	patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
+	return 0;
+}
+
+static int gitdiff_newname(const char *line, struct patch *patch)
+{
+	patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
+	return 0;
+}
+
+static int gitdiff_oldmode(const char *line, struct patch *patch)
+{
+	patch->old_mode = strtoul(line, NULL, 8);
+	return 0;
+}
+
+static int gitdiff_newmode(const char *line, struct patch *patch)
+{
+	patch->new_mode = strtoul(line, NULL, 8);
+	return 0;
+}
+
+static int gitdiff_delete(const char *line, struct patch *patch)
+{
+	patch->is_delete = 1;
+	patch->old_name = patch->def_name;
+	return gitdiff_oldmode(line, patch);
+}
+
+static int gitdiff_newfile(const char *line, struct patch *patch)
+{
+	patch->is_new = 1;
+	patch->new_name = patch->def_name;
+	return gitdiff_newmode(line, patch);
+}
+
+static int gitdiff_copysrc(const char *line, struct patch *patch)
+{
+	patch->is_copy = 1;
+	patch->old_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	return 0;
+}
+
+static int gitdiff_copydst(const char *line, struct patch *patch)
+{
+	patch->is_copy = 1;
+	patch->new_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	return 0;
+}
+
+static int gitdiff_renamesrc(const char *line, struct patch *patch)
+{
+	patch->is_rename = 1;
+	patch->old_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	return 0;
+}
+
+static int gitdiff_renamedst(const char *line, struct patch *patch)
+{
+	patch->is_rename = 1;
+	patch->new_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+	return 0;
+}
+
+static int gitdiff_similarity(const char *line, struct patch *patch)
+{
+	if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
+		patch->score = 0;
+	return 0;
+}
+
+static int gitdiff_dissimilarity(const char *line, struct patch *patch)
+{
+	if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
+		patch->score = 0;
+	return 0;
+}
+
+static int gitdiff_index(const char *line, struct patch *patch)
+{
+	/*
+	 * index line is N hexadecimal, "..", N hexadecimal,
+	 * and optional space with octal mode.
+	 */
+	const char *ptr, *eol;
+	int len;
+
+	ptr = strchr(line, '.');
+	if (!ptr || ptr[1] != '.' || 40 < ptr - line)
+		return 0;
+	len = ptr - line;
+	memcpy(patch->old_sha1_prefix, line, len);
+	patch->old_sha1_prefix[len] = 0;
+
+	line = ptr + 2;
+	ptr = strchr(line, ' ');
+	eol = strchr(line, '\n');
+
+	if (!ptr || eol < ptr)
+		ptr = eol;
+	len = ptr - line;
+
+	if (40 < len)
+		return 0;
+	memcpy(patch->new_sha1_prefix, line, len);
+	patch->new_sha1_prefix[len] = 0;
+	if (*ptr == ' ')
+		patch->old_mode = strtoul(ptr+1, NULL, 8);
+	return 0;
+}
+
+/*
+ * This is normal for a diff that doesn't change anything: we'll fall through
+ * into the next diff. Tell the parser to break out.
+ */
+static int gitdiff_unrecognized(const char *line, struct patch *patch)
+{
+	return -1;
+}
+
+static const char *stop_at_slash(const char *line, int llen)
+{
+	int nslash = p_value;
+	int i;
+
+	for (i = 0; i < llen; i++) {
+		int ch = line[i];
+		if (ch == '/' && --nslash <= 0)
+			return &line[i];
+	}
+	return NULL;
+}
+
+/*
+ * This is to extract the same name that appears on "diff --git"
+ * line.  We do not find and return anything if it is a rename
+ * patch, and it is OK because we will find the name elsewhere.
+ * We need to reliably find name only when it is mode-change only,
+ * creation or deletion of an empty file.  In any of these cases,
+ * both sides are the same name under a/ and b/ respectively.
+ */
+static char *git_header_name(char *line, int llen)
+{
+	const char *name;
+	const char *second = NULL;
+	size_t len, line_len;
+
+	line += strlen("diff --git ");
+	llen -= strlen("diff --git ");
+
+	if (*line == '"') {
+		const char *cp;
+		struct strbuf first = STRBUF_INIT;
+		struct strbuf sp = STRBUF_INIT;
+
+		if (unquote_c_style(&first, line, &second))
+			goto free_and_fail1;
+
+		/* advance to the first slash */
+		cp = stop_at_slash(first.buf, first.len);
+		/* we do not accept absolute paths */
+		if (!cp || cp == first.buf)
+			goto free_and_fail1;
+		strbuf_remove(&first, 0, cp + 1 - first.buf);
+
+		/*
+		 * second points at one past closing dq of name.
+		 * find the second name.
+		 */
+		while ((second < line + llen) && isspace(*second))
+			second++;
+
+		if (line + llen <= second)
+			goto free_and_fail1;
+		if (*second == '"') {
+			if (unquote_c_style(&sp, second, NULL))
+				goto free_and_fail1;
+			cp = stop_at_slash(sp.buf, sp.len);
+			if (!cp || cp == sp.buf)
+				goto free_and_fail1;
+			/* They must match, otherwise ignore */
+			if (strcmp(cp + 1, first.buf))
+				goto free_and_fail1;
+			strbuf_release(&sp);
+			return strbuf_detach(&first, NULL);
+		}
+
+		/* unquoted second */
+		cp = stop_at_slash(second, line + llen - second);
+		if (!cp || cp == second)
+			goto free_and_fail1;
+		cp++;
+		if (line + llen - cp != first.len + 1 ||
+		    memcmp(first.buf, cp, first.len))
+			goto free_and_fail1;
+		return strbuf_detach(&first, NULL);
+
+	free_and_fail1:
+		strbuf_release(&first);
+		strbuf_release(&sp);
+		return NULL;
+	}
+
+	/* unquoted first name */
+	name = stop_at_slash(line, llen);
+	if (!name || name == line)
+		return NULL;
+	name++;
+
+	/*
+	 * since the first name is unquoted, a dq if exists must be
+	 * the beginning of the second name.
+	 */
+	for (second = name; second < line + llen; second++) {
+		if (*second == '"') {
+			struct strbuf sp = STRBUF_INIT;
+			const char *np;
+
+			if (unquote_c_style(&sp, second, NULL))
+				goto free_and_fail2;
+
+			np = stop_at_slash(sp.buf, sp.len);
+			if (!np || np == sp.buf)
+				goto free_and_fail2;
+			np++;
+
+			len = sp.buf + sp.len - np;
+			if (len < second - name &&
+			    !strncmp(np, name, len) &&
+			    isspace(name[len])) {
+				/* Good */
+				strbuf_remove(&sp, 0, np - sp.buf);
+				return strbuf_detach(&sp, NULL);
+			}
+
+		free_and_fail2:
+			strbuf_release(&sp);
+			return NULL;
+		}
+	}
+
+	/*
+	 * Accept a name only if it shows up twice, exactly the same
+	 * form.
+	 */
+	second = strchr(name, '\n');
+	if (!second)
+		return NULL;
+	line_len = second - name;
+	for (len = 0 ; ; len++) {
+		switch (name[len]) {
+		default:
+			continue;
+		case '\n':
+			return NULL;
+		case '\t': case ' ':
+			second = stop_at_slash(name + len, line_len - len);
+			if (!second)
+				return NULL;
+			second++;
+			if (second[len] == '\n' && !strncmp(name, second, len)) {
+				return xmemdupz(name, len);
+			}
+		}
+	}
+}
+
+/* Verify that we recognize the lines following a git header */
+static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
+{
+	unsigned long offset;
+
+	/* A git diff has explicit new/delete information, so we don't guess */
+	patch->is_new = 0;
+	patch->is_delete = 0;
+
+	/*
+	 * Some things may not have the old name in the
+	 * rest of the headers anywhere (pure mode changes,
+	 * or removing or adding empty files), so we get
+	 * the default name from the header.
+	 */
+	patch->def_name = git_header_name(line, len);
+	if (patch->def_name && root) {
+		char *s = xmalloc(root_len + strlen(patch->def_name) + 1);
+		strcpy(s, root);
+		strcpy(s + root_len, patch->def_name);
+		free(patch->def_name);
+		patch->def_name = s;
+	}
+
+	line += len;
+	size -= len;
+	linenr++;
+	for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
+		static const struct opentry {
+			const char *str;
+			int (*fn)(const char *, struct patch *);
+		} optable[] = {
+			{ "@@ -", gitdiff_hdrend },
+			{ "--- ", gitdiff_oldname },
+			{ "+++ ", gitdiff_newname },
+			{ "old mode ", gitdiff_oldmode },
+			{ "new mode ", gitdiff_newmode },
+			{ "deleted file mode ", gitdiff_delete },
+			{ "new file mode ", gitdiff_newfile },
+			{ "copy from ", gitdiff_copysrc },
+			{ "copy to ", gitdiff_copydst },
+			{ "rename old ", gitdiff_renamesrc },
+			{ "rename new ", gitdiff_renamedst },
+			{ "rename from ", gitdiff_renamesrc },
+			{ "rename to ", gitdiff_renamedst },
+			{ "similarity index ", gitdiff_similarity },
+			{ "dissimilarity index ", gitdiff_dissimilarity },
+			{ "index ", gitdiff_index },
+			{ "", gitdiff_unrecognized },
+		};
+		int i;
+
+		len = linelen(line, size);
+		if (!len || line[len-1] != '\n')
+			break;
+		for (i = 0; i < ARRAY_SIZE(optable); i++) {
+			const struct opentry *p = optable + i;
+			int oplen = strlen(p->str);
+			if (len < oplen || memcmp(p->str, line, oplen))
+				continue;
+			if (p->fn(line + oplen, patch) < 0)
+				return offset;
+			break;
+		}
+	}
+
+	return offset;
+}
+
+static int parse_num(const char *line, unsigned long *p)
+{
+	char *ptr;
+
+	if (!isdigit(*line))
+		return 0;
+	*p = strtoul(line, &ptr, 10);
+	return ptr - line;
+}
+
+static int parse_range(const char *line, int len, int offset, const char *expect,
+		       unsigned long *p1, unsigned long *p2)
+{
+	int digits, ex;
+
+	if (offset < 0 || offset >= len)
+		return -1;
+	line += offset;
+	len -= offset;
+
+	digits = parse_num(line, p1);
+	if (!digits)
+		return -1;
+
+	offset += digits;
+	line += digits;
+	len -= digits;
+
+	*p2 = 1;
+	if (*line == ',') {
+		digits = parse_num(line+1, p2);
+		if (!digits)
+			return -1;
+
+		offset += digits+1;
+		line += digits+1;
+		len -= digits+1;
+	}
+
+	ex = strlen(expect);
+	if (ex > len)
+		return -1;
+	if (memcmp(line, expect, ex))
+		return -1;
+
+	return offset + ex;
+}
+
+static void recount_diff(char *line, int size, struct fragment *fragment)
+{
+	int oldlines = 0, newlines = 0, ret = 0;
+
+	if (size < 1) {
+		warning("recount: ignore empty hunk");
+		return;
+	}
+
+	for (;;) {
+		int len = linelen(line, size);
+		size -= len;
+		line += len;
+
+		if (size < 1)
+			break;
+
+		switch (*line) {
+		case ' ': case '\n':
+			newlines++;
+			/* fall through */
+		case '-':
+			oldlines++;
+			continue;
+		case '+':
+			newlines++;
+			continue;
+		case '\\':
+			continue;
+		case '@':
+			ret = size < 3 || prefixcmp(line, "@@ ");
+			break;
+		case 'd':
+			ret = size < 5 || prefixcmp(line, "diff ");
+			break;
+		default:
+			ret = -1;
+			break;
+		}
+		if (ret) {
+			warning("recount: unexpected line: %.*s",
+				(int)linelen(line, size), line);
+			return;
+		}
+		break;
+	}
+	fragment->oldlines = oldlines;
+	fragment->newlines = newlines;
+}
+
+/*
+ * Parse a unified diff fragment header of the
+ * form "@@ -a,b +c,d @@"
+ */
+static int parse_fragment_header(char *line, int len, struct fragment *fragment)
+{
+	int offset;
+
+	if (!len || line[len-1] != '\n')
+		return -1;
+
+	/* Figure out the number of lines in a fragment */
+	offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
+	offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
+
+	return offset;
+}
+
+static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
+{
+	unsigned long offset, len;
+
+	patch->is_toplevel_relative = 0;
+	patch->is_rename = patch->is_copy = 0;
+	patch->is_new = patch->is_delete = -1;
+	patch->old_mode = patch->new_mode = 0;
+	patch->old_name = patch->new_name = NULL;
+	for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
+		unsigned long nextlen;
+
+		len = linelen(line, size);
+		if (!len)
+			break;
+
+		/* Testing this early allows us to take a few shortcuts.. */
+		if (len < 6)
+			continue;
+
+		/*
+		 * Make sure we don't find any unconnected patch fragments.
+		 * That's a sign that we didn't find a header, and that a
+		 * patch has become corrupted/broken up.
+		 */
+		if (!memcmp("@@ -", line, 4)) {
+			struct fragment dummy;
+			if (parse_fragment_header(line, len, &dummy) < 0)
+				continue;
+			die("patch fragment without header at line %d: %.*s",
+			    linenr, (int)len-1, line);
+		}
+
+		if (size < len + 6)
+			break;
+
+		/*
+		 * Git patch? It might not have a real patch, just a rename
+		 * or mode change, so we handle that specially
+		 */
+		if (!memcmp("diff --git ", line, 11)) {
+			int git_hdr_len = parse_git_header(line, len, size, patch);
+			if (git_hdr_len <= len)
+				continue;
+			if (!patch->old_name && !patch->new_name) {
+				if (!patch->def_name)
+					die("git diff header lacks filename information when removing "
+					    "%d leading pathname components (line %d)" , p_value, linenr);
+				patch->old_name = patch->new_name = patch->def_name;
+			}
+			if (!patch->is_delete && !patch->new_name)
+				die("git diff header lacks filename information "
+				    "(line %d)", linenr);
+			patch->is_toplevel_relative = 1;
+			*hdrsize = git_hdr_len;
+			return offset;
+		}
+
+		/* --- followed by +++ ? */
+		if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
+			continue;
+
+		/*
+		 * We only accept unified patches, so we want it to
+		 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
+		 * minimum ("@@ -0,0 +1 @@\n" is the shortest).
+		 */
+		nextlen = linelen(line + len, size - len);
+		if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
+			continue;
+
+		/* Ok, we'll consider it a patch */
+		parse_traditional_patch(line, line+len, patch);
+		*hdrsize = len + nextlen;
+		linenr += 2;
+		return offset;
+	}
+	return -1;
+}
+
+static void record_ws_error(unsigned result, const char *line, int len, int linenr)
+{
+	char *err;
+
+	if (!result)
+		return;
+
+	whitespace_error++;
+	if (squelch_whitespace_errors &&
+	    squelch_whitespace_errors < whitespace_error)
+		return;
+
+	err = whitespace_error_string(result);
+	fprintf(stderr, "%s:%d: %s.\n%.*s\n",
+		patch_input_file, linenr, err, len, line);
+	free(err);
+}
+
+static void check_whitespace(const char *line, int len, unsigned ws_rule)
+{
+	unsigned result = ws_check(line + 1, len - 1, ws_rule);
+
+	record_ws_error(result, line + 1, len - 2, linenr);
+}
+
+/*
+ * Parse a unified diff. Note that this really needs to parse each
+ * fragment separately, since the only way to know the difference
+ * between a "---" that is part of a patch, and a "---" that starts
+ * the next patch is to look at the line counts..
+ */
+static int parse_fragment(char *line, unsigned long size,
+			  struct patch *patch, struct fragment *fragment)
+{
+	int added, deleted;
+	int len = linelen(line, size), offset;
+	unsigned long oldlines, newlines;
+	unsigned long leading, trailing;
+
+	offset = parse_fragment_header(line, len, fragment);
+	if (offset < 0)
+		return -1;
+	if (offset > 0 && patch->recount)
+		recount_diff(line + offset, size - offset, fragment);
+	oldlines = fragment->oldlines;
+	newlines = fragment->newlines;
+	leading = 0;
+	trailing = 0;
+
+	/* Parse the thing.. */
+	line += len;
+	size -= len;
+	linenr++;
+	added = deleted = 0;
+	for (offset = len;
+	     0 < size;
+	     offset += len, size -= len, line += len, linenr++) {
+		if (!oldlines && !newlines)
+			break;
+		len = linelen(line, size);
+		if (!len || line[len-1] != '\n')
+			return -1;
+		switch (*line) {
+		default:
+			return -1;
+		case '\n': /* newer GNU diff, an empty context line */
+		case ' ':
+			oldlines--;
+			newlines--;
+			if (!deleted && !added)
+				leading++;
+			trailing++;
+			break;
+		case '-':
+			if (apply_in_reverse &&
+			    ws_error_action != nowarn_ws_error)
+				check_whitespace(line, len, patch->ws_rule);
+			deleted++;
+			oldlines--;
+			trailing = 0;
+			break;
+		case '+':
+			if (!apply_in_reverse &&
+			    ws_error_action != nowarn_ws_error)
+				check_whitespace(line, len, patch->ws_rule);
+			added++;
+			newlines--;
+			trailing = 0;
+			break;
+
+		/*
+		 * We allow "\ No newline at end of file". Depending
+                 * on locale settings when the patch was produced we
+                 * don't know what this line looks like. The only
+                 * thing we do know is that it begins with "\ ".
+		 * Checking for 12 is just for sanity check -- any
+		 * l10n of "\ No newline..." is at least that long.
+		 */
+		case '\\':
+			if (len < 12 || memcmp(line, "\\ ", 2))
+				return -1;
+			break;
+		}
+	}
+	if (oldlines || newlines)
+		return -1;
+	fragment->leading = leading;
+	fragment->trailing = trailing;
+
+	/*
+	 * If a fragment ends with an incomplete line, we failed to include
+	 * it in the above loop because we hit oldlines == newlines == 0
+	 * before seeing it.
+	 */
+	if (12 < size && !memcmp(line, "\\ ", 2))
+		offset += linelen(line, size);
+
+	patch->lines_added += added;
+	patch->lines_deleted += deleted;
+
+	if (0 < patch->is_new && oldlines)
+		return error("new file depends on old contents");
+	if (0 < patch->is_delete && newlines)
+		return error("deleted file still has contents");
+	return offset;
+}
+
+static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
+{
+	unsigned long offset = 0;
+	unsigned long oldlines = 0, newlines = 0, context = 0;
+	struct fragment **fragp = &patch->fragments;
+
+	while (size > 4 && !memcmp(line, "@@ -", 4)) {
+		struct fragment *fragment;
+		int len;
+
+		fragment = xcalloc(1, sizeof(*fragment));
+		fragment->linenr = linenr;
+		len = parse_fragment(line, size, patch, fragment);
+		if (len <= 0)
+			die("corrupt patch at line %d", linenr);
+		fragment->patch = line;
+		fragment->size = len;
+		oldlines += fragment->oldlines;
+		newlines += fragment->newlines;
+		context += fragment->leading + fragment->trailing;
+
+		*fragp = fragment;
+		fragp = &fragment->next;
+
+		offset += len;
+		line += len;
+		size -= len;
+	}
+
+	/*
+	 * If something was removed (i.e. we have old-lines) it cannot
+	 * be creation, and if something was added it cannot be
+	 * deletion.  However, the reverse is not true; --unified=0
+	 * patches that only add are not necessarily creation even
+	 * though they do not have any old lines, and ones that only
+	 * delete are not necessarily deletion.
+	 *
+	 * Unfortunately, a real creation/deletion patch do _not_ have
+	 * any context line by definition, so we cannot safely tell it
+	 * apart with --unified=0 insanity.  At least if the patch has
+	 * more than one hunk it is not creation or deletion.
+	 */
+	if (patch->is_new < 0 &&
+	    (oldlines || (patch->fragments && patch->fragments->next)))
+		patch->is_new = 0;
+	if (patch->is_delete < 0 &&
+	    (newlines || (patch->fragments && patch->fragments->next)))
+		patch->is_delete = 0;
+
+	if (0 < patch->is_new && oldlines)
+		die("new file %s depends on old contents", patch->new_name);
+	if (0 < patch->is_delete && newlines)
+		die("deleted file %s still has contents", patch->old_name);
+	if (!patch->is_delete && !newlines && context)
+		fprintf(stderr, "** warning: file %s becomes empty but "
+			"is not deleted\n", patch->new_name);
+
+	return offset;
+}
+
+static inline int metadata_changes(struct patch *patch)
+{
+	return	patch->is_rename > 0 ||
+		patch->is_copy > 0 ||
+		patch->is_new > 0 ||
+		patch->is_delete ||
+		(patch->old_mode && patch->new_mode &&
+		 patch->old_mode != patch->new_mode);
+}
+
+static char *inflate_it(const void *data, unsigned long size,
+			unsigned long inflated_size)
+{
+	git_zstream stream;
+	void *out;
+	int st;
+
+	memset(&stream, 0, sizeof(stream));
+
+	stream.next_in = (unsigned char *)data;
+	stream.avail_in = size;
+	stream.next_out = out = xmalloc(inflated_size);
+	stream.avail_out = inflated_size;
+	git_inflate_init(&stream);
+	st = git_inflate(&stream, Z_FINISH);
+	git_inflate_end(&stream);
+	if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
+		free(out);
+		return NULL;
+	}
+	return out;
+}
+
+static struct fragment *parse_binary_hunk(char **buf_p,
+					  unsigned long *sz_p,
+					  int *status_p,
+					  int *used_p)
+{
+	/*
+	 * Expect a line that begins with binary patch method ("literal"
+	 * or "delta"), followed by the length of data before deflating.
+	 * a sequence of 'length-byte' followed by base-85 encoded data
+	 * should follow, terminated by a newline.
+	 *
+	 * Each 5-byte sequence of base-85 encodes up to 4 bytes,
+	 * and we would limit the patch line to 66 characters,
+	 * so one line can fit up to 13 groups that would decode
+	 * to 52 bytes max.  The length byte 'A'-'Z' corresponds
+	 * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
+	 */
+	int llen, used;
+	unsigned long size = *sz_p;
+	char *buffer = *buf_p;
+	int patch_method;
+	unsigned long origlen;
+	char *data = NULL;
+	int hunk_size = 0;
+	struct fragment *frag;
+
+	llen = linelen(buffer, size);
+	used = llen;
+
+	*status_p = 0;
+
+	if (!prefixcmp(buffer, "delta ")) {
+		patch_method = BINARY_DELTA_DEFLATED;
+		origlen = strtoul(buffer + 6, NULL, 10);
+	}
+	else if (!prefixcmp(buffer, "literal ")) {
+		patch_method = BINARY_LITERAL_DEFLATED;
+		origlen = strtoul(buffer + 8, NULL, 10);
+	}
+	else
+		return NULL;
+
+	linenr++;
+	buffer += llen;
+	while (1) {
+		int byte_length, max_byte_length, newsize;
+		llen = linelen(buffer, size);
+		used += llen;
+		linenr++;
+		if (llen == 1) {
+			/* consume the blank line */
+			buffer++;
+			size--;
+			break;
+		}
+		/*
+		 * Minimum line is "A00000\n" which is 7-byte long,
+		 * and the line length must be multiple of 5 plus 2.
+		 */
+		if ((llen < 7) || (llen-2) % 5)
+			goto corrupt;
+		max_byte_length = (llen - 2) / 5 * 4;
+		byte_length = *buffer;
+		if ('A' <= byte_length && byte_length <= 'Z')
+			byte_length = byte_length - 'A' + 1;
+		else if ('a' <= byte_length && byte_length <= 'z')
+			byte_length = byte_length - 'a' + 27;
+		else
+			goto corrupt;
+		/* if the input length was not multiple of 4, we would
+		 * have filler at the end but the filler should never
+		 * exceed 3 bytes
+		 */
+		if (max_byte_length < byte_length ||
+		    byte_length <= max_byte_length - 4)
+			goto corrupt;
+		newsize = hunk_size + byte_length;
+		data = xrealloc(data, newsize);
+		if (decode_85(data + hunk_size, buffer + 1, byte_length))
+			goto corrupt;
+		hunk_size = newsize;
+		buffer += llen;
+		size -= llen;
+	}
+
+	frag = xcalloc(1, sizeof(*frag));
+	frag->patch = inflate_it(data, hunk_size, origlen);
+	if (!frag->patch)
+		goto corrupt;
+	free(data);
+	frag->size = origlen;
+	*buf_p = buffer;
+	*sz_p = size;
+	*used_p = used;
+	frag->binary_patch_method = patch_method;
+	return frag;
+
+ corrupt:
+	free(data);
+	*status_p = -1;
+	error("corrupt binary patch at line %d: %.*s",
+	      linenr-1, llen-1, buffer);
+	return NULL;
+}
+
+static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+{
+	/*
+	 * We have read "GIT binary patch\n"; what follows is a line
+	 * that says the patch method (currently, either "literal" or
+	 * "delta") and the length of data before deflating; a
+	 * sequence of 'length-byte' followed by base-85 encoded data
+	 * follows.
+	 *
+	 * When a binary patch is reversible, there is another binary
+	 * hunk in the same format, starting with patch method (either
+	 * "literal" or "delta") with the length of data, and a sequence
+	 * of length-byte + base-85 encoded data, terminated with another
+	 * empty line.  This data, when applied to the postimage, produces
+	 * the preimage.
+	 */
+	struct fragment *forward;
+	struct fragment *reverse;
+	int status;
+	int used, used_1;
+
+	forward = parse_binary_hunk(&buffer, &size, &status, &used);
+	if (!forward && !status)
+		/* there has to be one hunk (forward hunk) */
+		return error("unrecognized binary patch at line %d", linenr-1);
+	if (status)
+		/* otherwise we already gave an error message */
+		return status;
+
+	reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
+	if (reverse)
+		used += used_1;
+	else if (status) {
+		/*
+		 * Not having reverse hunk is not an error, but having
+		 * a corrupt reverse hunk is.
+		 */
+		free((void*) forward->patch);
+		free(forward);
+		return status;
+	}
+	forward->next = reverse;
+	patch->fragments = forward;
+	patch->is_binary = 1;
+	return used;
+}
+
+static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
+{
+	int hdrsize, patchsize;
+	int offset = find_header(buffer, size, &hdrsize, patch);
+
+	if (offset < 0)
+		return offset;
+
+	patch->ws_rule = whitespace_rule(patch->new_name
+					 ? patch->new_name
+					 : patch->old_name);
+
+	patchsize = parse_single_patch(buffer + offset + hdrsize,
+				       size - offset - hdrsize, patch);
+
+	if (!patchsize) {
+		static const char *binhdr[] = {
+			"Binary files ",
+			"Files ",
+			NULL,
+		};
+		static const char git_binary[] = "GIT binary patch\n";
+		int i;
+		int hd = hdrsize + offset;
+		unsigned long llen = linelen(buffer + hd, size - hd);
+
+		if (llen == sizeof(git_binary) - 1 &&
+		    !memcmp(git_binary, buffer + hd, llen)) {
+			int used;
+			linenr++;
+			used = parse_binary(buffer + hd + llen,
+					    size - hd - llen, patch);
+			if (used)
+				patchsize = used + llen;
+			else
+				patchsize = 0;
+		}
+		else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
+			for (i = 0; binhdr[i]; i++) {
+				int len = strlen(binhdr[i]);
+				if (len < size - hd &&
+				    !memcmp(binhdr[i], buffer + hd, len)) {
+					linenr++;
+					patch->is_binary = 1;
+					patchsize = llen;
+					break;
+				}
+			}
+		}
+
+		/* Empty patch cannot be applied if it is a text patch
+		 * without metadata change.  A binary patch appears
+		 * empty to us here.
+		 */
+		if ((apply || check) &&
+		    (!patch->is_binary && !metadata_changes(patch)))
+			die("patch with only garbage at line %d", linenr);
+	}
+
+	return offset + hdrsize + patchsize;
+}
+
+#define swap(a,b) myswap((a),(b),sizeof(a))
+
+#define myswap(a, b, size) do {		\
+	unsigned char mytmp[size];	\
+	memcpy(mytmp, &a, size);		\
+	memcpy(&a, &b, size);		\
+	memcpy(&b, mytmp, size);		\
+} while (0)
+
+static void reverse_patches(struct patch *p)
+{
+	for (; p; p = p->next) {
+		struct fragment *frag = p->fragments;
+
+		swap(p->new_name, p->old_name);
+		swap(p->new_mode, p->old_mode);
+		swap(p->is_new, p->is_delete);
+		swap(p->lines_added, p->lines_deleted);
+		swap(p->old_sha1_prefix, p->new_sha1_prefix);
+
+		for (; frag; frag = frag->next) {
+			swap(frag->newpos, frag->oldpos);
+			swap(frag->newlines, frag->oldlines);
+		}
+	}
+}
+
+static const char pluses[] =
+"++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
+static const char minuses[]=
+"----------------------------------------------------------------------";
+
+static void show_stats(struct patch *patch)
+{
+	struct strbuf qname = STRBUF_INIT;
+	char *cp = patch->new_name ? patch->new_name : patch->old_name;
+	int max, add, del;
+
+	quote_c_style(cp, &qname, NULL, 0);
+
+	/*
+	 * "scale" the filename
+	 */
+	max = max_len;
+	if (max > 50)
+		max = 50;
+
+	if (qname.len > max) {
+		cp = strchr(qname.buf + qname.len + 3 - max, '/');
+		if (!cp)
+			cp = qname.buf + qname.len + 3 - max;
+		strbuf_splice(&qname, 0, cp - qname.buf, "...", 3);
+	}
+
+	if (patch->is_binary) {
+		printf(" %-*s |  Bin\n", max, qname.buf);
+		strbuf_release(&qname);
+		return;
+	}
+
+	printf(" %-*s |", max, qname.buf);
+	strbuf_release(&qname);
+
+	/*
+	 * scale the add/delete
+	 */
+	max = max + max_change > 70 ? 70 - max : max_change;
+	add = patch->lines_added;
+	del = patch->lines_deleted;
+
+	if (max_change > 0) {
+		int total = ((add + del) * max + max_change / 2) / max_change;
+		add = (add * max + max_change / 2) / max_change;
+		del = total - add;
+	}
+	printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
+		add, pluses, del, minuses);
+}
+
+static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
+{
+	switch (st->st_mode & S_IFMT) {
+	case S_IFLNK:
+		if (strbuf_readlink(buf, path, st->st_size) < 0)
+			return error("unable to read symlink %s", path);
+		return 0;
+	case S_IFREG:
+		if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
+			return error("unable to open or read %s", path);
+		convert_to_git(path, buf->buf, buf->len, buf, 0);
+		return 0;
+	default:
+		return -1;
+	}
+}
+
+/*
+ * Update the preimage, and the common lines in postimage,
+ * from buffer buf of length len. If postlen is 0 the postimage
+ * is updated in place, otherwise it's updated on a new buffer
+ * of length postlen
+ */
+
+static void update_pre_post_images(struct image *preimage,
+				   struct image *postimage,
+				   char *buf,
+				   size_t len, size_t postlen)
+{
+	int i, ctx;
+	char *new, *old, *fixed;
+	struct image fixed_preimage;
+
+	/*
+	 * Update the preimage with whitespace fixes.  Note that we
+	 * are not losing preimage->buf -- apply_one_fragment() will
+	 * free "oldlines".
+	 */
+	prepare_image(&fixed_preimage, buf, len, 1);
+	assert(fixed_preimage.nr == preimage->nr);
+	for (i = 0; i < preimage->nr; i++)
+		fixed_preimage.line[i].flag = preimage->line[i].flag;
+	free(preimage->line_allocated);
+	*preimage = fixed_preimage;
+
+	/*
+	 * Adjust the common context lines in postimage. This can be
+	 * done in-place when we are just doing whitespace fixing,
+	 * which does not make the string grow, but needs a new buffer
+	 * when ignoring whitespace causes the update, since in this case
+	 * we could have e.g. tabs converted to multiple spaces.
+	 * We trust the caller to tell us if the update can be done
+	 * in place (postlen==0) or not.
+	 */
+	old = postimage->buf;
+	if (postlen)
+		new = postimage->buf = xmalloc(postlen);
+	else
+		new = old;
+	fixed = preimage->buf;
+	for (i = ctx = 0; i < postimage->nr; i++) {
+		size_t len = postimage->line[i].len;
+		if (!(postimage->line[i].flag & LINE_COMMON)) {
+			/* an added line -- no counterparts in preimage */
+			memmove(new, old, len);
+			old += len;
+			new += len;
+			continue;
+		}
+
+		/* a common context -- skip it in the original postimage */
+		old += len;
+
+		/* and find the corresponding one in the fixed preimage */
+		while (ctx < preimage->nr &&
+		       !(preimage->line[ctx].flag & LINE_COMMON)) {
+			fixed += preimage->line[ctx].len;
+			ctx++;
+		}
+		if (preimage->nr <= ctx)
+			die("oops");
+
+		/* and copy it in, while fixing the line length */
+		len = preimage->line[ctx].len;
+		memcpy(new, fixed, len);
+		new += len;
+		fixed += len;
+		postimage->line[i].len = len;
+		ctx++;
+	}
+
+	/* Fix the length of the whole thing */
+	postimage->len = new - postimage->buf;
+}
+
+static int match_fragment(struct image *img,
+			  struct image *preimage,
+			  struct image *postimage,
+			  unsigned long try,
+			  int try_lno,
+			  unsigned ws_rule,
+			  int match_beginning, int match_end)
+{
+	int i;
+	char *fixed_buf, *buf, *orig, *target;
+	struct strbuf fixed;
+	size_t fixed_len;
+	int preimage_limit;
+
+	if (preimage->nr + try_lno <= img->nr) {
+		/*
+		 * The hunk falls within the boundaries of img.
+		 */
+		preimage_limit = preimage->nr;
+		if (match_end && (preimage->nr + try_lno != img->nr))
+			return 0;
+	} else if (ws_error_action == correct_ws_error &&
+		   (ws_rule & WS_BLANK_AT_EOF)) {
+		/*
+		 * This hunk extends beyond the end of img, and we are
+		 * removing blank lines at the end of the file.  This
+		 * many lines from the beginning of the preimage must
+		 * match with img, and the remainder of the preimage
+		 * must be blank.
+		 */
+		preimage_limit = img->nr - try_lno;
+	} else {
+		/*
+		 * The hunk extends beyond the end of the img and
+		 * we are not removing blanks at the end, so we
+		 * should reject the hunk at this position.
+		 */
+		return 0;
+	}
+
+	if (match_beginning && try_lno)
+		return 0;
+
+	/* Quick hash check */
+	for (i = 0; i < preimage_limit; i++)
+		if ((img->line[try_lno + i].flag & LINE_PATCHED) ||
+		    (preimage->line[i].hash != img->line[try_lno + i].hash))
+			return 0;
+
+	if (preimage_limit == preimage->nr) {
+		/*
+		 * Do we have an exact match?  If we were told to match
+		 * at the end, size must be exactly at try+fragsize,
+		 * otherwise try+fragsize must be still within the preimage,
+		 * and either case, the old piece should match the preimage
+		 * exactly.
+		 */
+		if ((match_end
+		     ? (try + preimage->len == img->len)
+		     : (try + preimage->len <= img->len)) &&
+		    !memcmp(img->buf + try, preimage->buf, preimage->len))
+			return 1;
+	} else {
+		/*
+		 * The preimage extends beyond the end of img, so
+		 * there cannot be an exact match.
+		 *
+		 * There must be one non-blank context line that match
+		 * a line before the end of img.
+		 */
+		char *buf_end;
+
+		buf = preimage->buf;
+		buf_end = buf;
+		for (i = 0; i < preimage_limit; i++)
+			buf_end += preimage->line[i].len;
+
+		for ( ; buf < buf_end; buf++)
+			if (!isspace(*buf))
+				break;
+		if (buf == buf_end)
+			return 0;
+	}
+
+	/*
+	 * No exact match. If we are ignoring whitespace, run a line-by-line
+	 * fuzzy matching. We collect all the line length information because
+	 * we need it to adjust whitespace if we match.
+	 */
+	if (ws_ignore_action == ignore_ws_change) {
+		size_t imgoff = 0;
+		size_t preoff = 0;
+		size_t postlen = postimage->len;
+		size_t extra_chars;
+		char *preimage_eof;
+		char *preimage_end;
+		for (i = 0; i < preimage_limit; i++) {
+			size_t prelen = preimage->line[i].len;
+			size_t imglen = img->line[try_lno+i].len;
+
+			if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
+					      preimage->buf + preoff, prelen))
+				return 0;
+			if (preimage->line[i].flag & LINE_COMMON)
+				postlen += imglen - prelen;
+			imgoff += imglen;
+			preoff += prelen;
+		}
+
+		/*
+		 * Ok, the preimage matches with whitespace fuzz.
+		 *
+		 * imgoff now holds the true length of the target that
+		 * matches the preimage before the end of the file.
+		 *
+		 * Count the number of characters in the preimage that fall
+		 * beyond the end of the file and make sure that all of them
+		 * are whitespace characters. (This can only happen if
+		 * we are removing blank lines at the end of the file.)
+		 */
+		buf = preimage_eof = preimage->buf + preoff;
+		for ( ; i < preimage->nr; i++)
+			preoff += preimage->line[i].len;
+		preimage_end = preimage->buf + preoff;
+		for ( ; buf < preimage_end; buf++)
+			if (!isspace(*buf))
+				return 0;
+
+		/*
+		 * Update the preimage and the common postimage context
+		 * lines to use the same whitespace as the target.
+		 * If whitespace is missing in the target (i.e.
+		 * if the preimage extends beyond the end of the file),
+		 * use the whitespace from the preimage.
+		 */
+		extra_chars = preimage_end - preimage_eof;
+		strbuf_init(&fixed, imgoff + extra_chars);
+		strbuf_add(&fixed, img->buf + try, imgoff);
+		strbuf_add(&fixed, preimage_eof, extra_chars);
+		fixed_buf = strbuf_detach(&fixed, &fixed_len);
+		update_pre_post_images(preimage, postimage,
+				fixed_buf, fixed_len, postlen);
+		return 1;
+	}
+
+	if (ws_error_action != correct_ws_error)
+		return 0;
+
+	/*
+	 * The hunk does not apply byte-by-byte, but the hash says
+	 * it might with whitespace fuzz. We haven't been asked to
+	 * ignore whitespace, we were asked to correct whitespace
+	 * errors, so let's try matching after whitespace correction.
+	 *
+	 * The preimage may extend beyond the end of the file,
+	 * but in this loop we will only handle the part of the
+	 * preimage that falls within the file.
+	 */
+	strbuf_init(&fixed, preimage->len + 1);
+	orig = preimage->buf;
+	target = img->buf + try;
+	for (i = 0; i < preimage_limit; i++) {
+		size_t oldlen = preimage->line[i].len;
+		size_t tgtlen = img->line[try_lno + i].len;
+		size_t fixstart = fixed.len;
+		struct strbuf tgtfix;
+		int match;
+
+		/* Try fixing the line in the preimage */
+		ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
+
+		/* Try fixing the line in the target */
+		strbuf_init(&tgtfix, tgtlen);
+		ws_fix_copy(&tgtfix, target, tgtlen, ws_rule, NULL);
+
+		/*
+		 * If they match, either the preimage was based on
+		 * a version before our tree fixed whitespace breakage,
+		 * or we are lacking a whitespace-fix patch the tree
+		 * the preimage was based on already had (i.e. target
+		 * has whitespace breakage, the preimage doesn't).
+		 * In either case, we are fixing the whitespace breakages
+		 * so we might as well take the fix together with their
+		 * real change.
+		 */
+		match = (tgtfix.len == fixed.len - fixstart &&
+			 !memcmp(tgtfix.buf, fixed.buf + fixstart,
+					     fixed.len - fixstart));
+
+		strbuf_release(&tgtfix);
+		if (!match)
+			goto unmatch_exit;
+
+		orig += oldlen;
+		target += tgtlen;
+	}
+
+
+	/*
+	 * Now handle the lines in the preimage that falls beyond the
+	 * end of the file (if any). They will only match if they are
+	 * empty or only contain whitespace (if WS_BLANK_AT_EOL is
+	 * false).
+	 */
+	for ( ; i < preimage->nr; i++) {
+		size_t fixstart = fixed.len; /* start of the fixed preimage */
+		size_t oldlen = preimage->line[i].len;
+		int j;
+
+		/* Try fixing the line in the preimage */
+		ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
+
+		for (j = fixstart; j < fixed.len; j++)
+			if (!isspace(fixed.buf[j]))
+				goto unmatch_exit;
+
+		orig += oldlen;
+	}
+
+	/*
+	 * Yes, the preimage is based on an older version that still
+	 * has whitespace breakages unfixed, and fixing them makes the
+	 * hunk match.  Update the context lines in the postimage.
+	 */
+	fixed_buf = strbuf_detach(&fixed, &fixed_len);
+	update_pre_post_images(preimage, postimage,
+			       fixed_buf, fixed_len, 0);
+	return 1;
+
+ unmatch_exit:
+	strbuf_release(&fixed);
+	return 0;
+}
+
+static int find_pos(struct image *img,
+		    struct image *preimage,
+		    struct image *postimage,
+		    int line,
+		    unsigned ws_rule,
+		    int match_beginning, int match_end)
+{
+	int i;
+	unsigned long backwards, forwards, try;
+	int backwards_lno, forwards_lno, try_lno;
+
+	/*
+	 * If match_beginning or match_end is specified, there is no
+	 * point starting from a wrong line that will never match and
+	 * wander around and wait for a match at the specified end.
+	 */
+	if (match_beginning)
+		line = 0;
+	else if (match_end)
+		line = img->nr - preimage->nr;
+
+	/*
+	 * Because the comparison is unsigned, the following test
+	 * will also take care of a negative line number that can
+	 * result when match_end and preimage is larger than the target.
+	 */
+	if ((size_t) line > img->nr)
+		line = img->nr;
+
+	try = 0;
+	for (i = 0; i < line; i++)
+		try += img->line[i].len;
+
+	/*
+	 * There's probably some smart way to do this, but I'll leave
+	 * that to the smart and beautiful people. I'm simple and stupid.
+	 */
+	backwards = try;
+	backwards_lno = line;
+	forwards = try;
+	forwards_lno = line;
+	try_lno = line;
+
+	for (i = 0; ; i++) {
+		if (match_fragment(img, preimage, postimage,
+				   try, try_lno, ws_rule,
+				   match_beginning, match_end))
+			return try_lno;
+
+	again:
+		if (backwards_lno == 0 && forwards_lno == img->nr)
+			break;
+
+		if (i & 1) {
+			if (backwards_lno == 0) {
+				i++;
+				goto again;
+			}
+			backwards_lno--;
+			backwards -= img->line[backwards_lno].len;
+			try = backwards;
+			try_lno = backwards_lno;
+		} else {
+			if (forwards_lno == img->nr) {
+				i++;
+				goto again;
+			}
+			forwards += img->line[forwards_lno].len;
+			forwards_lno++;
+			try = forwards;
+			try_lno = forwards_lno;
+		}
+
+	}
+	return -1;
+}
+
+static void remove_first_line(struct image *img)
+{
+	img->buf += img->line[0].len;
+	img->len -= img->line[0].len;
+	img->line++;
+	img->nr--;
+}
+
+static void remove_last_line(struct image *img)
+{
+	img->len -= img->line[--img->nr].len;
+}
+
+static void update_image(struct image *img,
+			 int applied_pos,
+			 struct image *preimage,
+			 struct image *postimage)
+{
+	/*
+	 * remove the copy of preimage at offset in img
+	 * and replace it with postimage
+	 */
+	int i, nr;
+	size_t remove_count, insert_count, applied_at = 0;
+	char *result;
+	int preimage_limit;
+
+	/*
+	 * If we are removing blank lines at the end of img,
+	 * the preimage may extend beyond the end.
+	 * If that is the case, we must be careful only to
+	 * remove the part of the preimage that falls within
+	 * the boundaries of img. Initialize preimage_limit
+	 * to the number of lines in the preimage that falls
+	 * within the boundaries.
+	 */
+	preimage_limit = preimage->nr;
+	if (preimage_limit > img->nr - applied_pos)
+		preimage_limit = img->nr - applied_pos;
+
+	for (i = 0; i < applied_pos; i++)
+		applied_at += img->line[i].len;
+
+	remove_count = 0;
+	for (i = 0; i < preimage_limit; i++)
+		remove_count += img->line[applied_pos + i].len;
+	insert_count = postimage->len;
+
+	/* Adjust the contents */
+	result = xmalloc(img->len + insert_count - remove_count + 1);
+	memcpy(result, img->buf, applied_at);
+	memcpy(result + applied_at, postimage->buf, postimage->len);
+	memcpy(result + applied_at + postimage->len,
+	       img->buf + (applied_at + remove_count),
+	       img->len - (applied_at + remove_count));
+	free(img->buf);
+	img->buf = result;
+	img->len += insert_count - remove_count;
+	result[img->len] = '\0';
+
+	/* Adjust the line table */
+	nr = img->nr + postimage->nr - preimage_limit;
+	if (preimage_limit < postimage->nr) {
+		/*
+		 * NOTE: this knows that we never call remove_first_line()
+		 * on anything other than pre/post image.
+		 */
+		img->line = xrealloc(img->line, nr * sizeof(*img->line));
+		img->line_allocated = img->line;
+	}
+	if (preimage_limit != postimage->nr)
+		memmove(img->line + applied_pos + postimage->nr,
+			img->line + applied_pos + preimage_limit,
+			(img->nr - (applied_pos + preimage_limit)) *
+			sizeof(*img->line));
+	memcpy(img->line + applied_pos,
+	       postimage->line,
+	       postimage->nr * sizeof(*img->line));
+	if (!allow_overlap)
+		for (i = 0; i < postimage->nr; i++)
+			img->line[applied_pos + i].flag |= LINE_PATCHED;
+	img->nr = nr;
+}
+
+static int apply_one_fragment(struct image *img, struct fragment *frag,
+			      int inaccurate_eof, unsigned ws_rule,
+			      int nth_fragment)
+{
+	int match_beginning, match_end;
+	const char *patch = frag->patch;
+	int size = frag->size;
+	char *old, *oldlines;
+	struct strbuf newlines;
+	int new_blank_lines_at_end = 0;
+	int found_new_blank_lines_at_end = 0;
+	int hunk_linenr = frag->linenr;
+	unsigned long leading, trailing;
+	int pos, applied_pos;
+	struct image preimage;
+	struct image postimage;
+
+	memset(&preimage, 0, sizeof(preimage));
+	memset(&postimage, 0, sizeof(postimage));
+	oldlines = xmalloc(size);
+	strbuf_init(&newlines, size);
+
+	old = oldlines;
+	while (size > 0) {
+		char first;
+		int len = linelen(patch, size);
+		int plen;
+		int added_blank_line = 0;
+		int is_blank_context = 0;
+		size_t start;
+
+		if (!len)
+			break;
+
+		/*
+		 * "plen" is how much of the line we should use for
+		 * the actual patch data. Normally we just remove the
+		 * first character on the line, but if the line is
+		 * followed by "\ No newline", then we also remove the
+		 * last one (which is the newline, of course).
+		 */
+		plen = len - 1;
+		if (len < size && patch[len] == '\\')
+			plen--;
+		first = *patch;
+		if (apply_in_reverse) {
+			if (first == '-')
+				first = '+';
+			else if (first == '+')
+				first = '-';
+		}
+
+		switch (first) {
+		case '\n':
+			/* Newer GNU diff, empty context line */
+			if (plen < 0)
+				/* ... followed by '\No newline'; nothing */
+				break;
+			*old++ = '\n';
+			strbuf_addch(&newlines, '\n');
+			add_line_info(&preimage, "\n", 1, LINE_COMMON);
+			add_line_info(&postimage, "\n", 1, LINE_COMMON);
+			is_blank_context = 1;
+			break;
+		case ' ':
+			if (plen && (ws_rule & WS_BLANK_AT_EOF) &&
+			    ws_blank_line(patch + 1, plen, ws_rule))
+				is_blank_context = 1;
+		case '-':
+			memcpy(old, patch + 1, plen);
+			add_line_info(&preimage, old, plen,
+				      (first == ' ' ? LINE_COMMON : 0));
+			old += plen;
+			if (first == '-')
+				break;
+		/* Fall-through for ' ' */
+		case '+':
+			/* --no-add does not add new lines */
+			if (first == '+' && no_add)
+				break;
+
+			start = newlines.len;
+			if (first != '+' ||
+			    !whitespace_error ||
+			    ws_error_action != correct_ws_error) {
+				strbuf_add(&newlines, patch + 1, plen);
+			}
+			else {
+				ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &applied_after_fixing_ws);
+			}
+			add_line_info(&postimage, newlines.buf + start, newlines.len - start,
+				      (first == '+' ? 0 : LINE_COMMON));
+			if (first == '+' &&
+			    (ws_rule & WS_BLANK_AT_EOF) &&
+			    ws_blank_line(patch + 1, plen, ws_rule))
+				added_blank_line = 1;
+			break;
+		case '@': case '\\':
+			/* Ignore it, we already handled it */
+			break;
+		default:
+			if (apply_verbosely)
+				error("invalid start of line: '%c'", first);
+			return -1;
+		}
+		if (added_blank_line) {
+			if (!new_blank_lines_at_end)
+				found_new_blank_lines_at_end = hunk_linenr;
+			new_blank_lines_at_end++;
+		}
+		else if (is_blank_context)
+			;
+		else
+			new_blank_lines_at_end = 0;
+		patch += len;
+		size -= len;
+		hunk_linenr++;
+	}
+	if (inaccurate_eof &&
+	    old > oldlines && old[-1] == '\n' &&
+	    newlines.len > 0 && newlines.buf[newlines.len - 1] == '\n') {
+		old--;
+		strbuf_setlen(&newlines, newlines.len - 1);
+	}
+
+	leading = frag->leading;
+	trailing = frag->trailing;
+
+	/*
+	 * A hunk to change lines at the beginning would begin with
+	 * @@ -1,L +N,M @@
+	 * but we need to be careful.  -U0 that inserts before the second
+	 * line also has this pattern.
+	 *
+	 * And a hunk to add to an empty file would begin with
+	 * @@ -0,0 +N,M @@
+	 *
+	 * In other words, a hunk that is (frag->oldpos <= 1) with or
+	 * without leading context must match at the beginning.
+	 */
+	match_beginning = (!frag->oldpos ||
+			   (frag->oldpos == 1 && !unidiff_zero));
+
+	/*
+	 * A hunk without trailing lines must match at the end.
+	 * However, we simply cannot tell if a hunk must match end
+	 * from the lack of trailing lines if the patch was generated
+	 * with unidiff without any context.
+	 */
+	match_end = !unidiff_zero && !trailing;
+
+	pos = frag->newpos ? (frag->newpos - 1) : 0;
+	preimage.buf = oldlines;
+	preimage.len = old - oldlines;
+	postimage.buf = newlines.buf;
+	postimage.len = newlines.len;
+	preimage.line = preimage.line_allocated;
+	postimage.line = postimage.line_allocated;
+
+	for (;;) {
+
+		applied_pos = find_pos(img, &preimage, &postimage, pos,
+				       ws_rule, match_beginning, match_end);
+
+		if (applied_pos >= 0)
+			break;
+
+		/* Am I at my context limits? */
+		if ((leading <= p_context) && (trailing <= p_context))
+			break;
+		if (match_beginning || match_end) {
+			match_beginning = match_end = 0;
+			continue;
+		}
+
+		/*
+		 * Reduce the number of context lines; reduce both
+		 * leading and trailing if they are equal otherwise
+		 * just reduce the larger context.
+		 */
+		if (leading >= trailing) {
+			remove_first_line(&preimage);
+			remove_first_line(&postimage);
+			pos--;
+			leading--;
+		}
+		if (trailing > leading) {
+			remove_last_line(&preimage);
+			remove_last_line(&postimage);
+			trailing--;
+		}
+	}
+
+	if (applied_pos >= 0) {
+		if (new_blank_lines_at_end &&
+		    preimage.nr + applied_pos >= img->nr &&
+		    (ws_rule & WS_BLANK_AT_EOF) &&
+		    ws_error_action != nowarn_ws_error) {
+			record_ws_error(WS_BLANK_AT_EOF, "+", 1,
+					found_new_blank_lines_at_end);
+			if (ws_error_action == correct_ws_error) {
+				while (new_blank_lines_at_end--)
+					remove_last_line(&postimage);
+			}
+			/*
+			 * We would want to prevent write_out_results()
+			 * from taking place in apply_patch() that follows
+			 * the callchain led us here, which is:
+			 * apply_patch->check_patch_list->check_patch->
+			 * apply_data->apply_fragments->apply_one_fragment
+			 */
+			if (ws_error_action == die_on_ws_error)
+				apply = 0;
+		}
+
+		if (apply_verbosely && applied_pos != pos) {
+			int offset = applied_pos - pos;
+			if (apply_in_reverse)
+				offset = 0 - offset;
+			fprintf(stderr,
+				"Hunk #%d succeeded at %d (offset %d lines).\n",
+				nth_fragment, applied_pos + 1, offset);
+		}
+
+		/*
+		 * Warn if it was necessary to reduce the number
+		 * of context lines.
+		 */
+		if ((leading != frag->leading) ||
+		    (trailing != frag->trailing))
+			fprintf(stderr, "Context reduced to (%ld/%ld)"
+				" to apply fragment at %d\n",
+				leading, trailing, applied_pos+1);
+		update_image(img, applied_pos, &preimage, &postimage);
+	} else {
+		if (apply_verbosely)
+			error("while searching for:\n%.*s",
+			      (int)(old - oldlines), oldlines);
+	}
+
+	free(oldlines);
+	strbuf_release(&newlines);
+	free(preimage.line_allocated);
+	free(postimage.line_allocated);
+
+	return (applied_pos < 0);
+}
+
+static int apply_binary_fragment(struct image *img, struct patch *patch)
+{
+	struct fragment *fragment = patch->fragments;
+	unsigned long len;
+	void *dst;
+
+	if (!fragment)
+		return error("missing binary patch data for '%s'",
+			     patch->new_name ?
+			     patch->new_name :
+			     patch->old_name);
+
+	/* Binary patch is irreversible without the optional second hunk */
+	if (apply_in_reverse) {
+		if (!fragment->next)
+			return error("cannot reverse-apply a binary patch "
+				     "without the reverse hunk to '%s'",
+				     patch->new_name
+				     ? patch->new_name : patch->old_name);
+		fragment = fragment->next;
+	}
+	switch (fragment->binary_patch_method) {
+	case BINARY_DELTA_DEFLATED:
+		dst = patch_delta(img->buf, img->len, fragment->patch,
+				  fragment->size, &len);
+		if (!dst)
+			return -1;
+		clear_image(img);
+		img->buf = dst;
+		img->len = len;
+		return 0;
+	case BINARY_LITERAL_DEFLATED:
+		clear_image(img);
+		img->len = fragment->size;
+		img->buf = xmalloc(img->len+1);
+		memcpy(img->buf, fragment->patch, img->len);
+		img->buf[img->len] = '\0';
+		return 0;
+	}
+	return -1;
+}
+
+static int apply_binary(struct image *img, struct patch *patch)
+{
+	const char *name = patch->old_name ? patch->old_name : patch->new_name;
+	unsigned char sha1[20];
+
+	/*
+	 * For safety, we require patch index line to contain
+	 * full 40-byte textual SHA1 for old and new, at least for now.
+	 */
+	if (strlen(patch->old_sha1_prefix) != 40 ||
+	    strlen(patch->new_sha1_prefix) != 40 ||
+	    get_sha1_hex(patch->old_sha1_prefix, sha1) ||
+	    get_sha1_hex(patch->new_sha1_prefix, sha1))
+		return error("cannot apply binary patch to '%s' "
+			     "without full index line", name);
+
+	if (patch->old_name) {
+		/*
+		 * See if the old one matches what the patch
+		 * applies to.
+		 */
+		hash_sha1_file(img->buf, img->len, blob_type, sha1);
+		if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
+			return error("the patch applies to '%s' (%s), "
+				     "which does not match the "
+				     "current contents.",
+				     name, sha1_to_hex(sha1));
+	}
+	else {
+		/* Otherwise, the old one must be empty. */
+		if (img->len)
+			return error("the patch applies to an empty "
+				     "'%s' but it is not empty", name);
+	}
+
+	get_sha1_hex(patch->new_sha1_prefix, sha1);
+	if (is_null_sha1(sha1)) {
+		clear_image(img);
+		return 0; /* deletion patch */
+	}
+
+	if (has_sha1_file(sha1)) {
+		/* We already have the postimage */
+		enum object_type type;
+		unsigned long size;
+		char *result;
+
+		result = read_sha1_file(sha1, &type, &size);
+		if (!result)
+			return error("the necessary postimage %s for "
+				     "'%s' cannot be read",
+				     patch->new_sha1_prefix, name);
+		clear_image(img);
+		img->buf = result;
+		img->len = size;
+	} else {
+		/*
+		 * We have verified buf matches the preimage;
+		 * apply the patch data to it, which is stored
+		 * in the patch->fragments->{patch,size}.
+		 */
+		if (apply_binary_fragment(img, patch))
+			return error("binary patch does not apply to '%s'",
+				     name);
+
+		/* verify that the result matches */
+		hash_sha1_file(img->buf, img->len, blob_type, sha1);
+		if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
+			return error("binary patch to '%s' creates incorrect result (expecting %s, got %s)",
+				name, patch->new_sha1_prefix, sha1_to_hex(sha1));
+	}
+
+	return 0;
+}
+
+static int apply_fragments(struct image *img, struct patch *patch)
+{
+	struct fragment *frag = patch->fragments;
+	const char *name = patch->old_name ? patch->old_name : patch->new_name;
+	unsigned ws_rule = patch->ws_rule;
+	unsigned inaccurate_eof = patch->inaccurate_eof;
+	int nth = 0;
+
+	if (patch->is_binary)
+		return apply_binary(img, patch);
+
+	while (frag) {
+		nth++;
+		if (apply_one_fragment(img, frag, inaccurate_eof, ws_rule, nth)) {
+			error("patch failed: %s:%ld", name, frag->oldpos);
+			if (!apply_with_reject)
+				return -1;
+			frag->rejected = 1;
+		}
+		frag = frag->next;
+	}
+	return 0;
+}
+
+static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
+{
+	if (!ce)
+		return 0;
+
+	if (S_ISGITLINK(ce->ce_mode)) {
+		strbuf_grow(buf, 100);
+		strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(ce->sha1));
+	} else {
+		enum object_type type;
+		unsigned long sz;
+		char *result;
+
+		result = read_sha1_file(ce->sha1, &type, &sz);
+		if (!result)
+			return -1;
+		/* XXX read_sha1_file NUL-terminates */
+		strbuf_attach(buf, result, sz, sz + 1);
+	}
+	return 0;
+}
+
+static struct patch *in_fn_table(const char *name)
+{
+	struct string_list_item *item;
+
+	if (name == NULL)
+		return NULL;
+
+	item = string_list_lookup(&fn_table, name);
+	if (item != NULL)
+		return (struct patch *)item->util;
+
+	return NULL;
+}
+
+/*
+ * item->util in the filename table records the status of the path.
+ * Usually it points at a patch (whose result records the contents
+ * of it after applying it), but it could be PATH_WAS_DELETED for a
+ * path that a previously applied patch has already removed.
+ */
+ #define PATH_TO_BE_DELETED ((struct patch *) -2)
+#define PATH_WAS_DELETED ((struct patch *) -1)
+
+static int to_be_deleted(struct patch *patch)
+{
+	return patch == PATH_TO_BE_DELETED;
+}
+
+static int was_deleted(struct patch *patch)
+{
+	return patch == PATH_WAS_DELETED;
+}
+
+static void add_to_fn_table(struct patch *patch)
+{
+	struct string_list_item *item;
+
+	/*
+	 * Always add new_name unless patch is a deletion
+	 * This should cover the cases for normal diffs,
+	 * file creations and copies
+	 */
+	if (patch->new_name != NULL) {
+		item = string_list_insert(&fn_table, patch->new_name);
+		item->util = patch;
+	}
+
+	/*
+	 * store a failure on rename/deletion cases because
+	 * later chunks shouldn't patch old names
+	 */
+	if ((patch->new_name == NULL) || (patch->is_rename)) {
+		item = string_list_insert(&fn_table, patch->old_name);
+		item->util = PATH_WAS_DELETED;
+	}
+}
+
+static void prepare_fn_table(struct patch *patch)
+{
+	/*
+	 * store information about incoming file deletion
+	 */
+	while (patch) {
+		if ((patch->new_name == NULL) || (patch->is_rename)) {
+			struct string_list_item *item;
+			item = string_list_insert(&fn_table, patch->old_name);
+			item->util = PATH_TO_BE_DELETED;
+		}
+		patch = patch->next;
+	}
+}
+
+static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct image image;
+	size_t len;
+	char *img;
+	struct patch *tpatch;
+
+	if (!(patch->is_copy || patch->is_rename) &&
+	    (tpatch = in_fn_table(patch->old_name)) != NULL && !to_be_deleted(tpatch)) {
+		if (was_deleted(tpatch)) {
+			return error("patch %s has been renamed/deleted",
+				patch->old_name);
+		}
+		/* We have a patched copy in memory use that */
+		strbuf_add(&buf, tpatch->result, tpatch->resultsize);
+	} else if (cached) {
+		if (read_file_or_gitlink(ce, &buf))
+			return error("read of %s failed", patch->old_name);
+	} else if (patch->old_name) {
+		if (S_ISGITLINK(patch->old_mode)) {
+			if (ce) {
+				read_file_or_gitlink(ce, &buf);
+			} else {
+				/*
+				 * There is no way to apply subproject
+				 * patch without looking at the index.
+				 */
+				patch->fragments = NULL;
+			}
+		} else {
+			if (read_old_data(st, patch->old_name, &buf))
+				return error("read of %s failed", patch->old_name);
+		}
+	}
+
+	img = strbuf_detach(&buf, &len);
+	prepare_image(&image, img, len, !patch->is_binary);
+
+	if (apply_fragments(&image, patch) < 0)
+		return -1; /* note with --reject this succeeds. */
+	patch->result = image.buf;
+	patch->resultsize = image.len;
+	add_to_fn_table(patch);
+	free(image.line_allocated);
+
+	if (0 < patch->is_delete && patch->resultsize)
+		return error("removal patch leaves file contents");
+
+	return 0;
+}
+
+static int check_to_create_blob(const char *new_name, int ok_if_exists)
+{
+	struct stat nst;
+	if (!lstat(new_name, &nst)) {
+		if (S_ISDIR(nst.st_mode) || ok_if_exists)
+			return 0;
+		/*
+		 * A leading component of new_name might be a symlink
+		 * that is going to be removed with this patch, but
+		 * still pointing at somewhere that has the path.
+		 * In such a case, path "new_name" does not exist as
+		 * far as git is concerned.
+		 */
+		if (has_symlink_leading_path(new_name, strlen(new_name)))
+			return 0;
+
+		return error("%s: already exists in working directory", new_name);
+	}
+	else if ((errno != ENOENT) && (errno != ENOTDIR))
+		return error("%s: %s", new_name, strerror(errno));
+	return 0;
+}
+
+static int verify_index_match(struct cache_entry *ce, struct stat *st)
+{
+	if (S_ISGITLINK(ce->ce_mode)) {
+		if (!S_ISDIR(st->st_mode))
+			return -1;
+		return 0;
+	}
+	return ce_match_stat(ce, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
+}
+
+static int check_preimage(struct patch *patch, struct cache_entry **ce, struct stat *st)
+{
+	const char *old_name = patch->old_name;
+	struct patch *tpatch = NULL;
+	int stat_ret = 0;
+	unsigned st_mode = 0;
+
+	/*
+	 * Make sure that we do not have local modifications from the
+	 * index when we are looking at the index.  Also make sure
+	 * we have the preimage file to be patched in the work tree,
+	 * unless --cached, which tells git to apply only in the index.
+	 */
+	if (!old_name)
+		return 0;
+
+	assert(patch->is_new <= 0);
+
+	if (!(patch->is_copy || patch->is_rename) &&
+	    (tpatch = in_fn_table(old_name)) != NULL && !to_be_deleted(tpatch)) {
+		if (was_deleted(tpatch))
+			return error("%s: has been deleted/renamed", old_name);
+		st_mode = tpatch->new_mode;
+	} else if (!cached) {
+		stat_ret = lstat(old_name, st);
+		if (stat_ret && errno != ENOENT)
+			return error("%s: %s", old_name, strerror(errno));
+	}
+
+	if (to_be_deleted(tpatch))
+		tpatch = NULL;
+
+	if (check_index && !tpatch) {
+		int pos = cache_name_pos(old_name, strlen(old_name));
+		if (pos < 0) {
+			if (patch->is_new < 0)
+				goto is_new;
+			return error("%s: does not exist in index", old_name);
+		}
+		*ce = active_cache[pos];
+		if (stat_ret < 0) {
+			struct checkout costate;
+			/* checkout */
+			memset(&costate, 0, sizeof(costate));
+			costate.base_dir = "";
+			costate.refresh_cache = 1;
+			if (checkout_entry(*ce, &costate, NULL) ||
+			    lstat(old_name, st))
+				return -1;
+		}
+		if (!cached && verify_index_match(*ce, st))
+			return error("%s: does not match index", old_name);
+		if (cached)
+			st_mode = (*ce)->ce_mode;
+	} else if (stat_ret < 0) {
+		if (patch->is_new < 0)
+			goto is_new;
+		return error("%s: %s", old_name, strerror(errno));
+	}
+
+	if (!cached && !tpatch)
+		st_mode = ce_mode_from_stat(*ce, st->st_mode);
+
+	if (patch->is_new < 0)
+		patch->is_new = 0;
+	if (!patch->old_mode)
+		patch->old_mode = st_mode;
+	if ((st_mode ^ patch->old_mode) & S_IFMT)
+		return error("%s: wrong type", old_name);
+	if (st_mode != patch->old_mode)
+		warning("%s has type %o, expected %o",
+			old_name, st_mode, patch->old_mode);
+	if (!patch->new_mode && !patch->is_delete)
+		patch->new_mode = st_mode;
+	return 0;
+
+ is_new:
+	patch->is_new = 1;
+	patch->is_delete = 0;
+	patch->old_name = NULL;
+	return 0;
+}
+
+static int check_patch(struct patch *patch)
+{
+	struct stat st;
+	const char *old_name = patch->old_name;
+	const char *new_name = patch->new_name;
+	const char *name = old_name ? old_name : new_name;
+	struct cache_entry *ce = NULL;
+	struct patch *tpatch;
+	int ok_if_exists;
+	int status;
+
+	patch->rejected = 1; /* we will drop this after we succeed */
+
+	status = check_preimage(patch, &ce, &st);
+	if (status)
+		return status;
+	old_name = patch->old_name;
+
+	if ((tpatch = in_fn_table(new_name)) &&
+			(was_deleted(tpatch) || to_be_deleted(tpatch)))
+		/*
+		 * A type-change diff is always split into a patch to
+		 * delete old, immediately followed by a patch to
+		 * create new (see diff.c::run_diff()); in such a case
+		 * it is Ok that the entry to be deleted by the
+		 * previous patch is still in the working tree and in
+		 * the index.
+		 */
+		ok_if_exists = 1;
+	else
+		ok_if_exists = 0;
+
+	if (new_name &&
+	    ((0 < patch->is_new) | (0 < patch->is_rename) | patch->is_copy)) {
+		if (check_index &&
+		    cache_name_pos(new_name, strlen(new_name)) >= 0 &&
+		    !ok_if_exists)
+			return error("%s: already exists in index", new_name);
+		if (!cached) {
+			int err = check_to_create_blob(new_name, ok_if_exists);
+			if (err)
+				return err;
+		}
+		if (!patch->new_mode) {
+			if (0 < patch->is_new)
+				patch->new_mode = S_IFREG | 0644;
+			else
+				patch->new_mode = patch->old_mode;
+		}
+	}
+
+	if (new_name && old_name) {
+		int same = !strcmp(old_name, new_name);
+		if (!patch->new_mode)
+			patch->new_mode = patch->old_mode;
+		if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
+			return error("new mode (%o) of %s does not match old mode (%o)%s%s",
+				patch->new_mode, new_name, patch->old_mode,
+				same ? "" : " of ", same ? "" : old_name);
+	}
+
+	if (apply_data(patch, &st, ce) < 0)
+		return error("%s: patch does not apply", name);
+	patch->rejected = 0;
+	return 0;
+}
+
+static int check_patch_list(struct patch *patch)
+{
+	int err = 0;
+
+	prepare_fn_table(patch);
+	while (patch) {
+		if (apply_verbosely)
+			say_patch_name(stderr,
+				       "Checking patch ", patch, "...\n");
+		err |= check_patch(patch);
+		patch = patch->next;
+	}
+	return err;
+}
+
+/* This function tries to read the sha1 from the current index */
+static int get_current_sha1(const char *path, unsigned char *sha1)
+{
+	int pos;
+
+	if (read_cache() < 0)
+		return -1;
+	pos = cache_name_pos(path, strlen(path));
+	if (pos < 0)
+		return -1;
+	hashcpy(sha1, active_cache[pos]->sha1);
+	return 0;
+}
+
+/* Build an index that contains the just the files needed for a 3way merge */
+static void build_fake_ancestor(struct patch *list, const char *filename)
+{
+	struct patch *patch;
+	struct index_state result = { NULL };
+	int fd;
+
+	/* Once we start supporting the reverse patch, it may be
+	 * worth showing the new sha1 prefix, but until then...
+	 */
+	for (patch = list; patch; patch = patch->next) {
+		const unsigned char *sha1_ptr;
+		unsigned char sha1[20];
+		struct cache_entry *ce;
+		const char *name;
+
+		name = patch->old_name ? patch->old_name : patch->new_name;
+		if (0 < patch->is_new)
+			continue;
+		else if (get_sha1(patch->old_sha1_prefix, sha1))
+			/* git diff has no index line for mode/type changes */
+			if (!patch->lines_added && !patch->lines_deleted) {
+				if (get_current_sha1(patch->old_name, sha1))
+					die("mode change for %s, which is not "
+						"in current HEAD", name);
+				sha1_ptr = sha1;
+			} else
+				die("sha1 information is lacking or useless "
+					"(%s).", name);
+		else
+			sha1_ptr = sha1;
+
+		ce = make_cache_entry(patch->old_mode, sha1_ptr, name, 0, 0);
+		if (!ce)
+			die("make_cache_entry failed for path '%s'", name);
+		if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD))
+			die ("Could not add %s to temporary index", name);
+	}
+
+	fd = open(filename, O_WRONLY | O_CREAT, 0666);
+	if (fd < 0 || write_index(&result, fd) || close(fd))
+		die ("Could not write temporary index to %s", filename);
+
+	discard_index(&result);
+}
+
+static void stat_patch_list(struct patch *patch)
+{
+	int files, adds, dels;
+
+	for (files = adds = dels = 0 ; patch ; patch = patch->next) {
+		files++;
+		adds += patch->lines_added;
+		dels += patch->lines_deleted;
+		show_stats(patch);
+	}
+
+	printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
+}
+
+static void numstat_patch_list(struct patch *patch)
+{
+	for ( ; patch; patch = patch->next) {
+		const char *name;
+		name = patch->new_name ? patch->new_name : patch->old_name;
+		if (patch->is_binary)
+			printf("-\t-\t");
+		else
+			printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
+		write_name_quoted(name, stdout, line_termination);
+	}
+}
+
+static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
+{
+	if (mode)
+		printf(" %s mode %06o %s\n", newdelete, mode, name);
+	else
+		printf(" %s %s\n", newdelete, name);
+}
+
+static void show_mode_change(struct patch *p, int show_name)
+{
+	if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
+		if (show_name)
+			printf(" mode change %06o => %06o %s\n",
+			       p->old_mode, p->new_mode, p->new_name);
+		else
+			printf(" mode change %06o => %06o\n",
+			       p->old_mode, p->new_mode);
+	}
+}
+
+static void show_rename_copy(struct patch *p)
+{
+	const char *renamecopy = p->is_rename ? "rename" : "copy";
+	const char *old, *new;
+
+	/* Find common prefix */
+	old = p->old_name;
+	new = p->new_name;
+	while (1) {
+		const char *slash_old, *slash_new;
+		slash_old = strchr(old, '/');
+		slash_new = strchr(new, '/');
+		if (!slash_old ||
+		    !slash_new ||
+		    slash_old - old != slash_new - new ||
+		    memcmp(old, new, slash_new - new))
+			break;
+		old = slash_old + 1;
+		new = slash_new + 1;
+	}
+	/* p->old_name thru old is the common prefix, and old and new
+	 * through the end of names are renames
+	 */
+	if (old != p->old_name)
+		printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
+		       (int)(old - p->old_name), p->old_name,
+		       old, new, p->score);
+	else
+		printf(" %s %s => %s (%d%%)\n", renamecopy,
+		       p->old_name, p->new_name, p->score);
+	show_mode_change(p, 0);
+}
+
+static void summary_patch_list(struct patch *patch)
+{
+	struct patch *p;
+
+	for (p = patch; p; p = p->next) {
+		if (p->is_new)
+			show_file_mode_name("create", p->new_mode, p->new_name);
+		else if (p->is_delete)
+			show_file_mode_name("delete", p->old_mode, p->old_name);
+		else {
+			if (p->is_rename || p->is_copy)
+				show_rename_copy(p);
+			else {
+				if (p->score) {
+					printf(" rewrite %s (%d%%)\n",
+					       p->new_name, p->score);
+					show_mode_change(p, 0);
+				}
+				else
+					show_mode_change(p, 1);
+			}
+		}
+	}
+}
+
+static void patch_stats(struct patch *patch)
+{
+	int lines = patch->lines_added + patch->lines_deleted;
+
+	if (lines > max_change)
+		max_change = lines;
+	if (patch->old_name) {
+		int len = quote_c_style(patch->old_name, NULL, NULL, 0);
+		if (!len)
+			len = strlen(patch->old_name);
+		if (len > max_len)
+			max_len = len;
+	}
+	if (patch->new_name) {
+		int len = quote_c_style(patch->new_name, NULL, NULL, 0);
+		if (!len)
+			len = strlen(patch->new_name);
+		if (len > max_len)
+			max_len = len;
+	}
+}
+
+static void remove_file(struct patch *patch, int rmdir_empty)
+{
+	if (update_index) {
+		if (remove_file_from_cache(patch->old_name) < 0)
+			die("unable to remove %s from index", patch->old_name);
+	}
+	if (!cached) {
+		if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
+			remove_path(patch->old_name);
+		}
+	}
+}
+
+static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
+{
+	struct stat st;
+	struct cache_entry *ce;
+	int namelen = strlen(path);
+	unsigned ce_size = cache_entry_size(namelen);
+
+	if (!update_index)
+		return;
+
+	ce = xcalloc(1, ce_size);
+	memcpy(ce->name, path, namelen);
+	ce->ce_mode = create_ce_mode(mode);
+	ce->ce_flags = namelen;
+	if (S_ISGITLINK(mode)) {
+		const char *s = buf;
+
+		if (get_sha1_hex(s + strlen("Subproject commit "), ce->sha1))
+			die("corrupt patch for subproject %s", path);
+	} else {
+		if (!cached) {
+			if (lstat(path, &st) < 0)
+				die_errno("unable to stat newly created file '%s'",
+					  path);
+			fill_stat_cache_info(ce, &st);
+		}
+		if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
+			die("unable to create backing store for newly created file %s", path);
+	}
+	if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
+		die("unable to add cache entry for %s", path);
+}
+
+static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
+{
+	int fd;
+	struct strbuf nbuf = STRBUF_INIT;
+
+	if (S_ISGITLINK(mode)) {
+		struct stat st;
+		if (!lstat(path, &st) && S_ISDIR(st.st_mode))
+			return 0;
+		return mkdir(path, 0777);
+	}
+
+	if (has_symlinks && S_ISLNK(mode))
+		/* Although buf:size is counted string, it also is NUL
+		 * terminated.
+		 */
+		return symlink(buf, path);
+
+	fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
+	if (fd < 0)
+		return -1;
+
+	if (convert_to_working_tree(path, buf, size, &nbuf)) {
+		size = nbuf.len;
+		buf  = nbuf.buf;
+	}
+	write_or_die(fd, buf, size);
+	strbuf_release(&nbuf);
+
+	if (close(fd) < 0)
+		die_errno("closing file '%s'", path);
+	return 0;
+}
+
+/*
+ * We optimistically assume that the directories exist,
+ * which is true 99% of the time anyway. If they don't,
+ * we create them and try again.
+ */
+static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
+{
+	if (cached)
+		return;
+	if (!try_create_file(path, mode, buf, size))
+		return;
+
+	if (errno == ENOENT) {
+		if (safe_create_leading_directories(path))
+			return;
+		if (!try_create_file(path, mode, buf, size))
+			return;
+	}
+
+	if (errno == EEXIST || errno == EACCES) {
+		/* We may be trying to create a file where a directory
+		 * used to be.
+		 */
+		struct stat st;
+		if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
+			errno = EEXIST;
+	}
+
+	if (errno == EEXIST) {
+		unsigned int nr = getpid();
+
+		for (;;) {
+			char newpath[PATH_MAX];
+			mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
+			if (!try_create_file(newpath, mode, buf, size)) {
+				if (!rename(newpath, path))
+					return;
+				unlink_or_warn(newpath);
+				break;
+			}
+			if (errno != EEXIST)
+				break;
+			++nr;
+		}
+	}
+	die_errno("unable to write file '%s' mode %o", path, mode);
+}
+
+static void create_file(struct patch *patch)
+{
+	char *path = patch->new_name;
+	unsigned mode = patch->new_mode;
+	unsigned long size = patch->resultsize;
+	char *buf = patch->result;
+
+	if (!mode)
+		mode = S_IFREG | 0644;
+	create_one_file(path, mode, buf, size);
+	add_index_file(path, mode, buf, size);
+}
+
+/* phase zero is to remove, phase one is to create */
+static void write_out_one_result(struct patch *patch, int phase)
+{
+	if (patch->is_delete > 0) {
+		if (phase == 0)
+			remove_file(patch, 1);
+		return;
+	}
+	if (patch->is_new > 0 || patch->is_copy) {
+		if (phase == 1)
+			create_file(patch);
+		return;
+	}
+	/*
+	 * Rename or modification boils down to the same
+	 * thing: remove the old, write the new
+	 */
+	if (phase == 0)
+		remove_file(patch, patch->is_rename);
+	if (phase == 1)
+		create_file(patch);
+}
+
+static int write_out_one_reject(struct patch *patch)
+{
+	FILE *rej;
+	char namebuf[PATH_MAX];
+	struct fragment *frag;
+	int cnt = 0;
+
+	for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
+		if (!frag->rejected)
+			continue;
+		cnt++;
+	}
+
+	if (!cnt) {
+		if (apply_verbosely)
+			say_patch_name(stderr,
+				       "Applied patch ", patch, " cleanly.\n");
+		return 0;
+	}
+
+	/* This should not happen, because a removal patch that leaves
+	 * contents are marked "rejected" at the patch level.
+	 */
+	if (!patch->new_name)
+		die("internal error");
+
+	/* Say this even without --verbose */
+	say_patch_name(stderr, "Applying patch ", patch, " with");
+	fprintf(stderr, " %d rejects...\n", cnt);
+
+	cnt = strlen(patch->new_name);
+	if (ARRAY_SIZE(namebuf) <= cnt + 5) {
+		cnt = ARRAY_SIZE(namebuf) - 5;
+		warning("truncating .rej filename to %.*s.rej",
+			cnt - 1, patch->new_name);
+	}
+	memcpy(namebuf, patch->new_name, cnt);
+	memcpy(namebuf + cnt, ".rej", 5);
+
+	rej = fopen(namebuf, "w");
+	if (!rej)
+		return error("cannot open %s: %s", namebuf, strerror(errno));
+
+	/* Normal git tools never deal with .rej, so do not pretend
+	 * this is a git patch by saying --git nor give extended
+	 * headers.  While at it, maybe please "kompare" that wants
+	 * the trailing TAB and some garbage at the end of line ;-).
+	 */
+	fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
+		patch->new_name, patch->new_name);
+	for (cnt = 1, frag = patch->fragments;
+	     frag;
+	     cnt++, frag = frag->next) {
+		if (!frag->rejected) {
+			fprintf(stderr, "Hunk #%d applied cleanly.\n", cnt);
+			continue;
+		}
+		fprintf(stderr, "Rejected hunk #%d.\n", cnt);
+		fprintf(rej, "%.*s", frag->size, frag->patch);
+		if (frag->patch[frag->size-1] != '\n')
+			fputc('\n', rej);
+	}
+	fclose(rej);
+	return -1;
+}
+
+static int write_out_results(struct patch *list, int skipped_patch)
+{
+	int phase;
+	int errs = 0;
+	struct patch *l;
+
+	if (!list && !skipped_patch)
+		return error("No changes");
+
+	for (phase = 0; phase < 2; phase++) {
+		l = list;
+		while (l) {
+			if (l->rejected)
+				errs = 1;
+			else {
+				write_out_one_result(l, phase);
+				if (phase == 1 && write_out_one_reject(l))
+					errs = 1;
+			}
+			l = l->next;
+		}
+	}
+	return errs;
+}
+
+static struct lock_file lock_file;
+
+static struct string_list limit_by_name;
+static int has_include;
+static void add_name_limit(const char *name, int exclude)
+{
+	struct string_list_item *it;
+
+	it = string_list_append(&limit_by_name, name);
+	it->util = exclude ? NULL : (void *) 1;
+}
+
+static int use_patch(struct patch *p)
+{
+	const char *pathname = p->new_name ? p->new_name : p->old_name;
+	int i;
+
+	/* Paths outside are not touched regardless of "--include" */
+	if (0 < prefix_length) {
+		int pathlen = strlen(pathname);
+		if (pathlen <= prefix_length ||
+		    memcmp(prefix, pathname, prefix_length))
+			return 0;
+	}
+
+	/* See if it matches any of exclude/include rule */
+	for (i = 0; i < limit_by_name.nr; i++) {
+		struct string_list_item *it = &limit_by_name.items[i];
+		if (!fnmatch(it->string, pathname, 0))
+			return (it->util != NULL);
+	}
+
+	/*
+	 * If we had any include, a path that does not match any rule is
+	 * not used.  Otherwise, we saw bunch of exclude rules (or none)
+	 * and such a path is used.
+	 */
+	return !has_include;
+}
+
+
+static void prefix_one(char **name)
+{
+	char *old_name = *name;
+	if (!old_name)
+		return;
+	*name = xstrdup(prefix_filename(prefix, prefix_length, *name));
+	free(old_name);
+}
+
+static void prefix_patches(struct patch *p)
+{
+	if (!prefix || p->is_toplevel_relative)
+		return;
+	for ( ; p; p = p->next) {
+		if (p->new_name == p->old_name) {
+			char *prefixed = p->new_name;
+			prefix_one(&prefixed);
+			p->new_name = p->old_name = prefixed;
+		}
+		else {
+			prefix_one(&p->new_name);
+			prefix_one(&p->old_name);
+		}
+	}
+}
+
+#define INACCURATE_EOF	(1<<0)
+#define RECOUNT		(1<<1)
+
+static int apply_patch(int fd, const char *filename, int options)
+{
+	size_t offset;
+	struct strbuf buf = STRBUF_INIT;
+	struct patch *list = NULL, **listp = &list;
+	int skipped_patch = 0;
+
+	/* FIXME - memory leak when using multiple patch files as inputs */
+	memset(&fn_table, 0, sizeof(struct string_list));
+	patch_input_file = filename;
+	read_patch_file(&buf, fd);
+	offset = 0;
+	while (offset < buf.len) {
+		struct patch *patch;
+		int nr;
+
+		patch = xcalloc(1, sizeof(*patch));
+		patch->inaccurate_eof = !!(options & INACCURATE_EOF);
+		patch->recount =  !!(options & RECOUNT);
+		nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
+		if (nr < 0)
+			break;
+		if (apply_in_reverse)
+			reverse_patches(patch);
+		if (prefix)
+			prefix_patches(patch);
+		if (use_patch(patch)) {
+			patch_stats(patch);
+			*listp = patch;
+			listp = &patch->next;
+		}
+		else {
+			/* perhaps free it a bit better? */
+			free(patch);
+			skipped_patch++;
+		}
+		offset += nr;
+	}
+
+	if (whitespace_error && (ws_error_action == die_on_ws_error))
+		apply = 0;
+
+	update_index = check_index && apply;
+	if (update_index && newfd < 0)
+		newfd = hold_locked_index(&lock_file, 1);
+
+	if (check_index) {
+		if (read_cache() < 0)
+			die("unable to read index file");
+	}
+
+	if ((check || apply) &&
+	    check_patch_list(list) < 0 &&
+	    !apply_with_reject)
+		exit(1);
+
+	if (apply && write_out_results(list, skipped_patch))
+		exit(1);
+
+	if (fake_ancestor)
+		build_fake_ancestor(list, fake_ancestor);
+
+	if (diffstat)
+		stat_patch_list(list);
+
+	if (numstat)
+		numstat_patch_list(list);
+
+	if (summary)
+		summary_patch_list(list);
+
+	strbuf_release(&buf);
+	return 0;
+}
+
+static int git_apply_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "apply.whitespace"))
+		return git_config_string(&apply_default_whitespace, var, value);
+	else if (!strcmp(var, "apply.ignorewhitespace"))
+		return git_config_string(&apply_default_ignorewhitespace, var, value);
+	return git_default_config(var, value, cb);
+}
+
+static int option_parse_exclude(const struct option *opt,
+				const char *arg, int unset)
+{
+	add_name_limit(arg, 1);
+	return 0;
+}
+
+static int option_parse_include(const struct option *opt,
+				const char *arg, int unset)
+{
+	add_name_limit(arg, 0);
+	has_include = 1;
+	return 0;
+}
+
+static int option_parse_p(const struct option *opt,
+			  const char *arg, int unset)
+{
+	p_value = atoi(arg);
+	p_value_known = 1;
+	return 0;
+}
+
+static int option_parse_z(const struct option *opt,
+			  const char *arg, int unset)
+{
+	if (unset)
+		line_termination = '\n';
+	else
+		line_termination = 0;
+	return 0;
+}
+
+static int option_parse_space_change(const struct option *opt,
+			  const char *arg, int unset)
+{
+	if (unset)
+		ws_ignore_action = ignore_ws_none;
+	else
+		ws_ignore_action = ignore_ws_change;
+	return 0;
+}
+
+static int option_parse_whitespace(const struct option *opt,
+				   const char *arg, int unset)
+{
+	const char **whitespace_option = opt->value;
+
+	*whitespace_option = arg;
+	parse_whitespace_option(arg);
+	return 0;
+}
+
+static int option_parse_directory(const struct option *opt,
+				  const char *arg, int unset)
+{
+	root_len = strlen(arg);
+	if (root_len && arg[root_len - 1] != '/') {
+		char *new_root;
+		root = new_root = xmalloc(root_len + 2);
+		strcpy(new_root, arg);
+		strcpy(new_root + root_len++, "/");
+	} else
+		root = arg;
+	return 0;
+}
+
+int cmd_apply(int argc, const char **argv, const char *prefix_)
+{
+	int i;
+	int errs = 0;
+	int is_not_gitdir = !startup_info->have_repository;
+	int binary;
+	int force_apply = 0;
+
+	const char *whitespace_option = NULL;
+
+	struct option builtin_apply_options[] = {
+		{ OPTION_CALLBACK, 0, "exclude", NULL, "path",
+			"don't apply changes matching the given path",
+			0, option_parse_exclude },
+		{ OPTION_CALLBACK, 0, "include", NULL, "path",
+			"apply changes matching the given path",
+			0, option_parse_include },
+		{ OPTION_CALLBACK, 'p', NULL, NULL, "num",
+			"remove <num> leading slashes from traditional diff paths",
+			0, option_parse_p },
+		OPT_BOOLEAN(0, "no-add", &no_add,
+			"ignore additions made by the patch"),
+		OPT_BOOLEAN(0, "stat", &diffstat,
+			"instead of applying the patch, output diffstat for the input"),
+		{ OPTION_BOOLEAN, 0, "allow-binary-replacement", &binary,
+		  NULL, "old option, now no-op",
+		  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG },
+		{ OPTION_BOOLEAN, 0, "binary", &binary,
+		  NULL, "old option, now no-op",
+		  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG },
+		OPT_BOOLEAN(0, "numstat", &numstat,
+			"shows number of added and deleted lines in decimal notation"),
+		OPT_BOOLEAN(0, "summary", &summary,
+			"instead of applying the patch, output a summary for the input"),
+		OPT_BOOLEAN(0, "check", &check,
+			"instead of applying the patch, see if the patch is applicable"),
+		OPT_BOOLEAN(0, "index", &check_index,
+			"make sure the patch is applicable to the current index"),
+		OPT_BOOLEAN(0, "cached", &cached,
+			"apply a patch without touching the working tree"),
+		OPT_BOOLEAN(0, "apply", &force_apply,
+			"also apply the patch (use with --stat/--summary/--check)"),
+		OPT_FILENAME(0, "build-fake-ancestor", &fake_ancestor,
+			"build a temporary index based on embedded index information"),
+		{ OPTION_CALLBACK, 'z', NULL, NULL, NULL,
+			"paths are separated with NUL character",
+			PARSE_OPT_NOARG, option_parse_z },
+		OPT_INTEGER('C', NULL, &p_context,
+				"ensure at least <n> lines of context match"),
+		{ OPTION_CALLBACK, 0, "whitespace", &whitespace_option, "action",
+			"detect new or modified lines that have whitespace errors",
+			0, option_parse_whitespace },
+		{ OPTION_CALLBACK, 0, "ignore-space-change", NULL, NULL,
+			"ignore changes in whitespace when finding context",
+			PARSE_OPT_NOARG, option_parse_space_change },
+		{ OPTION_CALLBACK, 0, "ignore-whitespace", NULL, NULL,
+			"ignore changes in whitespace when finding context",
+			PARSE_OPT_NOARG, option_parse_space_change },
+		OPT_BOOLEAN('R', "reverse", &apply_in_reverse,
+			"apply the patch in reverse"),
+		OPT_BOOLEAN(0, "unidiff-zero", &unidiff_zero,
+			"don't expect at least one line of context"),
+		OPT_BOOLEAN(0, "reject", &apply_with_reject,
+			"leave the rejected hunks in corresponding *.rej files"),
+		OPT_BOOLEAN(0, "allow-overlap", &allow_overlap,
+			"allow overlapping hunks"),
+		OPT__VERBOSE(&apply_verbosely, "be verbose"),
+		OPT_BIT(0, "inaccurate-eof", &options,
+			"tolerate incorrectly detected missing new-line at the end of file",
+			INACCURATE_EOF),
+		OPT_BIT(0, "recount", &options,
+			"do not trust the line counts in the hunk headers",
+			RECOUNT),
+		{ OPTION_CALLBACK, 0, "directory", NULL, "root",
+			"prepend <root> to all filenames",
+			0, option_parse_directory },
+		OPT_END()
+	};
+
+	prefix = prefix_;
+	prefix_length = prefix ? strlen(prefix) : 0;
+	git_config(git_apply_config, NULL);
+	if (apply_default_whitespace)
+		parse_whitespace_option(apply_default_whitespace);
+	if (apply_default_ignorewhitespace)
+		parse_ignorewhitespace_option(apply_default_ignorewhitespace);
+
+	argc = parse_options(argc, argv, prefix, builtin_apply_options,
+			apply_usage, 0);
+
+	if (apply_with_reject)
+		apply = apply_verbosely = 1;
+	if (!force_apply && (diffstat || numstat || summary || check || fake_ancestor))
+		apply = 0;
+	if (check_index && is_not_gitdir)
+		die("--index outside a repository");
+	if (cached) {
+		if (is_not_gitdir)
+			die("--cached outside a repository");
+		check_index = 1;
+	}
+	for (i = 0; i < argc; i++) {
+		const char *arg = argv[i];
+		int fd;
+
+		if (!strcmp(arg, "-")) {
+			errs |= apply_patch(0, "<stdin>", options);
+			read_stdin = 0;
+			continue;
+		} else if (0 < prefix_length)
+			arg = prefix_filename(prefix, prefix_length, arg);
+
+		fd = open(arg, O_RDONLY);
+		if (fd < 0)
+			die_errno("can't open patch '%s'", arg);
+		read_stdin = 0;
+		set_default_whitespace_mode(whitespace_option);
+		errs |= apply_patch(fd, arg, options);
+		close(fd);
+	}
+	set_default_whitespace_mode(whitespace_option);
+	if (read_stdin)
+		errs |= apply_patch(0, "<stdin>", options);
+	if (whitespace_error) {
+		if (squelch_whitespace_errors &&
+		    squelch_whitespace_errors < whitespace_error) {
+			int squelched =
+				whitespace_error - squelch_whitespace_errors;
+			warning("squelched %d "
+				"whitespace error%s",
+				squelched,
+				squelched == 1 ? "" : "s");
+		}
+		if (ws_error_action == die_on_ws_error)
+			die("%d line%s add%s whitespace errors.",
+			    whitespace_error,
+			    whitespace_error == 1 ? "" : "s",
+			    whitespace_error == 1 ? "s" : "");
+		if (applied_after_fixing_ws && apply)
+			warning("%d line%s applied after"
+				" fixing whitespace errors.",
+				applied_after_fixing_ws,
+				applied_after_fixing_ws == 1 ? "" : "s");
+		else if (whitespace_error)
+			warning("%d line%s add%s whitespace errors.",
+				whitespace_error,
+				whitespace_error == 1 ? "" : "s",
+				whitespace_error == 1 ? "s" : "");
+	}
+
+	if (update_index) {
+		if (write_cache(newfd, active_cache, active_nr) ||
+		    commit_locked_index(&lock_file))
+			die("Unable to write new index file");
+	}
+
+	return !!errs;
+}
diff --git a/builtin/archive.c b/builtin/archive.c
new file mode 100644
index 0000000..931956d
--- /dev/null
+++ b/builtin/archive.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2006 Franck Bui-Huu
+ * Copyright (c) 2006 Rene Scharfe
+ */
+#include "cache.h"
+#include "builtin.h"
+#include "archive.h"
+#include "transport.h"
+#include "parse-options.h"
+#include "pkt-line.h"
+#include "sideband.h"
+
+static void create_output_file(const char *output_file)
+{
+	int output_fd = open(output_file, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+	if (output_fd < 0)
+		die_errno(_("could not create archive file '%s'"), output_file);
+	if (output_fd != 1) {
+		if (dup2(output_fd, 1) < 0)
+			die_errno(_("could not redirect output"));
+		else
+			close(output_fd);
+	}
+}
+
+static int run_remote_archiver(int argc, const char **argv,
+			       const char *remote, const char *exec,
+			       const char *name_hint)
+{
+	char buf[LARGE_PACKET_MAX];
+	int fd[2], i, len, rv;
+	struct transport *transport;
+	struct remote *_remote;
+
+	_remote = remote_get(remote);
+	if (!_remote->url[0])
+		die(_("git archive: Remote with no URL"));
+	transport = transport_get(_remote, _remote->url[0]);
+	transport_connect(transport, "git-upload-archive", exec, fd);
+
+	/*
+	 * Inject a fake --format field at the beginning of the
+	 * arguments, with the format inferred from our output
+	 * filename. This way explicit --format options can override
+	 * it.
+	 */
+	if (name_hint) {
+		const char *format = archive_format_from_filename(name_hint);
+		if (format)
+			packet_write(fd[1], "argument --format=%s\n", format);
+	}
+	for (i = 1; i < argc; i++)
+		packet_write(fd[1], "argument %s\n", argv[i]);
+	packet_flush(fd[1]);
+
+	len = packet_read_line(fd[0], buf, sizeof(buf));
+	if (!len)
+		die(_("git archive: expected ACK/NAK, got EOF"));
+	if (buf[len-1] == '\n')
+		buf[--len] = 0;
+	if (strcmp(buf, "ACK")) {
+		if (len > 5 && !prefixcmp(buf, "NACK "))
+			die(_("git archive: NACK %s"), buf + 5);
+		if (len > 4 && !prefixcmp(buf, "ERR "))
+			die(_("remote error: %s"), buf + 4);
+		die(_("git archive: protocol error"));
+	}
+
+	len = packet_read_line(fd[0], buf, sizeof(buf));
+	if (len)
+		die(_("git archive: expected a flush"));
+
+	/* Now, start reading from fd[0] and spit it out to stdout */
+	rv = recv_sideband("archive", fd[0], 1);
+	rv |= transport_disconnect(transport);
+
+	return !!rv;
+}
+
+#define PARSE_OPT_KEEP_ALL ( PARSE_OPT_KEEP_DASHDASH | 	\
+			     PARSE_OPT_KEEP_ARGV0 | 	\
+			     PARSE_OPT_KEEP_UNKNOWN |	\
+			     PARSE_OPT_NO_INTERNAL_HELP	)
+
+int cmd_archive(int argc, const char **argv, const char *prefix)
+{
+	const char *exec = "git-upload-archive";
+	const char *output = NULL;
+	const char *remote = NULL;
+	struct option local_opts[] = {
+		OPT_STRING('o', "output", &output, "file",
+			"write the archive to this file"),
+		OPT_STRING(0, "remote", &remote, "repo",
+			"retrieve the archive from remote repository <repo>"),
+		OPT_STRING(0, "exec", &exec, "cmd",
+			"path to the remote git-upload-archive command"),
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, prefix, local_opts, NULL,
+			     PARSE_OPT_KEEP_ALL);
+
+	if (output)
+		create_output_file(output);
+
+	if (remote)
+		return run_remote_archiver(argc, argv, remote, exec, output);
+
+	setvbuf(stderr, NULL, _IOLBF, BUFSIZ);
+
+	return write_archive(argc, argv, prefix, 1, output, 0);
+}
diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
new file mode 100644
index 0000000..8d325a5
--- /dev/null
+++ b/builtin/bisect--helper.c
@@ -0,0 +1,31 @@
+#include "builtin.h"
+#include "cache.h"
+#include "parse-options.h"
+#include "bisect.h"
+
+static const char * const git_bisect_helper_usage[] = {
+	"git bisect--helper --next-all [--no-checkout]",
+	NULL
+};
+
+int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
+{
+	int next_all = 0;
+	int no_checkout = 0;
+	struct option options[] = {
+		OPT_BOOLEAN(0, "next-all", &next_all,
+			    "perform 'git bisect next'"),
+		OPT_BOOLEAN(0, "no-checkout", &no_checkout,
+			    "update BISECT_HEAD instead of checking out the current commit"),
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, prefix, options,
+			     git_bisect_helper_usage, 0);
+
+	if (!next_all)
+		usage_with_options(git_bisect_helper_usage, options);
+
+	/* next-all */
+	return bisect_next_all(prefix, no_checkout);
+}
diff --git a/builtin/blame.c b/builtin/blame.c
new file mode 100644
index 0000000..26a5d42
--- /dev/null
+++ b/builtin/blame.c
@@ -0,0 +1,2576 @@
+/*
+ * Blame
+ *
+ * Copyright (c) 2006, Junio C Hamano
+ */
+
+#include "cache.h"
+#include "builtin.h"
+#include "blob.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree-walk.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
+#include "quote.h"
+#include "xdiff-interface.h"
+#include "cache-tree.h"
+#include "string-list.h"
+#include "mailmap.h"
+#include "parse-options.h"
+#include "utf8.h"
+#include "userdiff.h"
+
+static char blame_usage[] = "git blame [options] [rev-opts] [rev] [--] file";
+
+static const char *blame_opt_usage[] = {
+	blame_usage,
+	"",
+	"[rev-opts] are documented in git-rev-list(1)",
+	NULL
+};
+
+static int longest_file;
+static int longest_author;
+static int max_orig_digits;
+static int max_digits;
+static int max_score_digits;
+static int show_root;
+static int reverse;
+static int blank_boundary;
+static int incremental;
+static int xdl_opts;
+static int abbrev = -1;
+
+static enum date_mode blame_date_mode = DATE_ISO8601;
+static size_t blame_date_width;
+
+static struct string_list mailmap;
+
+#ifndef DEBUG
+#define DEBUG 0
+#endif
+
+/* stats */
+static int num_read_blob;
+static int num_get_patch;
+static int num_commits;
+
+#define PICKAXE_BLAME_MOVE		01
+#define PICKAXE_BLAME_COPY		02
+#define PICKAXE_BLAME_COPY_HARDER	04
+#define PICKAXE_BLAME_COPY_HARDEST	010
+
+/*
+ * blame for a blame_entry with score lower than these thresholds
+ * is not passed to the parent using move/copy logic.
+ */
+static unsigned blame_move_score;
+static unsigned blame_copy_score;
+#define BLAME_DEFAULT_MOVE_SCORE	20
+#define BLAME_DEFAULT_COPY_SCORE	40
+
+/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
+#define METAINFO_SHOWN		(1u<<12)
+#define MORE_THAN_ONE_PATH	(1u<<13)
+
+/*
+ * One blob in a commit that is being suspected
+ */
+struct origin {
+	int refcnt;
+	struct origin *previous;
+	struct commit *commit;
+	mmfile_t file;
+	unsigned char blob_sha1[20];
+	unsigned mode;
+	char path[FLEX_ARRAY];
+};
+
+/*
+ * Prepare diff_filespec and convert it using diff textconv API
+ * if the textconv driver exists.
+ * Return 1 if the conversion succeeds, 0 otherwise.
+ */
+int textconv_object(const char *path,
+		    unsigned mode,
+		    const unsigned char *sha1,
+		    char **buf,
+		    unsigned long *buf_size)
+{
+	struct diff_filespec *df;
+	struct userdiff_driver *textconv;
+
+	df = alloc_filespec(path);
+	fill_filespec(df, sha1, mode);
+	textconv = get_textconv(df);
+	if (!textconv) {
+		free_filespec(df);
+		return 0;
+	}
+
+	*buf_size = fill_textconv(textconv, df, buf);
+	free_filespec(df);
+	return 1;
+}
+
+/*
+ * Given an origin, prepare mmfile_t structure to be used by the
+ * diff machinery
+ */
+static void fill_origin_blob(struct diff_options *opt,
+			     struct origin *o, mmfile_t *file)
+{
+	if (!o->file.ptr) {
+		enum object_type type;
+		unsigned long file_size;
+
+		num_read_blob++;
+		if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
+		    textconv_object(o->path, o->mode, o->blob_sha1, &file->ptr, &file_size))
+			;
+		else
+			file->ptr = read_sha1_file(o->blob_sha1, &type, &file_size);
+		file->size = file_size;
+
+		if (!file->ptr)
+			die("Cannot read blob %s for path %s",
+			    sha1_to_hex(o->blob_sha1),
+			    o->path);
+		o->file = *file;
+	}
+	else
+		*file = o->file;
+}
+
+/*
+ * Origin is refcounted and usually we keep the blob contents to be
+ * reused.
+ */
+static inline struct origin *origin_incref(struct origin *o)
+{
+	if (o)
+		o->refcnt++;
+	return o;
+}
+
+static void origin_decref(struct origin *o)
+{
+	if (o && --o->refcnt <= 0) {
+		if (o->previous)
+			origin_decref(o->previous);
+		free(o->file.ptr);
+		free(o);
+	}
+}
+
+static void drop_origin_blob(struct origin *o)
+{
+	if (o->file.ptr) {
+		free(o->file.ptr);
+		o->file.ptr = NULL;
+	}
+}
+
+/*
+ * Each group of lines is described by a blame_entry; it can be split
+ * as we pass blame to the parents.  They form a linked list in the
+ * scoreboard structure, sorted by the target line number.
+ */
+struct blame_entry {
+	struct blame_entry *prev;
+	struct blame_entry *next;
+
+	/* the first line of this group in the final image;
+	 * internally all line numbers are 0 based.
+	 */
+	int lno;
+
+	/* how many lines this group has */
+	int num_lines;
+
+	/* the commit that introduced this group into the final image */
+	struct origin *suspect;
+
+	/* true if the suspect is truly guilty; false while we have not
+	 * checked if the group came from one of its parents.
+	 */
+	char guilty;
+
+	/* true if the entry has been scanned for copies in the current parent
+	 */
+	char scanned;
+
+	/* the line number of the first line of this group in the
+	 * suspect's file; internally all line numbers are 0 based.
+	 */
+	int s_lno;
+
+	/* how significant this entry is -- cached to avoid
+	 * scanning the lines over and over.
+	 */
+	unsigned score;
+};
+
+/*
+ * The current state of the blame assignment.
+ */
+struct scoreboard {
+	/* the final commit (i.e. where we started digging from) */
+	struct commit *final;
+	struct rev_info *revs;
+	const char *path;
+
+	/*
+	 * The contents in the final image.
+	 * Used by many functions to obtain contents of the nth line,
+	 * indexed with scoreboard.lineno[blame_entry.lno].
+	 */
+	const char *final_buf;
+	unsigned long final_buf_size;
+
+	/* linked list of blames */
+	struct blame_entry *ent;
+
+	/* look-up a line in the final buffer */
+	int num_lines;
+	int *lineno;
+};
+
+static inline int same_suspect(struct origin *a, struct origin *b)
+{
+	if (a == b)
+		return 1;
+	if (a->commit != b->commit)
+		return 0;
+	return !strcmp(a->path, b->path);
+}
+
+static void sanity_check_refcnt(struct scoreboard *);
+
+/*
+ * If two blame entries that are next to each other came from
+ * contiguous lines in the same origin (i.e. <commit, path> pair),
+ * merge them together.
+ */
+static void coalesce(struct scoreboard *sb)
+{
+	struct blame_entry *ent, *next;
+
+	for (ent = sb->ent; ent && (next = ent->next); ent = next) {
+		if (same_suspect(ent->suspect, next->suspect) &&
+		    ent->guilty == next->guilty &&
+		    ent->s_lno + ent->num_lines == next->s_lno) {
+			ent->num_lines += next->num_lines;
+			ent->next = next->next;
+			if (ent->next)
+				ent->next->prev = ent;
+			origin_decref(next->suspect);
+			free(next);
+			ent->score = 0;
+			next = ent; /* again */
+		}
+	}
+
+	if (DEBUG) /* sanity */
+		sanity_check_refcnt(sb);
+}
+
+/*
+ * Given a commit and a path in it, create a new origin structure.
+ * The callers that add blame to the scoreboard should use
+ * get_origin() to obtain shared, refcounted copy instead of calling
+ * this function directly.
+ */
+static struct origin *make_origin(struct commit *commit, const char *path)
+{
+	struct origin *o;
+	o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
+	o->commit = commit;
+	o->refcnt = 1;
+	strcpy(o->path, path);
+	return o;
+}
+
+/*
+ * Locate an existing origin or create a new one.
+ */
+static struct origin *get_origin(struct scoreboard *sb,
+				 struct commit *commit,
+				 const char *path)
+{
+	struct blame_entry *e;
+
+	for (e = sb->ent; e; e = e->next) {
+		if (e->suspect->commit == commit &&
+		    !strcmp(e->suspect->path, path))
+			return origin_incref(e->suspect);
+	}
+	return make_origin(commit, path);
+}
+
+/*
+ * Fill the blob_sha1 field of an origin if it hasn't, so that later
+ * call to fill_origin_blob() can use it to locate the data.  blob_sha1
+ * for an origin is also used to pass the blame for the entire file to
+ * the parent to detect the case where a child's blob is identical to
+ * that of its parent's.
+ *
+ * This also fills origin->mode for corresponding tree path.
+ */
+static int fill_blob_sha1_and_mode(struct origin *origin)
+{
+	if (!is_null_sha1(origin->blob_sha1))
+		return 0;
+	if (get_tree_entry(origin->commit->object.sha1,
+			   origin->path,
+			   origin->blob_sha1, &origin->mode))
+		goto error_out;
+	if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
+		goto error_out;
+	return 0;
+ error_out:
+	hashclr(origin->blob_sha1);
+	origin->mode = S_IFINVALID;
+	return -1;
+}
+
+/*
+ * We have an origin -- check if the same path exists in the
+ * parent and return an origin structure to represent it.
+ */
+static struct origin *find_origin(struct scoreboard *sb,
+				  struct commit *parent,
+				  struct origin *origin)
+{
+	struct origin *porigin = NULL;
+	struct diff_options diff_opts;
+	const char *paths[2];
+
+	if (parent->util) {
+		/*
+		 * Each commit object can cache one origin in that
+		 * commit.  This is a freestanding copy of origin and
+		 * not refcounted.
+		 */
+		struct origin *cached = parent->util;
+		if (!strcmp(cached->path, origin->path)) {
+			/*
+			 * The same path between origin and its parent
+			 * without renaming -- the most common case.
+			 */
+			porigin = get_origin(sb, parent, cached->path);
+
+			/*
+			 * If the origin was newly created (i.e. get_origin
+			 * would call make_origin if none is found in the
+			 * scoreboard), it does not know the blob_sha1/mode,
+			 * so copy it.  Otherwise porigin was in the
+			 * scoreboard and already knows blob_sha1/mode.
+			 */
+			if (porigin->refcnt == 1) {
+				hashcpy(porigin->blob_sha1, cached->blob_sha1);
+				porigin->mode = cached->mode;
+			}
+			return porigin;
+		}
+		/* otherwise it was not very useful; free it */
+		free(parent->util);
+		parent->util = NULL;
+	}
+
+	/* See if the origin->path is different between parent
+	 * and origin first.  Most of the time they are the
+	 * same and diff-tree is fairly efficient about this.
+	 */
+	diff_setup(&diff_opts);
+	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.detect_rename = 0;
+	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+	paths[0] = origin->path;
+	paths[1] = NULL;
+
+	diff_tree_setup_paths(paths, &diff_opts);
+	if (diff_setup_done(&diff_opts) < 0)
+		die("diff-setup");
+
+	if (is_null_sha1(origin->commit->object.sha1))
+		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	else
+		diff_tree_sha1(parent->tree->object.sha1,
+			       origin->commit->tree->object.sha1,
+			       "", &diff_opts);
+	diffcore_std(&diff_opts);
+
+	if (!diff_queued_diff.nr) {
+		/* The path is the same as parent */
+		porigin = get_origin(sb, parent, origin->path);
+		hashcpy(porigin->blob_sha1, origin->blob_sha1);
+		porigin->mode = origin->mode;
+	} else {
+		/*
+		 * Since origin->path is a pathspec, if the parent
+		 * commit had it as a directory, we will see a whole
+		 * bunch of deletion of files in the directory that we
+		 * do not care about.
+		 */
+		int i;
+		struct diff_filepair *p = NULL;
+		for (i = 0; i < diff_queued_diff.nr; i++) {
+			const char *name;
+			p = diff_queued_diff.queue[i];
+			name = p->one->path ? p->one->path : p->two->path;
+			if (!strcmp(name, origin->path))
+				break;
+		}
+		if (!p)
+			die("internal error in blame::find_origin");
+		switch (p->status) {
+		default:
+			die("internal error in blame::find_origin (%c)",
+			    p->status);
+		case 'M':
+			porigin = get_origin(sb, parent, origin->path);
+			hashcpy(porigin->blob_sha1, p->one->sha1);
+			porigin->mode = p->one->mode;
+			break;
+		case 'A':
+		case 'T':
+			/* Did not exist in parent, or type changed */
+			break;
+		}
+	}
+	diff_flush(&diff_opts);
+	diff_tree_release_paths(&diff_opts);
+	if (porigin) {
+		/*
+		 * Create a freestanding copy that is not part of
+		 * the refcounted origin found in the scoreboard, and
+		 * cache it in the commit.
+		 */
+		struct origin *cached;
+
+		cached = make_origin(porigin->commit, porigin->path);
+		hashcpy(cached->blob_sha1, porigin->blob_sha1);
+		cached->mode = porigin->mode;
+		parent->util = cached;
+	}
+	return porigin;
+}
+
+/*
+ * We have an origin -- find the path that corresponds to it in its
+ * parent and return an origin structure to represent it.
+ */
+static struct origin *find_rename(struct scoreboard *sb,
+				  struct commit *parent,
+				  struct origin *origin)
+{
+	struct origin *porigin = NULL;
+	struct diff_options diff_opts;
+	int i;
+	const char *paths[2];
+
+	diff_setup(&diff_opts);
+	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.detect_rename = DIFF_DETECT_RENAME;
+	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+	diff_opts.single_follow = origin->path;
+	paths[0] = NULL;
+	diff_tree_setup_paths(paths, &diff_opts);
+	if (diff_setup_done(&diff_opts) < 0)
+		die("diff-setup");
+
+	if (is_null_sha1(origin->commit->object.sha1))
+		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	else
+		diff_tree_sha1(parent->tree->object.sha1,
+			       origin->commit->tree->object.sha1,
+			       "", &diff_opts);
+	diffcore_std(&diff_opts);
+
+	for (i = 0; i < diff_queued_diff.nr; i++) {
+		struct diff_filepair *p = diff_queued_diff.queue[i];
+		if ((p->status == 'R' || p->status == 'C') &&
+		    !strcmp(p->two->path, origin->path)) {
+			porigin = get_origin(sb, parent, p->one->path);
+			hashcpy(porigin->blob_sha1, p->one->sha1);
+			porigin->mode = p->one->mode;
+			break;
+		}
+	}
+	diff_flush(&diff_opts);
+	diff_tree_release_paths(&diff_opts);
+	return porigin;
+}
+
+/*
+ * Link in a new blame entry to the scoreboard.  Entries that cover the
+ * same line range have been removed from the scoreboard previously.
+ */
+static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
+{
+	struct blame_entry *ent, *prev = NULL;
+
+	origin_incref(e->suspect);
+
+	for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
+		prev = ent;
+
+	/* prev, if not NULL, is the last one that is below e */
+	e->prev = prev;
+	if (prev) {
+		e->next = prev->next;
+		prev->next = e;
+	}
+	else {
+		e->next = sb->ent;
+		sb->ent = e;
+	}
+	if (e->next)
+		e->next->prev = e;
+}
+
+/*
+ * src typically is on-stack; we want to copy the information in it to
+ * a malloced blame_entry that is already on the linked list of the
+ * scoreboard.  The origin of dst loses a refcnt while the origin of src
+ * gains one.
+ */
+static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
+{
+	struct blame_entry *p, *n;
+
+	p = dst->prev;
+	n = dst->next;
+	origin_incref(src->suspect);
+	origin_decref(dst->suspect);
+	memcpy(dst, src, sizeof(*src));
+	dst->prev = p;
+	dst->next = n;
+	dst->score = 0;
+}
+
+static const char *nth_line(struct scoreboard *sb, int lno)
+{
+	return sb->final_buf + sb->lineno[lno];
+}
+
+/*
+ * It is known that lines between tlno to same came from parent, and e
+ * has an overlap with that range.  it also is known that parent's
+ * line plno corresponds to e's line tlno.
+ *
+ *                <---- e ----->
+ *                   <------>
+ *                   <------------>
+ *             <------------>
+ *             <------------------>
+ *
+ * Split e into potentially three parts; before this chunk, the chunk
+ * to be blamed for the parent, and after that portion.
+ */
+static void split_overlap(struct blame_entry *split,
+			  struct blame_entry *e,
+			  int tlno, int plno, int same,
+			  struct origin *parent)
+{
+	int chunk_end_lno;
+	memset(split, 0, sizeof(struct blame_entry [3]));
+
+	if (e->s_lno < tlno) {
+		/* there is a pre-chunk part not blamed on parent */
+		split[0].suspect = origin_incref(e->suspect);
+		split[0].lno = e->lno;
+		split[0].s_lno = e->s_lno;
+		split[0].num_lines = tlno - e->s_lno;
+		split[1].lno = e->lno + tlno - e->s_lno;
+		split[1].s_lno = plno;
+	}
+	else {
+		split[1].lno = e->lno;
+		split[1].s_lno = plno + (e->s_lno - tlno);
+	}
+
+	if (same < e->s_lno + e->num_lines) {
+		/* there is a post-chunk part not blamed on parent */
+		split[2].suspect = origin_incref(e->suspect);
+		split[2].lno = e->lno + (same - e->s_lno);
+		split[2].s_lno = e->s_lno + (same - e->s_lno);
+		split[2].num_lines = e->s_lno + e->num_lines - same;
+		chunk_end_lno = split[2].lno;
+	}
+	else
+		chunk_end_lno = e->lno + e->num_lines;
+	split[1].num_lines = chunk_end_lno - split[1].lno;
+
+	/*
+	 * if it turns out there is nothing to blame the parent for,
+	 * forget about the splitting.  !split[1].suspect signals this.
+	 */
+	if (split[1].num_lines < 1)
+		return;
+	split[1].suspect = origin_incref(parent);
+}
+
+/*
+ * split_overlap() divided an existing blame e into up to three parts
+ * in split.  Adjust the linked list of blames in the scoreboard to
+ * reflect the split.
+ */
+static void split_blame(struct scoreboard *sb,
+			struct blame_entry *split,
+			struct blame_entry *e)
+{
+	struct blame_entry *new_entry;
+
+	if (split[0].suspect && split[2].suspect) {
+		/* The first part (reuse storage for the existing entry e) */
+		dup_entry(e, &split[0]);
+
+		/* The last part -- me */
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+
+		/* ... and the middle part -- parent */
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+	}
+	else if (!split[0].suspect && !split[2].suspect)
+		/*
+		 * The parent covers the entire area; reuse storage for
+		 * e and replace it with the parent.
+		 */
+		dup_entry(e, &split[1]);
+	else if (split[0].suspect) {
+		/* me and then parent */
+		dup_entry(e, &split[0]);
+
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+	}
+	else {
+		/* parent and then me */
+		dup_entry(e, &split[1]);
+
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+	}
+
+	if (DEBUG) { /* sanity */
+		struct blame_entry *ent;
+		int lno = sb->ent->lno, corrupt = 0;
+
+		for (ent = sb->ent; ent; ent = ent->next) {
+			if (lno != ent->lno)
+				corrupt = 1;
+			if (ent->s_lno < 0)
+				corrupt = 1;
+			lno += ent->num_lines;
+		}
+		if (corrupt) {
+			lno = sb->ent->lno;
+			for (ent = sb->ent; ent; ent = ent->next) {
+				printf("L %8d l %8d n %8d\n",
+				       lno, ent->lno, ent->num_lines);
+				lno = ent->lno + ent->num_lines;
+			}
+			die("oops");
+		}
+	}
+}
+
+/*
+ * After splitting the blame, the origins used by the
+ * on-stack blame_entry should lose one refcnt each.
+ */
+static void decref_split(struct blame_entry *split)
+{
+	int i;
+
+	for (i = 0; i < 3; i++)
+		origin_decref(split[i].suspect);
+}
+
+/*
+ * Helper for blame_chunk().  blame_entry e is known to overlap with
+ * the patch hunk; split it and pass blame to the parent.
+ */
+static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
+			  int tlno, int plno, int same,
+			  struct origin *parent)
+{
+	struct blame_entry split[3];
+
+	split_overlap(split, e, tlno, plno, same, parent);
+	if (split[1].suspect)
+		split_blame(sb, split, e);
+	decref_split(split);
+}
+
+/*
+ * Find the line number of the last line the target is suspected for.
+ */
+static int find_last_in_target(struct scoreboard *sb, struct origin *target)
+{
+	struct blame_entry *e;
+	int last_in_target = -1;
+
+	for (e = sb->ent; e; e = e->next) {
+		if (e->guilty || !same_suspect(e->suspect, target))
+			continue;
+		if (last_in_target < e->s_lno + e->num_lines)
+			last_in_target = e->s_lno + e->num_lines;
+	}
+	return last_in_target;
+}
+
+/*
+ * Process one hunk from the patch between the current suspect for
+ * blame_entry e and its parent.  Find and split the overlap, and
+ * pass blame to the overlapping part to the parent.
+ */
+static void blame_chunk(struct scoreboard *sb,
+			int tlno, int plno, int same,
+			struct origin *target, struct origin *parent)
+{
+	struct blame_entry *e;
+
+	for (e = sb->ent; e; e = e->next) {
+		if (e->guilty || !same_suspect(e->suspect, target))
+			continue;
+		if (same <= e->s_lno)
+			continue;
+		if (tlno < e->s_lno + e->num_lines)
+			blame_overlap(sb, e, tlno, plno, same, parent);
+	}
+}
+
+struct blame_chunk_cb_data {
+	struct scoreboard *sb;
+	struct origin *target;
+	struct origin *parent;
+	long plno;
+	long tlno;
+};
+
+static void blame_chunk_cb(void *data, long same, long p_next, long t_next)
+{
+	struct blame_chunk_cb_data *d = data;
+	blame_chunk(d->sb, d->tlno, d->plno, same, d->target, d->parent);
+	d->plno = p_next;
+	d->tlno = t_next;
+}
+
+/*
+ * We are looking at the origin 'target' and aiming to pass blame
+ * for the lines it is suspected to its parent.  Run diff to find
+ * which lines came from parent and pass blame for them.
+ */
+static int pass_blame_to_parent(struct scoreboard *sb,
+				struct origin *target,
+				struct origin *parent)
+{
+	int last_in_target;
+	mmfile_t file_p, file_o;
+	struct blame_chunk_cb_data d;
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
+	memset(&d, 0, sizeof(d));
+	d.sb = sb; d.target = target; d.parent = parent;
+	last_in_target = find_last_in_target(sb, target);
+	if (last_in_target < 0)
+		return 1; /* nothing remains for this target */
+
+	fill_origin_blob(&sb->revs->diffopt, parent, &file_p);
+	fill_origin_blob(&sb->revs->diffopt, target, &file_o);
+	num_get_patch++;
+
+	memset(&xpp, 0, sizeof(xpp));
+	xpp.flags = xdl_opts;
+	memset(&xecfg, 0, sizeof(xecfg));
+	xecfg.ctxlen = 0;
+	xdi_diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, &xpp, &xecfg);
+	/* The rest (i.e. anything after tlno) are the same as the parent */
+	blame_chunk(sb, d.tlno, d.plno, last_in_target, target, parent);
+
+	return 0;
+}
+
+/*
+ * The lines in blame_entry after splitting blames many times can become
+ * very small and trivial, and at some point it becomes pointless to
+ * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
+ * ordinary C program, and it is not worth to say it was copied from
+ * totally unrelated file in the parent.
+ *
+ * Compute how trivial the lines in the blame_entry are.
+ */
+static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
+{
+	unsigned score;
+	const char *cp, *ep;
+
+	if (e->score)
+		return e->score;
+
+	score = 1;
+	cp = nth_line(sb, e->lno);
+	ep = nth_line(sb, e->lno + e->num_lines);
+	while (cp < ep) {
+		unsigned ch = *((unsigned char *)cp);
+		if (isalnum(ch))
+			score++;
+		cp++;
+	}
+	e->score = score;
+	return score;
+}
+
+/*
+ * best_so_far[] and this[] are both a split of an existing blame_entry
+ * that passes blame to the parent.  Maintain best_so_far the best split
+ * so far, by comparing this and best_so_far and copying this into
+ * bst_so_far as needed.
+ */
+static void copy_split_if_better(struct scoreboard *sb,
+				 struct blame_entry *best_so_far,
+				 struct blame_entry *this)
+{
+	int i;
+
+	if (!this[1].suspect)
+		return;
+	if (best_so_far[1].suspect) {
+		if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
+			return;
+	}
+
+	for (i = 0; i < 3; i++)
+		origin_incref(this[i].suspect);
+	decref_split(best_so_far);
+	memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
+}
+
+/*
+ * We are looking at a part of the final image represented by
+ * ent (tlno and same are offset by ent->s_lno).
+ * tlno is where we are looking at in the final image.
+ * up to (but not including) same match preimage.
+ * plno is where we are looking at in the preimage.
+ *
+ * <-------------- final image ---------------------->
+ *       <------ent------>
+ *         ^tlno ^same
+ *    <---------preimage----->
+ *         ^plno
+ *
+ * All line numbers are 0-based.
+ */
+static void handle_split(struct scoreboard *sb,
+			 struct blame_entry *ent,
+			 int tlno, int plno, int same,
+			 struct origin *parent,
+			 struct blame_entry *split)
+{
+	if (ent->num_lines <= tlno)
+		return;
+	if (tlno < same) {
+		struct blame_entry this[3];
+		tlno += ent->s_lno;
+		same += ent->s_lno;
+		split_overlap(this, ent, tlno, plno, same, parent);
+		copy_split_if_better(sb, split, this);
+		decref_split(this);
+	}
+}
+
+struct handle_split_cb_data {
+	struct scoreboard *sb;
+	struct blame_entry *ent;
+	struct origin *parent;
+	struct blame_entry *split;
+	long plno;
+	long tlno;
+};
+
+static void handle_split_cb(void *data, long same, long p_next, long t_next)
+{
+	struct handle_split_cb_data *d = data;
+	handle_split(d->sb, d->ent, d->tlno, d->plno, same, d->parent, d->split);
+	d->plno = p_next;
+	d->tlno = t_next;
+}
+
+/*
+ * Find the lines from parent that are the same as ent so that
+ * we can pass blames to it.  file_p has the blob contents for
+ * the parent.
+ */
+static void find_copy_in_blob(struct scoreboard *sb,
+			      struct blame_entry *ent,
+			      struct origin *parent,
+			      struct blame_entry *split,
+			      mmfile_t *file_p)
+{
+	const char *cp;
+	int cnt;
+	mmfile_t file_o;
+	struct handle_split_cb_data d;
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
+	memset(&d, 0, sizeof(d));
+	d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
+	/*
+	 * Prepare mmfile that contains only the lines in ent.
+	 */
+	cp = nth_line(sb, ent->lno);
+	file_o.ptr = (char *) cp;
+	cnt = ent->num_lines;
+
+	while (cnt && cp < sb->final_buf + sb->final_buf_size) {
+		if (*cp++ == '\n')
+			cnt--;
+	}
+	file_o.size = cp - file_o.ptr;
+
+	/*
+	 * file_o is a part of final image we are annotating.
+	 * file_p partially may match that image.
+	 */
+	memset(&xpp, 0, sizeof(xpp));
+	xpp.flags = xdl_opts;
+	memset(&xecfg, 0, sizeof(xecfg));
+	xecfg.ctxlen = 1;
+	memset(split, 0, sizeof(struct blame_entry [3]));
+	xdi_diff_hunks(file_p, &file_o, handle_split_cb, &d, &xpp, &xecfg);
+	/* remainder, if any, all match the preimage */
+	handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
+}
+
+/*
+ * See if lines currently target is suspected for can be attributed to
+ * parent.
+ */
+static int find_move_in_parent(struct scoreboard *sb,
+			       struct origin *target,
+			       struct origin *parent)
+{
+	int last_in_target, made_progress;
+	struct blame_entry *e, split[3];
+	mmfile_t file_p;
+
+	last_in_target = find_last_in_target(sb, target);
+	if (last_in_target < 0)
+		return 1; /* nothing remains for this target */
+
+	fill_origin_blob(&sb->revs->diffopt, parent, &file_p);
+	if (!file_p.ptr)
+		return 0;
+
+	made_progress = 1;
+	while (made_progress) {
+		made_progress = 0;
+		for (e = sb->ent; e; e = e->next) {
+			if (e->guilty || !same_suspect(e->suspect, target) ||
+			    ent_score(sb, e) < blame_move_score)
+				continue;
+			find_copy_in_blob(sb, e, parent, split, &file_p);
+			if (split[1].suspect &&
+			    blame_move_score < ent_score(sb, &split[1])) {
+				split_blame(sb, split, e);
+				made_progress = 1;
+			}
+			decref_split(split);
+		}
+	}
+	return 0;
+}
+
+struct blame_list {
+	struct blame_entry *ent;
+	struct blame_entry split[3];
+};
+
+/*
+ * Count the number of entries the target is suspected for,
+ * and prepare a list of entry and the best split.
+ */
+static struct blame_list *setup_blame_list(struct scoreboard *sb,
+					   struct origin *target,
+					   int min_score,
+					   int *num_ents_p)
+{
+	struct blame_entry *e;
+	int num_ents, i;
+	struct blame_list *blame_list = NULL;
+
+	for (e = sb->ent, num_ents = 0; e; e = e->next)
+		if (!e->scanned && !e->guilty &&
+		    same_suspect(e->suspect, target) &&
+		    min_score < ent_score(sb, e))
+			num_ents++;
+	if (num_ents) {
+		blame_list = xcalloc(num_ents, sizeof(struct blame_list));
+		for (e = sb->ent, i = 0; e; e = e->next)
+			if (!e->scanned && !e->guilty &&
+			    same_suspect(e->suspect, target) &&
+			    min_score < ent_score(sb, e))
+				blame_list[i++].ent = e;
+	}
+	*num_ents_p = num_ents;
+	return blame_list;
+}
+
+/*
+ * Reset the scanned status on all entries.
+ */
+static void reset_scanned_flag(struct scoreboard *sb)
+{
+	struct blame_entry *e;
+	for (e = sb->ent; e; e = e->next)
+		e->scanned = 0;
+}
+
+/*
+ * For lines target is suspected for, see if we can find code movement
+ * across file boundary from the parent commit.  porigin is the path
+ * in the parent we already tried.
+ */
+static int find_copy_in_parent(struct scoreboard *sb,
+			       struct origin *target,
+			       struct commit *parent,
+			       struct origin *porigin,
+			       int opt)
+{
+	struct diff_options diff_opts;
+	const char *paths[1];
+	int i, j;
+	int retval;
+	struct blame_list *blame_list;
+	int num_ents;
+
+	blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
+	if (!blame_list)
+		return 1; /* nothing remains for this target */
+
+	diff_setup(&diff_opts);
+	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+
+	paths[0] = NULL;
+	diff_tree_setup_paths(paths, &diff_opts);
+	if (diff_setup_done(&diff_opts) < 0)
+		die("diff-setup");
+
+	/* Try "find copies harder" on new path if requested;
+	 * we do not want to use diffcore_rename() actually to
+	 * match things up; find_copies_harder is set only to
+	 * force diff_tree_sha1() to feed all filepairs to diff_queue,
+	 * and this code needs to be after diff_setup_done(), which
+	 * usually makes find-copies-harder imply copy detection.
+	 */
+	if ((opt & PICKAXE_BLAME_COPY_HARDEST)
+	    || ((opt & PICKAXE_BLAME_COPY_HARDER)
+		&& (!porigin || strcmp(target->path, porigin->path))))
+		DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
+
+	if (is_null_sha1(target->commit->object.sha1))
+		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	else
+		diff_tree_sha1(parent->tree->object.sha1,
+			       target->commit->tree->object.sha1,
+			       "", &diff_opts);
+
+	if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
+		diffcore_std(&diff_opts);
+
+	retval = 0;
+	while (1) {
+		int made_progress = 0;
+
+		for (i = 0; i < diff_queued_diff.nr; i++) {
+			struct diff_filepair *p = diff_queued_diff.queue[i];
+			struct origin *norigin;
+			mmfile_t file_p;
+			struct blame_entry this[3];
+
+			if (!DIFF_FILE_VALID(p->one))
+				continue; /* does not exist in parent */
+			if (S_ISGITLINK(p->one->mode))
+				continue; /* ignore git links */
+			if (porigin && !strcmp(p->one->path, porigin->path))
+				/* find_move already dealt with this path */
+				continue;
+
+			norigin = get_origin(sb, parent, p->one->path);
+			hashcpy(norigin->blob_sha1, p->one->sha1);
+			norigin->mode = p->one->mode;
+			fill_origin_blob(&sb->revs->diffopt, norigin, &file_p);
+			if (!file_p.ptr)
+				continue;
+
+			for (j = 0; j < num_ents; j++) {
+				find_copy_in_blob(sb, blame_list[j].ent,
+						  norigin, this, &file_p);
+				copy_split_if_better(sb, blame_list[j].split,
+						     this);
+				decref_split(this);
+			}
+			origin_decref(norigin);
+		}
+
+		for (j = 0; j < num_ents; j++) {
+			struct blame_entry *split = blame_list[j].split;
+			if (split[1].suspect &&
+			    blame_copy_score < ent_score(sb, &split[1])) {
+				split_blame(sb, split, blame_list[j].ent);
+				made_progress = 1;
+			}
+			else
+				blame_list[j].ent->scanned = 1;
+			decref_split(split);
+		}
+		free(blame_list);
+
+		if (!made_progress)
+			break;
+		blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
+		if (!blame_list) {
+			retval = 1;
+			break;
+		}
+	}
+	reset_scanned_flag(sb);
+	diff_flush(&diff_opts);
+	diff_tree_release_paths(&diff_opts);
+	return retval;
+}
+
+/*
+ * The blobs of origin and porigin exactly match, so everything
+ * origin is suspected for can be blamed on the parent.
+ */
+static void pass_whole_blame(struct scoreboard *sb,
+			     struct origin *origin, struct origin *porigin)
+{
+	struct blame_entry *e;
+
+	if (!porigin->file.ptr && origin->file.ptr) {
+		/* Steal its file */
+		porigin->file = origin->file;
+		origin->file.ptr = NULL;
+	}
+	for (e = sb->ent; e; e = e->next) {
+		if (!same_suspect(e->suspect, origin))
+			continue;
+		origin_incref(porigin);
+		origin_decref(e->suspect);
+		e->suspect = porigin;
+	}
+}
+
+/*
+ * We pass blame from the current commit to its parents.  We keep saying
+ * "parent" (and "porigin"), but what we mean is to find scapegoat to
+ * exonerate ourselves.
+ */
+static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit)
+{
+	if (!reverse)
+		return commit->parents;
+	return lookup_decoration(&revs->children, &commit->object);
+}
+
+static int num_scapegoats(struct rev_info *revs, struct commit *commit)
+{
+	int cnt;
+	struct commit_list *l = first_scapegoat(revs, commit);
+	for (cnt = 0; l; l = l->next)
+		cnt++;
+	return cnt;
+}
+
+#define MAXSG 16
+
+static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
+{
+	struct rev_info *revs = sb->revs;
+	int i, pass, num_sg;
+	struct commit *commit = origin->commit;
+	struct commit_list *sg;
+	struct origin *sg_buf[MAXSG];
+	struct origin *porigin, **sg_origin = sg_buf;
+
+	num_sg = num_scapegoats(revs, commit);
+	if (!num_sg)
+		goto finish;
+	else if (num_sg < ARRAY_SIZE(sg_buf))
+		memset(sg_buf, 0, sizeof(sg_buf));
+	else
+		sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
+
+	/*
+	 * The first pass looks for unrenamed path to optimize for
+	 * common cases, then we look for renames in the second pass.
+	 */
+	for (pass = 0; pass < 2; pass++) {
+		struct origin *(*find)(struct scoreboard *,
+				       struct commit *, struct origin *);
+		find = pass ? find_rename : find_origin;
+
+		for (i = 0, sg = first_scapegoat(revs, commit);
+		     i < num_sg && sg;
+		     sg = sg->next, i++) {
+			struct commit *p = sg->item;
+			int j, same;
+
+			if (sg_origin[i])
+				continue;
+			if (parse_commit(p))
+				continue;
+			porigin = find(sb, p, origin);
+			if (!porigin)
+				continue;
+			if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
+				pass_whole_blame(sb, origin, porigin);
+				origin_decref(porigin);
+				goto finish;
+			}
+			for (j = same = 0; j < i; j++)
+				if (sg_origin[j] &&
+				    !hashcmp(sg_origin[j]->blob_sha1,
+					     porigin->blob_sha1)) {
+					same = 1;
+					break;
+				}
+			if (!same)
+				sg_origin[i] = porigin;
+			else
+				origin_decref(porigin);
+		}
+	}
+
+	num_commits++;
+	for (i = 0, sg = first_scapegoat(revs, commit);
+	     i < num_sg && sg;
+	     sg = sg->next, i++) {
+		struct origin *porigin = sg_origin[i];
+		if (!porigin)
+			continue;
+		if (!origin->previous) {
+			origin_incref(porigin);
+			origin->previous = porigin;
+		}
+		if (pass_blame_to_parent(sb, origin, porigin))
+			goto finish;
+	}
+
+	/*
+	 * Optionally find moves in parents' files.
+	 */
+	if (opt & PICKAXE_BLAME_MOVE)
+		for (i = 0, sg = first_scapegoat(revs, commit);
+		     i < num_sg && sg;
+		     sg = sg->next, i++) {
+			struct origin *porigin = sg_origin[i];
+			if (!porigin)
+				continue;
+			if (find_move_in_parent(sb, origin, porigin))
+				goto finish;
+		}
+
+	/*
+	 * Optionally find copies from parents' files.
+	 */
+	if (opt & PICKAXE_BLAME_COPY)
+		for (i = 0, sg = first_scapegoat(revs, commit);
+		     i < num_sg && sg;
+		     sg = sg->next, i++) {
+			struct origin *porigin = sg_origin[i];
+			if (find_copy_in_parent(sb, origin, sg->item,
+						porigin, opt))
+				goto finish;
+		}
+
+ finish:
+	for (i = 0; i < num_sg; i++) {
+		if (sg_origin[i]) {
+			drop_origin_blob(sg_origin[i]);
+			origin_decref(sg_origin[i]);
+		}
+	}
+	drop_origin_blob(origin);
+	if (sg_buf != sg_origin)
+		free(sg_origin);
+}
+
+/*
+ * Information on commits, used for output.
+ */
+struct commit_info {
+	const char *author;
+	const char *author_mail;
+	unsigned long author_time;
+	const char *author_tz;
+
+	/* filled only when asked for details */
+	const char *committer;
+	const char *committer_mail;
+	unsigned long committer_time;
+	const char *committer_tz;
+
+	const char *summary;
+};
+
+/*
+ * Parse author/committer line in the commit object buffer
+ */
+static void get_ac_line(const char *inbuf, const char *what,
+			int person_len, char *person,
+			int mail_len, char *mail,
+			unsigned long *time, const char **tz)
+{
+	int len, tzlen, maillen;
+	char *tmp, *endp, *timepos, *mailpos;
+
+	tmp = strstr(inbuf, what);
+	if (!tmp)
+		goto error_out;
+	tmp += strlen(what);
+	endp = strchr(tmp, '\n');
+	if (!endp)
+		len = strlen(tmp);
+	else
+		len = endp - tmp;
+	if (person_len <= len) {
+	error_out:
+		/* Ugh */
+		*tz = "(unknown)";
+		strcpy(person, *tz);
+		strcpy(mail, *tz);
+		*time = 0;
+		return;
+	}
+	memcpy(person, tmp, len);
+
+	tmp = person;
+	tmp += len;
+	*tmp = 0;
+	while (person < tmp && *tmp != ' ')
+		tmp--;
+	if (tmp <= person)
+		goto error_out;
+	*tz = tmp+1;
+	tzlen = (person+len)-(tmp+1);
+
+	*tmp = 0;
+	while (person < tmp && *tmp != ' ')
+		tmp--;
+	if (tmp <= person)
+		goto error_out;
+	*time = strtoul(tmp, NULL, 10);
+	timepos = tmp;
+
+	*tmp = 0;
+	while (person < tmp && !(*tmp == ' ' && tmp[1] == '<'))
+		tmp--;
+	if (tmp <= person)
+		return;
+	mailpos = tmp + 1;
+	*tmp = 0;
+	maillen = timepos - tmp;
+	memcpy(mail, mailpos, maillen);
+
+	if (!mailmap.nr)
+		return;
+
+	/*
+	 * mailmap expansion may make the name longer.
+	 * make room by pushing stuff down.
+	 */
+	tmp = person + person_len - (tzlen + 1);
+	memmove(tmp, *tz, tzlen);
+	tmp[tzlen] = 0;
+	*tz = tmp;
+
+	/*
+	 * Now, convert both name and e-mail using mailmap
+	 */
+	if (map_user(&mailmap, mail+1, mail_len-1, person, tmp-person-1)) {
+		/* Add a trailing '>' to email, since map_user returns plain emails
+		   Note: It already has '<', since we replace from mail+1 */
+		mailpos = memchr(mail, '\0', mail_len);
+		if (mailpos && mailpos-mail < mail_len - 1) {
+			*mailpos = '>';
+			*(mailpos+1) = '\0';
+		}
+	}
+}
+
+static void get_commit_info(struct commit *commit,
+			    struct commit_info *ret,
+			    int detailed)
+{
+	int len;
+	const char *subject;
+	char *reencoded, *message;
+	static char author_name[1024];
+	static char author_mail[1024];
+	static char committer_name[1024];
+	static char committer_mail[1024];
+	static char summary_buf[1024];
+
+	/*
+	 * We've operated without save_commit_buffer, so
+	 * we now need to populate them for output.
+	 */
+	if (!commit->buffer) {
+		enum object_type type;
+		unsigned long size;
+		commit->buffer =
+			read_sha1_file(commit->object.sha1, &type, &size);
+		if (!commit->buffer)
+			die("Cannot read commit %s",
+			    sha1_to_hex(commit->object.sha1));
+	}
+	reencoded = reencode_commit_message(commit, NULL);
+	message   = reencoded ? reencoded : commit->buffer;
+	ret->author = author_name;
+	ret->author_mail = author_mail;
+	get_ac_line(message, "\nauthor ",
+		    sizeof(author_name), author_name,
+		    sizeof(author_mail), author_mail,
+		    &ret->author_time, &ret->author_tz);
+
+	if (!detailed) {
+		free(reencoded);
+		return;
+	}
+
+	ret->committer = committer_name;
+	ret->committer_mail = committer_mail;
+	get_ac_line(message, "\ncommitter ",
+		    sizeof(committer_name), committer_name,
+		    sizeof(committer_mail), committer_mail,
+		    &ret->committer_time, &ret->committer_tz);
+
+	ret->summary = summary_buf;
+	len = find_commit_subject(message, &subject);
+	if (len && len < sizeof(summary_buf)) {
+		memcpy(summary_buf, subject, len);
+		summary_buf[len] = 0;
+	} else {
+		sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
+	}
+	free(reencoded);
+}
+
+/*
+ * To allow LF and other nonportable characters in pathnames,
+ * they are c-style quoted as needed.
+ */
+static void write_filename_info(const char *path)
+{
+	printf("filename ");
+	write_name_quoted(path, stdout, '\n');
+}
+
+/*
+ * Porcelain/Incremental format wants to show a lot of details per
+ * commit.  Instead of repeating this every line, emit it only once,
+ * the first time each commit appears in the output (unless the
+ * user has specifically asked for us to repeat).
+ */
+static int emit_one_suspect_detail(struct origin *suspect, int repeat)
+{
+	struct commit_info ci;
+
+	if (!repeat && (suspect->commit->object.flags & METAINFO_SHOWN))
+		return 0;
+
+	suspect->commit->object.flags |= METAINFO_SHOWN;
+	get_commit_info(suspect->commit, &ci, 1);
+	printf("author %s\n", ci.author);
+	printf("author-mail %s\n", ci.author_mail);
+	printf("author-time %lu\n", ci.author_time);
+	printf("author-tz %s\n", ci.author_tz);
+	printf("committer %s\n", ci.committer);
+	printf("committer-mail %s\n", ci.committer_mail);
+	printf("committer-time %lu\n", ci.committer_time);
+	printf("committer-tz %s\n", ci.committer_tz);
+	printf("summary %s\n", ci.summary);
+	if (suspect->commit->object.flags & UNINTERESTING)
+		printf("boundary\n");
+	if (suspect->previous) {
+		struct origin *prev = suspect->previous;
+		printf("previous %s ", sha1_to_hex(prev->commit->object.sha1));
+		write_name_quoted(prev->path, stdout, '\n');
+	}
+	return 1;
+}
+
+/*
+ * The blame_entry is found to be guilty for the range.  Mark it
+ * as such, and show it in incremental output.
+ */
+static void found_guilty_entry(struct blame_entry *ent)
+{
+	if (ent->guilty)
+		return;
+	ent->guilty = 1;
+	if (incremental) {
+		struct origin *suspect = ent->suspect;
+
+		printf("%s %d %d %d\n",
+		       sha1_to_hex(suspect->commit->object.sha1),
+		       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
+		emit_one_suspect_detail(suspect, 0);
+		write_filename_info(suspect->path);
+		maybe_flush_or_die(stdout, "stdout");
+	}
+}
+
+/*
+ * The main loop -- while the scoreboard has lines whose true origin
+ * is still unknown, pick one blame_entry, and allow its current
+ * suspect to pass blames to its parents.
+ */
+static void assign_blame(struct scoreboard *sb, int opt)
+{
+	struct rev_info *revs = sb->revs;
+
+	while (1) {
+		struct blame_entry *ent;
+		struct commit *commit;
+		struct origin *suspect = NULL;
+
+		/* find one suspect to break down */
+		for (ent = sb->ent; !suspect && ent; ent = ent->next)
+			if (!ent->guilty)
+				suspect = ent->suspect;
+		if (!suspect)
+			return; /* all done */
+
+		/*
+		 * We will use this suspect later in the loop,
+		 * so hold onto it in the meantime.
+		 */
+		origin_incref(suspect);
+		commit = suspect->commit;
+		if (!commit->object.parsed)
+			parse_commit(commit);
+		if (reverse ||
+		    (!(commit->object.flags & UNINTERESTING) &&
+		     !(revs->max_age != -1 && commit->date < revs->max_age)))
+			pass_blame(sb, suspect, opt);
+		else {
+			commit->object.flags |= UNINTERESTING;
+			if (commit->object.parsed)
+				mark_parents_uninteresting(commit);
+		}
+		/* treat root commit as boundary */
+		if (!commit->parents && !show_root)
+			commit->object.flags |= UNINTERESTING;
+
+		/* Take responsibility for the remaining entries */
+		for (ent = sb->ent; ent; ent = ent->next)
+			if (same_suspect(ent->suspect, suspect))
+				found_guilty_entry(ent);
+		origin_decref(suspect);
+
+		if (DEBUG) /* sanity */
+			sanity_check_refcnt(sb);
+	}
+}
+
+static const char *format_time(unsigned long time, const char *tz_str,
+			       int show_raw_time)
+{
+	static char time_buf[128];
+	const char *time_str;
+	int time_len;
+	int tz;
+
+	if (show_raw_time) {
+		sprintf(time_buf, "%lu %s", time, tz_str);
+	}
+	else {
+		tz = atoi(tz_str);
+		time_str = show_date(time, tz, blame_date_mode);
+		time_len = strlen(time_str);
+		memcpy(time_buf, time_str, time_len);
+		memset(time_buf + time_len, ' ', blame_date_width - time_len);
+	}
+	return time_buf;
+}
+
+#define OUTPUT_ANNOTATE_COMPAT	001
+#define OUTPUT_LONG_OBJECT_NAME	002
+#define OUTPUT_RAW_TIMESTAMP	004
+#define OUTPUT_PORCELAIN	010
+#define OUTPUT_SHOW_NAME	020
+#define OUTPUT_SHOW_NUMBER	040
+#define OUTPUT_SHOW_SCORE      0100
+#define OUTPUT_NO_AUTHOR       0200
+#define OUTPUT_SHOW_EMAIL	0400
+#define OUTPUT_LINE_PORCELAIN 01000
+
+static void emit_porcelain_details(struct origin *suspect, int repeat)
+{
+	if (emit_one_suspect_detail(suspect, repeat) ||
+	    (suspect->commit->object.flags & MORE_THAN_ONE_PATH))
+		write_filename_info(suspect->path);
+}
+
+static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent,
+			   int opt)
+{
+	int repeat = opt & OUTPUT_LINE_PORCELAIN;
+	int cnt;
+	const char *cp;
+	struct origin *suspect = ent->suspect;
+	char hex[41];
+
+	strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
+	printf("%s%c%d %d %d\n",
+	       hex,
+	       ent->guilty ? ' ' : '*', /* purely for debugging */
+	       ent->s_lno + 1,
+	       ent->lno + 1,
+	       ent->num_lines);
+	emit_porcelain_details(suspect, repeat);
+
+	cp = nth_line(sb, ent->lno);
+	for (cnt = 0; cnt < ent->num_lines; cnt++) {
+		char ch;
+		if (cnt) {
+			printf("%s %d %d\n", hex,
+			       ent->s_lno + 1 + cnt,
+			       ent->lno + 1 + cnt);
+			if (repeat)
+				emit_porcelain_details(suspect, 1);
+		}
+		putchar('\t');
+		do {
+			ch = *cp++;
+			putchar(ch);
+		} while (ch != '\n' &&
+			 cp < sb->final_buf + sb->final_buf_size);
+	}
+
+	if (sb->final_buf_size && cp[-1] != '\n')
+		putchar('\n');
+}
+
+static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
+{
+	int cnt;
+	const char *cp;
+	struct origin *suspect = ent->suspect;
+	struct commit_info ci;
+	char hex[41];
+	int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
+
+	get_commit_info(suspect->commit, &ci, 1);
+	strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
+
+	cp = nth_line(sb, ent->lno);
+	for (cnt = 0; cnt < ent->num_lines; cnt++) {
+		char ch;
+		int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : abbrev;
+
+		if (suspect->commit->object.flags & UNINTERESTING) {
+			if (blank_boundary)
+				memset(hex, ' ', length);
+			else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
+				length--;
+				putchar('^');
+			}
+		}
+
+		printf("%.*s", length, hex);
+		if (opt & OUTPUT_ANNOTATE_COMPAT) {
+			const char *name;
+			if (opt & OUTPUT_SHOW_EMAIL)
+				name = ci.author_mail;
+			else
+				name = ci.author;
+			printf("\t(%10s\t%10s\t%d)", name,
+			       format_time(ci.author_time, ci.author_tz,
+					   show_raw_time),
+			       ent->lno + 1 + cnt);
+		} else {
+			if (opt & OUTPUT_SHOW_SCORE)
+				printf(" %*d %02d",
+				       max_score_digits, ent->score,
+				       ent->suspect->refcnt);
+			if (opt & OUTPUT_SHOW_NAME)
+				printf(" %-*.*s", longest_file, longest_file,
+				       suspect->path);
+			if (opt & OUTPUT_SHOW_NUMBER)
+				printf(" %*d", max_orig_digits,
+				       ent->s_lno + 1 + cnt);
+
+			if (!(opt & OUTPUT_NO_AUTHOR)) {
+				const char *name;
+				int pad;
+				if (opt & OUTPUT_SHOW_EMAIL)
+					name = ci.author_mail;
+				else
+					name = ci.author;
+				pad = longest_author - utf8_strwidth(name);
+				printf(" (%s%*s %10s",
+				       name, pad, "",
+				       format_time(ci.author_time,
+						   ci.author_tz,
+						   show_raw_time));
+			}
+			printf(" %*d) ",
+			       max_digits, ent->lno + 1 + cnt);
+		}
+		do {
+			ch = *cp++;
+			putchar(ch);
+		} while (ch != '\n' &&
+			 cp < sb->final_buf + sb->final_buf_size);
+	}
+
+	if (sb->final_buf_size && cp[-1] != '\n')
+		putchar('\n');
+}
+
+static void output(struct scoreboard *sb, int option)
+{
+	struct blame_entry *ent;
+
+	if (option & OUTPUT_PORCELAIN) {
+		for (ent = sb->ent; ent; ent = ent->next) {
+			struct blame_entry *oth;
+			struct origin *suspect = ent->suspect;
+			struct commit *commit = suspect->commit;
+			if (commit->object.flags & MORE_THAN_ONE_PATH)
+				continue;
+			for (oth = ent->next; oth; oth = oth->next) {
+				if ((oth->suspect->commit != commit) ||
+				    !strcmp(oth->suspect->path, suspect->path))
+					continue;
+				commit->object.flags |= MORE_THAN_ONE_PATH;
+				break;
+			}
+		}
+	}
+
+	for (ent = sb->ent; ent; ent = ent->next) {
+		if (option & OUTPUT_PORCELAIN)
+			emit_porcelain(sb, ent, option);
+		else {
+			emit_other(sb, ent, option);
+		}
+	}
+}
+
+/*
+ * To allow quick access to the contents of nth line in the
+ * final image, prepare an index in the scoreboard.
+ */
+static int prepare_lines(struct scoreboard *sb)
+{
+	const char *buf = sb->final_buf;
+	unsigned long len = sb->final_buf_size;
+	int num = 0, incomplete = 0, bol = 1;
+
+	if (len && buf[len-1] != '\n')
+		incomplete++; /* incomplete line at the end */
+	while (len--) {
+		if (bol) {
+			sb->lineno = xrealloc(sb->lineno,
+					      sizeof(int *) * (num + 1));
+			sb->lineno[num] = buf - sb->final_buf;
+			bol = 0;
+		}
+		if (*buf++ == '\n') {
+			num++;
+			bol = 1;
+		}
+	}
+	sb->lineno = xrealloc(sb->lineno,
+			      sizeof(int *) * (num + incomplete + 1));
+	sb->lineno[num + incomplete] = buf - sb->final_buf;
+	sb->num_lines = num + incomplete;
+	return sb->num_lines;
+}
+
+/*
+ * Add phony grafts for use with -S; this is primarily to
+ * support git's cvsserver that wants to give a linear history
+ * to its clients.
+ */
+static int read_ancestry(const char *graft_file)
+{
+	FILE *fp = fopen(graft_file, "r");
+	char buf[1024];
+	if (!fp)
+		return -1;
+	while (fgets(buf, sizeof(buf), fp)) {
+		/* The format is just "Commit Parent1 Parent2 ...\n" */
+		int len = strlen(buf);
+		struct commit_graft *graft = read_graft_line(buf, len);
+		if (graft)
+			register_commit_graft(graft, 0);
+	}
+	fclose(fp);
+	return 0;
+}
+
+/*
+ * How many columns do we need to show line numbers in decimal?
+ */
+static int lineno_width(int lines)
+{
+	int i, width;
+
+	for (width = 1, i = 10; i <= lines; width++)
+		i *= 10;
+	return width;
+}
+
+/*
+ * How many columns do we need to show line numbers, authors,
+ * and filenames?
+ */
+static void find_alignment(struct scoreboard *sb, int *option)
+{
+	int longest_src_lines = 0;
+	int longest_dst_lines = 0;
+	unsigned largest_score = 0;
+	struct blame_entry *e;
+
+	for (e = sb->ent; e; e = e->next) {
+		struct origin *suspect = e->suspect;
+		struct commit_info ci;
+		int num;
+
+		if (strcmp(suspect->path, sb->path))
+			*option |= OUTPUT_SHOW_NAME;
+		num = strlen(suspect->path);
+		if (longest_file < num)
+			longest_file = num;
+		if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
+			suspect->commit->object.flags |= METAINFO_SHOWN;
+			get_commit_info(suspect->commit, &ci, 1);
+			if (*option & OUTPUT_SHOW_EMAIL)
+				num = utf8_strwidth(ci.author_mail);
+			else
+				num = utf8_strwidth(ci.author);
+			if (longest_author < num)
+				longest_author = num;
+		}
+		num = e->s_lno + e->num_lines;
+		if (longest_src_lines < num)
+			longest_src_lines = num;
+		num = e->lno + e->num_lines;
+		if (longest_dst_lines < num)
+			longest_dst_lines = num;
+		if (largest_score < ent_score(sb, e))
+			largest_score = ent_score(sb, e);
+	}
+	max_orig_digits = lineno_width(longest_src_lines);
+	max_digits = lineno_width(longest_dst_lines);
+	max_score_digits = lineno_width(largest_score);
+}
+
+/*
+ * For debugging -- origin is refcounted, and this asserts that
+ * we do not underflow.
+ */
+static void sanity_check_refcnt(struct scoreboard *sb)
+{
+	int baa = 0;
+	struct blame_entry *ent;
+
+	for (ent = sb->ent; ent; ent = ent->next) {
+		/* Nobody should have zero or negative refcnt */
+		if (ent->suspect->refcnt <= 0) {
+			fprintf(stderr, "%s in %s has negative refcnt %d\n",
+				ent->suspect->path,
+				sha1_to_hex(ent->suspect->commit->object.sha1),
+				ent->suspect->refcnt);
+			baa = 1;
+		}
+	}
+	if (baa) {
+		int opt = 0160;
+		find_alignment(sb, &opt);
+		output(sb, opt);
+		die("Baa %d!", baa);
+	}
+}
+
+/*
+ * Used for the command line parsing; check if the path exists
+ * in the working tree.
+ */
+static int has_string_in_work_tree(const char *path)
+{
+	struct stat st;
+	return !lstat(path, &st);
+}
+
+static unsigned parse_score(const char *arg)
+{
+	char *end;
+	unsigned long score = strtoul(arg, &end, 10);
+	if (*end)
+		return 0;
+	return score;
+}
+
+static const char *add_prefix(const char *prefix, const char *path)
+{
+	return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
+}
+
+/*
+ * Parsing of (comma separated) one item in the -L option
+ */
+static const char *parse_loc(const char *spec,
+			     struct scoreboard *sb, long lno,
+			     long begin, long *ret)
+{
+	char *term;
+	const char *line;
+	long num;
+	int reg_error;
+	regex_t regexp;
+	regmatch_t match[1];
+
+	/* Allow "-L <something>,+20" to mean starting at <something>
+	 * for 20 lines, or "-L <something>,-5" for 5 lines ending at
+	 * <something>.
+	 */
+	if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
+		num = strtol(spec + 1, &term, 10);
+		if (term != spec + 1) {
+			if (spec[0] == '-')
+				num = 0 - num;
+			if (0 < num)
+				*ret = begin + num - 2;
+			else if (!num)
+				*ret = begin;
+			else
+				*ret = begin + num;
+			return term;
+		}
+		return spec;
+	}
+	num = strtol(spec, &term, 10);
+	if (term != spec) {
+		*ret = num;
+		return term;
+	}
+	if (spec[0] != '/')
+		return spec;
+
+	/* it could be a regexp of form /.../ */
+	for (term = (char *) spec + 1; *term && *term != '/'; term++) {
+		if (*term == '\\')
+			term++;
+	}
+	if (*term != '/')
+		return spec;
+
+	/* try [spec+1 .. term-1] as regexp */
+	*term = 0;
+	begin--; /* input is in human terms */
+	line = nth_line(sb, begin);
+
+	if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
+	    !(reg_error = regexec(&regexp, line, 1, match, 0))) {
+		const char *cp = line + match[0].rm_so;
+		const char *nline;
+
+		while (begin++ < lno) {
+			nline = nth_line(sb, begin);
+			if (line <= cp && cp < nline)
+				break;
+			line = nline;
+		}
+		*ret = begin;
+		regfree(&regexp);
+		*term++ = '/';
+		return term;
+	}
+	else {
+		char errbuf[1024];
+		regerror(reg_error, &regexp, errbuf, 1024);
+		die("-L parameter '%s': %s", spec + 1, errbuf);
+	}
+}
+
+/*
+ * Parsing of -L option
+ */
+static void prepare_blame_range(struct scoreboard *sb,
+				const char *bottomtop,
+				long lno,
+				long *bottom, long *top)
+{
+	const char *term;
+
+	term = parse_loc(bottomtop, sb, lno, 1, bottom);
+	if (*term == ',') {
+		term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
+		if (*term)
+			usage(blame_usage);
+	}
+	if (*term)
+		usage(blame_usage);
+}
+
+static int git_blame_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "blame.showroot")) {
+		show_root = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "blame.blankboundary")) {
+		blank_boundary = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "blame.date")) {
+		if (!value)
+			return config_error_nonbool(var);
+		blame_date_mode = parse_date_format(value);
+		return 0;
+	}
+
+	switch (userdiff_config(var, value)) {
+	case 0:
+		break;
+	case -1:
+		return -1;
+	default:
+		return 0;
+	}
+
+	return git_default_config(var, value, cb);
+}
+
+/*
+ * Prepare a dummy commit that represents the work tree (or staged) item.
+ * Note that annotating work tree item never works in the reverse.
+ */
+static struct commit *fake_working_tree_commit(struct diff_options *opt,
+					       const char *path,
+					       const char *contents_from)
+{
+	struct commit *commit;
+	struct origin *origin;
+	unsigned char head_sha1[20];
+	struct strbuf buf = STRBUF_INIT;
+	const char *ident;
+	time_t now;
+	int size, len;
+	struct cache_entry *ce;
+	unsigned mode;
+
+	if (get_sha1("HEAD", head_sha1))
+		die("No such ref: HEAD");
+
+	time(&now);
+	commit = xcalloc(1, sizeof(*commit));
+	commit->parents = xcalloc(1, sizeof(*commit->parents));
+	commit->parents->item = lookup_commit_reference(head_sha1);
+	commit->object.parsed = 1;
+	commit->date = now;
+	commit->object.type = OBJ_COMMIT;
+
+	origin = make_origin(commit, path);
+
+	if (!contents_from || strcmp("-", contents_from)) {
+		struct stat st;
+		const char *read_from;
+		unsigned long buf_len;
+
+		if (contents_from) {
+			if (stat(contents_from, &st) < 0)
+				die_errno("Cannot stat '%s'", contents_from);
+			read_from = contents_from;
+		}
+		else {
+			if (lstat(path, &st) < 0)
+				die_errno("Cannot lstat '%s'", path);
+			read_from = path;
+		}
+		mode = canon_mode(st.st_mode);
+
+		switch (st.st_mode & S_IFMT) {
+		case S_IFREG:
+			if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
+			    textconv_object(read_from, mode, null_sha1, &buf.buf, &buf_len))
+				buf.len = buf_len;
+			else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
+				die_errno("cannot open or read '%s'", read_from);
+			break;
+		case S_IFLNK:
+			if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
+				die_errno("cannot readlink '%s'", read_from);
+			break;
+		default:
+			die("unsupported file type %s", read_from);
+		}
+	}
+	else {
+		/* Reading from stdin */
+		contents_from = "standard input";
+		mode = 0;
+		if (strbuf_read(&buf, 0, 0) < 0)
+			die_errno("failed to read from stdin");
+	}
+	convert_to_git(path, buf.buf, buf.len, &buf, 0);
+	origin->file.ptr = buf.buf;
+	origin->file.size = buf.len;
+	pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
+	commit->util = origin;
+
+	/*
+	 * Read the current index, replace the path entry with
+	 * origin->blob_sha1 without mucking with its mode or type
+	 * bits; we are not going to write this index out -- we just
+	 * want to run "diff-index --cached".
+	 */
+	discard_cache();
+	read_cache();
+
+	len = strlen(path);
+	if (!mode) {
+		int pos = cache_name_pos(path, len);
+		if (0 <= pos)
+			mode = active_cache[pos]->ce_mode;
+		else
+			/* Let's not bother reading from HEAD tree */
+			mode = S_IFREG | 0644;
+	}
+	size = cache_entry_size(len);
+	ce = xcalloc(1, size);
+	hashcpy(ce->sha1, origin->blob_sha1);
+	memcpy(ce->name, path, len);
+	ce->ce_flags = create_ce_flags(len, 0);
+	ce->ce_mode = create_ce_mode(mode);
+	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
+
+	/*
+	 * We are not going to write this out, so this does not matter
+	 * right now, but someday we might optimize diff-index --cached
+	 * with cache-tree information.
+	 */
+	cache_tree_invalidate_path(active_cache_tree, path);
+
+	commit->buffer = xmalloc(400);
+	ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
+	snprintf(commit->buffer, 400,
+		"tree 0000000000000000000000000000000000000000\n"
+		"parent %s\n"
+		"author %s\n"
+		"committer %s\n\n"
+		"Version of %s from %s\n",
+		sha1_to_hex(head_sha1),
+		ident, ident, path, contents_from ? contents_from : path);
+	return commit;
+}
+
+static const char *prepare_final(struct scoreboard *sb)
+{
+	int i;
+	const char *final_commit_name = NULL;
+	struct rev_info *revs = sb->revs;
+
+	/*
+	 * There must be one and only one positive commit in the
+	 * revs->pending array.
+	 */
+	for (i = 0; i < revs->pending.nr; i++) {
+		struct object *obj = revs->pending.objects[i].item;
+		if (obj->flags & UNINTERESTING)
+			continue;
+		while (obj->type == OBJ_TAG)
+			obj = deref_tag(obj, NULL, 0);
+		if (obj->type != OBJ_COMMIT)
+			die("Non commit %s?", revs->pending.objects[i].name);
+		if (sb->final)
+			die("More than one commit to dig from %s and %s?",
+			    revs->pending.objects[i].name,
+			    final_commit_name);
+		sb->final = (struct commit *) obj;
+		final_commit_name = revs->pending.objects[i].name;
+	}
+	return final_commit_name;
+}
+
+static const char *prepare_initial(struct scoreboard *sb)
+{
+	int i;
+	const char *final_commit_name = NULL;
+	struct rev_info *revs = sb->revs;
+
+	/*
+	 * There must be one and only one negative commit, and it must be
+	 * the boundary.
+	 */
+	for (i = 0; i < revs->pending.nr; i++) {
+		struct object *obj = revs->pending.objects[i].item;
+		if (!(obj->flags & UNINTERESTING))
+			continue;
+		while (obj->type == OBJ_TAG)
+			obj = deref_tag(obj, NULL, 0);
+		if (obj->type != OBJ_COMMIT)
+			die("Non commit %s?", revs->pending.objects[i].name);
+		if (sb->final)
+			die("More than one commit to dig down to %s and %s?",
+			    revs->pending.objects[i].name,
+			    final_commit_name);
+		sb->final = (struct commit *) obj;
+		final_commit_name = revs->pending.objects[i].name;
+	}
+	if (!final_commit_name)
+		die("No commit to dig down to?");
+	return final_commit_name;
+}
+
+static int blame_copy_callback(const struct option *option, const char *arg, int unset)
+{
+	int *opt = option->value;
+
+	/*
+	 * -C enables copy from removed files;
+	 * -C -C enables copy from existing files, but only
+	 *       when blaming a new file;
+	 * -C -C -C enables copy from existing files for
+	 *          everybody
+	 */
+	if (*opt & PICKAXE_BLAME_COPY_HARDER)
+		*opt |= PICKAXE_BLAME_COPY_HARDEST;
+	if (*opt & PICKAXE_BLAME_COPY)
+		*opt |= PICKAXE_BLAME_COPY_HARDER;
+	*opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
+
+	if (arg)
+		blame_copy_score = parse_score(arg);
+	return 0;
+}
+
+static int blame_move_callback(const struct option *option, const char *arg, int unset)
+{
+	int *opt = option->value;
+
+	*opt |= PICKAXE_BLAME_MOVE;
+
+	if (arg)
+		blame_move_score = parse_score(arg);
+	return 0;
+}
+
+static int blame_bottomtop_callback(const struct option *option, const char *arg, int unset)
+{
+	const char **bottomtop = option->value;
+	if (!arg)
+		return -1;
+	if (*bottomtop)
+		die("More than one '-L n,m' option given");
+	*bottomtop = arg;
+	return 0;
+}
+
+int cmd_blame(int argc, const char **argv, const char *prefix)
+{
+	struct rev_info revs;
+	const char *path;
+	struct scoreboard sb;
+	struct origin *o;
+	struct blame_entry *ent;
+	long dashdash_pos, bottom, top, lno;
+	const char *final_commit_name = NULL;
+	enum object_type type;
+
+	static const char *bottomtop = NULL;
+	static int output_option = 0, opt = 0;
+	static int show_stats = 0;
+	static const char *revs_file = NULL;
+	static const char *contents_from = NULL;
+	static const struct option options[] = {
+		OPT_BOOLEAN(0, "incremental", &incremental, "Show blame entries as we find them, incrementally"),
+		OPT_BOOLEAN('b', NULL, &blank_boundary, "Show blank SHA-1 for boundary commits (Default: off)"),
+		OPT_BOOLEAN(0, "root", &show_root, "Do not treat root commits as boundaries (Default: off)"),
+		OPT_BOOLEAN(0, "show-stats", &show_stats, "Show work cost statistics"),
+		OPT_BIT(0, "score-debug", &output_option, "Show output score for blame entries", OUTPUT_SHOW_SCORE),
+		OPT_BIT('f', "show-name", &output_option, "Show original filename (Default: auto)", OUTPUT_SHOW_NAME),
+		OPT_BIT('n', "show-number", &output_option, "Show original linenumber (Default: off)", OUTPUT_SHOW_NUMBER),
+		OPT_BIT('p', "porcelain", &output_option, "Show in a format designed for machine consumption", OUTPUT_PORCELAIN),
+		OPT_BIT(0, "line-porcelain", &output_option, "Show porcelain format with per-line commit information", OUTPUT_PORCELAIN|OUTPUT_LINE_PORCELAIN),
+		OPT_BIT('c', NULL, &output_option, "Use the same output mode as git-annotate (Default: off)", OUTPUT_ANNOTATE_COMPAT),
+		OPT_BIT('t', NULL, &output_option, "Show raw timestamp (Default: off)", OUTPUT_RAW_TIMESTAMP),
+		OPT_BIT('l', NULL, &output_option, "Show long commit SHA1 (Default: off)", OUTPUT_LONG_OBJECT_NAME),
+		OPT_BIT('s', NULL, &output_option, "Suppress author name and timestamp (Default: off)", OUTPUT_NO_AUTHOR),
+		OPT_BIT('e', "show-email", &output_option, "Show author email instead of name (Default: off)", OUTPUT_SHOW_EMAIL),
+		OPT_BIT('w', NULL, &xdl_opts, "Ignore whitespace differences", XDF_IGNORE_WHITESPACE),
+		OPT_STRING('S', NULL, &revs_file, "file", "Use revisions from <file> instead of calling git-rev-list"),
+		OPT_STRING(0, "contents", &contents_from, "file", "Use <file>'s contents as the final image"),
+		{ OPTION_CALLBACK, 'C', NULL, &opt, "score", "Find line copies within and across files", PARSE_OPT_OPTARG, blame_copy_callback },
+		{ OPTION_CALLBACK, 'M', NULL, &opt, "score", "Find line movements within and across files", PARSE_OPT_OPTARG, blame_move_callback },
+		OPT_CALLBACK('L', NULL, &bottomtop, "n,m", "Process only line range n,m, counting from 1", blame_bottomtop_callback),
+		OPT__ABBREV(&abbrev),
+		OPT_END()
+	};
+
+	struct parse_opt_ctx_t ctx;
+	int cmd_is_annotate = !strcmp(argv[0], "annotate");
+
+	git_config(git_blame_config, NULL);
+	init_revisions(&revs, NULL);
+	revs.date_mode = blame_date_mode;
+	DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
+
+	save_commit_buffer = 0;
+	dashdash_pos = 0;
+
+	parse_options_start(&ctx, argc, argv, prefix, options,
+			    PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_ARGV0);
+	for (;;) {
+		switch (parse_options_step(&ctx, options, blame_opt_usage)) {
+		case PARSE_OPT_HELP:
+			exit(129);
+		case PARSE_OPT_DONE:
+			if (ctx.argv[0])
+				dashdash_pos = ctx.cpidx;
+			goto parse_done;
+		}
+
+		if (!strcmp(ctx.argv[0], "--reverse")) {
+			ctx.argv[0] = "--children";
+			reverse = 1;
+		}
+		parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
+	}
+parse_done:
+	argc = parse_options_end(&ctx);
+
+	if (abbrev == -1)
+		abbrev = default_abbrev;
+	/* one more abbrev length is needed for the boundary commit */
+	abbrev++;
+
+	if (revs_file && read_ancestry(revs_file))
+		die_errno("reading graft file '%s' failed", revs_file);
+
+	if (cmd_is_annotate) {
+		output_option |= OUTPUT_ANNOTATE_COMPAT;
+		blame_date_mode = DATE_ISO8601;
+	} else {
+		blame_date_mode = revs.date_mode;
+	}
+
+	/* The maximum width used to show the dates */
+	switch (blame_date_mode) {
+	case DATE_RFC2822:
+		blame_date_width = sizeof("Thu, 19 Oct 2006 16:00:04 -0700");
+		break;
+	case DATE_ISO8601:
+		blame_date_width = sizeof("2006-10-19 16:00:04 -0700");
+		break;
+	case DATE_RAW:
+		blame_date_width = sizeof("1161298804 -0700");
+		break;
+	case DATE_SHORT:
+		blame_date_width = sizeof("2006-10-19");
+		break;
+	case DATE_RELATIVE:
+		/* "normal" is used as the fallback for "relative" */
+	case DATE_LOCAL:
+	case DATE_NORMAL:
+		blame_date_width = sizeof("Thu Oct 19 16:00:04 2006 -0700");
+		break;
+	}
+	blame_date_width -= 1; /* strip the null */
+
+	if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
+		opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
+			PICKAXE_BLAME_COPY_HARDER);
+
+	if (!blame_move_score)
+		blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
+	if (!blame_copy_score)
+		blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
+
+	/*
+	 * We have collected options unknown to us in argv[1..unk]
+	 * which are to be passed to revision machinery if we are
+	 * going to do the "bottom" processing.
+	 *
+	 * The remaining are:
+	 *
+	 * (1) if dashdash_pos != 0, it is either
+	 *     "blame [revisions] -- <path>" or
+	 *     "blame -- <path> <rev>"
+	 *
+	 * (2) otherwise, it is one of the two:
+	 *     "blame [revisions] <path>"
+	 *     "blame <path> <rev>"
+	 *
+	 * Note that we must strip out <path> from the arguments: we do not
+	 * want the path pruning but we may want "bottom" processing.
+	 */
+	if (dashdash_pos) {
+		switch (argc - dashdash_pos - 1) {
+		case 2: /* (1b) */
+			if (argc != 4)
+				usage_with_options(blame_opt_usage, options);
+			/* reorder for the new way: <rev> -- <path> */
+			argv[1] = argv[3];
+			argv[3] = argv[2];
+			argv[2] = "--";
+			/* FALLTHROUGH */
+		case 1: /* (1a) */
+			path = add_prefix(prefix, argv[--argc]);
+			argv[argc] = NULL;
+			break;
+		default:
+			usage_with_options(blame_opt_usage, options);
+		}
+	} else {
+		if (argc < 2)
+			usage_with_options(blame_opt_usage, options);
+		path = add_prefix(prefix, argv[argc - 1]);
+		if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */
+			path = add_prefix(prefix, argv[1]);
+			argv[1] = argv[2];
+		}
+		argv[argc - 1] = "--";
+
+		setup_work_tree();
+		if (!has_string_in_work_tree(path))
+			die_errno("cannot stat path '%s'", path);
+	}
+
+	revs.disable_stdin = 1;
+	setup_revisions(argc, argv, &revs, NULL);
+	memset(&sb, 0, sizeof(sb));
+
+	sb.revs = &revs;
+	if (!reverse)
+		final_commit_name = prepare_final(&sb);
+	else if (contents_from)
+		die("--contents and --children do not blend well.");
+	else
+		final_commit_name = prepare_initial(&sb);
+
+	if (!sb.final) {
+		/*
+		 * "--not A B -- path" without anything positive;
+		 * do not default to HEAD, but use the working tree
+		 * or "--contents".
+		 */
+		setup_work_tree();
+		sb.final = fake_working_tree_commit(&sb.revs->diffopt,
+						    path, contents_from);
+		add_pending_object(&revs, &(sb.final->object), ":");
+	}
+	else if (contents_from)
+		die("Cannot use --contents with final commit object name");
+
+	/*
+	 * If we have bottom, this will mark the ancestors of the
+	 * bottom commits we would reach while traversing as
+	 * uninteresting.
+	 */
+	if (prepare_revision_walk(&revs))
+		die("revision walk setup failed");
+
+	if (is_null_sha1(sb.final->object.sha1)) {
+		char *buf;
+		o = sb.final->util;
+		buf = xmalloc(o->file.size + 1);
+		memcpy(buf, o->file.ptr, o->file.size + 1);
+		sb.final_buf = buf;
+		sb.final_buf_size = o->file.size;
+	}
+	else {
+		o = get_origin(&sb, sb.final, path);
+		if (fill_blob_sha1_and_mode(o))
+			die("no such path %s in %s", path, final_commit_name);
+
+		if (DIFF_OPT_TST(&sb.revs->diffopt, ALLOW_TEXTCONV) &&
+		    textconv_object(path, o->mode, o->blob_sha1, (char **) &sb.final_buf,
+				    &sb.final_buf_size))
+			;
+		else
+			sb.final_buf = read_sha1_file(o->blob_sha1, &type,
+						      &sb.final_buf_size);
+
+		if (!sb.final_buf)
+			die("Cannot read blob %s for path %s",
+			    sha1_to_hex(o->blob_sha1),
+			    path);
+	}
+	num_read_blob++;
+	lno = prepare_lines(&sb);
+
+	bottom = top = 0;
+	if (bottomtop)
+		prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
+	if (bottom && top && top < bottom) {
+		long tmp;
+		tmp = top; top = bottom; bottom = tmp;
+	}
+	if (bottom < 1)
+		bottom = 1;
+	if (top < 1)
+		top = lno;
+	bottom--;
+	if (lno < top || lno < bottom)
+		die("file %s has only %lu lines", path, lno);
+
+	ent = xcalloc(1, sizeof(*ent));
+	ent->lno = bottom;
+	ent->num_lines = top - bottom;
+	ent->suspect = o;
+	ent->s_lno = bottom;
+
+	sb.ent = ent;
+	sb.path = path;
+
+	read_mailmap(&mailmap, NULL);
+
+	if (!incremental)
+		setup_pager();
+
+	assign_blame(&sb, opt);
+
+	if (incremental)
+		return 0;
+
+	coalesce(&sb);
+
+	if (!(output_option & OUTPUT_PORCELAIN))
+		find_alignment(&sb, &output_option);
+
+	output(&sb, output_option);
+	free((void *)sb.final_buf);
+	for (ent = sb.ent; ent; ) {
+		struct blame_entry *e = ent->next;
+		free(ent);
+		ent = e;
+	}
+
+	if (show_stats) {
+		printf("num read blob: %d\n", num_read_blob);
+		printf("num get patch: %d\n", num_get_patch);
+		printf("num commits: %d\n", num_commits);
+	}
+	return 0;
+}
diff --git a/builtin/branch.c b/builtin/branch.c
new file mode 100644
index 0000000..f49596f
--- /dev/null
+++ b/builtin/branch.c
@@ -0,0 +1,712 @@
+/*
+ * Builtin "git branch"
+ *
+ * Copyright (c) 2006 Kristian Høgsberg <krh@redhat.com>
+ * Based on git-branch.sh by Junio C Hamano.
+ */
+
+#include "cache.h"
+#include "color.h"
+#include "refs.h"
+#include "commit.h"
+#include "builtin.h"
+#include "remote.h"
+#include "parse-options.h"
+#include "branch.h"
+#include "diff.h"
+#include "revision.h"
+
+static const char * const builtin_branch_usage[] = {
+	"git branch [options] [-r | -a] [--merged | --no-merged]",
+	"git branch [options] [-l] [-f] <branchname> [<start-point>]",
+	"git branch [options] [-r] (-d | -D) <branchname>...",
+	"git branch [options] (-m | -M) [<oldbranch>] <newbranch>",
+	NULL
+};
+
+#define REF_LOCAL_BRANCH    0x01
+#define REF_REMOTE_BRANCH   0x02
+
+static const char *head;
+static unsigned char head_sha1[20];
+
+static int branch_use_color = -1;
+static char branch_colors[][COLOR_MAXLEN] = {
+	GIT_COLOR_RESET,
+	GIT_COLOR_NORMAL,	/* PLAIN */
+	GIT_COLOR_RED,		/* REMOTE */
+	GIT_COLOR_NORMAL,	/* LOCAL */
+	GIT_COLOR_GREEN,	/* CURRENT */
+};
+enum color_branch {
+	BRANCH_COLOR_RESET = 0,
+	BRANCH_COLOR_PLAIN = 1,
+	BRANCH_COLOR_REMOTE = 2,
+	BRANCH_COLOR_LOCAL = 3,
+	BRANCH_COLOR_CURRENT = 4
+};
+
+static enum merge_filter {
+	NO_FILTER = 0,
+	SHOW_NOT_MERGED,
+	SHOW_MERGED
+} merge_filter;
+static unsigned char merge_filter_ref[20];
+
+static int parse_branch_color_slot(const char *var, int ofs)
+{
+	if (!strcasecmp(var+ofs, "plain"))
+		return BRANCH_COLOR_PLAIN;
+	if (!strcasecmp(var+ofs, "reset"))
+		return BRANCH_COLOR_RESET;
+	if (!strcasecmp(var+ofs, "remote"))
+		return BRANCH_COLOR_REMOTE;
+	if (!strcasecmp(var+ofs, "local"))
+		return BRANCH_COLOR_LOCAL;
+	if (!strcasecmp(var+ofs, "current"))
+		return BRANCH_COLOR_CURRENT;
+	return -1;
+}
+
+static int git_branch_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "color.branch")) {
+		branch_use_color = git_config_colorbool(var, value);
+		return 0;
+	}
+	if (!prefixcmp(var, "color.branch.")) {
+		int slot = parse_branch_color_slot(var, 13);
+		if (slot < 0)
+			return 0;
+		if (!value)
+			return config_error_nonbool(var);
+		color_parse(value, var, branch_colors[slot]);
+		return 0;
+	}
+	return git_color_default_config(var, value, cb);
+}
+
+static const char *branch_get_color(enum color_branch ix)
+{
+	if (want_color(branch_use_color))
+		return branch_colors[ix];
+	return "";
+}
+
+static int branch_merged(int kind, const char *name,
+			 struct commit *rev, struct commit *head_rev)
+{
+	/*
+	 * This checks whether the merge bases of branch and HEAD (or
+	 * the other branch this branch builds upon) contains the
+	 * branch, which means that the branch has already been merged
+	 * safely to HEAD (or the other branch).
+	 */
+	struct commit *reference_rev = NULL;
+	const char *reference_name = NULL;
+	int merged;
+
+	if (kind == REF_LOCAL_BRANCH) {
+		struct branch *branch = branch_get(name);
+		unsigned char sha1[20];
+
+		if (branch &&
+		    branch->merge &&
+		    branch->merge[0] &&
+		    branch->merge[0]->dst &&
+		    (reference_name =
+		     resolve_ref(branch->merge[0]->dst, sha1, 1, NULL)) != NULL)
+			reference_rev = lookup_commit_reference(sha1);
+	}
+	if (!reference_rev)
+		reference_rev = head_rev;
+
+	merged = in_merge_bases(rev, &reference_rev, 1);
+
+	/*
+	 * After the safety valve is fully redefined to "check with
+	 * upstream, if any, otherwise with HEAD", we should just
+	 * return the result of the in_merge_bases() above without
+	 * any of the following code, but during the transition period,
+	 * a gentle reminder is in order.
+	 */
+	if ((head_rev != reference_rev) &&
+	    in_merge_bases(rev, &head_rev, 1) != merged) {
+		if (merged)
+			warning(_("deleting branch '%s' that has been merged to\n"
+				"         '%s', but not yet merged to HEAD."),
+				name, reference_name);
+		else
+			warning(_("not deleting branch '%s' that is not yet merged to\n"
+				"         '%s', even though it is merged to HEAD."),
+				name, reference_name);
+	}
+	return merged;
+}
+
+static int delete_branches(int argc, const char **argv, int force, int kinds)
+{
+	struct commit *rev, *head_rev = NULL;
+	unsigned char sha1[20];
+	char *name = NULL;
+	const char *fmt, *remote;
+	int i;
+	int ret = 0;
+	struct strbuf bname = STRBUF_INIT;
+
+	switch (kinds) {
+	case REF_REMOTE_BRANCH:
+		fmt = "refs/remotes/%s";
+		/* TRANSLATORS: This is "remote " in "remote branch '%s' not found" */
+		remote = _("remote ");
+		force = 1;
+		break;
+	case REF_LOCAL_BRANCH:
+		fmt = "refs/heads/%s";
+		remote = "";
+		break;
+	default:
+		die(_("cannot use -a with -d"));
+	}
+
+	if (!force) {
+		head_rev = lookup_commit_reference(head_sha1);
+		if (!head_rev)
+			die(_("Couldn't look up commit object for HEAD"));
+	}
+	for (i = 0; i < argc; i++, strbuf_release(&bname)) {
+		strbuf_branchname(&bname, argv[i]);
+		if (kinds == REF_LOCAL_BRANCH && !strcmp(head, bname.buf)) {
+			error(_("Cannot delete the branch '%s' "
+			      "which you are currently on."), bname.buf);
+			ret = 1;
+			continue;
+		}
+
+		free(name);
+
+		name = xstrdup(mkpath(fmt, bname.buf));
+		if (!resolve_ref(name, sha1, 1, NULL)) {
+			error(_("%sbranch '%s' not found."),
+					remote, bname.buf);
+			ret = 1;
+			continue;
+		}
+
+		rev = lookup_commit_reference(sha1);
+		if (!rev) {
+			error(_("Couldn't look up commit object for '%s'"), name);
+			ret = 1;
+			continue;
+		}
+
+		if (!force && !branch_merged(kinds, bname.buf, rev, head_rev)) {
+			error(_("The branch '%s' is not fully merged.\n"
+			      "If you are sure you want to delete it, "
+			      "run 'git branch -D %s'."), bname.buf, bname.buf);
+			ret = 1;
+			continue;
+		}
+
+		if (delete_ref(name, sha1, 0)) {
+			error(_("Error deleting %sbranch '%s'"), remote,
+			      bname.buf);
+			ret = 1;
+		} else {
+			struct strbuf buf = STRBUF_INIT;
+			printf(_("Deleted %sbranch %s (was %s).\n"), remote,
+			       bname.buf,
+			       find_unique_abbrev(sha1, DEFAULT_ABBREV));
+			strbuf_addf(&buf, "branch.%s", bname.buf);
+			if (git_config_rename_section(buf.buf, NULL) < 0)
+				warning(_("Update of config-file failed"));
+			strbuf_release(&buf);
+		}
+	}
+
+	free(name);
+
+	return(ret);
+}
+
+struct ref_item {
+	char *name;
+	char *dest;
+	unsigned int kind, len;
+	struct commit *commit;
+};
+
+struct ref_list {
+	struct rev_info revs;
+	int index, alloc, maxwidth, verbose, abbrev;
+	struct ref_item *list;
+	struct commit_list *with_commit;
+	int kinds;
+};
+
+static char *resolve_symref(const char *src, const char *prefix)
+{
+	unsigned char sha1[20];
+	int flag;
+	const char *dst, *cp;
+
+	dst = resolve_ref(src, sha1, 0, &flag);
+	if (!(dst && (flag & REF_ISSYMREF)))
+		return NULL;
+	if (prefix && (cp = skip_prefix(dst, prefix)))
+		dst = cp;
+	return xstrdup(dst);
+}
+
+struct append_ref_cb {
+	struct ref_list *ref_list;
+	int ret;
+};
+
+static int append_ref(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
+{
+	struct append_ref_cb *cb = (struct append_ref_cb *)(cb_data);
+	struct ref_list *ref_list = cb->ref_list;
+	struct ref_item *newitem;
+	struct commit *commit;
+	int kind, i;
+	const char *prefix, *orig_refname = refname;
+
+	static struct {
+		int kind;
+		const char *prefix;
+		int pfxlen;
+	} ref_kind[] = {
+		{ REF_LOCAL_BRANCH, "refs/heads/", 11 },
+		{ REF_REMOTE_BRANCH, "refs/remotes/", 13 },
+	};
+
+	/* Detect kind */
+	for (i = 0; i < ARRAY_SIZE(ref_kind); i++) {
+		prefix = ref_kind[i].prefix;
+		if (strncmp(refname, prefix, ref_kind[i].pfxlen))
+			continue;
+		kind = ref_kind[i].kind;
+		refname += ref_kind[i].pfxlen;
+		break;
+	}
+	if (ARRAY_SIZE(ref_kind) <= i)
+		return 0;
+
+	/* Don't add types the caller doesn't want */
+	if ((kind & ref_list->kinds) == 0)
+		return 0;
+
+	commit = NULL;
+	if (ref_list->verbose || ref_list->with_commit || merge_filter != NO_FILTER) {
+		commit = lookup_commit_reference_gently(sha1, 1);
+		if (!commit) {
+			cb->ret = error(_("branch '%s' does not point at a commit"), refname);
+			return 0;
+		}
+
+		/* Filter with with_commit if specified */
+		if (!is_descendant_of(commit, ref_list->with_commit))
+			return 0;
+
+		if (merge_filter != NO_FILTER)
+			add_pending_object(&ref_list->revs,
+					   (struct object *)commit, refname);
+	}
+
+	ALLOC_GROW(ref_list->list, ref_list->index + 1, ref_list->alloc);
+
+	/* Record the new item */
+	newitem = &(ref_list->list[ref_list->index++]);
+	newitem->name = xstrdup(refname);
+	newitem->kind = kind;
+	newitem->commit = commit;
+	newitem->len = strlen(refname);
+	newitem->dest = resolve_symref(orig_refname, prefix);
+	/* adjust for "remotes/" */
+	if (newitem->kind == REF_REMOTE_BRANCH &&
+	    ref_list->kinds != REF_REMOTE_BRANCH)
+		newitem->len += 8;
+	if (newitem->len > ref_list->maxwidth)
+		ref_list->maxwidth = newitem->len;
+
+	return 0;
+}
+
+static void free_ref_list(struct ref_list *ref_list)
+{
+	int i;
+
+	for (i = 0; i < ref_list->index; i++) {
+		free(ref_list->list[i].name);
+		free(ref_list->list[i].dest);
+	}
+	free(ref_list->list);
+}
+
+static int ref_cmp(const void *r1, const void *r2)
+{
+	struct ref_item *c1 = (struct ref_item *)(r1);
+	struct ref_item *c2 = (struct ref_item *)(r2);
+
+	if (c1->kind != c2->kind)
+		return c1->kind - c2->kind;
+	return strcmp(c1->name, c2->name);
+}
+
+static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
+		int show_upstream_ref)
+{
+	int ours, theirs;
+	struct branch *branch = branch_get(branch_name);
+
+	if (!stat_tracking_info(branch, &ours, &theirs)) {
+		if (branch && branch->merge && branch->merge[0]->dst &&
+		    show_upstream_ref)
+			strbuf_addf(stat, "[%s] ",
+			    shorten_unambiguous_ref(branch->merge[0]->dst, 0));
+		return;
+	}
+
+	strbuf_addch(stat, '[');
+	if (show_upstream_ref)
+		strbuf_addf(stat, "%s: ",
+			shorten_unambiguous_ref(branch->merge[0]->dst, 0));
+	if (!ours)
+		strbuf_addf(stat, _("behind %d] "), theirs);
+	else if (!theirs)
+		strbuf_addf(stat, _("ahead %d] "), ours);
+	else
+		strbuf_addf(stat, _("ahead %d, behind %d] "), ours, theirs);
+}
+
+static int matches_merge_filter(struct commit *commit)
+{
+	int is_merged;
+
+	if (merge_filter == NO_FILTER)
+		return 1;
+
+	is_merged = !!(commit->object.flags & UNINTERESTING);
+	return (is_merged == (merge_filter == SHOW_MERGED));
+}
+
+static void add_verbose_info(struct strbuf *out, struct ref_item *item,
+			     int verbose, int abbrev)
+{
+	struct strbuf subject = STRBUF_INIT, stat = STRBUF_INIT;
+	const char *sub = " **** invalid ref ****";
+	struct commit *commit = item->commit;
+
+	if (commit && !parse_commit(commit)) {
+		pp_commit_easy(CMIT_FMT_ONELINE, commit, &subject);
+		sub = subject.buf;
+	}
+
+	if (item->kind == REF_LOCAL_BRANCH)
+		fill_tracking_info(&stat, item->name, verbose > 1);
+
+	strbuf_addf(out, " %s %s%s",
+		find_unique_abbrev(item->commit->object.sha1, abbrev),
+		stat.buf, sub);
+	strbuf_release(&stat);
+	strbuf_release(&subject);
+}
+
+static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
+			   int abbrev, int current, char *prefix)
+{
+	char c;
+	int color;
+	struct commit *commit = item->commit;
+	struct strbuf out = STRBUF_INIT, name = STRBUF_INIT;
+
+	if (!matches_merge_filter(commit))
+		return;
+
+	switch (item->kind) {
+	case REF_LOCAL_BRANCH:
+		color = BRANCH_COLOR_LOCAL;
+		break;
+	case REF_REMOTE_BRANCH:
+		color = BRANCH_COLOR_REMOTE;
+		break;
+	default:
+		color = BRANCH_COLOR_PLAIN;
+		break;
+	}
+
+	c = ' ';
+	if (current) {
+		c = '*';
+		color = BRANCH_COLOR_CURRENT;
+	}
+
+	strbuf_addf(&name, "%s%s", prefix, item->name);
+	if (verbose)
+		strbuf_addf(&out, "%c %s%-*s%s", c, branch_get_color(color),
+			    maxwidth, name.buf,
+			    branch_get_color(BRANCH_COLOR_RESET));
+	else
+		strbuf_addf(&out, "%c %s%s%s", c, branch_get_color(color),
+			    name.buf, branch_get_color(BRANCH_COLOR_RESET));
+
+	if (item->dest)
+		strbuf_addf(&out, " -> %s", item->dest);
+	else if (verbose)
+		/* " f7c0c00 [ahead 58, behind 197] vcs-svn: drop obj_pool.h" */
+		add_verbose_info(&out, item, verbose, abbrev);
+	printf("%s\n", out.buf);
+	strbuf_release(&name);
+	strbuf_release(&out);
+}
+
+static int calc_maxwidth(struct ref_list *refs)
+{
+	int i, w = 0;
+	for (i = 0; i < refs->index; i++) {
+		if (!matches_merge_filter(refs->list[i].commit))
+			continue;
+		if (refs->list[i].len > w)
+			w = refs->list[i].len;
+	}
+	return w;
+}
+
+
+static void show_detached(struct ref_list *ref_list)
+{
+	struct commit *head_commit = lookup_commit_reference_gently(head_sha1, 1);
+
+	if (head_commit && is_descendant_of(head_commit, ref_list->with_commit)) {
+		struct ref_item item;
+		item.name = xstrdup(_("(no branch)"));
+		item.len = strlen(item.name);
+		item.kind = REF_LOCAL_BRANCH;
+		item.dest = NULL;
+		item.commit = head_commit;
+		if (item.len > ref_list->maxwidth)
+			ref_list->maxwidth = item.len;
+		print_ref_item(&item, ref_list->maxwidth, ref_list->verbose, ref_list->abbrev, 1, "");
+		free(item.name);
+	}
+}
+
+static int print_ref_list(int kinds, int detached, int verbose, int abbrev, struct commit_list *with_commit)
+{
+	int i;
+	struct append_ref_cb cb;
+	struct ref_list ref_list;
+
+	memset(&ref_list, 0, sizeof(ref_list));
+	ref_list.kinds = kinds;
+	ref_list.verbose = verbose;
+	ref_list.abbrev = abbrev;
+	ref_list.with_commit = with_commit;
+	if (merge_filter != NO_FILTER)
+		init_revisions(&ref_list.revs, NULL);
+	cb.ref_list = &ref_list;
+	cb.ret = 0;
+	for_each_rawref(append_ref, &cb);
+	if (merge_filter != NO_FILTER) {
+		struct commit *filter;
+		filter = lookup_commit_reference_gently(merge_filter_ref, 0);
+		filter->object.flags |= UNINTERESTING;
+		add_pending_object(&ref_list.revs,
+				   (struct object *) filter, "");
+		ref_list.revs.limited = 1;
+		prepare_revision_walk(&ref_list.revs);
+		if (verbose)
+			ref_list.maxwidth = calc_maxwidth(&ref_list);
+	}
+
+	qsort(ref_list.list, ref_list.index, sizeof(struct ref_item), ref_cmp);
+
+	detached = (detached && (kinds & REF_LOCAL_BRANCH));
+	if (detached)
+		show_detached(&ref_list);
+
+	for (i = 0; i < ref_list.index; i++) {
+		int current = !detached &&
+			(ref_list.list[i].kind == REF_LOCAL_BRANCH) &&
+			!strcmp(ref_list.list[i].name, head);
+		char *prefix = (kinds != REF_REMOTE_BRANCH &&
+				ref_list.list[i].kind == REF_REMOTE_BRANCH)
+				? "remotes/" : "";
+		print_ref_item(&ref_list.list[i], ref_list.maxwidth, verbose,
+			       abbrev, current, prefix);
+	}
+
+	free_ref_list(&ref_list);
+
+	if (cb.ret)
+		error(_("some refs could not be read"));
+
+	return cb.ret;
+}
+
+static void rename_branch(const char *oldname, const char *newname, int force)
+{
+	struct strbuf oldref = STRBUF_INIT, newref = STRBUF_INIT, logmsg = STRBUF_INIT;
+	unsigned char sha1[20];
+	struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
+	int recovery = 0;
+
+	if (!oldname)
+		die(_("cannot rename the current branch while not on any."));
+
+	if (strbuf_check_branch_ref(&oldref, oldname)) {
+		/*
+		 * Bad name --- this could be an attempt to rename a
+		 * ref that we used to allow to be created by accident.
+		 */
+		if (resolve_ref(oldref.buf, sha1, 1, NULL))
+			recovery = 1;
+		else
+			die(_("Invalid branch name: '%s'"), oldname);
+	}
+
+	validate_new_branchname(newname, &newref, force, 0);
+
+	strbuf_addf(&logmsg, "Branch: renamed %s to %s",
+		 oldref.buf, newref.buf);
+
+	if (rename_ref(oldref.buf, newref.buf, logmsg.buf))
+		die(_("Branch rename failed"));
+	strbuf_release(&logmsg);
+
+	if (recovery)
+		warning(_("Renamed a misnamed branch '%s' away"), oldref.buf + 11);
+
+	/* no need to pass logmsg here as HEAD didn't really move */
+	if (!strcmp(oldname, head) && create_symref("HEAD", newref.buf, NULL))
+		die(_("Branch renamed to %s, but HEAD is not updated!"), newname);
+
+	strbuf_addf(&oldsection, "branch.%s", oldref.buf + 11);
+	strbuf_release(&oldref);
+	strbuf_addf(&newsection, "branch.%s", newref.buf + 11);
+	strbuf_release(&newref);
+	if (git_config_rename_section(oldsection.buf, newsection.buf) < 0)
+		die(_("Branch is renamed, but update of config-file failed"));
+	strbuf_release(&oldsection);
+	strbuf_release(&newsection);
+}
+
+static int opt_parse_merge_filter(const struct option *opt, const char *arg, int unset)
+{
+	merge_filter = ((opt->long_name[0] == 'n')
+			? SHOW_NOT_MERGED
+			: SHOW_MERGED);
+	if (unset)
+		merge_filter = SHOW_NOT_MERGED; /* b/c for --no-merged */
+	if (!arg)
+		arg = "HEAD";
+	if (get_sha1(arg, merge_filter_ref))
+		die(_("malformed object name %s"), arg);
+	return 0;
+}
+
+int cmd_branch(int argc, const char **argv, const char *prefix)
+{
+	int delete = 0, rename = 0, force_create = 0;
+	int verbose = 0, abbrev = -1, detached = 0;
+	int reflog = 0;
+	enum branch_track track;
+	int kinds = REF_LOCAL_BRANCH;
+	struct commit_list *with_commit = NULL;
+
+	struct option options[] = {
+		OPT_GROUP("Generic options"),
+		OPT__VERBOSE(&verbose,
+			"show hash and subject, give twice for upstream branch"),
+		OPT_SET_INT('t', "track",  &track, "set up tracking mode (see git-pull(1))",
+			BRANCH_TRACK_EXPLICIT),
+		OPT_SET_INT( 0, "set-upstream",  &track, "change upstream info",
+			BRANCH_TRACK_OVERRIDE),
+		OPT__COLOR(&branch_use_color, "use colored output"),
+		OPT_SET_INT('r', NULL,     &kinds, "act on remote-tracking branches",
+			REF_REMOTE_BRANCH),
+		{
+			OPTION_CALLBACK, 0, "contains", &with_commit, "commit",
+			"print only branches that contain the commit",
+			PARSE_OPT_LASTARG_DEFAULT,
+			parse_opt_with_commit, (intptr_t)"HEAD",
+		},
+		{
+			OPTION_CALLBACK, 0, "with", &with_commit, "commit",
+			"print only branches that contain the commit",
+			PARSE_OPT_HIDDEN | PARSE_OPT_LASTARG_DEFAULT,
+			parse_opt_with_commit, (intptr_t) "HEAD",
+		},
+		OPT__ABBREV(&abbrev),
+
+		OPT_GROUP("Specific git-branch actions:"),
+		OPT_SET_INT('a', NULL, &kinds, "list both remote-tracking and local branches",
+			REF_REMOTE_BRANCH | REF_LOCAL_BRANCH),
+		OPT_BIT('d', NULL, &delete, "delete fully merged branch", 1),
+		OPT_BIT('D', NULL, &delete, "delete branch (even if not merged)", 2),
+		OPT_BIT('m', NULL, &rename, "move/rename a branch and its reflog", 1),
+		OPT_BIT('M', NULL, &rename, "move/rename a branch, even if target exists", 2),
+		OPT_BOOLEAN('l', NULL, &reflog, "create the branch's reflog"),
+		OPT__FORCE(&force_create, "force creation (when already exists)"),
+		{
+			OPTION_CALLBACK, 0, "no-merged", &merge_filter_ref,
+			"commit", "print only not merged branches",
+			PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG,
+			opt_parse_merge_filter, (intptr_t) "HEAD",
+		},
+		{
+			OPTION_CALLBACK, 0, "merged", &merge_filter_ref,
+			"commit", "print only merged branches",
+			PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG,
+			opt_parse_merge_filter, (intptr_t) "HEAD",
+		},
+		OPT_END(),
+	};
+
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(builtin_branch_usage, options);
+
+	git_config(git_branch_config, NULL);
+
+	track = git_branch_track;
+
+	head = resolve_ref("HEAD", head_sha1, 0, NULL);
+	if (!head)
+		die(_("Failed to resolve HEAD as a valid ref."));
+	head = xstrdup(head);
+	if (!strcmp(head, "HEAD")) {
+		detached = 1;
+	} else {
+		if (prefixcmp(head, "refs/heads/"))
+			die(_("HEAD not found below refs/heads!"));
+		head += 11;
+	}
+	hashcpy(merge_filter_ref, head_sha1);
+
+	argc = parse_options(argc, argv, prefix, options, builtin_branch_usage,
+			     0);
+	if (!!delete + !!rename + !!force_create > 1)
+		usage_with_options(builtin_branch_usage, options);
+
+	if (abbrev == -1)
+		abbrev = DEFAULT_ABBREV;
+
+	if (delete)
+		return delete_branches(argc, argv, delete > 1, kinds);
+	else if (argc == 0)
+		return print_ref_list(kinds, detached, verbose, abbrev, with_commit);
+	else if (rename && (argc == 1))
+		rename_branch(head, argv[0], rename > 1);
+	else if (rename && (argc == 2))
+		rename_branch(argv[0], argv[1], rename > 1);
+	else if (argc <= 2) {
+		if (kinds != REF_LOCAL_BRANCH)
+			die(_("-a and -r options to 'git branch' do not make sense with a branch name"));
+		create_branch(head, argv[0], (argc == 2) ? argv[1] : head,
+			      force_create, reflog, track);
+	} else
+		usage_with_options(builtin_branch_usage, options);
+
+	return 0;
+}
diff --git a/builtin/bundle.c b/builtin/bundle.c
new file mode 100644
index 0000000..92a8a60
--- /dev/null
+++ b/builtin/bundle.c
@@ -0,0 +1,65 @@
+#include "builtin.h"
+#include "cache.h"
+#include "bundle.h"
+
+/*
+ * Basic handler for bundle files to connect repositories via sneakernet.
+ * Invocation must include action.
+ * This function can create a bundle or provide information on an existing
+ * bundle supporting "fetch", "pull", and "ls-remote".
+ */
+
+static const char builtin_bundle_usage[] =
+  "git bundle create <file> <git-rev-list args>\n"
+  "   or: git bundle verify <file>\n"
+  "   or: git bundle list-heads <file> [<refname>...]\n"
+  "   or: git bundle unbundle <file> [<refname>...]";
+
+int cmd_bundle(int argc, const char **argv, const char *prefix)
+{
+	struct bundle_header header;
+	const char *cmd, *bundle_file;
+	int bundle_fd = -1;
+	char buffer[PATH_MAX];
+
+	if (argc < 3)
+		usage(builtin_bundle_usage);
+
+	cmd = argv[1];
+	bundle_file = argv[2];
+	argc -= 2;
+	argv += 2;
+
+	if (prefix && bundle_file[0] != '/') {
+		snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
+		bundle_file = buffer;
+	}
+
+	memset(&header, 0, sizeof(header));
+	if (strcmp(cmd, "create") && (bundle_fd =
+				read_bundle_header(bundle_file, &header)) < 0)
+		return 1;
+
+	if (!strcmp(cmd, "verify")) {
+		close(bundle_fd);
+		if (verify_bundle(&header, 1))
+			return 1;
+		fprintf(stderr, _("%s is okay\n"), bundle_file);
+		return 0;
+	}
+	if (!strcmp(cmd, "list-heads")) {
+		close(bundle_fd);
+		return !!list_bundle_refs(&header, argc, argv);
+	}
+	if (!strcmp(cmd, "create")) {
+		if (!startup_info->have_repository)
+			die(_("Need a repository to create a bundle."));
+		return !!create_bundle(&header, bundle_file, argc, argv);
+	} else if (!strcmp(cmd, "unbundle")) {
+		if (!startup_info->have_repository)
+			die(_("Need a repository to unbundle."));
+		return !!unbundle(&header, bundle_fd, 0) ||
+			list_bundle_refs(&header, argc, argv);
+	} else
+		usage(builtin_bundle_usage);
+}
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
new file mode 100644
index 0000000..07bd984
--- /dev/null
+++ b/builtin/cat-file.c
@@ -0,0 +1,292 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+#include "cache.h"
+#include "exec_cmd.h"
+#include "tag.h"
+#include "tree.h"
+#include "builtin.h"
+#include "parse-options.h"
+#include "diff.h"
+#include "userdiff.h"
+
+#define BATCH 1
+#define BATCH_CHECK 2
+
+static void pprint_tag(const unsigned char *sha1, const char *buf, unsigned long size)
+{
+	/* the parser in tag.c is useless here. */
+	const char *endp = buf + size;
+	const char *cp = buf;
+
+	while (cp < endp) {
+		char c = *cp++;
+		if (c != '\n')
+			continue;
+		if (7 <= endp - cp && !memcmp("tagger ", cp, 7)) {
+			const char *tagger = cp;
+
+			/* Found the tagger line.  Copy out the contents
+			 * of the buffer so far.
+			 */
+			write_or_die(1, buf, cp - buf);
+
+			/*
+			 * Do something intelligent, like pretty-printing
+			 * the date.
+			 */
+			while (cp < endp) {
+				if (*cp++ == '\n') {
+					/* tagger to cp is a line
+					 * that has ident and time.
+					 */
+					const char *sp = tagger;
+					char *ep;
+					unsigned long date;
+					long tz;
+					while (sp < cp && *sp != '>')
+						sp++;
+					if (sp == cp) {
+						/* give up */
+						write_or_die(1, tagger,
+							     cp - tagger);
+						break;
+					}
+					while (sp < cp &&
+					       !('0' <= *sp && *sp <= '9'))
+						sp++;
+					write_or_die(1, tagger, sp - tagger);
+					date = strtoul(sp, &ep, 10);
+					tz = strtol(ep, NULL, 10);
+					sp = show_date(date, tz, 0);
+					write_or_die(1, sp, strlen(sp));
+					xwrite(1, "\n", 1);
+					break;
+				}
+			}
+			break;
+		}
+		if (cp < endp && *cp == '\n')
+			/* end of header */
+			break;
+	}
+	/* At this point, we have copied out the header up to the end of
+	 * the tagger line and cp points at one past \n.  It could be the
+	 * next header line after the tagger line, or it could be another
+	 * \n that marks the end of the headers.  We need to copy out the
+	 * remainder as is.
+	 */
+	if (cp < endp)
+		write_or_die(1, cp, endp - cp);
+}
+
+static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
+{
+	unsigned char sha1[20];
+	enum object_type type;
+	char *buf;
+	unsigned long size;
+	struct object_context obj_context;
+
+	if (get_sha1_with_context(obj_name, sha1, &obj_context))
+		die("Not a valid object name %s", obj_name);
+
+	buf = NULL;
+	switch (opt) {
+	case 't':
+		type = sha1_object_info(sha1, NULL);
+		if (type > 0) {
+			printf("%s\n", typename(type));
+			return 0;
+		}
+		break;
+
+	case 's':
+		type = sha1_object_info(sha1, &size);
+		if (type > 0) {
+			printf("%lu\n", size);
+			return 0;
+		}
+		break;
+
+	case 'e':
+		return !has_sha1_file(sha1);
+
+	case 'p':
+		type = sha1_object_info(sha1, NULL);
+		if (type < 0)
+			die("Not a valid object name %s", obj_name);
+
+		/* custom pretty-print here */
+		if (type == OBJ_TREE) {
+			const char *ls_args[3] = { NULL };
+			ls_args[0] =  "ls-tree";
+			ls_args[1] =  obj_name;
+			return cmd_ls_tree(2, ls_args, NULL);
+		}
+
+		buf = read_sha1_file(sha1, &type, &size);
+		if (!buf)
+			die("Cannot read object %s", obj_name);
+		if (type == OBJ_TAG) {
+			pprint_tag(sha1, buf, size);
+			return 0;
+		}
+
+		/* otherwise just spit out the data */
+		break;
+
+	case 'c':
+		if (!obj_context.path[0])
+			die("git cat-file --textconv %s: <object> must be <sha1:path>",
+			    obj_name);
+
+		if (!textconv_object(obj_context.path, obj_context.mode, sha1, &buf, &size))
+			die("git cat-file --textconv: unable to run textconv on %s",
+			    obj_name);
+		break;
+
+	case 0:
+		buf = read_object_with_reference(sha1, exp_type, &size, NULL);
+		break;
+
+	default:
+		die("git cat-file: unknown option: %s", exp_type);
+	}
+
+	if (!buf)
+		die("git cat-file %s: bad file", obj_name);
+
+	write_or_die(1, buf, size);
+	return 0;
+}
+
+static int batch_one_object(const char *obj_name, int print_contents)
+{
+	unsigned char sha1[20];
+	enum object_type type = 0;
+	unsigned long size;
+	void *contents = contents;
+
+	if (!obj_name)
+	   return 1;
+
+	if (get_sha1(obj_name, sha1)) {
+		printf("%s missing\n", obj_name);
+		fflush(stdout);
+		return 0;
+	}
+
+	if (print_contents == BATCH)
+		contents = read_sha1_file(sha1, &type, &size);
+	else
+		type = sha1_object_info(sha1, &size);
+
+	if (type <= 0) {
+		printf("%s missing\n", obj_name);
+		fflush(stdout);
+		if (print_contents == BATCH)
+			free(contents);
+		return 0;
+	}
+
+	printf("%s %s %lu\n", sha1_to_hex(sha1), typename(type), size);
+	fflush(stdout);
+
+	if (print_contents == BATCH) {
+		write_or_die(1, contents, size);
+		printf("\n");
+		fflush(stdout);
+		free(contents);
+	}
+
+	return 0;
+}
+
+static int batch_objects(int print_contents)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	while (strbuf_getline(&buf, stdin, '\n') != EOF) {
+		int error = batch_one_object(buf.buf, print_contents);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+
+static const char * const cat_file_usage[] = {
+	"git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>",
+	"git cat-file (--batch|--batch-check) < <list_of_objects>",
+	NULL
+};
+
+static int git_cat_file_config(const char *var, const char *value, void *cb)
+{
+	switch (userdiff_config(var, value)) {
+	case 0:
+		break;
+	case -1:
+		return -1;
+	default:
+		return 0;
+	}
+
+	return git_default_config(var, value, cb);
+}
+
+int cmd_cat_file(int argc, const char **argv, const char *prefix)
+{
+	int opt = 0, batch = 0;
+	const char *exp_type = NULL, *obj_name = NULL;
+
+	const struct option options[] = {
+		OPT_GROUP("<type> can be one of: blob, tree, commit, tag"),
+		OPT_SET_INT('t', NULL, &opt, "show object type", 't'),
+		OPT_SET_INT('s', NULL, &opt, "show object size", 's'),
+		OPT_SET_INT('e', NULL, &opt,
+			    "exit with zero when there's no error", 'e'),
+		OPT_SET_INT('p', NULL, &opt, "pretty-print object's content", 'p'),
+		OPT_SET_INT(0, "textconv", &opt,
+			    "for blob objects, run textconv on object's content", 'c'),
+		OPT_SET_INT(0, "batch", &batch,
+			    "show info and content of objects fed from the standard input",
+			    BATCH),
+		OPT_SET_INT(0, "batch-check", &batch,
+			    "show info about objects fed from the standard input",
+			    BATCH_CHECK),
+		OPT_END()
+	};
+
+	git_config(git_cat_file_config, NULL);
+
+	if (argc != 3 && argc != 2)
+		usage_with_options(cat_file_usage, options);
+
+	argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
+
+	if (opt) {
+		if (argc == 1)
+			obj_name = argv[0];
+		else
+			usage_with_options(cat_file_usage, options);
+	}
+	if (!opt && !batch) {
+		if (argc == 2) {
+			exp_type = argv[0];
+			obj_name = argv[1];
+		} else
+			usage_with_options(cat_file_usage, options);
+	}
+	if (batch && (opt || argc)) {
+		usage_with_options(cat_file_usage, options);
+	}
+
+	if (batch)
+		return batch_objects(batch);
+
+	return cat_one_file(opt, exp_type, obj_name);
+}
diff --git a/builtin/check-attr.c b/builtin/check-attr.c
new file mode 100644
index 0000000..abb1165
--- /dev/null
+++ b/builtin/check-attr.c
@@ -0,0 +1,170 @@
+#include "builtin.h"
+#include "cache.h"
+#include "attr.h"
+#include "quote.h"
+#include "parse-options.h"
+
+static int all_attrs;
+static int stdin_paths;
+static const char * const check_attr_usage[] = {
+"git check-attr [-a | --all | attr...] [--] pathname...",
+"git check-attr --stdin [-a | --all | attr...] < <list-of-paths>",
+NULL
+};
+
+static int null_term_line;
+
+static const struct option check_attr_options[] = {
+	OPT_BOOLEAN('a', "all", &all_attrs, "report all attributes set on file"),
+	OPT_BOOLEAN(0 , "stdin", &stdin_paths, "read file names from stdin"),
+	OPT_BOOLEAN('z', NULL, &null_term_line,
+		"input paths are terminated by a null character"),
+	OPT_END()
+};
+
+static void output_attr(int cnt, struct git_attr_check *check,
+	const char *file)
+{
+	int j;
+	for (j = 0; j < cnt; j++) {
+		const char *value = check[j].value;
+
+		if (ATTR_TRUE(value))
+			value = "set";
+		else if (ATTR_FALSE(value))
+			value = "unset";
+		else if (ATTR_UNSET(value))
+			value = "unspecified";
+
+		quote_c_style(file, NULL, stdout, 0);
+		printf(": %s: %s\n", git_attr_name(check[j].attr), value);
+	}
+}
+
+static void check_attr(const char *prefix, int cnt,
+	struct git_attr_check *check, const char *file)
+{
+	char *full_path =
+		prefix_path(prefix, prefix ? strlen(prefix) : 0, file);
+	if (check != NULL) {
+		if (git_check_attr(full_path, cnt, check))
+			die("git_check_attr died");
+		output_attr(cnt, check, file);
+	} else {
+		if (git_all_attrs(full_path, &cnt, &check))
+			die("git_all_attrs died");
+		output_attr(cnt, check, file);
+		free(check);
+	}
+	free(full_path);
+}
+
+static void check_attr_stdin_paths(const char *prefix, int cnt,
+	struct git_attr_check *check)
+{
+	struct strbuf buf, nbuf;
+	int line_termination = null_term_line ? 0 : '\n';
+
+	strbuf_init(&buf, 0);
+	strbuf_init(&nbuf, 0);
+	while (strbuf_getline(&buf, stdin, line_termination) != EOF) {
+		if (line_termination && buf.buf[0] == '"') {
+			strbuf_reset(&nbuf);
+			if (unquote_c_style(&nbuf, buf.buf, NULL))
+				die("line is badly quoted");
+			strbuf_swap(&buf, &nbuf);
+		}
+		check_attr(prefix, cnt, check, buf.buf);
+		maybe_flush_or_die(stdout, "attribute to stdout");
+	}
+	strbuf_release(&buf);
+	strbuf_release(&nbuf);
+}
+
+static NORETURN void error_with_usage(const char *msg)
+{
+	error("%s", msg);
+	usage_with_options(check_attr_usage, check_attr_options);
+}
+
+int cmd_check_attr(int argc, const char **argv, const char *prefix)
+{
+	struct git_attr_check *check;
+	int cnt, i, doubledash, filei;
+
+	git_config(git_default_config, NULL);
+
+	argc = parse_options(argc, argv, prefix, check_attr_options,
+			     check_attr_usage, PARSE_OPT_KEEP_DASHDASH);
+
+	if (read_cache() < 0) {
+		die("invalid cache");
+	}
+
+	doubledash = -1;
+	for (i = 0; doubledash < 0 && i < argc; i++) {
+		if (!strcmp(argv[i], "--"))
+			doubledash = i;
+	}
+
+	/* Process --all and/or attribute arguments: */
+	if (all_attrs) {
+		if (doubledash >= 1)
+			error_with_usage("Attributes and --all both specified");
+
+		cnt = 0;
+		filei = doubledash + 1;
+	} else if (doubledash == 0) {
+		error_with_usage("No attribute specified");
+	} else if (doubledash < 0) {
+		if (!argc)
+			error_with_usage("No attribute specified");
+
+		if (stdin_paths) {
+			/* Treat all arguments as attribute names. */
+			cnt = argc;
+			filei = argc;
+		} else {
+			/* Treat exactly one argument as an attribute name. */
+			cnt = 1;
+			filei = 1;
+		}
+	} else {
+		cnt = doubledash;
+		filei = doubledash + 1;
+	}
+
+	/* Check file argument(s): */
+	if (stdin_paths) {
+		if (filei < argc)
+			error_with_usage("Can't specify files with --stdin");
+	} else {
+		if (filei >= argc)
+			error_with_usage("No file specified");
+	}
+
+	if (all_attrs) {
+		check = NULL;
+	} else {
+		check = xcalloc(cnt, sizeof(*check));
+		for (i = 0; i < cnt; i++) {
+			const char *name;
+			struct git_attr *a;
+			name = argv[i];
+			a = git_attr(name);
+			if (!a)
+				return error("%s: not a valid attribute name",
+					name);
+			check[i].attr = a;
+		}
+	}
+
+	if (stdin_paths)
+		check_attr_stdin_paths(prefix, cnt, check);
+	else {
+		for (i = filei; i < argc; i++)
+			check_attr(prefix, cnt, check, argv[i]);
+		maybe_flush_or_die(stdout, "attribute to stdout");
+	}
+	return 0;
+}
diff --git a/builtin/check-ref-format.c b/builtin/check-ref-format.c
new file mode 100644
index 0000000..0723cf2
--- /dev/null
+++ b/builtin/check-ref-format.c
@@ -0,0 +1,71 @@
+/*
+ * GIT - The information manager from hell
+ */
+
+#include "cache.h"
+#include "refs.h"
+#include "builtin.h"
+#include "strbuf.h"
+
+static const char builtin_check_ref_format_usage[] =
+"git check-ref-format [--print] <refname>\n"
+"   or: git check-ref-format --branch <branchname-shorthand>";
+
+/*
+ * Remove leading slashes and replace each run of adjacent slashes in
+ * src with a single slash, and write the result to dst.
+ *
+ * This function is similar to normalize_path_copy(), but stripped down
+ * to meet check_ref_format's simpler needs.
+ */
+static void collapse_slashes(char *dst, const char *src)
+{
+	char ch;
+	char prev = '/';
+
+	while ((ch = *src++) != '\0') {
+		if (prev == '/' && ch == prev)
+			continue;
+
+		*dst++ = ch;
+		prev = ch;
+	}
+	*dst = '\0';
+}
+
+static int check_ref_format_branch(const char *arg)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int nongit;
+
+	setup_git_directory_gently(&nongit);
+	if (strbuf_check_branch_ref(&sb, arg))
+		die("'%s' is not a valid branch name", arg);
+	printf("%s\n", sb.buf + 11);
+	return 0;
+}
+
+static int check_ref_format_print(const char *arg)
+{
+	char *refname = xmalloc(strlen(arg) + 1);
+
+	if (check_ref_format(arg))
+		return 1;
+	collapse_slashes(refname, arg);
+	printf("%s\n", refname);
+	return 0;
+}
+
+int cmd_check_ref_format(int argc, const char **argv, const char *prefix)
+{
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage(builtin_check_ref_format_usage);
+
+	if (argc == 3 && !strcmp(argv[1], "--branch"))
+		return check_ref_format_branch(argv[2]);
+	if (argc == 3 && !strcmp(argv[1], "--print"))
+		return check_ref_format_print(argv[2]);
+	if (argc != 2)
+		usage(builtin_check_ref_format_usage);
+	return !!check_ref_format(argv[1]);
+}
diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
new file mode 100644
index 0000000..c16d82b
--- /dev/null
+++ b/builtin/checkout-index.c
@@ -0,0 +1,286 @@
+/*
+ * Check-out files from the "current cache directory"
+ *
+ * Copyright (C) 2005 Linus Torvalds
+ *
+ */
+#include "builtin.h"
+#include "cache.h"
+#include "quote.h"
+#include "cache-tree.h"
+#include "parse-options.h"
+
+#define CHECKOUT_ALL 4
+static int line_termination = '\n';
+static int checkout_stage; /* default to checkout stage0 */
+static int to_tempfile;
+static char topath[4][PATH_MAX + 1];
+
+static struct checkout state;
+
+static void write_tempfile_record(const char *name, int prefix_length)
+{
+	int i;
+
+	if (CHECKOUT_ALL == checkout_stage) {
+		for (i = 1; i < 4; i++) {
+			if (i > 1)
+				putchar(' ');
+			if (topath[i][0])
+				fputs(topath[i], stdout);
+			else
+				putchar('.');
+		}
+	} else
+		fputs(topath[checkout_stage], stdout);
+
+	putchar('\t');
+	write_name_quoted(name + prefix_length, stdout, line_termination);
+
+	for (i = 0; i < 4; i++) {
+		topath[i][0] = 0;
+	}
+}
+
+static int checkout_file(const char *name, int prefix_length)
+{
+	int namelen = strlen(name);
+	int pos = cache_name_pos(name, namelen);
+	int has_same_name = 0;
+	int did_checkout = 0;
+	int errs = 0;
+
+	if (pos < 0)
+		pos = -pos - 1;
+
+	while (pos < active_nr) {
+		struct cache_entry *ce = active_cache[pos];
+		if (ce_namelen(ce) != namelen ||
+		    memcmp(ce->name, name, namelen))
+			break;
+		has_same_name = 1;
+		pos++;
+		if (ce_stage(ce) != checkout_stage
+		    && (CHECKOUT_ALL != checkout_stage || !ce_stage(ce)))
+			continue;
+		did_checkout = 1;
+		if (checkout_entry(ce, &state,
+		    to_tempfile ? topath[ce_stage(ce)] : NULL) < 0)
+			errs++;
+	}
+
+	if (did_checkout) {
+		if (to_tempfile)
+			write_tempfile_record(name, prefix_length);
+		return errs > 0 ? -1 : 0;
+	}
+
+	if (!state.quiet) {
+		fprintf(stderr, "git checkout-index: %s ", name);
+		if (!has_same_name)
+			fprintf(stderr, "is not in the cache");
+		else if (checkout_stage)
+			fprintf(stderr, "does not exist at stage %d",
+				checkout_stage);
+		else
+			fprintf(stderr, "is unmerged");
+		fputc('\n', stderr);
+	}
+	return -1;
+}
+
+static void checkout_all(const char *prefix, int prefix_length)
+{
+	int i, errs = 0;
+	struct cache_entry *last_ce = NULL;
+
+	for (i = 0; i < active_nr ; i++) {
+		struct cache_entry *ce = active_cache[i];
+		if (ce_stage(ce) != checkout_stage
+		    && (CHECKOUT_ALL != checkout_stage || !ce_stage(ce)))
+			continue;
+		if (prefix && *prefix &&
+		    (ce_namelen(ce) <= prefix_length ||
+		     memcmp(prefix, ce->name, prefix_length)))
+			continue;
+		if (last_ce && to_tempfile) {
+			if (ce_namelen(last_ce) != ce_namelen(ce)
+			    || memcmp(last_ce->name, ce->name, ce_namelen(ce)))
+				write_tempfile_record(last_ce->name, prefix_length);
+		}
+		if (checkout_entry(ce, &state,
+		    to_tempfile ? topath[ce_stage(ce)] : NULL) < 0)
+			errs++;
+		last_ce = ce;
+	}
+	if (last_ce && to_tempfile)
+		write_tempfile_record(last_ce->name, prefix_length);
+	if (errs)
+		/* we have already done our error reporting.
+		 * exit with the same code as die().
+		 */
+		exit(128);
+}
+
+static const char * const builtin_checkout_index_usage[] = {
+	"git checkout-index [options] [--] [<file>...]",
+	NULL
+};
+
+static struct lock_file lock_file;
+
+static int option_parse_u(const struct option *opt,
+			      const char *arg, int unset)
+{
+	int *newfd = opt->value;
+
+	state.refresh_cache = 1;
+	if (*newfd < 0)
+		*newfd = hold_locked_index(&lock_file, 1);
+	return 0;
+}
+
+static int option_parse_z(const struct option *opt,
+			  const char *arg, int unset)
+{
+	if (unset)
+		line_termination = '\n';
+	else
+		line_termination = 0;
+	return 0;
+}
+
+static int option_parse_prefix(const struct option *opt,
+			       const char *arg, int unset)
+{
+	state.base_dir = arg;
+	state.base_dir_len = strlen(arg);
+	return 0;
+}
+
+static int option_parse_stage(const struct option *opt,
+			      const char *arg, int unset)
+{
+	if (!strcmp(arg, "all")) {
+		to_tempfile = 1;
+		checkout_stage = CHECKOUT_ALL;
+	} else {
+		int ch = arg[0];
+		if ('1' <= ch && ch <= '3')
+			checkout_stage = arg[0] - '0';
+		else
+			die("stage should be between 1 and 3 or all");
+	}
+	return 0;
+}
+
+int cmd_checkout_index(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	int newfd = -1;
+	int all = 0;
+	int read_from_stdin = 0;
+	int prefix_length;
+	int force = 0, quiet = 0, not_new = 0;
+	struct option builtin_checkout_index_options[] = {
+		OPT_BOOLEAN('a', "all", &all,
+			"checks out all files in the index"),
+		OPT__FORCE(&force, "forces overwrite of existing files"),
+		OPT__QUIET(&quiet,
+			"no warning for existing files and files not in index"),
+		OPT_BOOLEAN('n', "no-create", &not_new,
+			"don't checkout new files"),
+		{ OPTION_CALLBACK, 'u', "index", &newfd, NULL,
+			"update stat information in the index file",
+			PARSE_OPT_NOARG, option_parse_u },
+		{ OPTION_CALLBACK, 'z', NULL, NULL, NULL,
+			"paths are separated with NUL character",
+			PARSE_OPT_NOARG, option_parse_z },
+		OPT_BOOLEAN(0, "stdin", &read_from_stdin,
+			"read list of paths from the standard input"),
+		OPT_BOOLEAN(0, "temp", &to_tempfile,
+			"write the content to temporary files"),
+		OPT_CALLBACK(0, "prefix", NULL, "string",
+			"when creating files, prepend <string>",
+			option_parse_prefix),
+		OPT_CALLBACK(0, "stage", NULL, NULL,
+			"copy out the files from named stage",
+			option_parse_stage),
+		OPT_END()
+	};
+
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(builtin_checkout_index_usage,
+				   builtin_checkout_index_options);
+	git_config(git_default_config, NULL);
+	state.base_dir = "";
+	prefix_length = prefix ? strlen(prefix) : 0;
+
+	if (read_cache() < 0) {
+		die("invalid cache");
+	}
+
+	argc = parse_options(argc, argv, prefix, builtin_checkout_index_options,
+			builtin_checkout_index_usage, 0);
+	state.force = force;
+	state.quiet = quiet;
+	state.not_new = not_new;
+
+	if (state.base_dir_len || to_tempfile) {
+		/* when --prefix is specified we do not
+		 * want to update cache.
+		 */
+		if (state.refresh_cache) {
+			rollback_lock_file(&lock_file);
+			newfd = -1;
+		}
+		state.refresh_cache = 0;
+	}
+
+	/* Check out named files first */
+	for (i = 0; i < argc; i++) {
+		const char *arg = argv[i];
+		const char *p;
+
+		if (all)
+			die("git checkout-index: don't mix '--all' and explicit filenames");
+		if (read_from_stdin)
+			die("git checkout-index: don't mix '--stdin' and explicit filenames");
+		p = prefix_path(prefix, prefix_length, arg);
+		checkout_file(p, prefix_length);
+		if (p < arg || p > arg + strlen(arg))
+			free((char *)p);
+	}
+
+	if (read_from_stdin) {
+		struct strbuf buf = STRBUF_INIT, nbuf = STRBUF_INIT;
+
+		if (all)
+			die("git checkout-index: don't mix '--all' and '--stdin'");
+
+		while (strbuf_getline(&buf, stdin, line_termination) != EOF) {
+			const char *p;
+			if (line_termination && buf.buf[0] == '"') {
+				strbuf_reset(&nbuf);
+				if (unquote_c_style(&nbuf, buf.buf, NULL))
+					die("line is badly quoted");
+				strbuf_swap(&buf, &nbuf);
+			}
+			p = prefix_path(prefix, prefix_length, buf.buf);
+			checkout_file(p, prefix_length);
+			if (p < buf.buf || p > buf.buf + buf.len)
+				free((char *)p);
+		}
+		strbuf_release(&nbuf);
+		strbuf_release(&buf);
+	}
+
+	if (all)
+		checkout_all(prefix, prefix_length);
+
+	if (0 <= newfd &&
+	    (write_cache(newfd, active_cache, active_nr) ||
+	     commit_locked_index(&lock_file)))
+		die("Unable to write new index file");
+	return 0;
+}
diff --git a/builtin/checkout.c b/builtin/checkout.c
new file mode 100644
index 0000000..a7a493c
--- /dev/null
+++ b/builtin/checkout.c
@@ -0,0 +1,1082 @@
+#include "cache.h"
+#include "builtin.h"
+#include "parse-options.h"
+#include "refs.h"
+#include "commit.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "cache-tree.h"
+#include "unpack-trees.h"
+#include "dir.h"
+#include "run-command.h"
+#include "merge-recursive.h"
+#include "branch.h"
+#include "diff.h"
+#include "revision.h"
+#include "remote.h"
+#include "blob.h"
+#include "xdiff-interface.h"
+#include "ll-merge.h"
+#include "resolve-undo.h"
+#include "submodule.h"
+#include "argv-array.h"
+
+static const char * const checkout_usage[] = {
+	"git checkout [options] <branch>",
+	"git checkout [options] [<branch>] -- <file>...",
+	NULL,
+};
+
+struct checkout_opts {
+	int quiet;
+	int merge;
+	int force;
+	int force_detach;
+	int writeout_stage;
+	int writeout_error;
+
+	/* not set by parse_options */
+	int branch_exists;
+
+	const char *new_branch;
+	const char *new_branch_force;
+	const char *new_orphan_branch;
+	int new_branch_log;
+	enum branch_track track;
+	struct diff_options diff_options;
+};
+
+static int post_checkout_hook(struct commit *old, struct commit *new,
+			      int changed)
+{
+	return run_hook(NULL, "post-checkout",
+			sha1_to_hex(old ? old->object.sha1 : null_sha1),
+			sha1_to_hex(new ? new->object.sha1 : null_sha1),
+			changed ? "1" : "0", NULL);
+	/* "new" can be NULL when checking out from the index before
+	   a commit exists. */
+
+}
+
+static int update_some(const unsigned char *sha1, const char *base, int baselen,
+		const char *pathname, unsigned mode, int stage, void *context)
+{
+	int len;
+	struct cache_entry *ce;
+
+	if (S_ISDIR(mode))
+		return READ_TREE_RECURSIVE;
+
+	len = baselen + strlen(pathname);
+	ce = xcalloc(1, cache_entry_size(len));
+	hashcpy(ce->sha1, sha1);
+	memcpy(ce->name, base, baselen);
+	memcpy(ce->name + baselen, pathname, len - baselen);
+	ce->ce_flags = create_ce_flags(len, 0) | CE_UPDATE;
+	ce->ce_mode = create_ce_mode(mode);
+	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
+	return 0;
+}
+
+static int read_tree_some(struct tree *tree, const char **pathspec)
+{
+	struct pathspec ps;
+	init_pathspec(&ps, pathspec);
+	read_tree_recursive(tree, "", 0, 0, &ps, update_some, NULL);
+	free_pathspec(&ps);
+
+	/* update the index with the given tree's info
+	 * for all args, expanding wildcards, and exit
+	 * with any non-zero return code.
+	 */
+	return 0;
+}
+
+static int skip_same_name(struct cache_entry *ce, int pos)
+{
+	while (++pos < active_nr &&
+	       !strcmp(active_cache[pos]->name, ce->name))
+		; /* skip */
+	return pos;
+}
+
+static int check_stage(int stage, struct cache_entry *ce, int pos)
+{
+	while (pos < active_nr &&
+	       !strcmp(active_cache[pos]->name, ce->name)) {
+		if (ce_stage(active_cache[pos]) == stage)
+			return 0;
+		pos++;
+	}
+	if (stage == 2)
+		return error(_("path '%s' does not have our version"), ce->name);
+	else
+		return error(_("path '%s' does not have their version"), ce->name);
+}
+
+static int check_all_stages(struct cache_entry *ce, int pos)
+{
+	if (ce_stage(ce) != 1 ||
+	    active_nr <= pos + 2 ||
+	    strcmp(active_cache[pos+1]->name, ce->name) ||
+	    ce_stage(active_cache[pos+1]) != 2 ||
+	    strcmp(active_cache[pos+2]->name, ce->name) ||
+	    ce_stage(active_cache[pos+2]) != 3)
+		return error(_("path '%s' does not have all three versions"),
+			     ce->name);
+	return 0;
+}
+
+static int checkout_stage(int stage, struct cache_entry *ce, int pos,
+			  struct checkout *state)
+{
+	while (pos < active_nr &&
+	       !strcmp(active_cache[pos]->name, ce->name)) {
+		if (ce_stage(active_cache[pos]) == stage)
+			return checkout_entry(active_cache[pos], state, NULL);
+		pos++;
+	}
+	if (stage == 2)
+		return error(_("path '%s' does not have our version"), ce->name);
+	else
+		return error(_("path '%s' does not have their version"), ce->name);
+}
+
+static int checkout_merged(int pos, struct checkout *state)
+{
+	struct cache_entry *ce = active_cache[pos];
+	const char *path = ce->name;
+	mmfile_t ancestor, ours, theirs;
+	int status;
+	unsigned char sha1[20];
+	mmbuffer_t result_buf;
+
+	if (ce_stage(ce) != 1 ||
+	    active_nr <= pos + 2 ||
+	    strcmp(active_cache[pos+1]->name, path) ||
+	    ce_stage(active_cache[pos+1]) != 2 ||
+	    strcmp(active_cache[pos+2]->name, path) ||
+	    ce_stage(active_cache[pos+2]) != 3)
+		return error(_("path '%s' does not have all 3 versions"), path);
+
+	read_mmblob(&ancestor, active_cache[pos]->sha1);
+	read_mmblob(&ours, active_cache[pos+1]->sha1);
+	read_mmblob(&theirs, active_cache[pos+2]->sha1);
+
+	/*
+	 * NEEDSWORK: re-create conflicts from merges with
+	 * merge.renormalize set, too
+	 */
+	status = ll_merge(&result_buf, path, &ancestor, "base",
+			  &ours, "ours", &theirs, "theirs", NULL);
+	free(ancestor.ptr);
+	free(ours.ptr);
+	free(theirs.ptr);
+	if (status < 0 || !result_buf.ptr) {
+		free(result_buf.ptr);
+		return error(_("path '%s': cannot merge"), path);
+	}
+
+	/*
+	 * NEEDSWORK:
+	 * There is absolutely no reason to write this as a blob object
+	 * and create a phony cache entry just to leak.  This hack is
+	 * primarily to get to the write_entry() machinery that massages
+	 * the contents to work-tree format and writes out which only
+	 * allows it for a cache entry.  The code in write_entry() needs
+	 * to be refactored to allow us to feed a <buffer, size, mode>
+	 * instead of a cache entry.  Such a refactoring would help
+	 * merge_recursive as well (it also writes the merge result to the
+	 * object database even when it may contain conflicts).
+	 */
+	if (write_sha1_file(result_buf.ptr, result_buf.size,
+			    blob_type, sha1))
+		die(_("Unable to add merge result for '%s'"), path);
+	ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
+			      sha1,
+			      path, 2, 0);
+	if (!ce)
+		die(_("make_cache_entry failed for path '%s'"), path);
+	status = checkout_entry(ce, state, NULL);
+	return status;
+}
+
+static int checkout_paths(struct tree *source_tree, const char **pathspec,
+			  const char *prefix, struct checkout_opts *opts)
+{
+	int pos;
+	struct checkout state;
+	static char *ps_matched;
+	unsigned char rev[20];
+	int flag;
+	struct commit *head;
+	int errs = 0;
+	int stage = opts->writeout_stage;
+	int merge = opts->merge;
+	int newfd;
+	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+
+	newfd = hold_locked_index(lock_file, 1);
+	if (read_cache_preload(pathspec) < 0)
+		return error(_("corrupt index file"));
+
+	if (source_tree)
+		read_tree_some(source_tree, pathspec);
+
+	for (pos = 0; pathspec[pos]; pos++)
+		;
+	ps_matched = xcalloc(1, pos);
+
+	for (pos = 0; pos < active_nr; pos++) {
+		struct cache_entry *ce = active_cache[pos];
+		if (source_tree && !(ce->ce_flags & CE_UPDATE))
+			continue;
+		match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
+	}
+
+	if (report_path_error(ps_matched, pathspec, prefix))
+		return 1;
+
+	/* "checkout -m path" to recreate conflicted state */
+	if (opts->merge)
+		unmerge_cache(pathspec);
+
+	/* Any unmerged paths? */
+	for (pos = 0; pos < active_nr; pos++) {
+		struct cache_entry *ce = active_cache[pos];
+		if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
+			if (!ce_stage(ce))
+				continue;
+			if (opts->force) {
+				warning(_("path '%s' is unmerged"), ce->name);
+			} else if (stage) {
+				errs |= check_stage(stage, ce, pos);
+			} else if (opts->merge) {
+				errs |= check_all_stages(ce, pos);
+			} else {
+				errs = 1;
+				error(_("path '%s' is unmerged"), ce->name);
+			}
+			pos = skip_same_name(ce, pos) - 1;
+		}
+	}
+	if (errs)
+		return 1;
+
+	/* Now we are committed to check them out */
+	memset(&state, 0, sizeof(state));
+	state.force = 1;
+	state.refresh_cache = 1;
+	for (pos = 0; pos < active_nr; pos++) {
+		struct cache_entry *ce = active_cache[pos];
+		if (source_tree && !(ce->ce_flags & CE_UPDATE))
+			continue;
+		if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
+			if (!ce_stage(ce)) {
+				errs |= checkout_entry(ce, &state, NULL);
+				continue;
+			}
+			if (stage)
+				errs |= checkout_stage(stage, ce, pos, &state);
+			else if (merge)
+				errs |= checkout_merged(pos, &state);
+			pos = skip_same_name(ce, pos) - 1;
+		}
+	}
+
+	if (write_cache(newfd, active_cache, active_nr) ||
+	    commit_locked_index(lock_file))
+		die(_("unable to write new index file"));
+
+	resolve_ref("HEAD", rev, 0, &flag);
+	head = lookup_commit_reference_gently(rev, 1);
+
+	errs |= post_checkout_hook(head, head, 0);
+	return errs;
+}
+
+static void show_local_changes(struct object *head, struct diff_options *opts)
+{
+	struct rev_info rev;
+	/* I think we want full paths, even if we're in a subdirectory. */
+	init_revisions(&rev, NULL);
+	rev.diffopt.flags = opts->flags;
+	rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
+	if (diff_setup_done(&rev.diffopt) < 0)
+		die(_("diff_setup_done failed"));
+	add_pending_object(&rev, head, NULL);
+	run_diff_index(&rev, 0);
+}
+
+static void describe_detached_head(const char *msg, struct commit *commit)
+{
+	struct strbuf sb = STRBUF_INIT;
+	parse_commit(commit);
+	pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
+	fprintf(stderr, "%s %s... %s\n", msg,
+		find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
+	strbuf_release(&sb);
+}
+
+static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
+{
+	struct unpack_trees_options opts;
+	struct tree_desc tree_desc;
+
+	memset(&opts, 0, sizeof(opts));
+	opts.head_idx = -1;
+	opts.update = worktree;
+	opts.skip_unmerged = !worktree;
+	opts.reset = 1;
+	opts.merge = 1;
+	opts.fn = oneway_merge;
+	opts.verbose_update = !o->quiet;
+	opts.src_index = &the_index;
+	opts.dst_index = &the_index;
+	parse_tree(tree);
+	init_tree_desc(&tree_desc, tree->buffer, tree->size);
+	switch (unpack_trees(1, &tree_desc, &opts)) {
+	case -2:
+		o->writeout_error = 1;
+		/*
+		 * We return 0 nevertheless, as the index is all right
+		 * and more importantly we have made best efforts to
+		 * update paths in the work tree, and we cannot revert
+		 * them.
+		 */
+	case 0:
+		return 0;
+	default:
+		return 128;
+	}
+}
+
+struct branch_info {
+	const char *name; /* The short name used */
+	const char *path; /* The full name of a real branch */
+	struct commit *commit; /* The named commit */
+};
+
+static void setup_branch_path(struct branch_info *branch)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	strbuf_branchname(&buf, branch->name);
+	if (strcmp(buf.buf, branch->name))
+		branch->name = xstrdup(buf.buf);
+	strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
+	branch->path = strbuf_detach(&buf, NULL);
+}
+
+static int merge_working_tree(struct checkout_opts *opts,
+			      struct branch_info *old, struct branch_info *new)
+{
+	int ret;
+	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+	int newfd = hold_locked_index(lock_file, 1);
+
+	if (read_cache_preload(NULL) < 0)
+		return error(_("corrupt index file"));
+
+	resolve_undo_clear();
+	if (opts->force) {
+		ret = reset_tree(new->commit->tree, opts, 1);
+		if (ret)
+			return ret;
+	} else {
+		struct tree_desc trees[2];
+		struct tree *tree;
+		struct unpack_trees_options topts;
+
+		memset(&topts, 0, sizeof(topts));
+		topts.head_idx = -1;
+		topts.src_index = &the_index;
+		topts.dst_index = &the_index;
+
+		setup_unpack_trees_porcelain(&topts, "checkout");
+
+		refresh_cache(REFRESH_QUIET);
+
+		if (unmerged_cache()) {
+			error(_("you need to resolve your current index first"));
+			return 1;
+		}
+
+		/* 2-way merge to the new branch */
+		topts.initial_checkout = is_cache_unborn();
+		topts.update = 1;
+		topts.merge = 1;
+		topts.gently = opts->merge && old->commit;
+		topts.verbose_update = !opts->quiet;
+		topts.fn = twoway_merge;
+		topts.dir = xcalloc(1, sizeof(*topts.dir));
+		topts.dir->flags |= DIR_SHOW_IGNORED;
+		topts.dir->exclude_per_dir = ".gitignore";
+		tree = parse_tree_indirect(old->commit ?
+					   old->commit->object.sha1 :
+					   EMPTY_TREE_SHA1_BIN);
+		init_tree_desc(&trees[0], tree->buffer, tree->size);
+		tree = parse_tree_indirect(new->commit->object.sha1);
+		init_tree_desc(&trees[1], tree->buffer, tree->size);
+
+		ret = unpack_trees(2, trees, &topts);
+		if (ret == -1) {
+			/*
+			 * Unpack couldn't do a trivial merge; either
+			 * give up or do a real merge, depending on
+			 * whether the merge flag was used.
+			 */
+			struct tree *result;
+			struct tree *work;
+			struct merge_options o;
+			if (!opts->merge)
+				return 1;
+
+			/*
+			 * Without old->commit, the below is the same as
+			 * the two-tree unpack we already tried and failed.
+			 */
+			if (!old->commit)
+				return 1;
+
+			/* Do more real merge */
+
+			/*
+			 * We update the index fully, then write the
+			 * tree from the index, then merge the new
+			 * branch with the current tree, with the old
+			 * branch as the base. Then we reset the index
+			 * (but not the working tree) to the new
+			 * branch, leaving the working tree as the
+			 * merged version, but skipping unmerged
+			 * entries in the index.
+			 */
+
+			add_files_to_cache(NULL, NULL, 0);
+			/*
+			 * NEEDSWORK: carrying over local changes
+			 * when branches have different end-of-line
+			 * normalization (or clean+smudge rules) is
+			 * a pain; plumb in an option to set
+			 * o.renormalize?
+			 */
+			init_merge_options(&o);
+			o.verbosity = 0;
+			work = write_tree_from_memory(&o);
+
+			ret = reset_tree(new->commit->tree, opts, 1);
+			if (ret)
+				return ret;
+			o.ancestor = old->name;
+			o.branch1 = new->name;
+			o.branch2 = "local";
+			merge_trees(&o, new->commit->tree, work,
+				old->commit->tree, &result);
+			ret = reset_tree(new->commit->tree, opts, 0);
+			if (ret)
+				return ret;
+		}
+	}
+
+	if (write_cache(newfd, active_cache, active_nr) ||
+	    commit_locked_index(lock_file))
+		die(_("unable to write new index file"));
+
+	if (!opts->force && !opts->quiet)
+		show_local_changes(&new->commit->object, &opts->diff_options);
+
+	return 0;
+}
+
+static void report_tracking(struct branch_info *new)
+{
+	struct strbuf sb = STRBUF_INIT;
+	struct branch *branch = branch_get(new->name);
+
+	if (!format_tracking_info(branch, &sb))
+		return;
+	fputs(sb.buf, stdout);
+	strbuf_release(&sb);
+}
+
+static void detach_advice(const char *old_path, const char *new_name)
+{
+	const char fmt[] =
+	"Note: checking out '%s'.\n\n"
+	"You are in 'detached HEAD' state. You can look around, make experimental\n"
+	"changes and commit them, and you can discard any commits you make in this\n"
+	"state without impacting any branches by performing another checkout.\n\n"
+	"If you want to create a new branch to retain commits you create, you may\n"
+	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
+	"  git checkout -b new_branch_name\n\n";
+
+	fprintf(stderr, fmt, new_name);
+}
+
+static void update_refs_for_switch(struct checkout_opts *opts,
+				   struct branch_info *old,
+				   struct branch_info *new)
+{
+	struct strbuf msg = STRBUF_INIT;
+	const char *old_desc;
+	if (opts->new_branch) {
+		if (opts->new_orphan_branch) {
+			if (opts->new_branch_log && !log_all_ref_updates) {
+				int temp;
+				char log_file[PATH_MAX];
+				char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
+
+				temp = log_all_ref_updates;
+				log_all_ref_updates = 1;
+				if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
+					fprintf(stderr, _("Can not do reflog for '%s'\n"),
+					    opts->new_orphan_branch);
+					log_all_ref_updates = temp;
+					return;
+				}
+				log_all_ref_updates = temp;
+			}
+		}
+		else
+			create_branch(old->name, opts->new_branch, new->name,
+				      opts->new_branch_force ? 1 : 0,
+				      opts->new_branch_log, opts->track);
+		new->name = opts->new_branch;
+		setup_branch_path(new);
+	}
+
+	old_desc = old->name;
+	if (!old_desc && old->commit)
+		old_desc = sha1_to_hex(old->commit->object.sha1);
+	strbuf_addf(&msg, "checkout: moving from %s to %s",
+		    old_desc ? old_desc : "(invalid)", new->name);
+
+	if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
+		/* Nothing to do. */
+	} else if (opts->force_detach || !new->path) {	/* No longer on any branch. */
+		update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
+			   REF_NODEREF, DIE_ON_ERR);
+		if (!opts->quiet) {
+			if (old->path && advice_detached_head)
+				detach_advice(old->path, new->name);
+			describe_detached_head(_("HEAD is now at"), new->commit);
+		}
+	} else if (new->path) {	/* Switch branches. */
+		create_symref("HEAD", new->path, msg.buf);
+		if (!opts->quiet) {
+			if (old->path && !strcmp(new->path, old->path)) {
+				fprintf(stderr, _("Already on '%s'\n"),
+					new->name);
+			} else if (opts->new_branch) {
+				if (opts->branch_exists)
+					fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
+				else
+					fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
+			} else {
+				fprintf(stderr, _("Switched to branch '%s'\n"),
+					new->name);
+			}
+		}
+		if (old->path && old->name) {
+			char log_file[PATH_MAX], ref_file[PATH_MAX];
+
+			git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
+			git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
+			if (!file_exists(ref_file) && file_exists(log_file))
+				remove_path(log_file);
+		}
+	}
+	remove_branch_state();
+	strbuf_release(&msg);
+	if (!opts->quiet &&
+	    (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
+		report_tracking(new);
+}
+
+static int add_one_ref_to_rev_list_arg(const char *refname,
+				       const unsigned char *sha1,
+				       int flags,
+				       void *cb_data)
+{
+	argv_array_push(cb_data, refname);
+	return 0;
+}
+
+static int clear_commit_marks_from_one_ref(const char *refname,
+				      const unsigned char *sha1,
+				      int flags,
+				      void *cb_data)
+{
+	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+	if (commit)
+		clear_commit_marks(commit, -1);
+	return 0;
+}
+
+static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
+{
+	parse_commit(commit);
+	strbuf_addstr(sb, "  ");
+	strbuf_addstr(sb,
+		find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
+	strbuf_addch(sb, ' ');
+	pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
+	strbuf_addch(sb, '\n');
+}
+
+#define ORPHAN_CUTOFF 4
+static void suggest_reattach(struct commit *commit, struct rev_info *revs)
+{
+	struct commit *c, *last = NULL;
+	struct strbuf sb = STRBUF_INIT;
+	int lost = 0;
+	while ((c = get_revision(revs)) != NULL) {
+		if (lost < ORPHAN_CUTOFF)
+			describe_one_orphan(&sb, c);
+		last = c;
+		lost++;
+	}
+	if (ORPHAN_CUTOFF < lost) {
+		int more = lost - ORPHAN_CUTOFF;
+		if (more == 1)
+			describe_one_orphan(&sb, last);
+		else
+			strbuf_addf(&sb, _(" ... and %d more.\n"), more);
+	}
+
+	fprintf(stderr,
+		Q_(
+		/* The singular version */
+		"Warning: you are leaving %d commit behind, "
+		"not connected to\n"
+		"any of your branches:\n\n"
+		"%s\n",
+		/* The plural version */
+		"Warning: you are leaving %d commits behind, "
+		"not connected to\n"
+		"any of your branches:\n\n"
+		"%s\n",
+		/* Give ngettext() the count */
+		lost),
+		lost,
+		sb.buf);
+	strbuf_release(&sb);
+
+	if (advice_detached_head)
+		fprintf(stderr,
+			_(
+			"If you want to keep them by creating a new branch, "
+			"this may be a good time\nto do so with:\n\n"
+			" git branch new_branch_name %s\n\n"),
+			sha1_to_hex(commit->object.sha1));
+}
+
+/*
+ * We are about to leave commit that was at the tip of a detached
+ * HEAD.  If it is not reachable from any ref, this is the last chance
+ * for the user to do so without resorting to reflog.
+ */
+static void orphaned_commit_warning(struct commit *commit)
+{
+	struct argv_array args = ARGV_ARRAY_INIT;
+	struct rev_info revs;
+
+	argv_array_push(&args, "(internal)");
+	argv_array_push(&args, sha1_to_hex(commit->object.sha1));
+	argv_array_push(&args, "--not");
+	for_each_ref(add_one_ref_to_rev_list_arg, &args);
+	argv_array_push(&args, "--");
+
+	init_revisions(&revs, NULL);
+	if (setup_revisions(args.argc - 1, args.argv, &revs, NULL) != 1)
+		die(_("internal error: only -- alone should have been left"));
+	if (prepare_revision_walk(&revs))
+		die(_("internal error in revision walk"));
+	if (!(commit->object.flags & UNINTERESTING))
+		suggest_reattach(commit, &revs);
+	else
+		describe_detached_head(_("Previous HEAD position was"), commit);
+
+	argv_array_clear(&args);
+	clear_commit_marks(commit, -1);
+	for_each_ref(clear_commit_marks_from_one_ref, NULL);
+}
+
+static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
+{
+	int ret = 0;
+	struct branch_info old;
+	unsigned char rev[20];
+	int flag;
+	memset(&old, 0, sizeof(old));
+	old.path = xstrdup(resolve_ref("HEAD", rev, 0, &flag));
+	old.commit = lookup_commit_reference_gently(rev, 1);
+	if (!(flag & REF_ISSYMREF)) {
+		free((char *)old.path);
+		old.path = NULL;
+	}
+
+	if (old.path && !prefixcmp(old.path, "refs/heads/"))
+		old.name = old.path + strlen("refs/heads/");
+
+	if (!new->name) {
+		new->name = "HEAD";
+		new->commit = old.commit;
+		if (!new->commit)
+			die(_("You are on a branch yet to be born"));
+		parse_commit(new->commit);
+	}
+
+	ret = merge_working_tree(opts, &old, new);
+	if (ret)
+		return ret;
+
+	if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
+		orphaned_commit_warning(old.commit);
+
+	update_refs_for_switch(opts, &old, new);
+
+	ret = post_checkout_hook(old.commit, new->commit, 1);
+	free((char *)old.path);
+	return ret || opts->writeout_error;
+}
+
+static int git_checkout_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "diff.ignoresubmodules")) {
+		struct checkout_opts *opts = cb;
+		handle_ignore_submodules_arg(&opts->diff_options, value);
+		return 0;
+	}
+
+	if (!prefixcmp(var, "submodule."))
+		return parse_submodule_config_option(var, value);
+
+	return git_xmerge_config(var, value, NULL);
+}
+
+static int interactive_checkout(const char *revision, const char **pathspec,
+				struct checkout_opts *opts)
+{
+	return run_add_interactive(revision, "--patch=checkout", pathspec);
+}
+
+struct tracking_name_data {
+	const char *name;
+	char *remote;
+	int unique;
+};
+
+static int check_tracking_name(const char *refname, const unsigned char *sha1,
+			       int flags, void *cb_data)
+{
+	struct tracking_name_data *cb = cb_data;
+	const char *slash;
+
+	if (prefixcmp(refname, "refs/remotes/"))
+		return 0;
+	slash = strchr(refname + 13, '/');
+	if (!slash || strcmp(slash + 1, cb->name))
+		return 0;
+	if (cb->remote) {
+		cb->unique = 0;
+		return 0;
+	}
+	cb->remote = xstrdup(refname);
+	return 0;
+}
+
+static const char *unique_tracking_name(const char *name)
+{
+	struct tracking_name_data cb_data = { NULL, NULL, 1 };
+	cb_data.name = name;
+	for_each_ref(check_tracking_name, &cb_data);
+	if (cb_data.unique)
+		return cb_data.remote;
+	free(cb_data.remote);
+	return NULL;
+}
+
+static int parse_branchname_arg(int argc, const char **argv,
+				int dwim_new_local_branch_ok,
+				struct branch_info *new,
+				struct tree **source_tree,
+				unsigned char rev[20],
+				const char **new_branch)
+{
+	int argcount = 0;
+	unsigned char branch_rev[20];
+	const char *arg;
+	int has_dash_dash;
+
+	/*
+	 * case 1: git checkout <ref> -- [<paths>]
+	 *
+	 *   <ref> must be a valid tree, everything after the '--' must be
+	 *   a path.
+	 *
+	 * case 2: git checkout -- [<paths>]
+	 *
+	 *   everything after the '--' must be paths.
+	 *
+	 * case 3: git checkout <something> [<paths>]
+	 *
+	 *   With no paths, if <something> is a commit, that is to
+	 *   switch to the branch or detach HEAD at it.  As a special case,
+	 *   if <something> is A...B (missing A or B means HEAD but you can
+	 *   omit at most one side), and if there is a unique merge base
+	 *   between A and B, A...B names that merge base.
+	 *
+	 *   With no paths, if <something> is _not_ a commit, no -t nor -b
+	 *   was given, and there is a tracking branch whose name is
+	 *   <something> in one and only one remote, then this is a short-hand
+	 *   to fork local <something> from that remote-tracking branch.
+	 *
+	 *   Otherwise <something> shall not be ambiguous.
+	 *   - If it's *only* a reference, treat it like case (1).
+	 *   - If it's only a path, treat it like case (2).
+	 *   - else: fail.
+	 *
+	 */
+	if (!argc)
+		return 0;
+
+	if (!strcmp(argv[0], "--"))	/* case (2) */
+		return 1;
+
+	arg = argv[0];
+	has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
+
+	if (!strcmp(arg, "-"))
+		arg = "@{-1}";
+
+	if (get_sha1_mb(arg, rev)) {
+		if (has_dash_dash)          /* case (1) */
+			die(_("invalid reference: %s"), arg);
+		if (dwim_new_local_branch_ok &&
+		    !check_filename(NULL, arg) &&
+		    argc == 1) {
+			const char *remote = unique_tracking_name(arg);
+			if (!remote || get_sha1(remote, rev))
+				return argcount;
+			*new_branch = arg;
+			arg = remote;
+			/* DWIMmed to create local branch */
+		} else {
+			return argcount;
+		}
+	}
+
+	/* we can't end up being in (2) anymore, eat the argument */
+	argcount++;
+	argv++;
+	argc--;
+
+	new->name = arg;
+	setup_branch_path(new);
+
+	if (check_ref_format(new->path) == CHECK_REF_FORMAT_OK &&
+	    resolve_ref(new->path, branch_rev, 1, NULL))
+		hashcpy(rev, branch_rev);
+	else
+		new->path = NULL; /* not an existing branch */
+
+	new->commit = lookup_commit_reference_gently(rev, 1);
+	if (!new->commit) {
+		/* not a commit */
+		*source_tree = parse_tree_indirect(rev);
+	} else {
+		parse_commit(new->commit);
+		*source_tree = new->commit->tree;
+	}
+
+	if (!*source_tree)                   /* case (1): want a tree */
+		die(_("reference is not a tree: %s"), arg);
+	if (!has_dash_dash) {/* case (3 -> 1) */
+		/*
+		 * Do not complain the most common case
+		 *	git checkout branch
+		 * even if there happen to be a file called 'branch';
+		 * it would be extremely annoying.
+		 */
+		if (argc)
+			verify_non_filename(NULL, arg);
+	} else {
+		argcount++;
+		argv++;
+		argc--;
+	}
+
+	return argcount;
+}
+
+int cmd_checkout(int argc, const char **argv, const char *prefix)
+{
+	struct checkout_opts opts;
+	unsigned char rev[20];
+	struct branch_info new;
+	struct tree *source_tree = NULL;
+	char *conflict_style = NULL;
+	int patch_mode = 0;
+	int dwim_new_local_branch = 1;
+	struct option options[] = {
+		OPT__QUIET(&opts.quiet, "suppress progress reporting"),
+		OPT_STRING('b', NULL, &opts.new_branch, "branch",
+			   "create and checkout a new branch"),
+		OPT_STRING('B', NULL, &opts.new_branch_force, "branch",
+			   "create/reset and checkout a branch"),
+		OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "create reflog for new branch"),
+		OPT_BOOLEAN(0, "detach", &opts.force_detach, "detach the HEAD at named commit"),
+		OPT_SET_INT('t', "track",  &opts.track, "set upstream info for new branch",
+			BRANCH_TRACK_EXPLICIT),
+		OPT_STRING(0, "orphan", &opts.new_orphan_branch, "new branch", "new unparented branch"),
+		OPT_SET_INT('2', "ours", &opts.writeout_stage, "checkout our version for unmerged files",
+			    2),
+		OPT_SET_INT('3', "theirs", &opts.writeout_stage, "checkout their version for unmerged files",
+			    3),
+		OPT__FORCE(&opts.force, "force checkout (throw away local modifications)"),
+		OPT_BOOLEAN('m', "merge", &opts.merge, "perform a 3-way merge with the new branch"),
+		OPT_STRING(0, "conflict", &conflict_style, "style",
+			   "conflict style (merge or diff3)"),
+		OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
+		{ OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
+		  "second guess 'git checkout no-such-branch'",
+		  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
+		OPT_END(),
+	};
+
+	memset(&opts, 0, sizeof(opts));
+	memset(&new, 0, sizeof(new));
+
+	gitmodules_config();
+	git_config(git_checkout_config, &opts);
+
+	opts.track = BRANCH_TRACK_UNSPECIFIED;
+
+	argc = parse_options(argc, argv, prefix, options, checkout_usage,
+			     PARSE_OPT_KEEP_DASHDASH);
+
+	/* we can assume from now on new_branch = !new_branch_force */
+	if (opts.new_branch && opts.new_branch_force)
+		die(_("-B cannot be used with -b"));
+
+	/* copy -B over to -b, so that we can just check the latter */
+	if (opts.new_branch_force)
+		opts.new_branch = opts.new_branch_force;
+
+	if (patch_mode && (opts.track > 0 || opts.new_branch
+			   || opts.new_branch_log || opts.merge || opts.force
+			   || opts.force_detach))
+		die (_("--patch is incompatible with all other options"));
+
+	if (opts.force_detach && (opts.new_branch || opts.new_orphan_branch))
+		die(_("--detach cannot be used with -b/-B/--orphan"));
+	if (opts.force_detach && 0 < opts.track)
+		die(_("--detach cannot be used with -t"));
+
+	/* --track without -b should DWIM */
+	if (0 < opts.track && !opts.new_branch) {
+		const char *argv0 = argv[0];
+		if (!argc || !strcmp(argv0, "--"))
+			die (_("--track needs a branch name"));
+		if (!prefixcmp(argv0, "refs/"))
+			argv0 += 5;
+		if (!prefixcmp(argv0, "remotes/"))
+			argv0 += 8;
+		argv0 = strchr(argv0, '/');
+		if (!argv0 || !argv0[1])
+			die (_("Missing branch name; try -b"));
+		opts.new_branch = argv0 + 1;
+	}
+
+	if (opts.new_orphan_branch) {
+		if (opts.new_branch)
+			die(_("--orphan and -b|-B are mutually exclusive"));
+		if (opts.track > 0)
+			die(_("--orphan cannot be used with -t"));
+		opts.new_branch = opts.new_orphan_branch;
+	}
+
+	if (conflict_style) {
+		opts.merge = 1; /* implied */
+		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
+	}
+
+	if (opts.force && opts.merge)
+		die(_("git checkout: -f and -m are incompatible"));
+
+	/*
+	 * Extract branch name from command line arguments, so
+	 * all that is left is pathspecs.
+	 *
+	 * Handle
+	 *
+	 *  1) git checkout <tree> -- [<paths>]
+	 *  2) git checkout -- [<paths>]
+	 *  3) git checkout <something> [<paths>]
+	 *
+	 * including "last branch" syntax and DWIM-ery for names of
+	 * remote branches, erroring out for invalid or ambiguous cases.
+	 */
+	if (argc) {
+		int dwim_ok =
+			!patch_mode &&
+			dwim_new_local_branch &&
+			opts.track == BRANCH_TRACK_UNSPECIFIED &&
+			!opts.new_branch;
+		int n = parse_branchname_arg(argc, argv, dwim_ok,
+				&new, &source_tree, rev, &opts.new_branch);
+		argv += n;
+		argc -= n;
+	}
+
+	if (opts.track == BRANCH_TRACK_UNSPECIFIED)
+		opts.track = git_branch_track;
+
+	if (argc) {
+		const char **pathspec = get_pathspec(prefix, argv);
+
+		if (!pathspec)
+			die(_("invalid path specification"));
+
+		if (patch_mode)
+			return interactive_checkout(new.name, pathspec, &opts);
+
+		/* Checkout paths */
+		if (opts.new_branch) {
+			if (argc == 1) {
+				die(_("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?"), argv[0]);
+			} else {
+				die(_("git checkout: updating paths is incompatible with switching branches."));
+			}
+		}
+
+		if (opts.force_detach)
+			die(_("git checkout: --detach does not take a path argument"));
+
+		if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
+			die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index."));
+
+		return checkout_paths(source_tree, pathspec, prefix, &opts);
+	}
+
+	if (patch_mode)
+		return interactive_checkout(new.name, NULL, &opts);
+
+	if (opts.new_branch) {
+		struct strbuf buf = STRBUF_INIT;
+
+		opts.branch_exists = validate_new_branchname(opts.new_branch, &buf,
+							     !!opts.new_branch_force, 0);
+
+		strbuf_release(&buf);
+	}
+
+	if (new.name && !new.commit) {
+		die(_("Cannot switch branch to a non-commit."));
+	}
+	if (opts.writeout_stage)
+		die(_("--ours/--theirs is incompatible with switching branches."));
+
+	return switch_branches(&opts, &new);
+}
diff --git a/builtin/clean.c b/builtin/clean.c
new file mode 100644
index 0000000..0c7b3d0
--- /dev/null
+++ b/builtin/clean.c
@@ -0,0 +1,192 @@
+/*
+ * "git clean" builtin command
+ *
+ * Copyright (C) 2007 Shawn Bohrer
+ *
+ * Based on git-clean.sh by Pavel Roskin
+ */
+
+#include "builtin.h"
+#include "cache.h"
+#include "dir.h"
+#include "parse-options.h"
+#include "string-list.h"
+#include "quote.h"
+
+static int force = -1; /* unset */
+
+static const char *const builtin_clean_usage[] = {
+	"git clean [-d] [-f] [-n] [-q] [-e <pattern>] [-x | -X] [--] <paths>...",
+	NULL
+};
+
+static int git_clean_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "clean.requireforce"))
+		force = !git_config_bool(var, value);
+	return git_default_config(var, value, cb);
+}
+
+static int exclude_cb(const struct option *opt, const char *arg, int unset)
+{
+	struct string_list *exclude_list = opt->value;
+	string_list_append(exclude_list, arg);
+	return 0;
+}
+
+int cmd_clean(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	int show_only = 0, remove_directories = 0, quiet = 0, ignored = 0;
+	int ignored_only = 0, config_set = 0, errors = 0;
+	int rm_flags = REMOVE_DIR_KEEP_NESTED_GIT;
+	struct strbuf directory = STRBUF_INIT;
+	struct dir_struct dir;
+	static const char **pathspec;
+	struct strbuf buf = STRBUF_INIT;
+	struct string_list exclude_list = STRING_LIST_INIT_NODUP;
+	const char *qname;
+	char *seen = NULL;
+	struct option options[] = {
+		OPT__QUIET(&quiet, "do not print names of files removed"),
+		OPT__DRY_RUN(&show_only, "dry run"),
+		OPT__FORCE(&force, "force"),
+		OPT_BOOLEAN('d', NULL, &remove_directories,
+				"remove whole directories"),
+		{ OPTION_CALLBACK, 'e', "exclude", &exclude_list, "pattern",
+		  "add <pattern> to ignore rules", PARSE_OPT_NONEG, exclude_cb },
+		OPT_BOOLEAN('x', NULL, &ignored, "remove ignored files, too"),
+		OPT_BOOLEAN('X', NULL, &ignored_only,
+				"remove only ignored files"),
+		OPT_END()
+	};
+
+	git_config(git_clean_config, NULL);
+	if (force < 0)
+		force = 0;
+	else
+		config_set = 1;
+
+	argc = parse_options(argc, argv, prefix, options, builtin_clean_usage,
+			     0);
+
+	memset(&dir, 0, sizeof(dir));
+	if (ignored_only)
+		dir.flags |= DIR_SHOW_IGNORED;
+
+	if (ignored && ignored_only)
+		die(_("-x and -X cannot be used together"));
+
+	if (!show_only && !force) {
+		if (config_set)
+			die(_("clean.requireForce set to true and neither -n nor -f given; "
+				  "refusing to clean"));
+		else
+			die(_("clean.requireForce defaults to true and neither -n nor -f given; "
+				  "refusing to clean"));
+	}
+
+	if (force > 1)
+		rm_flags = 0;
+
+	dir.flags |= DIR_SHOW_OTHER_DIRECTORIES;
+
+	if (read_cache() < 0)
+		die(_("index file corrupt"));
+
+	if (!ignored)
+		setup_standard_excludes(&dir);
+
+	for (i = 0; i < exclude_list.nr; i++)
+		add_exclude(exclude_list.items[i].string, "", 0,
+			    &dir.exclude_list[EXC_CMDL]);
+
+	pathspec = get_pathspec(prefix, argv);
+
+	fill_directory(&dir, pathspec);
+
+	if (pathspec)
+		seen = xmalloc(argc > 0 ? argc : 1);
+
+	for (i = 0; i < dir.nr; i++) {
+		struct dir_entry *ent = dir.entries[i];
+		int len, pos;
+		int matches = 0;
+		struct cache_entry *ce;
+		struct stat st;
+
+		/*
+		 * Remove the '/' at the end that directory
+		 * walking adds for directory entries.
+		 */
+		len = ent->len;
+		if (len && ent->name[len-1] == '/')
+			len--;
+		pos = cache_name_pos(ent->name, len);
+		if (0 <= pos)
+			continue;	/* exact match */
+		pos = -pos - 1;
+		if (pos < active_nr) {
+			ce = active_cache[pos];
+			if (ce_namelen(ce) == len &&
+			    !memcmp(ce->name, ent->name, len))
+				continue; /* Yup, this one exists unmerged */
+		}
+
+		/*
+		 * we might have removed this as part of earlier
+		 * recursive directory removal, so lstat() here could
+		 * fail with ENOENT.
+		 */
+		if (lstat(ent->name, &st))
+			continue;
+
+		if (pathspec) {
+			memset(seen, 0, argc > 0 ? argc : 1);
+			matches = match_pathspec(pathspec, ent->name, len,
+						 0, seen);
+		}
+
+		if (S_ISDIR(st.st_mode)) {
+			strbuf_addstr(&directory, ent->name);
+			qname = quote_path_relative(directory.buf, directory.len, &buf, prefix);
+			if (show_only && (remove_directories ||
+			    (matches == MATCHED_EXACTLY))) {
+				printf(_("Would remove %s\n"), qname);
+			} else if (remove_directories ||
+				   (matches == MATCHED_EXACTLY)) {
+				if (!quiet)
+					printf(_("Removing %s\n"), qname);
+				if (remove_dir_recursively(&directory,
+							   rm_flags) != 0) {
+					warning(_("failed to remove %s"), qname);
+					errors++;
+				}
+			} else if (show_only) {
+				printf(_("Would not remove %s\n"), qname);
+			} else {
+				printf(_("Not removing %s\n"), qname);
+			}
+			strbuf_reset(&directory);
+		} else {
+			if (pathspec && !matches)
+				continue;
+			qname = quote_path_relative(ent->name, -1, &buf, prefix);
+			if (show_only) {
+				printf(_("Would remove %s\n"), qname);
+				continue;
+			} else if (!quiet) {
+				printf(_("Removing %s\n"), qname);
+			}
+			if (unlink(ent->name) != 0) {
+				warning(_("failed to remove %s"), qname);
+				errors++;
+			}
+		}
+	}
+	free(seen);
+
+	strbuf_release(&directory);
+	string_list_clear(&exclude_list, 0);
+	return (errors != 0);
+}
diff --git a/builtin/clone.c b/builtin/clone.c
new file mode 100644
index 0000000..efe8b6c
--- /dev/null
+++ b/builtin/clone.c
@@ -0,0 +1,785 @@
+/*
+ * Builtin "git clone"
+ *
+ * Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>,
+ *		 2008 Daniel Barkalow <barkalow@iabervon.org>
+ * Based on git-commit.sh by Junio C Hamano and Linus Torvalds
+ *
+ * Clone a repository into a different directory that does not yet exist.
+ */
+
+#include "builtin.h"
+#include "parse-options.h"
+#include "fetch-pack.h"
+#include "refs.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "unpack-trees.h"
+#include "transport.h"
+#include "strbuf.h"
+#include "dir.h"
+#include "pack-refs.h"
+#include "sigchain.h"
+#include "branch.h"
+#include "remote.h"
+#include "run-command.h"
+
+/*
+ * Overall FIXMEs:
+ *  - respect DB_ENVIRONMENT for .git/objects.
+ *
+ * Implementation notes:
+ *  - dropping use-separate-remote and no-separate-remote compatibility
+ *
+ */
+static const char * const builtin_clone_usage[] = {
+	"git clone [options] [--] <repo> [<dir>]",
+	NULL
+};
+
+static int option_no_checkout, option_bare, option_mirror;
+static int option_local, option_no_hardlinks, option_shared, option_recursive;
+static char *option_template, *option_depth;
+static char *option_origin = NULL;
+static char *option_branch = NULL;
+static const char *real_git_dir;
+static char *option_upload_pack = "git-upload-pack";
+static int option_verbosity;
+static int option_progress;
+static struct string_list option_config;
+static struct string_list option_reference;
+
+static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
+{
+	struct string_list *option_reference = opt->value;
+	if (!arg)
+		return -1;
+	string_list_append(option_reference, arg);
+	return 0;
+}
+
+static struct option builtin_clone_options[] = {
+	OPT__VERBOSITY(&option_verbosity),
+	OPT_BOOLEAN(0, "progress", &option_progress,
+			"force progress reporting"),
+	OPT_BOOLEAN('n', "no-checkout", &option_no_checkout,
+		    "don't create a checkout"),
+	OPT_BOOLEAN(0, "bare", &option_bare, "create a bare repository"),
+	{ OPTION_BOOLEAN, 0, "naked", &option_bare, NULL,
+		"create a bare repository",
+		PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
+	OPT_BOOLEAN(0, "mirror", &option_mirror,
+		    "create a mirror repository (implies bare)"),
+	OPT_BOOLEAN('l', "local", &option_local,
+		    "to clone from a local repository"),
+	OPT_BOOLEAN(0, "no-hardlinks", &option_no_hardlinks,
+		    "don't use local hardlinks, always copy"),
+	OPT_BOOLEAN('s', "shared", &option_shared,
+		    "setup as shared repository"),
+	OPT_BOOLEAN(0, "recursive", &option_recursive,
+		    "initialize submodules in the clone"),
+	OPT_BOOLEAN(0, "recurse-submodules", &option_recursive,
+		    "initialize submodules in the clone"),
+	OPT_STRING(0, "template", &option_template, "template-directory",
+		   "directory from which templates will be used"),
+	OPT_CALLBACK(0 , "reference", &option_reference, "repo",
+		     "reference repository", &opt_parse_reference),
+	OPT_STRING('o', "origin", &option_origin, "branch",
+		   "use <branch> instead of 'origin' to track upstream"),
+	OPT_STRING('b', "branch", &option_branch, "branch",
+		   "checkout <branch> instead of the remote's HEAD"),
+	OPT_STRING('u', "upload-pack", &option_upload_pack, "path",
+		   "path to git-upload-pack on the remote"),
+	OPT_STRING(0, "depth", &option_depth, "depth",
+		    "create a shallow clone of that depth"),
+	OPT_STRING(0, "separate-git-dir", &real_git_dir, "gitdir",
+		   "separate git dir from working tree"),
+	OPT_STRING_LIST('c', "config", &option_config, "key=value",
+			"set config inside the new repository"),
+	OPT_END()
+};
+
+static const char *argv_submodule[] = {
+	"submodule", "update", "--init", "--recursive", NULL
+};
+
+static char *get_repo_path(const char *repo, int *is_bundle)
+{
+	static char *suffix[] = { "/.git", ".git", "" };
+	static char *bundle_suffix[] = { ".bundle", "" };
+	struct stat st;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(suffix); i++) {
+		const char *path;
+		path = mkpath("%s%s", repo, suffix[i]);
+		if (stat(path, &st))
+			continue;
+		if (S_ISDIR(st.st_mode)) {
+			*is_bundle = 0;
+			return xstrdup(absolute_path(path));
+		} else if (S_ISREG(st.st_mode) && st.st_size > 8) {
+			/* Is it a "gitfile"? */
+			char signature[8];
+			int len, fd = open(path, O_RDONLY);
+			if (fd < 0)
+				continue;
+			len = read_in_full(fd, signature, 8);
+			close(fd);
+			if (len != 8 || strncmp(signature, "gitdir: ", 8))
+				continue;
+			path = read_gitfile(path);
+			if (path) {
+				*is_bundle = 0;
+				return xstrdup(absolute_path(path));
+			}
+		}
+	}
+
+	for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
+		const char *path;
+		path = mkpath("%s%s", repo, bundle_suffix[i]);
+		if (!stat(path, &st) && S_ISREG(st.st_mode)) {
+			*is_bundle = 1;
+			return xstrdup(absolute_path(path));
+		}
+	}
+
+	return NULL;
+}
+
+static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
+{
+	const char *end = repo + strlen(repo), *start;
+	char *dir;
+
+	/*
+	 * Strip trailing spaces, slashes and /.git
+	 */
+	while (repo < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
+		end--;
+	if (end - repo > 5 && is_dir_sep(end[-5]) &&
+	    !strncmp(end - 4, ".git", 4)) {
+		end -= 5;
+		while (repo < end && is_dir_sep(end[-1]))
+			end--;
+	}
+
+	/*
+	 * Find last component, but be prepared that repo could have
+	 * the form  "remote.example.com:foo.git", i.e. no slash
+	 * in the directory part.
+	 */
+	start = end;
+	while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
+		start--;
+
+	/*
+	 * Strip .{bundle,git}.
+	 */
+	if (is_bundle) {
+		if (end - start > 7 && !strncmp(end - 7, ".bundle", 7))
+			end -= 7;
+	} else {
+		if (end - start > 4 && !strncmp(end - 4, ".git", 4))
+			end -= 4;
+	}
+
+	if (is_bare) {
+		struct strbuf result = STRBUF_INIT;
+		strbuf_addf(&result, "%.*s.git", (int)(end - start), start);
+		dir = strbuf_detach(&result, NULL);
+	} else
+		dir = xstrndup(start, end - start);
+	/*
+	 * Replace sequences of 'control' characters and whitespace
+	 * with one ascii space, remove leading and trailing spaces.
+	 */
+	if (*dir) {
+		char *out = dir;
+		int prev_space = 1 /* strip leading whitespace */;
+		for (end = dir; *end; ++end) {
+			char ch = *end;
+			if ((unsigned char)ch < '\x20')
+				ch = '\x20';
+			if (isspace(ch)) {
+				if (prev_space)
+					continue;
+				prev_space = 1;
+			} else
+				prev_space = 0;
+			*out++ = ch;
+		}
+		*out = '\0';
+		if (out > dir && prev_space)
+			out[-1] = '\0';
+	}
+	return dir;
+}
+
+static void strip_trailing_slashes(char *dir)
+{
+	char *end = dir + strlen(dir);
+
+	while (dir < end - 1 && is_dir_sep(end[-1]))
+		end--;
+	*end = '\0';
+}
+
+static int add_one_reference(struct string_list_item *item, void *cb_data)
+{
+	char *ref_git;
+	struct strbuf alternate = STRBUF_INIT;
+	struct remote *remote;
+	struct transport *transport;
+	const struct ref *extra;
+
+	/* Beware: real_path() and mkpath() return static buffer */
+	ref_git = xstrdup(real_path(item->string));
+	if (is_directory(mkpath("%s/.git/objects", ref_git))) {
+		char *ref_git_git = xstrdup(mkpath("%s/.git", ref_git));
+		free(ref_git);
+		ref_git = ref_git_git;
+	} else if (!is_directory(mkpath("%s/objects", ref_git)))
+		die(_("reference repository '%s' is not a local directory."),
+		    item->string);
+
+	strbuf_addf(&alternate, "%s/objects", ref_git);
+	add_to_alternates_file(alternate.buf);
+	strbuf_release(&alternate);
+
+	remote = remote_get(ref_git);
+	transport = transport_get(remote, ref_git);
+	for (extra = transport_get_remote_refs(transport); extra;
+	     extra = extra->next)
+		add_extra_ref(extra->name, extra->old_sha1, 0);
+
+	transport_disconnect(transport);
+	free(ref_git);
+	return 0;
+}
+
+static void setup_reference(void)
+{
+	for_each_string_list(&option_reference, add_one_reference, NULL);
+}
+
+static void copy_alternates(struct strbuf *src, struct strbuf *dst,
+			    const char *src_repo)
+{
+	/*
+	 * Read from the source objects/info/alternates file
+	 * and copy the entries to corresponding file in the
+	 * destination repository with add_to_alternates_file().
+	 * Both src and dst have "$path/objects/info/alternates".
+	 *
+	 * Instead of copying bit-for-bit from the original,
+	 * we need to append to existing one so that the already
+	 * created entry via "clone -s" is not lost, and also
+	 * to turn entries with paths relative to the original
+	 * absolute, so that they can be used in the new repository.
+	 */
+	FILE *in = fopen(src->buf, "r");
+	struct strbuf line = STRBUF_INIT;
+
+	while (strbuf_getline(&line, in, '\n') != EOF) {
+		char *abs_path, abs_buf[PATH_MAX];
+		if (!line.len || line.buf[0] == '#')
+			continue;
+		if (is_absolute_path(line.buf)) {
+			add_to_alternates_file(line.buf);
+			continue;
+		}
+		abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
+		normalize_path_copy(abs_buf, abs_path);
+		add_to_alternates_file(abs_buf);
+	}
+	strbuf_release(&line);
+	fclose(in);
+}
+
+static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
+				   const char *src_repo, int src_baselen)
+{
+	struct dirent *de;
+	struct stat buf;
+	int src_len, dest_len;
+	DIR *dir;
+
+	dir = opendir(src->buf);
+	if (!dir)
+		die_errno(_("failed to open '%s'"), src->buf);
+
+	if (mkdir(dest->buf, 0777)) {
+		if (errno != EEXIST)
+			die_errno(_("failed to create directory '%s'"), dest->buf);
+		else if (stat(dest->buf, &buf))
+			die_errno(_("failed to stat '%s'"), dest->buf);
+		else if (!S_ISDIR(buf.st_mode))
+			die(_("%s exists and is not a directory"), dest->buf);
+	}
+
+	strbuf_addch(src, '/');
+	src_len = src->len;
+	strbuf_addch(dest, '/');
+	dest_len = dest->len;
+
+	while ((de = readdir(dir)) != NULL) {
+		strbuf_setlen(src, src_len);
+		strbuf_addstr(src, de->d_name);
+		strbuf_setlen(dest, dest_len);
+		strbuf_addstr(dest, de->d_name);
+		if (stat(src->buf, &buf)) {
+			warning (_("failed to stat %s\n"), src->buf);
+			continue;
+		}
+		if (S_ISDIR(buf.st_mode)) {
+			if (de->d_name[0] != '.')
+				copy_or_link_directory(src, dest,
+						       src_repo, src_baselen);
+			continue;
+		}
+
+		/* Files that cannot be copied bit-for-bit... */
+		if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
+			copy_alternates(src, dest, src_repo);
+			continue;
+		}
+
+		if (unlink(dest->buf) && errno != ENOENT)
+			die_errno(_("failed to unlink '%s'"), dest->buf);
+		if (!option_no_hardlinks) {
+			if (!link(src->buf, dest->buf))
+				continue;
+			if (option_local)
+				die_errno(_("failed to create link '%s'"), dest->buf);
+			option_no_hardlinks = 1;
+		}
+		if (copy_file_with_time(dest->buf, src->buf, 0666))
+			die_errno(_("failed to copy file to '%s'"), dest->buf);
+	}
+	closedir(dir);
+}
+
+static const struct ref *clone_local(const char *src_repo,
+				     const char *dest_repo)
+{
+	const struct ref *ret;
+	struct remote *remote;
+	struct transport *transport;
+
+	if (option_shared) {
+		struct strbuf alt = STRBUF_INIT;
+		strbuf_addf(&alt, "%s/objects", src_repo);
+		add_to_alternates_file(alt.buf);
+		strbuf_release(&alt);
+	} else {
+		struct strbuf src = STRBUF_INIT;
+		struct strbuf dest = STRBUF_INIT;
+		strbuf_addf(&src, "%s/objects", src_repo);
+		strbuf_addf(&dest, "%s/objects", dest_repo);
+		copy_or_link_directory(&src, &dest, src_repo, src.len);
+		strbuf_release(&src);
+		strbuf_release(&dest);
+	}
+
+	remote = remote_get(src_repo);
+	transport = transport_get(remote, src_repo);
+	ret = transport_get_remote_refs(transport);
+	transport_disconnect(transport);
+	if (0 <= option_verbosity)
+		printf(_("done.\n"));
+	return ret;
+}
+
+static const char *junk_work_tree;
+static const char *junk_git_dir;
+static pid_t junk_pid;
+
+static void remove_junk(void)
+{
+	struct strbuf sb = STRBUF_INIT;
+	if (getpid() != junk_pid)
+		return;
+	if (junk_git_dir) {
+		strbuf_addstr(&sb, junk_git_dir);
+		remove_dir_recursively(&sb, 0);
+		strbuf_reset(&sb);
+	}
+	if (junk_work_tree) {
+		strbuf_addstr(&sb, junk_work_tree);
+		remove_dir_recursively(&sb, 0);
+		strbuf_reset(&sb);
+	}
+}
+
+static void remove_junk_on_signal(int signo)
+{
+	remove_junk();
+	sigchain_pop(signo);
+	raise(signo);
+}
+
+static struct ref *wanted_peer_refs(const struct ref *refs,
+		struct refspec *refspec)
+{
+	struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
+	struct ref *local_refs = head;
+	struct ref **tail = head ? &head->next : &local_refs;
+
+	get_fetch_map(refs, refspec, &tail, 0);
+	if (!option_mirror)
+		get_fetch_map(refs, tag_refspec, &tail, 0);
+
+	return local_refs;
+}
+
+static void write_remote_refs(const struct ref *local_refs)
+{
+	const struct ref *r;
+
+	for (r = local_refs; r; r = r->next) {
+		if (!r->peer_ref)
+			continue;
+		add_extra_ref(r->peer_ref->name, r->old_sha1, 0);
+	}
+
+	pack_refs(PACK_REFS_ALL);
+	clear_extra_refs();
+}
+
+static int write_one_config(const char *key, const char *value, void *data)
+{
+	return git_config_set_multivar(key, value ? value : "true", "^$", 0);
+}
+
+static void write_config(struct string_list *config)
+{
+	int i;
+
+	for (i = 0; i < config->nr; i++) {
+		if (git_config_parse_parameter(config->items[i].string,
+					       write_one_config, NULL) < 0)
+			die("unable to write parameters to config file");
+	}
+}
+
+int cmd_clone(int argc, const char **argv, const char *prefix)
+{
+	int is_bundle = 0, is_local;
+	struct stat buf;
+	const char *repo_name, *repo, *work_tree, *git_dir;
+	char *path, *dir;
+	int dest_exists;
+	const struct ref *refs, *remote_head;
+	const struct ref *remote_head_points_at;
+	const struct ref *our_head_points_at;
+	struct ref *mapped_refs;
+	struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
+	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
+	struct transport *transport = NULL;
+	char *src_ref_prefix = "refs/heads/";
+	int err = 0;
+
+	struct refspec *refspec;
+	const char *fetch_pattern;
+
+	junk_pid = getpid();
+
+	packet_trace_identity("clone");
+	argc = parse_options(argc, argv, prefix, builtin_clone_options,
+			     builtin_clone_usage, 0);
+
+	if (argc > 2)
+		usage_msg_opt(_("Too many arguments."),
+			builtin_clone_usage, builtin_clone_options);
+
+	if (argc == 0)
+		usage_msg_opt(_("You must specify a repository to clone."),
+			builtin_clone_usage, builtin_clone_options);
+
+	if (option_mirror)
+		option_bare = 1;
+
+	if (option_bare) {
+		if (option_origin)
+			die(_("--bare and --origin %s options are incompatible."),
+			    option_origin);
+		option_no_checkout = 1;
+	}
+
+	if (!option_origin)
+		option_origin = "origin";
+
+	repo_name = argv[0];
+
+	path = get_repo_path(repo_name, &is_bundle);
+	if (path)
+		repo = xstrdup(absolute_path(repo_name));
+	else if (!strchr(repo_name, ':'))
+		die(_("repository '%s' does not exist"), repo_name);
+	else
+		repo = repo_name;
+	is_local = path && !is_bundle;
+	if (is_local && option_depth)
+		warning(_("--depth is ignored in local clones; use file:// instead."));
+
+	if (argc == 2)
+		dir = xstrdup(argv[1]);
+	else
+		dir = guess_dir_name(repo_name, is_bundle, option_bare);
+	strip_trailing_slashes(dir);
+
+	dest_exists = !stat(dir, &buf);
+	if (dest_exists && !is_empty_dir(dir))
+		die(_("destination path '%s' already exists and is not "
+			"an empty directory."), dir);
+
+	strbuf_addf(&reflog_msg, "clone: from %s", repo);
+
+	if (option_bare)
+		work_tree = NULL;
+	else {
+		work_tree = getenv("GIT_WORK_TREE");
+		if (work_tree && !stat(work_tree, &buf))
+			die(_("working tree '%s' already exists."), work_tree);
+	}
+
+	if (option_bare || work_tree)
+		git_dir = xstrdup(dir);
+	else {
+		work_tree = dir;
+		git_dir = xstrdup(mkpath("%s/.git", dir));
+	}
+
+	if (!option_bare) {
+		junk_work_tree = work_tree;
+		if (safe_create_leading_directories_const(work_tree) < 0)
+			die_errno(_("could not create leading directories of '%s'"),
+				  work_tree);
+		if (!dest_exists && mkdir(work_tree, 0755))
+			die_errno(_("could not create work tree dir '%s'."),
+				  work_tree);
+		set_git_work_tree(work_tree);
+	}
+	junk_git_dir = git_dir;
+	atexit(remove_junk);
+	sigchain_push_common(remove_junk_on_signal);
+
+	setenv(CONFIG_ENVIRONMENT, mkpath("%s/config", git_dir), 1);
+
+	if (safe_create_leading_directories_const(git_dir) < 0)
+		die(_("could not create leading directories of '%s'"), git_dir);
+
+	set_git_dir_init(git_dir, real_git_dir, 0);
+	if (real_git_dir)
+		git_dir = real_git_dir;
+
+	if (0 <= option_verbosity) {
+		if (option_bare)
+			printf(_("Cloning into bare repository '%s'...\n"), dir);
+		else
+			printf(_("Cloning into '%s'...\n"), dir);
+	}
+	init_db(option_template, INIT_DB_QUIET);
+	write_config(&option_config);
+
+	/*
+	 * At this point, the config exists, so we do not need the
+	 * environment variable.  We actually need to unset it, too, to
+	 * re-enable parsing of the global configs.
+	 */
+	unsetenv(CONFIG_ENVIRONMENT);
+
+	git_config(git_default_config, NULL);
+
+	if (option_bare) {
+		if (option_mirror)
+			src_ref_prefix = "refs/";
+		strbuf_addstr(&branch_top, src_ref_prefix);
+
+		git_config_set("core.bare", "true");
+	} else {
+		strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
+	}
+
+	strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
+
+	if (option_mirror || !option_bare) {
+		/* Configure the remote */
+		strbuf_addf(&key, "remote.%s.fetch", option_origin);
+		git_config_set_multivar(key.buf, value.buf, "^$", 0);
+		strbuf_reset(&key);
+
+		if (option_mirror) {
+			strbuf_addf(&key, "remote.%s.mirror", option_origin);
+			git_config_set(key.buf, "true");
+			strbuf_reset(&key);
+		}
+	}
+
+	strbuf_addf(&key, "remote.%s.url", option_origin);
+	git_config_set(key.buf, repo);
+	strbuf_reset(&key);
+
+	if (option_reference.nr)
+		setup_reference();
+
+	fetch_pattern = value.buf;
+	refspec = parse_fetch_refspec(1, &fetch_pattern);
+
+	strbuf_reset(&value);
+
+	if (is_local) {
+		refs = clone_local(path, git_dir);
+		mapped_refs = wanted_peer_refs(refs, refspec);
+	} else {
+		struct remote *remote = remote_get(option_origin);
+		transport = transport_get(remote, remote->url[0]);
+
+		if (!transport->get_refs_list || !transport->fetch)
+			die(_("Don't know how to clone %s"), transport->url);
+
+		transport_set_option(transport, TRANS_OPT_KEEP, "yes");
+
+		if (option_depth)
+			transport_set_option(transport, TRANS_OPT_DEPTH,
+					     option_depth);
+
+		transport_set_verbosity(transport, option_verbosity, option_progress);
+
+		if (option_upload_pack)
+			transport_set_option(transport, TRANS_OPT_UPLOADPACK,
+					     option_upload_pack);
+
+		refs = transport_get_remote_refs(transport);
+		if (refs) {
+			mapped_refs = wanted_peer_refs(refs, refspec);
+			transport_fetch_refs(transport, mapped_refs);
+		}
+	}
+
+	if (refs) {
+		clear_extra_refs();
+
+		write_remote_refs(mapped_refs);
+
+		remote_head = find_ref_by_name(refs, "HEAD");
+		remote_head_points_at =
+			guess_remote_head(remote_head, mapped_refs, 0);
+
+		if (option_branch) {
+			struct strbuf head = STRBUF_INIT;
+			strbuf_addstr(&head, src_ref_prefix);
+			strbuf_addstr(&head, option_branch);
+			our_head_points_at =
+				find_ref_by_name(mapped_refs, head.buf);
+			strbuf_release(&head);
+
+			if (!our_head_points_at) {
+				warning(_("Remote branch %s not found in "
+					"upstream %s, using HEAD instead"),
+					option_branch, option_origin);
+				our_head_points_at = remote_head_points_at;
+			}
+		}
+		else
+			our_head_points_at = remote_head_points_at;
+	}
+	else {
+		warning(_("You appear to have cloned an empty repository."));
+		our_head_points_at = NULL;
+		remote_head_points_at = NULL;
+		remote_head = NULL;
+		option_no_checkout = 1;
+		if (!option_bare)
+			install_branch_config(0, "master", option_origin,
+					      "refs/heads/master");
+	}
+
+	if (remote_head_points_at && !option_bare) {
+		struct strbuf head_ref = STRBUF_INIT;
+		strbuf_addstr(&head_ref, branch_top.buf);
+		strbuf_addstr(&head_ref, "HEAD");
+		create_symref(head_ref.buf,
+			      remote_head_points_at->peer_ref->name,
+			      reflog_msg.buf);
+	}
+
+	if (our_head_points_at) {
+		/* Local default branch link */
+		create_symref("HEAD", our_head_points_at->name, NULL);
+		if (!option_bare) {
+			const char *head = skip_prefix(our_head_points_at->name,
+						       "refs/heads/");
+			update_ref(reflog_msg.buf, "HEAD",
+				   our_head_points_at->old_sha1,
+				   NULL, 0, DIE_ON_ERR);
+			install_branch_config(0, head, option_origin,
+					      our_head_points_at->name);
+		}
+	} else if (remote_head) {
+		/* Source had detached HEAD pointing somewhere. */
+		if (!option_bare) {
+			update_ref(reflog_msg.buf, "HEAD",
+				   remote_head->old_sha1,
+				   NULL, REF_NODEREF, DIE_ON_ERR);
+			our_head_points_at = remote_head;
+		}
+	} else {
+		/* Nothing to checkout out */
+		if (!option_no_checkout)
+			warning(_("remote HEAD refers to nonexistent ref, "
+				"unable to checkout.\n"));
+		option_no_checkout = 1;
+	}
+
+	if (transport) {
+		transport_unlock_pack(transport);
+		transport_disconnect(transport);
+	}
+
+	if (!option_no_checkout) {
+		struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+		struct unpack_trees_options opts;
+		struct tree *tree;
+		struct tree_desc t;
+		int fd;
+
+		/* We need to be in the new work tree for the checkout */
+		setup_work_tree();
+
+		fd = hold_locked_index(lock_file, 1);
+
+		memset(&opts, 0, sizeof opts);
+		opts.update = 1;
+		opts.merge = 1;
+		opts.fn = oneway_merge;
+		opts.verbose_update = (option_verbosity > 0);
+		opts.src_index = &the_index;
+		opts.dst_index = &the_index;
+
+		tree = parse_tree_indirect(our_head_points_at->old_sha1);
+		parse_tree(tree);
+		init_tree_desc(&t, tree->buffer, tree->size);
+		unpack_trees(1, &t, &opts);
+
+		if (write_cache(fd, active_cache, active_nr) ||
+		    commit_locked_index(lock_file))
+			die(_("unable to write new index file"));
+
+		err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
+				sha1_to_hex(our_head_points_at->old_sha1), "1",
+				NULL);
+
+		if (!err && option_recursive)
+			err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
+	}
+
+	strbuf_release(&reflog_msg);
+	strbuf_release(&branch_top);
+	strbuf_release(&key);
+	strbuf_release(&value);
+	junk_pid = 0;
+	return err;
+}
diff --git a/builtin/commit-tree.c b/builtin/commit-tree.c
new file mode 100644
index 0000000..d083795
--- /dev/null
+++ b/builtin/commit-tree.c
@@ -0,0 +1,67 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+#include "cache.h"
+#include "commit.h"
+#include "tree.h"
+#include "builtin.h"
+#include "utf8.h"
+
+static const char commit_tree_usage[] = "git commit-tree <sha1> [(-p <sha1>)...] < changelog";
+
+static void new_parent(struct commit *parent, struct commit_list **parents_p)
+{
+	unsigned char *sha1 = parent->object.sha1;
+	struct commit_list *parents;
+	for (parents = *parents_p; parents; parents = parents->next) {
+		if (parents->item == parent) {
+			error("duplicate parent %s ignored", sha1_to_hex(sha1));
+			return;
+		}
+		parents_p = &parents->next;
+	}
+	commit_list_insert(parent, parents_p);
+}
+
+int cmd_commit_tree(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	struct commit_list *parents = NULL;
+	unsigned char tree_sha1[20];
+	unsigned char commit_sha1[20];
+	struct strbuf buffer = STRBUF_INIT;
+
+	git_config(git_default_config, NULL);
+
+	if (argc < 2 || !strcmp(argv[1], "-h"))
+		usage(commit_tree_usage);
+	if (get_sha1(argv[1], tree_sha1))
+		die("Not a valid object name %s", argv[1]);
+
+	for (i = 2; i < argc; i += 2) {
+		unsigned char sha1[20];
+		const char *a, *b;
+		a = argv[i]; b = argv[i+1];
+		if (!b || strcmp(a, "-p"))
+			usage(commit_tree_usage);
+
+		if (get_sha1(b, sha1))
+			die("Not a valid object name %s", b);
+		assert_sha1_type(sha1, OBJ_COMMIT);
+		new_parent(lookup_commit(sha1), &parents);
+	}
+
+	if (strbuf_read(&buffer, 0, 0) < 0)
+		die_errno("git commit-tree: failed to read");
+
+	if (commit_tree(buffer.buf, tree_sha1, parents, commit_sha1, NULL)) {
+		strbuf_release(&buffer);
+		return 1;
+	}
+
+	printf("%s\n", sha1_to_hex(commit_sha1));
+	strbuf_release(&buffer);
+	return 0;
+}
diff --git a/builtin/commit.c b/builtin/commit.c
new file mode 100644
index 0000000..66ffe31
--- /dev/null
+++ b/builtin/commit.c
@@ -0,0 +1,1542 @@
+/*
+ * Builtin "git commit"
+ *
+ * Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>
+ * Based on git-commit.sh by Junio C Hamano and Linus Torvalds
+ */
+
+#include "cache.h"
+#include "cache-tree.h"
+#include "color.h"
+#include "dir.h"
+#include "builtin.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "commit.h"
+#include "revision.h"
+#include "wt-status.h"
+#include "run-command.h"
+#include "refs.h"
+#include "log-tree.h"
+#include "strbuf.h"
+#include "utf8.h"
+#include "parse-options.h"
+#include "string-list.h"
+#include "rerere.h"
+#include "unpack-trees.h"
+#include "quote.h"
+#include "submodule.h"
+
+static const char * const builtin_commit_usage[] = {
+	"git commit [options] [--] <filepattern>...",
+	NULL
+};
+
+static const char * const builtin_status_usage[] = {
+	"git status [options] [--] <filepattern>...",
+	NULL
+};
+
+static const char implicit_ident_advice[] =
+N_("Your name and email address were configured automatically based\n"
+"on your username and hostname. Please check that they are accurate.\n"
+"You can suppress this message by setting them explicitly:\n"
+"\n"
+"    git config --global user.name \"Your Name\"\n"
+"    git config --global user.email you@example.com\n"
+"\n"
+"After doing this, you may fix the identity used for this commit with:\n"
+"\n"
+"    git commit --amend --reset-author\n");
+
+static const char empty_amend_advice[] =
+N_("You asked to amend the most recent commit, but doing so would make\n"
+"it empty. You can repeat your command with --allow-empty, or you can\n"
+"remove the commit entirely with \"git reset HEAD^\".\n");
+
+static const char empty_cherry_pick_advice[] =
+N_("The previous cherry-pick is now empty, possibly due to conflict resolution.\n"
+"If you wish to commit it anyway, use:\n"
+"\n"
+"    git commit --allow-empty\n"
+"\n"
+"Otherwise, please use 'git reset'\n");
+
+static const char *use_message_buffer;
+static const char commit_editmsg[] = "COMMIT_EDITMSG";
+static struct lock_file index_lock; /* real index */
+static struct lock_file false_lock; /* used only for partial commits */
+static enum {
+	COMMIT_AS_IS = 1,
+	COMMIT_NORMAL,
+	COMMIT_PARTIAL
+} commit_style;
+
+static const char *logfile, *force_author;
+static const char *template_file;
+/*
+ * The _message variables are commit names from which to take
+ * the commit message and/or authorship.
+ */
+static const char *author_message, *author_message_buffer;
+static char *edit_message, *use_message;
+static char *fixup_message, *squash_message;
+static int all, edit_flag, also, interactive, patch_interactive, only, amend, signoff;
+static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
+static int no_post_rewrite, allow_empty_message;
+static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
+/*
+ * The default commit message cleanup mode will remove the lines
+ * beginning with # (shell comments) and leading and trailing
+ * whitespaces (empty lines or containing only whitespaces)
+ * if editor is used, and only the whitespaces if the message
+ * is specified explicitly.
+ */
+static enum {
+	CLEANUP_SPACE,
+	CLEANUP_NONE,
+	CLEANUP_ALL
+} cleanup_mode;
+static char *cleanup_arg;
+
+static enum commit_whence whence;
+static int use_editor = 1, include_status = 1;
+static int show_ignored_in_status;
+static const char *only_include_assumed;
+static struct strbuf message;
+
+static int null_termination;
+static enum {
+	STATUS_FORMAT_LONG,
+	STATUS_FORMAT_SHORT,
+	STATUS_FORMAT_PORCELAIN
+} status_format = STATUS_FORMAT_LONG;
+static int status_show_branch;
+
+static int opt_parse_m(const struct option *opt, const char *arg, int unset)
+{
+	struct strbuf *buf = opt->value;
+	if (unset)
+		strbuf_setlen(buf, 0);
+	else {
+		strbuf_addstr(buf, arg);
+		strbuf_addstr(buf, "\n\n");
+	}
+	return 0;
+}
+
+static struct option builtin_commit_options[] = {
+	OPT__QUIET(&quiet, "suppress summary after successful commit"),
+	OPT__VERBOSE(&verbose, "show diff in commit message template"),
+
+	OPT_GROUP("Commit message options"),
+	OPT_FILENAME('F', "file", &logfile, "read message from file"),
+	OPT_STRING(0, "author", &force_author, "author", "override author for commit"),
+	OPT_STRING(0, "date", &force_date, "date", "override date for commit"),
+	OPT_CALLBACK('m', "message", &message, "message", "commit message", opt_parse_m),
+	OPT_STRING('c', "reedit-message", &edit_message, "commit", "reuse and edit message from specified commit"),
+	OPT_STRING('C', "reuse-message", &use_message, "commit", "reuse message from specified commit"),
+	OPT_STRING(0, "fixup", &fixup_message, "commit", "use autosquash formatted message to fixup specified commit"),
+	OPT_STRING(0, "squash", &squash_message, "commit", "use autosquash formatted message to squash specified commit"),
+	OPT_BOOLEAN(0, "reset-author", &renew_authorship, "the commit is authored by me now (used with -C-c/--amend)"),
+	OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
+	OPT_FILENAME('t', "template", &template_file, "use specified template file"),
+	OPT_BOOLEAN('e', "edit", &edit_flag, "force edit of commit"),
+	OPT_STRING(0, "cleanup", &cleanup_arg, "default", "how to strip spaces and #comments from message"),
+	OPT_BOOLEAN(0, "status", &include_status, "include status in commit message template"),
+	/* end commit message options */
+
+	OPT_GROUP("Commit contents options"),
+	OPT_BOOLEAN('a', "all", &all, "commit all changed files"),
+	OPT_BOOLEAN('i', "include", &also, "add specified files to index for commit"),
+	OPT_BOOLEAN(0, "interactive", &interactive, "interactively add files"),
+	OPT_BOOLEAN('p', "patch", &patch_interactive, "interactively add changes"),
+	OPT_BOOLEAN('o', "only", &only, "commit only specified files"),
+	OPT_BOOLEAN('n', "no-verify", &no_verify, "bypass pre-commit hook"),
+	OPT_BOOLEAN(0, "dry-run", &dry_run, "show what would be committed"),
+	OPT_SET_INT(0, "short", &status_format, "show status concisely",
+		    STATUS_FORMAT_SHORT),
+	OPT_BOOLEAN(0, "branch", &status_show_branch, "show branch information"),
+	OPT_SET_INT(0, "porcelain", &status_format,
+		    "machine-readable output", STATUS_FORMAT_PORCELAIN),
+	OPT_BOOLEAN('z', "null", &null_termination,
+		    "terminate entries with NUL"),
+	OPT_BOOLEAN(0, "amend", &amend, "amend previous commit"),
+	OPT_BOOLEAN(0, "no-post-rewrite", &no_post_rewrite, "bypass post-rewrite hook"),
+	{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, "mode", "show untracked files, optional modes: all, normal, no. (Default: all)", PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+	/* end commit contents options */
+
+	{ OPTION_BOOLEAN, 0, "allow-empty", &allow_empty, NULL,
+	  "ok to record an empty change",
+	  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
+	{ OPTION_BOOLEAN, 0, "allow-empty-message", &allow_empty_message, NULL,
+	  "ok to record a change with an empty message",
+	  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
+
+	OPT_END()
+};
+
+static void determine_whence(struct wt_status *s)
+{
+	if (file_exists(git_path("MERGE_HEAD")))
+		whence = FROM_MERGE;
+	else if (file_exists(git_path("CHERRY_PICK_HEAD")))
+		whence = FROM_CHERRY_PICK;
+	else
+		whence = FROM_COMMIT;
+	if (s)
+		s->whence = whence;
+}
+
+static const char *whence_s(void)
+{
+	char *s = "";
+
+	switch (whence) {
+	case FROM_COMMIT:
+		break;
+	case FROM_MERGE:
+		s = "merge";
+		break;
+	case FROM_CHERRY_PICK:
+		s = "cherry-pick";
+		break;
+	}
+
+	return s;
+}
+
+static void rollback_index_files(void)
+{
+	switch (commit_style) {
+	case COMMIT_AS_IS:
+		break; /* nothing to do */
+	case COMMIT_NORMAL:
+		rollback_lock_file(&index_lock);
+		break;
+	case COMMIT_PARTIAL:
+		rollback_lock_file(&index_lock);
+		rollback_lock_file(&false_lock);
+		break;
+	}
+}
+
+static int commit_index_files(void)
+{
+	int err = 0;
+
+	switch (commit_style) {
+	case COMMIT_AS_IS:
+		break; /* nothing to do */
+	case COMMIT_NORMAL:
+		err = commit_lock_file(&index_lock);
+		break;
+	case COMMIT_PARTIAL:
+		err = commit_lock_file(&index_lock);
+		rollback_lock_file(&false_lock);
+		break;
+	}
+
+	return err;
+}
+
+/*
+ * Take a union of paths in the index and the named tree (typically, "HEAD"),
+ * and return the paths that match the given pattern in list.
+ */
+static int list_paths(struct string_list *list, const char *with_tree,
+		      const char *prefix, const char **pattern)
+{
+	int i;
+	char *m;
+
+	for (i = 0; pattern[i]; i++)
+		;
+	m = xcalloc(1, i);
+
+	if (with_tree) {
+		const char *max_prefix = pathspec_prefix(prefix, pattern);
+		overlay_tree_on_cache(with_tree, max_prefix);
+	}
+
+	for (i = 0; i < active_nr; i++) {
+		struct cache_entry *ce = active_cache[i];
+		struct string_list_item *item;
+
+		if (ce->ce_flags & CE_UPDATE)
+			continue;
+		if (!match_pathspec(pattern, ce->name, ce_namelen(ce), 0, m))
+			continue;
+		item = string_list_insert(list, ce->name);
+		if (ce_skip_worktree(ce))
+			item->util = item; /* better a valid pointer than a fake one */
+	}
+
+	return report_path_error(m, pattern, prefix);
+}
+
+static void add_remove_files(struct string_list *list)
+{
+	int i;
+	for (i = 0; i < list->nr; i++) {
+		struct stat st;
+		struct string_list_item *p = &(list->items[i]);
+
+		/* p->util is skip-worktree */
+		if (p->util)
+			continue;
+
+		if (!lstat(p->string, &st)) {
+			if (add_to_cache(p->string, &st, 0))
+				die(_("updating files failed"));
+		} else
+			remove_file_from_cache(p->string);
+	}
+}
+
+static void create_base_index(const struct commit *current_head)
+{
+	struct tree *tree;
+	struct unpack_trees_options opts;
+	struct tree_desc t;
+
+	if (!current_head) {
+		discard_cache();
+		return;
+	}
+
+	memset(&opts, 0, sizeof(opts));
+	opts.head_idx = 1;
+	opts.index_only = 1;
+	opts.merge = 1;
+	opts.src_index = &the_index;
+	opts.dst_index = &the_index;
+
+	opts.fn = oneway_merge;
+	tree = parse_tree_indirect(current_head->object.sha1);
+	if (!tree)
+		die(_("failed to unpack HEAD tree object"));
+	parse_tree(tree);
+	init_tree_desc(&t, tree->buffer, tree->size);
+	if (unpack_trees(1, &t, &opts))
+		exit(128); /* We've already reported the error, finish dying */
+}
+
+static void refresh_cache_or_die(int refresh_flags)
+{
+	/*
+	 * refresh_flags contains REFRESH_QUIET, so the only errors
+	 * are for unmerged entries.
+	 */
+	if (refresh_cache(refresh_flags | REFRESH_IN_PORCELAIN))
+		die_resolve_conflict("commit");
+}
+
+static char *prepare_index(int argc, const char **argv, const char *prefix,
+			   const struct commit *current_head, int is_status)
+{
+	int fd;
+	struct string_list partial;
+	const char **pathspec = NULL;
+	char *old_index_env = NULL;
+	int refresh_flags = REFRESH_QUIET;
+
+	if (is_status)
+		refresh_flags |= REFRESH_UNMERGED;
+
+	if (*argv)
+		pathspec = get_pathspec(prefix, argv);
+
+	if (read_cache_preload(pathspec) < 0)
+		die(_("index file corrupt"));
+
+	if (interactive) {
+		fd = hold_locked_index(&index_lock, 1);
+
+		refresh_cache_or_die(refresh_flags);
+
+		if (write_cache(fd, active_cache, active_nr) ||
+		    close_lock_file(&index_lock))
+			die(_("unable to create temporary index"));
+
+		old_index_env = getenv(INDEX_ENVIRONMENT);
+		setenv(INDEX_ENVIRONMENT, index_lock.filename, 1);
+
+		if (interactive_add(argc, argv, prefix, patch_interactive) != 0)
+			die(_("interactive add failed"));
+
+		if (old_index_env && *old_index_env)
+			setenv(INDEX_ENVIRONMENT, old_index_env, 1);
+		else
+			unsetenv(INDEX_ENVIRONMENT);
+
+		discard_cache();
+		read_cache_from(index_lock.filename);
+
+		commit_style = COMMIT_NORMAL;
+		return index_lock.filename;
+	}
+
+	/*
+	 * Non partial, non as-is commit.
+	 *
+	 * (1) get the real index;
+	 * (2) update the_index as necessary;
+	 * (3) write the_index out to the real index (still locked);
+	 * (4) return the name of the locked index file.
+	 *
+	 * The caller should run hooks on the locked real index, and
+	 * (A) if all goes well, commit the real index;
+	 * (B) on failure, rollback the real index.
+	 */
+	if (all || (also && pathspec && *pathspec)) {
+		fd = hold_locked_index(&index_lock, 1);
+		add_files_to_cache(also ? prefix : NULL, pathspec, 0);
+		refresh_cache_or_die(refresh_flags);
+		if (write_cache(fd, active_cache, active_nr) ||
+		    close_lock_file(&index_lock))
+			die(_("unable to write new_index file"));
+		commit_style = COMMIT_NORMAL;
+		return index_lock.filename;
+	}
+
+	/*
+	 * As-is commit.
+	 *
+	 * (1) return the name of the real index file.
+	 *
+	 * The caller should run hooks on the real index,
+	 * and create commit from the_index.
+	 * We still need to refresh the index here.
+	 */
+	if (!pathspec || !*pathspec) {
+		fd = hold_locked_index(&index_lock, 1);
+		refresh_cache_or_die(refresh_flags);
+		if (active_cache_changed) {
+			if (write_cache(fd, active_cache, active_nr) ||
+			    commit_locked_index(&index_lock))
+				die(_("unable to write new_index file"));
+		} else {
+			rollback_lock_file(&index_lock);
+		}
+		commit_style = COMMIT_AS_IS;
+		return get_index_file();
+	}
+
+	/*
+	 * A partial commit.
+	 *
+	 * (0) find the set of affected paths;
+	 * (1) get lock on the real index file;
+	 * (2) update the_index with the given paths;
+	 * (3) write the_index out to the real index (still locked);
+	 * (4) get lock on the false index file;
+	 * (5) reset the_index from HEAD;
+	 * (6) update the_index the same way as (2);
+	 * (7) write the_index out to the false index file;
+	 * (8) return the name of the false index file (still locked);
+	 *
+	 * The caller should run hooks on the locked false index, and
+	 * create commit from it.  Then
+	 * (A) if all goes well, commit the real index;
+	 * (B) on failure, rollback the real index;
+	 * In either case, rollback the false index.
+	 */
+	commit_style = COMMIT_PARTIAL;
+
+	if (whence != FROM_COMMIT)
+		die(_("cannot do a partial commit during a %s."), whence_s());
+
+	memset(&partial, 0, sizeof(partial));
+	partial.strdup_strings = 1;
+	if (list_paths(&partial, !current_head ? NULL : "HEAD", prefix, pathspec))
+		exit(1);
+
+	discard_cache();
+	if (read_cache() < 0)
+		die(_("cannot read the index"));
+
+	fd = hold_locked_index(&index_lock, 1);
+	add_remove_files(&partial);
+	refresh_cache(REFRESH_QUIET);
+	if (write_cache(fd, active_cache, active_nr) ||
+	    close_lock_file(&index_lock))
+		die(_("unable to write new_index file"));
+
+	fd = hold_lock_file_for_update(&false_lock,
+				       git_path("next-index-%"PRIuMAX,
+						(uintmax_t) getpid()),
+				       LOCK_DIE_ON_ERROR);
+
+	create_base_index(current_head);
+	add_remove_files(&partial);
+	refresh_cache(REFRESH_QUIET);
+
+	if (write_cache(fd, active_cache, active_nr) ||
+	    close_lock_file(&false_lock))
+		die(_("unable to write temporary index file"));
+
+	discard_cache();
+	read_cache_from(false_lock.filename);
+
+	return false_lock.filename;
+}
+
+static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,
+		      struct wt_status *s)
+{
+	unsigned char sha1[20];
+
+	if (s->relative_paths)
+		s->prefix = prefix;
+
+	if (amend) {
+		s->amend = 1;
+		s->reference = "HEAD^1";
+	}
+	s->verbose = verbose;
+	s->index_file = index_file;
+	s->fp = fp;
+	s->nowarn = nowarn;
+	s->is_initial = get_sha1(s->reference, sha1) ? 1 : 0;
+
+	wt_status_collect(s);
+
+	switch (status_format) {
+	case STATUS_FORMAT_SHORT:
+		wt_shortstatus_print(s, null_termination, status_show_branch);
+		break;
+	case STATUS_FORMAT_PORCELAIN:
+		wt_porcelain_print(s, null_termination);
+		break;
+	case STATUS_FORMAT_LONG:
+		wt_status_print(s);
+		break;
+	}
+
+	return s->commitable;
+}
+
+static int is_a_merge(const struct commit *current_head)
+{
+	return !!(current_head->parents && current_head->parents->next);
+}
+
+static const char sign_off_header[] = "Signed-off-by: ";
+
+static void determine_author_info(struct strbuf *author_ident)
+{
+	char *name, *email, *date;
+
+	name = getenv("GIT_AUTHOR_NAME");
+	email = getenv("GIT_AUTHOR_EMAIL");
+	date = getenv("GIT_AUTHOR_DATE");
+
+	if (author_message) {
+		const char *a, *lb, *rb, *eol;
+
+		a = strstr(author_message_buffer, "\nauthor ");
+		if (!a)
+			die(_("invalid commit: %s"), author_message);
+
+		lb = strchrnul(a + strlen("\nauthor "), '<');
+		rb = strchrnul(lb, '>');
+		eol = strchrnul(rb, '\n');
+		if (!*lb || !*rb || !*eol)
+			die(_("invalid commit: %s"), author_message);
+
+		if (lb == a + strlen("\nauthor "))
+			/* \nauthor <foo@example.com> */
+			name = xcalloc(1, 1);
+		else
+			name = xmemdupz(a + strlen("\nauthor "),
+					(lb - strlen(" ") -
+					 (a + strlen("\nauthor "))));
+		email = xmemdupz(lb + strlen("<"), rb - (lb + strlen("<")));
+		date = xmemdupz(rb + strlen("> "), eol - (rb + strlen("> ")));
+	}
+
+	if (force_author) {
+		const char *lb = strstr(force_author, " <");
+		const char *rb = strchr(force_author, '>');
+
+		if (!lb || !rb)
+			die(_("malformed --author parameter"));
+		name = xstrndup(force_author, lb - force_author);
+		email = xstrndup(lb + 2, rb - (lb + 2));
+	}
+
+	if (force_date)
+		date = force_date;
+	strbuf_addstr(author_ident, fmt_ident(name, email, date,
+					      IDENT_ERROR_ON_NO_NAME));
+}
+
+static int ends_rfc2822_footer(struct strbuf *sb)
+{
+	int ch;
+	int hit = 0;
+	int i, j, k;
+	int len = sb->len;
+	int first = 1;
+	const char *buf = sb->buf;
+
+	for (i = len - 1; i > 0; i--) {
+		if (hit && buf[i] == '\n')
+			break;
+		hit = (buf[i] == '\n');
+	}
+
+	while (i < len - 1 && buf[i] == '\n')
+		i++;
+
+	for (; i < len; i = k) {
+		for (k = i; k < len && buf[k] != '\n'; k++)
+			; /* do nothing */
+		k++;
+
+		if ((buf[k] == ' ' || buf[k] == '\t') && !first)
+			continue;
+
+		first = 0;
+
+		for (j = 0; i + j < len; j++) {
+			ch = buf[i + j];
+			if (ch == ':')
+				break;
+			if (isalnum(ch) ||
+			    (ch == '-'))
+				continue;
+			return 0;
+		}
+	}
+	return 1;
+}
+
+static char *cut_ident_timestamp_part(char *string)
+{
+	char *ket = strrchr(string, '>');
+	if (!ket || ket[1] != ' ')
+		die(_("Malformed ident string: '%s'"), string);
+	*++ket = '\0';
+	return ket;
+}
+
+static int prepare_to_commit(const char *index_file, const char *prefix,
+			     struct commit *current_head,
+			     struct wt_status *s,
+			     struct strbuf *author_ident)
+{
+	struct stat statbuf;
+	struct strbuf committer_ident = STRBUF_INIT;
+	int commitable, saved_color_setting;
+	struct strbuf sb = STRBUF_INIT;
+	char *buffer;
+	const char *hook_arg1 = NULL;
+	const char *hook_arg2 = NULL;
+	int ident_shown = 0;
+	int clean_message_contents = (cleanup_mode != CLEANUP_NONE);
+
+	if (!no_verify && run_hook(index_file, "pre-commit", NULL))
+		return 0;
+
+	if (squash_message) {
+		/*
+		 * Insert the proper subject line before other commit
+		 * message options add their content.
+		 */
+		if (use_message && !strcmp(use_message, squash_message))
+			strbuf_addstr(&sb, "squash! ");
+		else {
+			struct pretty_print_context ctx = {0};
+			struct commit *c;
+			c = lookup_commit_reference_by_name(squash_message);
+			if (!c)
+				die(_("could not lookup commit %s"), squash_message);
+			ctx.output_encoding = get_commit_output_encoding();
+			format_commit_message(c, "squash! %s\n\n", &sb,
+					      &ctx);
+		}
+	}
+
+	if (message.len) {
+		strbuf_addbuf(&sb, &message);
+		hook_arg1 = "message";
+	} else if (logfile && !strcmp(logfile, "-")) {
+		if (isatty(0))
+			fprintf(stderr, _("(reading log message from standard input)\n"));
+		if (strbuf_read(&sb, 0, 0) < 0)
+			die_errno(_("could not read log from standard input"));
+		hook_arg1 = "message";
+	} else if (logfile) {
+		if (strbuf_read_file(&sb, logfile, 0) < 0)
+			die_errno(_("could not read log file '%s'"),
+				  logfile);
+		hook_arg1 = "message";
+	} else if (use_message) {
+		buffer = strstr(use_message_buffer, "\n\n");
+		if (!buffer || buffer[2] == '\0')
+			die(_("commit has empty message"));
+		strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
+		hook_arg1 = "commit";
+		hook_arg2 = use_message;
+	} else if (fixup_message) {
+		struct pretty_print_context ctx = {0};
+		struct commit *commit;
+		commit = lookup_commit_reference_by_name(fixup_message);
+		if (!commit)
+			die(_("could not lookup commit %s"), fixup_message);
+		ctx.output_encoding = get_commit_output_encoding();
+		format_commit_message(commit, "fixup! %s\n\n",
+				      &sb, &ctx);
+		hook_arg1 = "message";
+	} else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
+		if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
+			die_errno(_("could not read MERGE_MSG"));
+		hook_arg1 = "merge";
+	} else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
+		if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
+			die_errno(_("could not read SQUASH_MSG"));
+		hook_arg1 = "squash";
+	} else if (template_file) {
+		if (strbuf_read_file(&sb, template_file, 0) < 0)
+			die_errno(_("could not read '%s'"), template_file);
+		hook_arg1 = "template";
+		clean_message_contents = 0;
+	}
+
+	/*
+	 * The remaining cases don't modify the template message, but
+	 * just set the argument(s) to the prepare-commit-msg hook.
+	 */
+	else if (whence == FROM_MERGE)
+		hook_arg1 = "merge";
+	else if (whence == FROM_CHERRY_PICK) {
+		hook_arg1 = "commit";
+		hook_arg2 = "CHERRY_PICK_HEAD";
+	}
+
+	if (squash_message) {
+		/*
+		 * If squash_commit was used for the commit subject,
+		 * then we're possibly hijacking other commit log options.
+		 * Reset the hook args to tell the real story.
+		 */
+		hook_arg1 = "message";
+		hook_arg2 = "";
+	}
+
+	s->fp = fopen(git_path(commit_editmsg), "w");
+	if (s->fp == NULL)
+		die_errno(_("could not open '%s'"), git_path(commit_editmsg));
+
+	if (clean_message_contents)
+		stripspace(&sb, 0);
+
+	if (signoff) {
+		struct strbuf sob = STRBUF_INIT;
+		int i;
+
+		strbuf_addstr(&sob, sign_off_header);
+		strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
+					     getenv("GIT_COMMITTER_EMAIL")));
+		strbuf_addch(&sob, '\n');
+		for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
+			; /* do nothing */
+		if (prefixcmp(sb.buf + i, sob.buf)) {
+			if (!i || !ends_rfc2822_footer(&sb))
+				strbuf_addch(&sb, '\n');
+			strbuf_addbuf(&sb, &sob);
+		}
+		strbuf_release(&sob);
+	}
+
+	if (fwrite(sb.buf, 1, sb.len, s->fp) < sb.len)
+		die_errno(_("could not write commit template"));
+
+	strbuf_release(&sb);
+
+	/* This checks and barfs if author is badly specified */
+	determine_author_info(author_ident);
+
+	/* This checks if committer ident is explicitly given */
+	strbuf_addstr(&committer_ident, git_committer_info(0));
+	if (use_editor && include_status) {
+		char *ai_tmp, *ci_tmp;
+		if (whence != FROM_COMMIT)
+			status_printf_ln(s, GIT_COLOR_NORMAL,
+				_("\n"
+				"It looks like you may be committing a %s.\n"
+				"If this is not correct, please remove the file\n"
+				"	%s\n"
+				"and try again.\n"
+				""),
+				whence_s(),
+				git_path(whence == FROM_MERGE
+					 ? "MERGE_HEAD"
+					 : "CHERRY_PICK_HEAD"));
+
+		fprintf(s->fp, "\n");
+		status_printf(s, GIT_COLOR_NORMAL,
+			_("Please enter the commit message for your changes."));
+		if (cleanup_mode == CLEANUP_ALL)
+			status_printf_more(s, GIT_COLOR_NORMAL,
+				_(" Lines starting\n"
+				"with '#' will be ignored, and an empty"
+				" message aborts the commit.\n"));
+		else /* CLEANUP_SPACE, that is. */
+			status_printf_more(s, GIT_COLOR_NORMAL,
+				_(" Lines starting\n"
+				"with '#' will be kept; you may remove them"
+				" yourself if you want to.\n"
+				"An empty message aborts the commit.\n"));
+		if (only_include_assumed)
+			status_printf_ln(s, GIT_COLOR_NORMAL,
+					"%s", only_include_assumed);
+
+		ai_tmp = cut_ident_timestamp_part(author_ident->buf);
+		ci_tmp = cut_ident_timestamp_part(committer_ident.buf);
+		if (strcmp(author_ident->buf, committer_ident.buf))
+			status_printf_ln(s, GIT_COLOR_NORMAL,
+				_("%s"
+				"Author:    %s"),
+				ident_shown++ ? "" : "\n",
+				author_ident->buf);
+
+		if (!user_ident_sufficiently_given())
+			status_printf_ln(s, GIT_COLOR_NORMAL,
+				_("%s"
+				"Committer: %s"),
+				ident_shown++ ? "" : "\n",
+				committer_ident.buf);
+
+		if (ident_shown)
+			status_printf_ln(s, GIT_COLOR_NORMAL, "");
+
+		saved_color_setting = s->use_color;
+		s->use_color = 0;
+		commitable = run_status(s->fp, index_file, prefix, 1, s);
+		s->use_color = saved_color_setting;
+
+		*ai_tmp = ' ';
+		*ci_tmp = ' ';
+	} else {
+		unsigned char sha1[20];
+		const char *parent = "HEAD";
+
+		if (!active_nr && read_cache() < 0)
+			die(_("Cannot read index"));
+
+		if (amend)
+			parent = "HEAD^1";
+
+		if (get_sha1(parent, sha1))
+			commitable = !!active_nr;
+		else
+			commitable = index_differs_from(parent, 0);
+	}
+	strbuf_release(&committer_ident);
+
+	fclose(s->fp);
+
+	/*
+	 * Reject an attempt to record a non-merge empty commit without
+	 * explicit --allow-empty. In the cherry-pick case, it may be
+	 * empty due to conflict resolution, which the user should okay.
+	 */
+	if (!commitable && whence != FROM_MERGE && !allow_empty &&
+	    !(amend && is_a_merge(current_head))) {
+		run_status(stdout, index_file, prefix, 0, s);
+		if (amend)
+			fputs(_(empty_amend_advice), stderr);
+		else if (whence == FROM_CHERRY_PICK)
+			fputs(_(empty_cherry_pick_advice), stderr);
+		return 0;
+	}
+
+	/*
+	 * Re-read the index as pre-commit hook could have updated it,
+	 * and write it out as a tree.  We must do this before we invoke
+	 * the editor and after we invoke run_status above.
+	 */
+	discard_cache();
+	read_cache_from(index_file);
+	if (!active_cache_tree)
+		active_cache_tree = cache_tree();
+	if (cache_tree_update(active_cache_tree,
+			      active_cache, active_nr, 0, 0) < 0) {
+		error(_("Error building trees"));
+		return 0;
+	}
+
+	if (run_hook(index_file, "prepare-commit-msg",
+		     git_path(commit_editmsg), hook_arg1, hook_arg2, NULL))
+		return 0;
+
+	if (use_editor) {
+		char index[PATH_MAX];
+		const char *env[2] = { NULL };
+		env[0] =  index;
+		snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
+		if (launch_editor(git_path(commit_editmsg), NULL, env)) {
+			fprintf(stderr,
+			_("Please supply the message using either -m or -F option.\n"));
+			exit(1);
+		}
+	}
+
+	if (!no_verify &&
+	    run_hook(index_file, "commit-msg", git_path(commit_editmsg), NULL)) {
+		return 0;
+	}
+
+	return 1;
+}
+
+/*
+ * Find out if the message in the strbuf contains only whitespace and
+ * Signed-off-by lines.
+ */
+static int message_is_empty(struct strbuf *sb)
+{
+	struct strbuf tmpl = STRBUF_INIT;
+	const char *nl;
+	int eol, i, start = 0;
+
+	if (cleanup_mode == CLEANUP_NONE && sb->len)
+		return 0;
+
+	/* See if the template is just a prefix of the message. */
+	if (template_file && strbuf_read_file(&tmpl, template_file, 0) > 0) {
+		stripspace(&tmpl, cleanup_mode == CLEANUP_ALL);
+		if (start + tmpl.len <= sb->len &&
+		    memcmp(tmpl.buf, sb->buf + start, tmpl.len) == 0)
+			start += tmpl.len;
+	}
+	strbuf_release(&tmpl);
+
+	/* Check if the rest is just whitespace and Signed-of-by's. */
+	for (i = start; i < sb->len; i++) {
+		nl = memchr(sb->buf + i, '\n', sb->len - i);
+		if (nl)
+			eol = nl - sb->buf;
+		else
+			eol = sb->len;
+
+		if (strlen(sign_off_header) <= eol - i &&
+		    !prefixcmp(sb->buf + i, sign_off_header)) {
+			i = eol;
+			continue;
+		}
+		while (i < eol)
+			if (!isspace(sb->buf[i++]))
+				return 0;
+	}
+
+	return 1;
+}
+
+static const char *find_author_by_nickname(const char *name)
+{
+	struct rev_info revs;
+	struct commit *commit;
+	struct strbuf buf = STRBUF_INIT;
+	const char *av[20];
+	int ac = 0;
+
+	init_revisions(&revs, NULL);
+	strbuf_addf(&buf, "--author=%s", name);
+	av[++ac] = "--all";
+	av[++ac] = "-i";
+	av[++ac] = buf.buf;
+	av[++ac] = NULL;
+	setup_revisions(ac, av, &revs, NULL);
+	prepare_revision_walk(&revs);
+	commit = get_revision(&revs);
+	if (commit) {
+		struct pretty_print_context ctx = {0};
+		ctx.date_mode = DATE_NORMAL;
+		strbuf_release(&buf);
+		format_commit_message(commit, "%an <%ae>", &buf, &ctx);
+		return strbuf_detach(&buf, NULL);
+	}
+	die(_("No existing author found with '%s'"), name);
+}
+
+
+static void handle_untracked_files_arg(struct wt_status *s)
+{
+	if (!untracked_files_arg)
+		; /* default already initialized */
+	else if (!strcmp(untracked_files_arg, "no"))
+		s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
+	else if (!strcmp(untracked_files_arg, "normal"))
+		s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
+	else if (!strcmp(untracked_files_arg, "all"))
+		s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
+	else
+		die(_("Invalid untracked files mode '%s'"), untracked_files_arg);
+}
+
+static const char *read_commit_message(const char *name)
+{
+	const char *out_enc, *out;
+	struct commit *commit;
+
+	commit = lookup_commit_reference_by_name(name);
+	if (!commit)
+		die(_("could not lookup commit %s"), name);
+	out_enc = get_commit_output_encoding();
+	out = logmsg_reencode(commit, out_enc);
+
+	/*
+	 * If we failed to reencode the buffer, just copy it
+	 * byte for byte so the user can try to fix it up.
+	 * This also handles the case where input and output
+	 * encodings are identical.
+	 */
+	if (out == NULL)
+		out = xstrdup(commit->buffer);
+	return out;
+}
+
+static int parse_and_validate_options(int argc, const char *argv[],
+				      const char * const usage[],
+				      const char *prefix,
+				      struct commit *current_head,
+				      struct wt_status *s)
+{
+	int f = 0;
+
+	argc = parse_options(argc, argv, prefix, builtin_commit_options, usage,
+			     0);
+
+	if (force_author && !strchr(force_author, '>'))
+		force_author = find_author_by_nickname(force_author);
+
+	if (force_author && renew_authorship)
+		die(_("Using both --reset-author and --author does not make sense"));
+
+	if (logfile || message.len || use_message || fixup_message)
+		use_editor = 0;
+	if (edit_flag)
+		use_editor = 1;
+	if (!use_editor)
+		setenv("GIT_EDITOR", ":", 1);
+
+	/* Sanity check options */
+	if (amend && !current_head)
+		die(_("You have nothing to amend."));
+	if (amend && whence != FROM_COMMIT)
+		die(_("You are in the middle of a %s -- cannot amend."), whence_s());
+	if (fixup_message && squash_message)
+		die(_("Options --squash and --fixup cannot be used together"));
+	if (use_message)
+		f++;
+	if (edit_message)
+		f++;
+	if (fixup_message)
+		f++;
+	if (logfile)
+		f++;
+	if (f > 1)
+		die(_("Only one of -c/-C/-F/--fixup can be used."));
+	if (message.len && f > 0)
+		die((_("Option -m cannot be combined with -c/-C/-F/--fixup.")));
+	if (edit_message)
+		use_message = edit_message;
+	if (amend && !use_message && !fixup_message)
+		use_message = "HEAD";
+	if (!use_message && whence != FROM_CHERRY_PICK && renew_authorship)
+		die(_("--reset-author can be used only with -C, -c or --amend."));
+	if (use_message) {
+		use_message_buffer = read_commit_message(use_message);
+		if (!renew_authorship) {
+			author_message = use_message;
+			author_message_buffer = use_message_buffer;
+		}
+	}
+	if (whence == FROM_CHERRY_PICK && !renew_authorship) {
+		author_message = "CHERRY_PICK_HEAD";
+		author_message_buffer = read_commit_message(author_message);
+	}
+
+	if (patch_interactive)
+		interactive = 1;
+
+	if (!!also + !!only + !!all + !!interactive > 1)
+		die(_("Only one of --include/--only/--all/--interactive/--patch can be used."));
+	if (argc == 0 && (also || (only && !amend)))
+		die(_("No paths with --include/--only does not make sense."));
+	if (argc == 0 && only && amend)
+		only_include_assumed = _("Clever... amending the last one with dirty index.");
+	if (argc > 0 && !also && !only)
+		only_include_assumed = _("Explicit paths specified without -i nor -o; assuming --only paths...");
+	if (!cleanup_arg || !strcmp(cleanup_arg, "default"))
+		cleanup_mode = use_editor ? CLEANUP_ALL : CLEANUP_SPACE;
+	else if (!strcmp(cleanup_arg, "verbatim"))
+		cleanup_mode = CLEANUP_NONE;
+	else if (!strcmp(cleanup_arg, "whitespace"))
+		cleanup_mode = CLEANUP_SPACE;
+	else if (!strcmp(cleanup_arg, "strip"))
+		cleanup_mode = CLEANUP_ALL;
+	else
+		die(_("Invalid cleanup mode %s"), cleanup_arg);
+
+	handle_untracked_files_arg(s);
+
+	if (all && argc > 0)
+		die(_("Paths with -a does not make sense."));
+
+	if (null_termination && status_format == STATUS_FORMAT_LONG)
+		status_format = STATUS_FORMAT_PORCELAIN;
+	if (status_format != STATUS_FORMAT_LONG)
+		dry_run = 1;
+
+	return argc;
+}
+
+static int dry_run_commit(int argc, const char **argv, const char *prefix,
+			  const struct commit *current_head, struct wt_status *s)
+{
+	int commitable;
+	const char *index_file;
+
+	index_file = prepare_index(argc, argv, prefix, current_head, 1);
+	commitable = run_status(stdout, index_file, prefix, 0, s);
+	rollback_index_files();
+
+	return commitable ? 0 : 1;
+}
+
+static int parse_status_slot(const char *var, int offset)
+{
+	if (!strcasecmp(var+offset, "header"))
+		return WT_STATUS_HEADER;
+	if (!strcasecmp(var+offset, "branch"))
+		return WT_STATUS_ONBRANCH;
+	if (!strcasecmp(var+offset, "updated")
+		|| !strcasecmp(var+offset, "added"))
+		return WT_STATUS_UPDATED;
+	if (!strcasecmp(var+offset, "changed"))
+		return WT_STATUS_CHANGED;
+	if (!strcasecmp(var+offset, "untracked"))
+		return WT_STATUS_UNTRACKED;
+	if (!strcasecmp(var+offset, "nobranch"))
+		return WT_STATUS_NOBRANCH;
+	if (!strcasecmp(var+offset, "unmerged"))
+		return WT_STATUS_UNMERGED;
+	return -1;
+}
+
+static int git_status_config(const char *k, const char *v, void *cb)
+{
+	struct wt_status *s = cb;
+
+	if (!strcmp(k, "status.submodulesummary")) {
+		int is_bool;
+		s->submodule_summary = git_config_bool_or_int(k, v, &is_bool);
+		if (is_bool && s->submodule_summary)
+			s->submodule_summary = -1;
+		return 0;
+	}
+	if (!strcmp(k, "status.color") || !strcmp(k, "color.status")) {
+		s->use_color = git_config_colorbool(k, v);
+		return 0;
+	}
+	if (!prefixcmp(k, "status.color.") || !prefixcmp(k, "color.status.")) {
+		int slot = parse_status_slot(k, 13);
+		if (slot < 0)
+			return 0;
+		if (!v)
+			return config_error_nonbool(k);
+		color_parse(v, k, s->color_palette[slot]);
+		return 0;
+	}
+	if (!strcmp(k, "status.relativepaths")) {
+		s->relative_paths = git_config_bool(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "status.showuntrackedfiles")) {
+		if (!v)
+			return config_error_nonbool(k);
+		else if (!strcmp(v, "no"))
+			s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
+		else if (!strcmp(v, "normal"))
+			s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
+		else if (!strcmp(v, "all"))
+			s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
+		else
+			return error(_("Invalid untracked files mode '%s'"), v);
+		return 0;
+	}
+	return git_diff_ui_config(k, v, NULL);
+}
+
+int cmd_status(int argc, const char **argv, const char *prefix)
+{
+	struct wt_status s;
+	int fd;
+	unsigned char sha1[20];
+	static struct option builtin_status_options[] = {
+		OPT__VERBOSE(&verbose, "be verbose"),
+		OPT_SET_INT('s', "short", &status_format,
+			    "show status concisely", STATUS_FORMAT_SHORT),
+		OPT_BOOLEAN('b', "branch", &status_show_branch,
+			    "show branch information"),
+		OPT_SET_INT(0, "porcelain", &status_format,
+			    "machine-readable output",
+			    STATUS_FORMAT_PORCELAIN),
+		OPT_BOOLEAN('z', "null", &null_termination,
+			    "terminate entries with NUL"),
+		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg,
+		  "mode",
+		  "show untracked files, optional modes: all, normal, no. (Default: all)",
+		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+		OPT_BOOLEAN(0, "ignored", &show_ignored_in_status,
+			    "show ignored files"),
+		{ OPTION_STRING, 0, "ignore-submodules", &ignore_submodule_arg, "when",
+		  "ignore changes to submodules, optional when: all, dirty, untracked. (Default: all)",
+		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+		OPT_END(),
+	};
+
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(builtin_status_usage, builtin_status_options);
+
+	wt_status_prepare(&s);
+	gitmodules_config();
+	git_config(git_status_config, &s);
+	determine_whence(&s);
+	argc = parse_options(argc, argv, prefix,
+			     builtin_status_options,
+			     builtin_status_usage, 0);
+
+	if (null_termination && status_format == STATUS_FORMAT_LONG)
+		status_format = STATUS_FORMAT_PORCELAIN;
+
+	handle_untracked_files_arg(&s);
+	if (show_ignored_in_status)
+		s.show_ignored_files = 1;
+	if (*argv)
+		s.pathspec = get_pathspec(prefix, argv);
+
+	read_cache_preload(s.pathspec);
+	refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, s.pathspec, NULL, NULL);
+
+	fd = hold_locked_index(&index_lock, 0);
+	if (0 <= fd)
+		update_index_if_able(&the_index, &index_lock);
+
+	s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
+	s.ignore_submodule_arg = ignore_submodule_arg;
+	wt_status_collect(&s);
+
+	if (s.relative_paths)
+		s.prefix = prefix;
+
+	switch (status_format) {
+	case STATUS_FORMAT_SHORT:
+		wt_shortstatus_print(&s, null_termination, status_show_branch);
+		break;
+	case STATUS_FORMAT_PORCELAIN:
+		wt_porcelain_print(&s, null_termination);
+		break;
+	case STATUS_FORMAT_LONG:
+		s.verbose = verbose;
+		s.ignore_submodule_arg = ignore_submodule_arg;
+		wt_status_print(&s);
+		break;
+	}
+	return 0;
+}
+
+static void print_summary(const char *prefix, const unsigned char *sha1,
+			  int initial_commit)
+{
+	struct rev_info rev;
+	struct commit *commit;
+	struct strbuf format = STRBUF_INIT;
+	unsigned char junk_sha1[20];
+	const char *head = resolve_ref("HEAD", junk_sha1, 0, NULL);
+	struct pretty_print_context pctx = {0};
+	struct strbuf author_ident = STRBUF_INIT;
+	struct strbuf committer_ident = STRBUF_INIT;
+
+	commit = lookup_commit(sha1);
+	if (!commit)
+		die(_("couldn't look up newly created commit"));
+	if (!commit || parse_commit(commit))
+		die(_("could not parse newly created commit"));
+
+	strbuf_addstr(&format, "format:%h] %s");
+
+	format_commit_message(commit, "%an <%ae>", &author_ident, &pctx);
+	format_commit_message(commit, "%cn <%ce>", &committer_ident, &pctx);
+	if (strbuf_cmp(&author_ident, &committer_ident)) {
+		strbuf_addstr(&format, "\n Author: ");
+		strbuf_addbuf_percentquote(&format, &author_ident);
+	}
+	if (!user_ident_sufficiently_given()) {
+		strbuf_addstr(&format, "\n Committer: ");
+		strbuf_addbuf_percentquote(&format, &committer_ident);
+		if (advice_implicit_identity) {
+			strbuf_addch(&format, '\n');
+			strbuf_addstr(&format, _(implicit_ident_advice));
+		}
+	}
+	strbuf_release(&author_ident);
+	strbuf_release(&committer_ident);
+
+	init_revisions(&rev, prefix);
+	setup_revisions(0, NULL, &rev, NULL);
+
+	rev.diff = 1;
+	rev.diffopt.output_format =
+		DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
+
+	rev.verbose_header = 1;
+	rev.show_root_diff = 1;
+	get_commit_format(format.buf, &rev);
+	rev.always_show_header = 0;
+	rev.diffopt.detect_rename = 1;
+	rev.diffopt.break_opt = 0;
+	diff_setup_done(&rev.diffopt);
+
+	printf("[%s%s ",
+		!prefixcmp(head, "refs/heads/") ?
+			head + 11 :
+			!strcmp(head, "HEAD") ?
+				_("detached HEAD") :
+				head,
+		initial_commit ? _(" (root-commit)") : "");
+
+	if (!log_tree_commit(&rev, commit)) {
+		rev.always_show_header = 1;
+		rev.use_terminator = 1;
+		log_tree_commit(&rev, commit);
+	}
+
+	strbuf_release(&format);
+}
+
+static int git_commit_config(const char *k, const char *v, void *cb)
+{
+	struct wt_status *s = cb;
+
+	if (!strcmp(k, "commit.template"))
+		return git_config_pathname(&template_file, k, v);
+	if (!strcmp(k, "commit.status")) {
+		include_status = git_config_bool(k, v);
+		return 0;
+	}
+
+	return git_status_config(k, v, s);
+}
+
+static const char post_rewrite_hook[] = "hooks/post-rewrite";
+
+static int run_rewrite_hook(const unsigned char *oldsha1,
+			    const unsigned char *newsha1)
+{
+	/* oldsha1 SP newsha1 LF NUL */
+	static char buf[2*40 + 3];
+	struct child_process proc;
+	const char *argv[3];
+	int code;
+	size_t n;
+
+	if (access(git_path(post_rewrite_hook), X_OK) < 0)
+		return 0;
+
+	argv[0] = git_path(post_rewrite_hook);
+	argv[1] = "amend";
+	argv[2] = NULL;
+
+	memset(&proc, 0, sizeof(proc));
+	proc.argv = argv;
+	proc.in = -1;
+	proc.stdout_to_stderr = 1;
+
+	code = start_command(&proc);
+	if (code)
+		return code;
+	n = snprintf(buf, sizeof(buf), "%s %s\n",
+		     sha1_to_hex(oldsha1), sha1_to_hex(newsha1));
+	write_in_full(proc.in, buf, n);
+	close(proc.in);
+	return finish_command(&proc);
+}
+
+int cmd_commit(int argc, const char **argv, const char *prefix)
+{
+	struct strbuf sb = STRBUF_INIT;
+	struct strbuf author_ident = STRBUF_INIT;
+	const char *index_file, *reflog_msg;
+	char *nl, *p;
+	unsigned char sha1[20];
+	struct ref_lock *ref_lock;
+	struct commit_list *parents = NULL, **pptr = &parents;
+	struct stat statbuf;
+	int allow_fast_forward = 1;
+	struct wt_status s;
+	struct commit *current_head = NULL;
+
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(builtin_commit_usage, builtin_commit_options);
+
+	wt_status_prepare(&s);
+	git_config(git_commit_config, &s);
+	determine_whence(&s);
+
+	if (get_sha1("HEAD", sha1))
+		current_head = NULL;
+	else {
+		current_head = lookup_commit_or_die(sha1, "HEAD");
+		if (!current_head || parse_commit(current_head))
+			die(_("could not parse HEAD commit"));
+	}
+	argc = parse_and_validate_options(argc, argv, builtin_commit_usage,
+					  prefix, current_head, &s);
+	if (dry_run)
+		return dry_run_commit(argc, argv, prefix, current_head, &s);
+	index_file = prepare_index(argc, argv, prefix, current_head, 0);
+
+	/* Set up everything for writing the commit object.  This includes
+	   running hooks, writing the trees, and interacting with the user.  */
+	if (!prepare_to_commit(index_file, prefix,
+			       current_head, &s, &author_ident)) {
+		rollback_index_files();
+		return 1;
+	}
+
+	/* Determine parents */
+	reflog_msg = getenv("GIT_REFLOG_ACTION");
+	if (!current_head) {
+		if (!reflog_msg)
+			reflog_msg = "commit (initial)";
+	} else if (amend) {
+		struct commit_list *c;
+
+		if (!reflog_msg)
+			reflog_msg = "commit (amend)";
+		for (c = current_head->parents; c; c = c->next)
+			pptr = &commit_list_insert(c->item, pptr)->next;
+	} else if (whence == FROM_MERGE) {
+		struct strbuf m = STRBUF_INIT;
+		struct commit *commit;
+		FILE *fp;
+
+		if (!reflog_msg)
+			reflog_msg = "commit (merge)";
+		pptr = &commit_list_insert(current_head, pptr)->next;
+		fp = fopen(git_path("MERGE_HEAD"), "r");
+		if (fp == NULL)
+			die_errno(_("could not open '%s' for reading"),
+				  git_path("MERGE_HEAD"));
+		while (strbuf_getline(&m, fp, '\n') != EOF) {
+			unsigned char sha1[20];
+			if (get_sha1_hex(m.buf, sha1) < 0)
+				die(_("Corrupt MERGE_HEAD file (%s)"), m.buf);
+			commit = lookup_commit_or_die(sha1, "MERGE_HEAD");
+			pptr = &commit_list_insert(commit, pptr)->next;
+		}
+		fclose(fp);
+		strbuf_release(&m);
+		if (!stat(git_path("MERGE_MODE"), &statbuf)) {
+			if (strbuf_read_file(&sb, git_path("MERGE_MODE"), 0) < 0)
+				die_errno(_("could not read MERGE_MODE"));
+			if (!strcmp(sb.buf, "no-ff"))
+				allow_fast_forward = 0;
+		}
+		if (allow_fast_forward)
+			parents = reduce_heads(parents);
+	} else {
+		if (!reflog_msg)
+			reflog_msg = (whence == FROM_CHERRY_PICK)
+					? "commit (cherry-pick)"
+					: "commit";
+		pptr = &commit_list_insert(current_head, pptr)->next;
+	}
+
+	/* Finally, get the commit message */
+	strbuf_reset(&sb);
+	if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
+		int saved_errno = errno;
+		rollback_index_files();
+		die(_("could not read commit message: %s"), strerror(saved_errno));
+	}
+
+	/* Truncate the message just before the diff, if any. */
+	if (verbose) {
+		p = strstr(sb.buf, "\ndiff --git ");
+		if (p != NULL)
+			strbuf_setlen(&sb, p - sb.buf + 1);
+	}
+
+	if (cleanup_mode != CLEANUP_NONE)
+		stripspace(&sb, cleanup_mode == CLEANUP_ALL);
+	if (message_is_empty(&sb) && !allow_empty_message) {
+		rollback_index_files();
+		fprintf(stderr, _("Aborting commit due to empty commit message.\n"));
+		exit(1);
+	}
+
+	if (commit_tree(sb.buf, active_cache_tree->sha1, parents, sha1,
+			author_ident.buf)) {
+		rollback_index_files();
+		die(_("failed to write commit object"));
+	}
+	strbuf_release(&author_ident);
+
+	ref_lock = lock_any_ref_for_update("HEAD",
+					   !current_head
+					   ? NULL
+					   : current_head->object.sha1,
+					   0);
+
+	nl = strchr(sb.buf, '\n');
+	if (nl)
+		strbuf_setlen(&sb, nl + 1 - sb.buf);
+	else
+		strbuf_addch(&sb, '\n');
+	strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
+	strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
+
+	if (!ref_lock) {
+		rollback_index_files();
+		die(_("cannot lock HEAD ref"));
+	}
+	if (write_ref_sha1(ref_lock, sha1, sb.buf) < 0) {
+		rollback_index_files();
+		die(_("cannot update HEAD ref"));
+	}
+
+	unlink(git_path("CHERRY_PICK_HEAD"));
+	unlink(git_path("MERGE_HEAD"));
+	unlink(git_path("MERGE_MSG"));
+	unlink(git_path("MERGE_MODE"));
+	unlink(git_path("SQUASH_MSG"));
+
+	if (commit_index_files())
+		die (_("Repository has been updated, but unable to write\n"
+		     "new_index file. Check that disk is not full or quota is\n"
+		     "not exceeded, and then \"git reset HEAD\" to recover."));
+
+	rerere(0);
+	run_hook(get_index_file(), "post-commit", NULL);
+	if (amend && !no_post_rewrite) {
+		struct notes_rewrite_cfg *cfg;
+		cfg = init_copy_notes_for_rewrite("amend");
+		if (cfg) {
+			/* we are amending, so current_head is not NULL */
+			copy_note_for_rewrite(cfg, current_head->object.sha1, sha1);
+			finish_copy_notes_for_rewrite(cfg);
+		}
+		run_rewrite_hook(current_head->object.sha1, sha1);
+	}
+	if (!quiet)
+		print_summary(prefix, sha1, !current_head);
+
+	return 0;
+}
diff --git a/builtin/config.c b/builtin/config.c
new file mode 100644
index 0000000..0315ad7
--- /dev/null
+++ b/builtin/config.c
@@ -0,0 +1,526 @@
+#include "builtin.h"
+#include "cache.h"
+#include "color.h"
+#include "parse-options.h"
+
+static const char *const builtin_config_usage[] = {
+	"git config [options]",
+	NULL
+};
+
+static char *key;
+static regex_t *key_regexp;
+static regex_t *regexp;
+static int show_keys;
+static int use_key_regexp;
+static int do_all;
+static int do_not_match;
+static int seen;
+static char delim = '=';
+static char key_delim = ' ';
+static char term = '\n';
+
+static int use_global_config, use_system_config, use_local_config;
+static const char *given_config_file;
+static int actions, types;
+static const char *get_color_slot, *get_colorbool_slot;
+static int end_null;
+
+#define ACTION_GET (1<<0)
+#define ACTION_GET_ALL (1<<1)
+#define ACTION_GET_REGEXP (1<<2)
+#define ACTION_REPLACE_ALL (1<<3)
+#define ACTION_ADD (1<<4)
+#define ACTION_UNSET (1<<5)
+#define ACTION_UNSET_ALL (1<<6)
+#define ACTION_RENAME_SECTION (1<<7)
+#define ACTION_REMOVE_SECTION (1<<8)
+#define ACTION_LIST (1<<9)
+#define ACTION_EDIT (1<<10)
+#define ACTION_SET (1<<11)
+#define ACTION_SET_ALL (1<<12)
+#define ACTION_GET_COLOR (1<<13)
+#define ACTION_GET_COLORBOOL (1<<14)
+
+#define TYPE_BOOL (1<<0)
+#define TYPE_INT (1<<1)
+#define TYPE_BOOL_OR_INT (1<<2)
+#define TYPE_PATH (1<<3)
+
+static struct option builtin_config_options[] = {
+	OPT_GROUP("Config file location"),
+	OPT_BOOLEAN(0, "global", &use_global_config, "use global config file"),
+	OPT_BOOLEAN(0, "system", &use_system_config, "use system config file"),
+	OPT_BOOLEAN(0, "local", &use_local_config, "use repository config file"),
+	OPT_STRING('f', "file", &given_config_file, "file", "use given config file"),
+	OPT_GROUP("Action"),
+	OPT_BIT(0, "get", &actions, "get value: name [value-regex]", ACTION_GET),
+	OPT_BIT(0, "get-all", &actions, "get all values: key [value-regex]", ACTION_GET_ALL),
+	OPT_BIT(0, "get-regexp", &actions, "get values for regexp: name-regex [value-regex]", ACTION_GET_REGEXP),
+	OPT_BIT(0, "replace-all", &actions, "replace all matching variables: name value [value_regex]", ACTION_REPLACE_ALL),
+	OPT_BIT(0, "add", &actions, "adds a new variable: name value", ACTION_ADD),
+	OPT_BIT(0, "unset", &actions, "removes a variable: name [value-regex]", ACTION_UNSET),
+	OPT_BIT(0, "unset-all", &actions, "removes all matches: name [value-regex]", ACTION_UNSET_ALL),
+	OPT_BIT(0, "rename-section", &actions, "rename section: old-name new-name", ACTION_RENAME_SECTION),
+	OPT_BIT(0, "remove-section", &actions, "remove a section: name", ACTION_REMOVE_SECTION),
+	OPT_BIT('l', "list", &actions, "list all", ACTION_LIST),
+	OPT_BIT('e', "edit", &actions, "opens an editor", ACTION_EDIT),
+	OPT_STRING(0, "get-color", &get_color_slot, "slot", "find the color configured: [default]"),
+	OPT_STRING(0, "get-colorbool", &get_colorbool_slot, "slot", "find the color setting: [stdout-is-tty]"),
+	OPT_GROUP("Type"),
+	OPT_BIT(0, "bool", &types, "value is \"true\" or \"false\"", TYPE_BOOL),
+	OPT_BIT(0, "int", &types, "value is decimal number", TYPE_INT),
+	OPT_BIT(0, "bool-or-int", &types, "value is --bool or --int", TYPE_BOOL_OR_INT),
+	OPT_BIT(0, "path", &types, "value is a path (file or directory name)", TYPE_PATH),
+	OPT_GROUP("Other"),
+	OPT_BOOLEAN('z', "null", &end_null, "terminate values with NUL byte"),
+	OPT_END(),
+};
+
+static void check_argc(int argc, int min, int max) {
+	if (argc >= min && argc <= max)
+		return;
+	error("wrong number of arguments");
+	usage_with_options(builtin_config_usage, builtin_config_options);
+}
+
+static int show_all_config(const char *key_, const char *value_, void *cb)
+{
+	if (value_)
+		printf("%s%c%s%c", key_, delim, value_, term);
+	else
+		printf("%s%c", key_, term);
+	return 0;
+}
+
+static int show_config(const char *key_, const char *value_, void *cb)
+{
+	char value[256];
+	const char *vptr = value;
+	int must_free_vptr = 0;
+	int dup_error = 0;
+	int must_print_delim = 0;
+
+	if (!use_key_regexp && strcmp(key_, key))
+		return 0;
+	if (use_key_regexp && regexec(key_regexp, key_, 0, NULL, 0))
+		return 0;
+	if (regexp != NULL &&
+	    (do_not_match ^ !!regexec(regexp, (value_?value_:""), 0, NULL, 0)))
+		return 0;
+
+	if (show_keys) {
+		printf("%s", key_);
+		must_print_delim = 1;
+	}
+	if (seen && !do_all)
+		dup_error = 1;
+	if (types == TYPE_INT)
+		sprintf(value, "%d", git_config_int(key_, value_?value_:""));
+	else if (types == TYPE_BOOL)
+		vptr = git_config_bool(key_, value_) ? "true" : "false";
+	else if (types == TYPE_BOOL_OR_INT) {
+		int is_bool, v;
+		v = git_config_bool_or_int(key_, value_, &is_bool);
+		if (is_bool)
+			vptr = v ? "true" : "false";
+		else
+			sprintf(value, "%d", v);
+	} else if (types == TYPE_PATH) {
+		git_config_pathname(&vptr, key_, value_);
+		must_free_vptr = 1;
+	} else if (value_) {
+		vptr = value_;
+	} else {
+		/* Just show the key name */
+		vptr = "";
+		must_print_delim = 0;
+	}
+	seen++;
+	if (dup_error) {
+		error("More than one value for the key %s: %s",
+				key_, vptr);
+	}
+	else {
+		if (must_print_delim)
+			printf("%c", key_delim);
+		printf("%s%c", vptr, term);
+	}
+	if (must_free_vptr)
+		/* If vptr must be freed, it's a pointer to a
+		 * dynamically allocated buffer, it's safe to cast to
+		 * const.
+		*/
+		free((char *)vptr);
+
+	return 0;
+}
+
+static int get_value(const char *key_, const char *regex_)
+{
+	int ret = -1;
+	char *global = NULL, *repo_config = NULL;
+	const char *system_wide = NULL, *local;
+
+	local = config_exclusive_filename;
+	if (!local) {
+		const char *home = getenv("HOME");
+		local = repo_config = git_pathdup("config");
+		if (home)
+			global = xstrdup(mkpath("%s/.gitconfig", home));
+		if (git_config_system())
+			system_wide = git_etc_gitconfig();
+	}
+
+	if (use_key_regexp) {
+		char *tl;
+
+		/*
+		 * NEEDSWORK: this naive pattern lowercasing obviously does not
+		 * work for more complex patterns like "^[^.]*Foo.*bar".
+		 * Perhaps we should deprecate this altogether someday.
+		 */
+
+		key = xstrdup(key_);
+		for (tl = key + strlen(key) - 1;
+		     tl >= key && *tl != '.';
+		     tl--)
+			*tl = tolower(*tl);
+		for (tl = key; *tl && *tl != '.'; tl++)
+			*tl = tolower(*tl);
+
+		key_regexp = (regex_t*)xmalloc(sizeof(regex_t));
+		if (regcomp(key_regexp, key, REG_EXTENDED)) {
+			fprintf(stderr, "Invalid key pattern: %s\n", key_);
+			free(key);
+			goto free_strings;
+		}
+	} else {
+		if (git_config_parse_key(key_, &key, NULL))
+			goto free_strings;
+	}
+
+	if (regex_) {
+		if (regex_[0] == '!') {
+			do_not_match = 1;
+			regex_++;
+		}
+
+		regexp = (regex_t*)xmalloc(sizeof(regex_t));
+		if (regcomp(regexp, regex_, REG_EXTENDED)) {
+			fprintf(stderr, "Invalid pattern: %s\n", regex_);
+			goto free_strings;
+		}
+	}
+
+	if (do_all && system_wide)
+		git_config_from_file(show_config, system_wide, NULL);
+	if (do_all && global)
+		git_config_from_file(show_config, global, NULL);
+	if (do_all)
+		git_config_from_file(show_config, local, NULL);
+	git_config_from_parameters(show_config, NULL);
+	if (!do_all && !seen)
+		git_config_from_file(show_config, local, NULL);
+	if (!do_all && !seen && global)
+		git_config_from_file(show_config, global, NULL);
+	if (!do_all && !seen && system_wide)
+		git_config_from_file(show_config, system_wide, NULL);
+
+	free(key);
+	if (regexp) {
+		regfree(regexp);
+		free(regexp);
+	}
+
+	if (do_all)
+		ret = !seen;
+	else
+		ret = (seen == 1) ? 0 : seen > 1 ? 2 : 1;
+
+free_strings:
+	free(repo_config);
+	free(global);
+	return ret;
+}
+
+static char *normalize_value(const char *key, const char *value)
+{
+	char *normalized;
+
+	if (!value)
+		return NULL;
+
+	if (types == 0 || types == TYPE_PATH)
+		/*
+		 * We don't do normalization for TYPE_PATH here: If
+		 * the path is like ~/foobar/, we prefer to store
+		 * "~/foobar/" in the config file, and to expand the ~
+		 * when retrieving the value.
+		 */
+		normalized = xstrdup(value);
+	else {
+		normalized = xmalloc(64);
+		if (types == TYPE_INT) {
+			int v = git_config_int(key, value);
+			sprintf(normalized, "%d", v);
+		}
+		else if (types == TYPE_BOOL)
+			sprintf(normalized, "%s",
+				git_config_bool(key, value) ? "true" : "false");
+		else if (types == TYPE_BOOL_OR_INT) {
+			int is_bool, v;
+			v = git_config_bool_or_int(key, value, &is_bool);
+			if (!is_bool)
+				sprintf(normalized, "%d", v);
+			else
+				sprintf(normalized, "%s", v ? "true" : "false");
+		}
+	}
+
+	return normalized;
+}
+
+static int get_color_found;
+static const char *get_color_slot;
+static const char *get_colorbool_slot;
+static char parsed_color[COLOR_MAXLEN];
+
+static int git_get_color_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, get_color_slot)) {
+		if (!value)
+			config_error_nonbool(var);
+		color_parse(value, var, parsed_color);
+		get_color_found = 1;
+	}
+	return 0;
+}
+
+static void get_color(const char *def_color)
+{
+	get_color_found = 0;
+	parsed_color[0] = '\0';
+	git_config(git_get_color_config, NULL);
+
+	if (!get_color_found && def_color)
+		color_parse(def_color, "command line", parsed_color);
+
+	fputs(parsed_color, stdout);
+}
+
+static int get_colorbool_found;
+static int get_diff_color_found;
+static int get_color_ui_found;
+static int git_get_colorbool_config(const char *var, const char *value,
+		void *cb)
+{
+	if (!strcmp(var, get_colorbool_slot))
+		get_colorbool_found = git_config_colorbool(var, value);
+	else if (!strcmp(var, "diff.color"))
+		get_diff_color_found = git_config_colorbool(var, value);
+	else if (!strcmp(var, "color.ui"))
+		get_color_ui_found = git_config_colorbool(var, value);
+	return 0;
+}
+
+static int get_colorbool(int print)
+{
+	get_colorbool_found = -1;
+	get_diff_color_found = -1;
+	git_config(git_get_colorbool_config, NULL);
+
+	if (get_colorbool_found < 0) {
+		if (!strcmp(get_colorbool_slot, "color.diff"))
+			get_colorbool_found = get_diff_color_found;
+		if (get_colorbool_found < 0)
+			get_colorbool_found = get_color_ui_found;
+	}
+
+	get_colorbool_found = want_color(get_colorbool_found);
+
+	if (print) {
+		printf("%s\n", get_colorbool_found ? "true" : "false");
+		return 0;
+	} else
+		return get_colorbool_found ? 0 : 1;
+}
+
+int cmd_config(int argc, const char **argv, const char *prefix)
+{
+	int nongit = !startup_info->have_repository;
+	char *value;
+
+	config_exclusive_filename = getenv(CONFIG_ENVIRONMENT);
+
+	argc = parse_options(argc, argv, prefix, builtin_config_options,
+			     builtin_config_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (use_global_config + use_system_config + use_local_config + !!given_config_file > 1) {
+		error("only one config file at a time.");
+		usage_with_options(builtin_config_usage, builtin_config_options);
+	}
+
+	if (use_global_config) {
+		char *home = getenv("HOME");
+		if (home) {
+			char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
+			config_exclusive_filename = user_config;
+		} else {
+			die("$HOME not set");
+		}
+	}
+	else if (use_system_config)
+		config_exclusive_filename = git_etc_gitconfig();
+	else if (use_local_config)
+		config_exclusive_filename = git_pathdup("config");
+	else if (given_config_file) {
+		if (!is_absolute_path(given_config_file) && prefix)
+			config_exclusive_filename = prefix_filename(prefix,
+								    strlen(prefix),
+								    given_config_file);
+		else
+			config_exclusive_filename = given_config_file;
+	}
+
+	if (end_null) {
+		term = '\0';
+		delim = '\n';
+		key_delim = '\n';
+	}
+
+	if (HAS_MULTI_BITS(types)) {
+		error("only one type at a time.");
+		usage_with_options(builtin_config_usage, builtin_config_options);
+	}
+
+	if (get_color_slot)
+	    actions |= ACTION_GET_COLOR;
+	if (get_colorbool_slot)
+	    actions |= ACTION_GET_COLORBOOL;
+
+	if ((get_color_slot || get_colorbool_slot) && types) {
+		error("--get-color and variable type are incoherent");
+		usage_with_options(builtin_config_usage, builtin_config_options);
+	}
+
+	if (HAS_MULTI_BITS(actions)) {
+		error("only one action at a time.");
+		usage_with_options(builtin_config_usage, builtin_config_options);
+	}
+	if (actions == 0)
+		switch (argc) {
+		case 1: actions = ACTION_GET; break;
+		case 2: actions = ACTION_SET; break;
+		case 3: actions = ACTION_SET_ALL; break;
+		default:
+			usage_with_options(builtin_config_usage, builtin_config_options);
+		}
+
+	if (actions == ACTION_LIST) {
+		check_argc(argc, 0, 0);
+		if (git_config(show_all_config, NULL) < 0) {
+			if (config_exclusive_filename)
+				die_errno("unable to read config file '%s'",
+					  config_exclusive_filename);
+			else
+				die("error processing config file(s)");
+		}
+	}
+	else if (actions == ACTION_EDIT) {
+		check_argc(argc, 0, 0);
+		if (!config_exclusive_filename && nongit)
+			die("not in a git directory");
+		git_config(git_default_config, NULL);
+		launch_editor(config_exclusive_filename ?
+			      config_exclusive_filename : git_path("config"),
+			      NULL, NULL);
+	}
+	else if (actions == ACTION_SET) {
+		int ret;
+		check_argc(argc, 2, 2);
+		value = normalize_value(argv[0], argv[1]);
+		ret = git_config_set(argv[0], value);
+		if (ret == CONFIG_NOTHING_SET)
+			error("cannot overwrite multiple values with a single value\n"
+			"       Use a regexp, --add or --set-all to change %s.", argv[0]);
+		return ret;
+	}
+	else if (actions == ACTION_SET_ALL) {
+		check_argc(argc, 2, 3);
+		value = normalize_value(argv[0], argv[1]);
+		return git_config_set_multivar(argv[0], value, argv[2], 0);
+	}
+	else if (actions == ACTION_ADD) {
+		check_argc(argc, 2, 2);
+		value = normalize_value(argv[0], argv[1]);
+		return git_config_set_multivar(argv[0], value, "^$", 0);
+	}
+	else if (actions == ACTION_REPLACE_ALL) {
+		check_argc(argc, 2, 3);
+		value = normalize_value(argv[0], argv[1]);
+		return git_config_set_multivar(argv[0], value, argv[2], 1);
+	}
+	else if (actions == ACTION_GET) {
+		check_argc(argc, 1, 2);
+		return get_value(argv[0], argv[1]);
+	}
+	else if (actions == ACTION_GET_ALL) {
+		do_all = 1;
+		check_argc(argc, 1, 2);
+		return get_value(argv[0], argv[1]);
+	}
+	else if (actions == ACTION_GET_REGEXP) {
+		show_keys = 1;
+		use_key_regexp = 1;
+		do_all = 1;
+		check_argc(argc, 1, 2);
+		return get_value(argv[0], argv[1]);
+	}
+	else if (actions == ACTION_UNSET) {
+		check_argc(argc, 1, 2);
+		if (argc == 2)
+			return git_config_set_multivar(argv[0], NULL, argv[1], 0);
+		else
+			return git_config_set(argv[0], NULL);
+	}
+	else if (actions == ACTION_UNSET_ALL) {
+		check_argc(argc, 1, 2);
+		return git_config_set_multivar(argv[0], NULL, argv[1], 1);
+	}
+	else if (actions == ACTION_RENAME_SECTION) {
+		int ret;
+		check_argc(argc, 2, 2);
+		ret = git_config_rename_section(argv[0], argv[1]);
+		if (ret < 0)
+			return ret;
+		if (ret == 0)
+			die("No such section!");
+	}
+	else if (actions == ACTION_REMOVE_SECTION) {
+		int ret;
+		check_argc(argc, 1, 1);
+		ret = git_config_rename_section(argv[0], NULL);
+		if (ret < 0)
+			return ret;
+		if (ret == 0)
+			die("No such section!");
+	}
+	else if (actions == ACTION_GET_COLOR) {
+		get_color(argv[0]);
+	}
+	else if (actions == ACTION_GET_COLORBOOL) {
+		if (argc == 1)
+			color_stdout_is_tty = git_config_bool("command line", argv[0]);
+		return get_colorbool(argc != 0);
+	}
+
+	return 0;
+}
+
+int cmd_repo_config(int argc, const char **argv, const char *prefix)
+{
+	fprintf(stderr, "WARNING: git repo-config is deprecated in favor of git config.\n");
+	return cmd_config(argc, argv, prefix);
+}
diff --git a/builtin/count-objects.c b/builtin/count-objects.c
new file mode 100644
index 0000000..c37cb98
--- /dev/null
+++ b/builtin/count-objects.c
@@ -0,0 +1,130 @@
+/*
+ * Builtin "git count-objects".
+ *
+ * Copyright (c) 2006 Junio C Hamano
+ */
+
+#include "cache.h"
+#include "dir.h"
+#include "builtin.h"
+#include "parse-options.h"
+
+static void count_objects(DIR *d, char *path, int len, int verbose,
+			  unsigned long *loose,
+			  off_t *loose_size,
+			  unsigned long *packed_loose,
+			  unsigned long *garbage)
+{
+	struct dirent *ent;
+	while ((ent = readdir(d)) != NULL) {
+		char hex[41];
+		unsigned char sha1[20];
+		const char *cp;
+		int bad = 0;
+
+		if (is_dot_or_dotdot(ent->d_name))
+			continue;
+		for (cp = ent->d_name; *cp; cp++) {
+			int ch = *cp;
+			if (('0' <= ch && ch <= '9') ||
+			    ('a' <= ch && ch <= 'f'))
+				continue;
+			bad = 1;
+			break;
+		}
+		if (cp - ent->d_name != 38)
+			bad = 1;
+		else {
+			struct stat st;
+			memcpy(path + len + 3, ent->d_name, 38);
+			path[len + 2] = '/';
+			path[len + 41] = 0;
+			if (lstat(path, &st) || !S_ISREG(st.st_mode))
+				bad = 1;
+			else
+				(*loose_size) += xsize_t(on_disk_bytes(st));
+		}
+		if (bad) {
+			if (verbose) {
+				error("garbage found: %.*s/%s",
+				      len + 2, path, ent->d_name);
+				(*garbage)++;
+			}
+			continue;
+		}
+		(*loose)++;
+		if (!verbose)
+			continue;
+		memcpy(hex, path+len, 2);
+		memcpy(hex+2, ent->d_name, 38);
+		hex[40] = 0;
+		if (get_sha1_hex(hex, sha1))
+			die("internal error");
+		if (has_sha1_pack(sha1))
+			(*packed_loose)++;
+	}
+}
+
+static char const * const count_objects_usage[] = {
+	"git count-objects [-v]",
+	NULL
+};
+
+int cmd_count_objects(int argc, const char **argv, const char *prefix)
+{
+	int i, verbose = 0;
+	const char *objdir = get_object_directory();
+	int len = strlen(objdir);
+	char *path = xmalloc(len + 50);
+	unsigned long loose = 0, packed = 0, packed_loose = 0, garbage = 0;
+	off_t loose_size = 0;
+	struct option opts[] = {
+		OPT__VERBOSE(&verbose, "be verbose"),
+		OPT_END(),
+	};
+
+	argc = parse_options(argc, argv, prefix, opts, count_objects_usage, 0);
+	/* we do not take arguments other than flags for now */
+	if (argc)
+		usage_with_options(count_objects_usage, opts);
+	memcpy(path, objdir, len);
+	if (len && objdir[len-1] != '/')
+		path[len++] = '/';
+	for (i = 0; i < 256; i++) {
+		DIR *d;
+		sprintf(path + len, "%02x", i);
+		d = opendir(path);
+		if (!d)
+			continue;
+		count_objects(d, path, len, verbose,
+			      &loose, &loose_size, &packed_loose, &garbage);
+		closedir(d);
+	}
+	if (verbose) {
+		struct packed_git *p;
+		unsigned long num_pack = 0;
+		off_t size_pack = 0;
+		if (!packed_git)
+			prepare_packed_git();
+		for (p = packed_git; p; p = p->next) {
+			if (!p->pack_local)
+				continue;
+			if (open_pack_index(p))
+				continue;
+			packed += p->num_objects;
+			size_pack += p->pack_size + p->index_size;
+			num_pack++;
+		}
+		printf("count: %lu\n", loose);
+		printf("size: %lu\n", (unsigned long) (loose_size / 1024));
+		printf("in-pack: %lu\n", packed);
+		printf("packs: %lu\n", num_pack);
+		printf("size-pack: %lu\n", (unsigned long) (size_pack / 1024));
+		printf("prune-packable: %lu\n", packed_loose);
+		printf("garbage: %lu\n", garbage);
+	}
+	else
+		printf("%lu objects, %lu kilobytes\n",
+		       loose, (unsigned long) (loose_size / 1024));
+	return 0;
+}
diff --git a/builtin/describe.c b/builtin/describe.c
new file mode 100644
index 0000000..9f63067
--- /dev/null
+++ b/builtin/describe.c
@@ -0,0 +1,489 @@
+#include "cache.h"
+#include "commit.h"
+#include "tag.h"
+#include "refs.h"
+#include "builtin.h"
+#include "exec_cmd.h"
+#include "parse-options.h"
+#include "diff.h"
+#include "hash.h"
+
+#define SEEN		(1u<<0)
+#define MAX_TAGS	(FLAG_BITS - 1)
+
+static const char * const describe_usage[] = {
+	"git describe [options] <committish>*",
+	"git describe [options] --dirty",
+	NULL
+};
+
+static int debug;	/* Display lots of verbose info */
+static int all;	/* Any valid ref can be used */
+static int tags;	/* Allow lightweight tags */
+static int longformat;
+static int abbrev = -1; /* unspecified */
+static int max_candidates = 10;
+static struct hash_table names;
+static int have_util;
+static const char *pattern;
+static int always;
+static const char *dirty;
+
+/* diff-index command arguments to check if working tree is dirty. */
+static const char *diff_index_args[] = {
+	"diff-index", "--quiet", "HEAD", "--", NULL
+};
+
+
+struct commit_name {
+	struct commit_name *next;
+	unsigned char peeled[20];
+	struct tag *tag;
+	unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
+	unsigned name_checked:1;
+	unsigned char sha1[20];
+	const char *path;
+};
+static const char *prio_names[] = {
+	"head", "lightweight", "annotated",
+};
+
+static inline unsigned int hash_sha1(const unsigned char *sha1)
+{
+	unsigned int hash;
+	memcpy(&hash, sha1, sizeof(hash));
+	return hash;
+}
+
+static inline struct commit_name *find_commit_name(const unsigned char *peeled)
+{
+	struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
+	while (n && !!hashcmp(peeled, n->peeled))
+		n = n->next;
+	return n;
+}
+
+static int set_util(void *chain, void *data)
+{
+	struct commit_name *n;
+	for (n = chain; n; n = n->next) {
+		struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
+		if (c)
+			c->util = n;
+	}
+	return 0;
+}
+
+static int replace_name(struct commit_name *e,
+			       int prio,
+			       const unsigned char *sha1,
+			       struct tag **tag)
+{
+	if (!e || e->prio < prio)
+		return 1;
+
+	if (e->prio == 2 && prio == 2) {
+		/* Multiple annotated tags point to the same commit.
+		 * Select one to keep based upon their tagger date.
+		 */
+		struct tag *t;
+
+		if (!e->tag) {
+			t = lookup_tag(e->sha1);
+			if (!t || parse_tag(t))
+				return 1;
+			e->tag = t;
+		}
+
+		t = lookup_tag(sha1);
+		if (!t || parse_tag(t))
+			return 0;
+		*tag = t;
+
+		if (e->tag->date < t->date)
+			return 1;
+	}
+
+	return 0;
+}
+
+static void add_to_known_names(const char *path,
+			       const unsigned char *peeled,
+			       int prio,
+			       const unsigned char *sha1)
+{
+	struct commit_name *e = find_commit_name(peeled);
+	struct tag *tag = NULL;
+	if (replace_name(e, prio, sha1, &tag)) {
+		if (!e) {
+			void **pos;
+			e = xmalloc(sizeof(struct commit_name));
+			hashcpy(e->peeled, peeled);
+			pos = insert_hash(hash_sha1(peeled), e, &names);
+			if (pos) {
+				e->next = *pos;
+				*pos = e;
+			} else {
+				e->next = NULL;
+			}
+		}
+		e->tag = tag;
+		e->prio = prio;
+		e->name_checked = 0;
+		hashcpy(e->sha1, sha1);
+		e->path = path;
+	}
+}
+
+static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	int might_be_tag = !prefixcmp(path, "refs/tags/");
+	unsigned char peeled[20];
+	int is_tag, prio;
+
+	if (!all && !might_be_tag)
+		return 0;
+
+	if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
+		is_tag = !!hashcmp(sha1, peeled);
+	} else {
+		hashcpy(peeled, sha1);
+		is_tag = 0;
+	}
+
+	/* If --all, then any refs are used.
+	 * If --tags, then any tags are used.
+	 * Otherwise only annotated tags are used.
+	 */
+	if (might_be_tag) {
+		if (is_tag)
+			prio = 2;
+		else
+			prio = 1;
+
+		if (pattern && fnmatch(pattern, path + 10, 0))
+			prio = 0;
+	}
+	else
+		prio = 0;
+
+	if (!all) {
+		if (!prio)
+			return 0;
+	}
+	add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
+	return 0;
+}
+
+struct possible_tag {
+	struct commit_name *name;
+	int depth;
+	int found_order;
+	unsigned flag_within;
+};
+
+static int compare_pt(const void *a_, const void *b_)
+{
+	struct possible_tag *a = (struct possible_tag *)a_;
+	struct possible_tag *b = (struct possible_tag *)b_;
+	if (a->depth != b->depth)
+		return a->depth - b->depth;
+	if (a->found_order != b->found_order)
+		return a->found_order - b->found_order;
+	return 0;
+}
+
+static unsigned long finish_depth_computation(
+	struct commit_list **list,
+	struct possible_tag *best)
+{
+	unsigned long seen_commits = 0;
+	while (*list) {
+		struct commit *c = pop_commit(list);
+		struct commit_list *parents = c->parents;
+		seen_commits++;
+		if (c->object.flags & best->flag_within) {
+			struct commit_list *a = *list;
+			while (a) {
+				struct commit *i = a->item;
+				if (!(i->object.flags & best->flag_within))
+					break;
+				a = a->next;
+			}
+			if (!a)
+				break;
+		} else
+			best->depth++;
+		while (parents) {
+			struct commit *p = parents->item;
+			parse_commit(p);
+			if (!(p->object.flags & SEEN))
+				commit_list_insert_by_date(p, list);
+			p->object.flags |= c->object.flags;
+			parents = parents->next;
+		}
+	}
+	return seen_commits;
+}
+
+static void display_name(struct commit_name *n)
+{
+	if (n->prio == 2 && !n->tag) {
+		n->tag = lookup_tag(n->sha1);
+		if (!n->tag || parse_tag(n->tag))
+			die(_("annotated tag %s not available"), n->path);
+	}
+	if (n->tag && !n->name_checked) {
+		if (!n->tag->tag)
+			die(_("annotated tag %s has no embedded name"), n->path);
+		if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
+			warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
+		n->name_checked = 1;
+	}
+
+	if (n->tag)
+		printf("%s", n->tag->tag);
+	else
+		printf("%s", n->path);
+}
+
+static void show_suffix(int depth, const unsigned char *sha1)
+{
+	printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
+}
+
+static void describe(const char *arg, int last_one)
+{
+	unsigned char sha1[20];
+	struct commit *cmit, *gave_up_on = NULL;
+	struct commit_list *list;
+	struct commit_name *n;
+	struct possible_tag all_matches[MAX_TAGS];
+	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
+	unsigned long seen_commits = 0;
+	unsigned int unannotated_cnt = 0;
+
+	if (get_sha1(arg, sha1))
+		die(_("Not a valid object name %s"), arg);
+	cmit = lookup_commit_reference(sha1);
+	if (!cmit)
+		die(_("%s is not a valid '%s' object"), arg, commit_type);
+
+	n = find_commit_name(cmit->object.sha1);
+	if (n && (tags || all || n->prio == 2)) {
+		/*
+		 * Exact match to an existing ref.
+		 */
+		display_name(n);
+		if (longformat)
+			show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
+		if (dirty)
+			printf("%s", dirty);
+		printf("\n");
+		return;
+	}
+
+	if (!max_candidates)
+		die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
+	if (debug)
+		fprintf(stderr, _("searching to describe %s\n"), arg);
+
+	if (!have_util) {
+		for_each_hash(&names, set_util, NULL);
+		have_util = 1;
+	}
+
+	list = NULL;
+	cmit->object.flags = SEEN;
+	commit_list_insert(cmit, &list);
+	while (list) {
+		struct commit *c = pop_commit(&list);
+		struct commit_list *parents = c->parents;
+		seen_commits++;
+		n = c->util;
+		if (n) {
+			if (!tags && !all && n->prio < 2) {
+				unannotated_cnt++;
+			} else if (match_cnt < max_candidates) {
+				struct possible_tag *t = &all_matches[match_cnt++];
+				t->name = n;
+				t->depth = seen_commits - 1;
+				t->flag_within = 1u << match_cnt;
+				t->found_order = match_cnt;
+				c->object.flags |= t->flag_within;
+				if (n->prio == 2)
+					annotated_cnt++;
+			}
+			else {
+				gave_up_on = c;
+				break;
+			}
+		}
+		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
+			struct possible_tag *t = &all_matches[cur_match];
+			if (!(c->object.flags & t->flag_within))
+				t->depth++;
+		}
+		if (annotated_cnt && !list) {
+			if (debug)
+				fprintf(stderr, _("finished search at %s\n"),
+					sha1_to_hex(c->object.sha1));
+			break;
+		}
+		while (parents) {
+			struct commit *p = parents->item;
+			parse_commit(p);
+			if (!(p->object.flags & SEEN))
+				commit_list_insert_by_date(p, &list);
+			p->object.flags |= c->object.flags;
+			parents = parents->next;
+		}
+	}
+
+	if (!match_cnt) {
+		const unsigned char *sha1 = cmit->object.sha1;
+		if (always) {
+			printf("%s", find_unique_abbrev(sha1, abbrev));
+			if (dirty)
+				printf("%s", dirty);
+			printf("\n");
+			return;
+		}
+		if (unannotated_cnt)
+			die(_("No annotated tags can describe '%s'.\n"
+			    "However, there were unannotated tags: try --tags."),
+			    sha1_to_hex(sha1));
+		else
+			die(_("No tags can describe '%s'.\n"
+			    "Try --always, or create some tags."),
+			    sha1_to_hex(sha1));
+	}
+
+	qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
+
+	if (gave_up_on) {
+		commit_list_insert_by_date(gave_up_on, &list);
+		seen_commits--;
+	}
+	seen_commits += finish_depth_computation(&list, &all_matches[0]);
+	free_commit_list(list);
+
+	if (debug) {
+		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
+			struct possible_tag *t = &all_matches[cur_match];
+			fprintf(stderr, " %-11s %8d %s\n",
+				prio_names[t->name->prio],
+				t->depth, t->name->path);
+		}
+		fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
+		if (gave_up_on) {
+			fprintf(stderr,
+				_("more than %i tags found; listed %i most recent\n"
+				"gave up search at %s\n"),
+				max_candidates, max_candidates,
+				sha1_to_hex(gave_up_on->object.sha1));
+		}
+	}
+
+	display_name(all_matches[0].name);
+	if (abbrev)
+		show_suffix(all_matches[0].depth, cmit->object.sha1);
+	if (dirty)
+		printf("%s", dirty);
+	printf("\n");
+
+	if (!last_one)
+		clear_commit_marks(cmit, -1);
+}
+
+int cmd_describe(int argc, const char **argv, const char *prefix)
+{
+	int contains = 0;
+	struct option options[] = {
+		OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
+		OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
+		OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
+		OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
+		OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
+		OPT__ABBREV(&abbrev),
+		OPT_SET_INT(0, "exact-match", &max_candidates,
+			    "only output exact matches", 0),
+		OPT_INTEGER(0, "candidates", &max_candidates,
+			    "consider <n> most recent tags (default: 10)"),
+		OPT_STRING(0, "match",       &pattern, "pattern",
+			   "only consider tags matching <pattern>"),
+		OPT_BOOLEAN(0, "always",     &always,
+			   "show abbreviated commit object as fallback"),
+		{OPTION_STRING, 0, "dirty",  &dirty, "mark",
+			   "append <mark> on dirty working tree (default: \"-dirty\")",
+		 PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
+		OPT_END(),
+	};
+
+	git_config(git_default_config, NULL);
+	argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
+	if (abbrev < 0)
+		abbrev = DEFAULT_ABBREV;
+
+	if (max_candidates < 0)
+		max_candidates = 0;
+	else if (max_candidates > MAX_TAGS)
+		max_candidates = MAX_TAGS;
+
+	save_commit_buffer = 0;
+
+	if (longformat && abbrev == 0)
+		die(_("--long is incompatible with --abbrev=0"));
+
+	if (contains) {
+		const char **args = xmalloc((7 + argc) * sizeof(char *));
+		int i = 0;
+		args[i++] = "name-rev";
+		args[i++] = "--name-only";
+		args[i++] = "--no-undefined";
+		if (always)
+			args[i++] = "--always";
+		if (!all) {
+			args[i++] = "--tags";
+			if (pattern) {
+				char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
+				sprintf(s, "--refs=refs/tags/%s", pattern);
+				args[i++] = s;
+			}
+		}
+		memcpy(args + i, argv, argc * sizeof(char *));
+		args[i + argc] = NULL;
+		return cmd_name_rev(i + argc, args, prefix);
+	}
+
+	init_hash(&names);
+	for_each_rawref(get_name, NULL);
+	if (!names.nr && !always)
+		die(_("No names found, cannot describe anything."));
+
+	if (argc == 0) {
+		if (dirty) {
+			static struct lock_file index_lock;
+			int fd;
+
+			read_cache_preload(NULL);
+			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
+				      NULL, NULL, NULL);
+			fd = hold_locked_index(&index_lock, 0);
+			if (0 <= fd)
+				update_index_if_able(&the_index, &index_lock);
+
+			if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
+					    diff_index_args, prefix))
+				dirty = NULL;
+		}
+		describe("HEAD", 1);
+	} else if (dirty) {
+		die(_("--dirty is incompatible with committishes"));
+	} else {
+		while (argc-- > 0) {
+			describe(*argv++, argc == 0);
+		}
+	}
+	return 0;
+}
diff --git a/builtin/diff-files.c b/builtin/diff-files.c
new file mode 100644
index 0000000..46085f8
--- /dev/null
+++ b/builtin/diff-files.c
@@ -0,0 +1,70 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+#include "cache.h"
+#include "diff.h"
+#include "commit.h"
+#include "revision.h"
+#include "builtin.h"
+#include "submodule.h"
+
+static const char diff_files_usage[] =
+"git diff-files [-q] [-0/-1/2/3 |-c|--cc] [<common diff options>] [<path>...]"
+COMMON_DIFF_OPTIONS_HELP;
+
+int cmd_diff_files(int argc, const char **argv, const char *prefix)
+{
+	struct rev_info rev;
+	int result;
+	unsigned options = 0;
+
+	init_revisions(&rev, prefix);
+	gitmodules_config();
+	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
+	rev.abbrev = 0;
+
+	argc = setup_revisions(argc, argv, &rev, NULL);
+	while (1 < argc && argv[1][0] == '-') {
+		if (!strcmp(argv[1], "--base"))
+			rev.max_count = 1;
+		else if (!strcmp(argv[1], "--ours"))
+			rev.max_count = 2;
+		else if (!strcmp(argv[1], "--theirs"))
+			rev.max_count = 3;
+		else if (!strcmp(argv[1], "-q"))
+			options |= DIFF_SILENT_ON_REMOVED;
+		else
+			usage(diff_files_usage);
+		argv++; argc--;
+	}
+	if (!rev.diffopt.output_format)
+		rev.diffopt.output_format = DIFF_FORMAT_RAW;
+
+	/*
+	 * Make sure there are NO revision (i.e. pending object) parameter,
+	 * rev.max_count is reasonable (0 <= n <= 3), and
+	 * there is no other revision filtering parameters.
+	 */
+	if (rev.pending.nr ||
+	    rev.min_age != -1 || rev.max_age != -1 ||
+	    3 < rev.max_count)
+		usage(diff_files_usage);
+
+	/*
+	 * "diff-files --base -p" should not combine merges because it
+	 * was not asked to.  "diff-files -c -p" should not densify
+	 * (the user should ask with "diff-files --cc" explicitly).
+	 */
+	if (rev.max_count == -1 && !rev.combine_merges &&
+	    (rev.diffopt.output_format & DIFF_FORMAT_PATCH))
+		rev.combine_merges = rev.dense_combined_merges = 1;
+
+	if (read_cache_preload(rev.diffopt.pathspec.raw) < 0) {
+		perror("read_cache_preload");
+		return -1;
+	}
+	result = run_diff_files(&rev, options);
+	return diff_result_code(&rev.diffopt, result);
+}
diff --git a/builtin/diff-index.c b/builtin/diff-index.c
new file mode 100644
index 0000000..2eb32bd
--- /dev/null
+++ b/builtin/diff-index.c
@@ -0,0 +1,52 @@
+#include "cache.h"
+#include "diff.h"
+#include "commit.h"
+#include "revision.h"
+#include "builtin.h"
+#include "submodule.h"
+
+static const char diff_cache_usage[] =
+"git diff-index [-m] [--cached] "
+"[<common diff options>] <tree-ish> [<path>...]"
+COMMON_DIFF_OPTIONS_HELP;
+
+int cmd_diff_index(int argc, const char **argv, const char *prefix)
+{
+	struct rev_info rev;
+	int cached = 0;
+	int i;
+	int result;
+
+	init_revisions(&rev, prefix);
+	gitmodules_config();
+	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
+	rev.abbrev = 0;
+
+	argc = setup_revisions(argc, argv, &rev, NULL);
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+
+		if (!strcmp(arg, "--cached"))
+			cached = 1;
+		else
+			usage(diff_cache_usage);
+	}
+	if (!rev.diffopt.output_format)
+		rev.diffopt.output_format = DIFF_FORMAT_RAW;
+
+	/*
+	 * Make sure there is one revision (i.e. pending object),
+	 * and there is no revision filtering parameters.
+	 */
+	if (rev.pending.nr != 1 ||
+	    rev.max_count != -1 || rev.min_age != -1 || rev.max_age != -1)
+		usage(diff_cache_usage);
+	if (!cached)
+		setup_work_tree();
+	if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
+	result = run_diff_index(&rev, cached);
+	return diff_result_code(&rev.diffopt, result);
+}
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
new file mode 100644
index 0000000..be6417d
--- /dev/null
+++ b/builtin/diff-tree.c
@@ -0,0 +1,192 @@
+#include "cache.h"
+#include "diff.h"
+#include "commit.h"
+#include "log-tree.h"
+#include "builtin.h"
+#include "submodule.h"
+
+static struct rev_info log_tree_opt;
+
+static int diff_tree_commit_sha1(const unsigned char *sha1)
+{
+	struct commit *commit = lookup_commit_reference(sha1);
+	if (!commit)
+		return -1;
+	return log_tree_commit(&log_tree_opt, commit);
+}
+
+/* Diff one or more commits. */
+static int stdin_diff_commit(struct commit *commit, char *line, int len)
+{
+	unsigned char sha1[20];
+	if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
+		/* Graft the fake parents locally to the commit */
+		int pos = 41;
+		struct commit_list **pptr, *parents;
+
+		/* Free the real parent list */
+		for (parents = commit->parents; parents; ) {
+			struct commit_list *tmp = parents->next;
+			free(parents);
+			parents = tmp;
+		}
+		commit->parents = NULL;
+		pptr = &(commit->parents);
+		while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
+			struct commit *parent = lookup_commit(sha1);
+			if (parent) {
+				pptr = &commit_list_insert(parent, pptr)->next;
+			}
+			pos += 41;
+		}
+	}
+	return log_tree_commit(&log_tree_opt, commit);
+}
+
+/* Diff two trees. */
+static int stdin_diff_trees(struct tree *tree1, char *line, int len)
+{
+	unsigned char sha1[20];
+	struct tree *tree2;
+	if (len != 82 || !isspace(line[40]) || get_sha1_hex(line + 41, sha1))
+		return error("Need exactly two trees, separated by a space");
+	tree2 = lookup_tree(sha1);
+	if (!tree2 || parse_tree(tree2))
+		return -1;
+	printf("%s %s\n", sha1_to_hex(tree1->object.sha1),
+			  sha1_to_hex(tree2->object.sha1));
+	diff_tree_sha1(tree1->object.sha1, tree2->object.sha1,
+		       "", &log_tree_opt.diffopt);
+	log_tree_diff_flush(&log_tree_opt);
+	return 0;
+}
+
+static int diff_tree_stdin(char *line)
+{
+	int len = strlen(line);
+	unsigned char sha1[20];
+	struct object *obj;
+
+	if (!len || line[len-1] != '\n')
+		return -1;
+	line[len-1] = 0;
+	if (get_sha1_hex(line, sha1))
+		return -1;
+	obj = lookup_unknown_object(sha1);
+	if (!obj || !obj->parsed)
+		obj = parse_object(sha1);
+	if (!obj)
+		return -1;
+	if (obj->type == OBJ_COMMIT)
+		return stdin_diff_commit((struct commit *)obj, line, len);
+	if (obj->type == OBJ_TREE)
+		return stdin_diff_trees((struct tree *)obj, line, len);
+	error("Object %s is a %s, not a commit or tree",
+	      sha1_to_hex(sha1), typename(obj->type));
+	return -1;
+}
+
+static const char diff_tree_usage[] =
+"git diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
+"[<common diff options>] <tree-ish> [<tree-ish>] [<path>...]\n"
+"  -r            diff recursively\n"
+"  --root        include the initial commit as diff against /dev/null\n"
+COMMON_DIFF_OPTIONS_HELP;
+
+static void diff_tree_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
+{
+	if (!rev->diffopt.output_format) {
+		if (rev->dense_combined_merges)
+			rev->diffopt.output_format = DIFF_FORMAT_PATCH;
+		else
+			rev->diffopt.output_format = DIFF_FORMAT_RAW;
+	}
+}
+
+int cmd_diff_tree(int argc, const char **argv, const char *prefix)
+{
+	int nr_sha1;
+	char line[1000];
+	struct object *tree1, *tree2;
+	static struct rev_info *opt = &log_tree_opt;
+	struct setup_revision_opt s_r_opt;
+	int read_stdin = 0;
+
+	init_revisions(opt, prefix);
+	gitmodules_config();
+	git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
+	opt->abbrev = 0;
+	opt->diff = 1;
+	opt->disable_stdin = 1;
+	memset(&s_r_opt, 0, sizeof(s_r_opt));
+	s_r_opt.tweak = diff_tree_tweak_rev;
+	argc = setup_revisions(argc, argv, opt, &s_r_opt);
+
+	while (--argc > 0) {
+		const char *arg = *++argv;
+
+		if (!strcmp(arg, "--stdin")) {
+			read_stdin = 1;
+			continue;
+		}
+		usage(diff_tree_usage);
+	}
+
+	/*
+	 * NOTE! We expect "a ^b" to be equal to "a..b", so we
+	 * reverse the order of the objects if the second one
+	 * is marked UNINTERESTING.
+	 */
+	nr_sha1 = opt->pending.nr;
+	switch (nr_sha1) {
+	case 0:
+		if (!read_stdin)
+			usage(diff_tree_usage);
+		break;
+	case 1:
+		tree1 = opt->pending.objects[0].item;
+		diff_tree_commit_sha1(tree1->sha1);
+		break;
+	case 2:
+		tree1 = opt->pending.objects[0].item;
+		tree2 = opt->pending.objects[1].item;
+		if (tree2->flags & UNINTERESTING) {
+			struct object *tmp = tree2;
+			tree2 = tree1;
+			tree1 = tmp;
+		}
+		diff_tree_sha1(tree1->sha1,
+			       tree2->sha1,
+			       "", &opt->diffopt);
+		log_tree_diff_flush(opt);
+		break;
+	}
+
+	if (read_stdin) {
+		int saved_nrl = 0;
+		int saved_dcctc = 0;
+
+		if (opt->diffopt.detect_rename)
+			opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
+					       DIFF_SETUP_USE_CACHE);
+		while (fgets(line, sizeof(line), stdin)) {
+			unsigned char sha1[20];
+
+			if (get_sha1_hex(line, sha1)) {
+				fputs(line, stdout);
+				fflush(stdout);
+			}
+			else {
+				diff_tree_stdin(line);
+				if (saved_nrl < opt->diffopt.needed_rename_limit)
+					saved_nrl = opt->diffopt.needed_rename_limit;
+				if (opt->diffopt.degraded_cc_to_c)
+					saved_dcctc = 1;
+			}
+		}
+		opt->diffopt.degraded_cc_to_c = saved_dcctc;
+		opt->diffopt.needed_rename_limit = saved_nrl;
+	}
+
+	return diff_result_code(&opt->diffopt, 0);
+}
diff --git a/builtin/diff.c b/builtin/diff.c
new file mode 100644
index 0000000..1118689
--- /dev/null
+++ b/builtin/diff.c
@@ -0,0 +1,419 @@
+/*
+ * Builtin "git diff"
+ *
+ * Copyright (c) 2006 Junio C Hamano
+ */
+#include "cache.h"
+#include "color.h"
+#include "commit.h"
+#include "blob.h"
+#include "tag.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
+#include "log-tree.h"
+#include "builtin.h"
+#include "submodule.h"
+
+struct blobinfo {
+	unsigned char sha1[20];
+	const char *name;
+	unsigned mode;
+};
+
+static const char builtin_diff_usage[] =
+"git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
+
+static void stuff_change(struct diff_options *opt,
+			 unsigned old_mode, unsigned new_mode,
+			 const unsigned char *old_sha1,
+			 const unsigned char *new_sha1,
+			 const char *old_name,
+			 const char *new_name)
+{
+	struct diff_filespec *one, *two;
+
+	if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
+	    !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
+		return;
+
+	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
+		unsigned tmp;
+		const unsigned char *tmp_u;
+		const char *tmp_c;
+		tmp = old_mode; old_mode = new_mode; new_mode = tmp;
+		tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
+		tmp_c = old_name; old_name = new_name; new_name = tmp_c;
+	}
+
+	if (opt->prefix &&
+	    (strncmp(old_name, opt->prefix, opt->prefix_length) ||
+	     strncmp(new_name, opt->prefix, opt->prefix_length)))
+		return;
+
+	one = alloc_filespec(old_name);
+	two = alloc_filespec(new_name);
+	fill_filespec(one, old_sha1, old_mode);
+	fill_filespec(two, new_sha1, new_mode);
+
+	diff_queue(&diff_queued_diff, one, two);
+}
+
+static int builtin_diff_b_f(struct rev_info *revs,
+			    int argc, const char **argv,
+			    struct blobinfo *blob,
+			    const char *path)
+{
+	/* Blob vs file in the working tree*/
+	struct stat st;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (lstat(path, &st))
+		die_errno(_("failed to stat '%s'"), path);
+	if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
+		die(_("'%s': not a regular file or symlink"), path);
+
+	diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
+
+	if (blob[0].mode == S_IFINVALID)
+		blob[0].mode = canon_mode(st.st_mode);
+
+	stuff_change(&revs->diffopt,
+		     blob[0].mode, canon_mode(st.st_mode),
+		     blob[0].sha1, null_sha1,
+		     path, path);
+	diffcore_std(&revs->diffopt);
+	diff_flush(&revs->diffopt);
+	return 0;
+}
+
+static int builtin_diff_blobs(struct rev_info *revs,
+			      int argc, const char **argv,
+			      struct blobinfo *blob)
+{
+	unsigned mode = canon_mode(S_IFREG | 0644);
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (blob[0].mode == S_IFINVALID)
+		blob[0].mode = mode;
+
+	if (blob[1].mode == S_IFINVALID)
+		blob[1].mode = mode;
+
+	stuff_change(&revs->diffopt,
+		     blob[0].mode, blob[1].mode,
+		     blob[0].sha1, blob[1].sha1,
+		     blob[0].name, blob[1].name);
+	diffcore_std(&revs->diffopt);
+	diff_flush(&revs->diffopt);
+	return 0;
+}
+
+static int builtin_diff_index(struct rev_info *revs,
+			      int argc, const char **argv)
+{
+	int cached = 0;
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
+			cached = 1;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	if (!cached)
+		setup_work_tree();
+	/*
+	 * Make sure there is one revision (i.e. pending object),
+	 * and there is no revision filtering parameters.
+	 */
+	if (revs->pending.nr != 1 ||
+	    revs->max_count != -1 || revs->min_age != -1 ||
+	    revs->max_age != -1)
+		usage(builtin_diff_usage);
+	if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
+		perror("read_cache_preload");
+		return -1;
+	}
+	return run_diff_index(revs, cached);
+}
+
+static int builtin_diff_tree(struct rev_info *revs,
+			     int argc, const char **argv,
+			     struct object_array_entry *ent)
+{
+	const unsigned char *(sha1[2]);
+	int swap = 0;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	/* We saw two trees, ent[0] and ent[1].
+	 * if ent[1] is uninteresting, they are swapped
+	 */
+	if (ent[1].item->flags & UNINTERESTING)
+		swap = 1;
+	sha1[swap] = ent[0].item->sha1;
+	sha1[1-swap] = ent[1].item->sha1;
+	diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
+	log_tree_diff_flush(revs);
+	return 0;
+}
+
+static int builtin_diff_combined(struct rev_info *revs,
+				 int argc, const char **argv,
+				 struct object_array_entry *ent,
+				 int ents)
+{
+	const unsigned char (*parent)[20];
+	int i;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (!revs->dense_combined_merges && !revs->combine_merges)
+		revs->dense_combined_merges = revs->combine_merges = 1;
+	parent = xmalloc(ents * sizeof(*parent));
+	for (i = 0; i < ents; i++)
+		hashcpy((unsigned char *)(parent + i), ent[i].item->sha1);
+	diff_tree_combined(parent[0], parent + 1, ents - 1,
+			   revs->dense_combined_merges, revs);
+	free(parent);
+	return 0;
+}
+
+static void refresh_index_quietly(void)
+{
+	struct lock_file *lock_file;
+	int fd;
+
+	lock_file = xcalloc(1, sizeof(struct lock_file));
+	fd = hold_locked_index(lock_file, 0);
+	if (fd < 0)
+		return;
+	discard_cache();
+	read_cache();
+	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
+	update_index_if_able(&the_index, lock_file);
+}
+
+static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
+{
+	unsigned int options = 0;
+
+	while (1 < argc && argv[1][0] == '-') {
+		if (!strcmp(argv[1], "--base"))
+			revs->max_count = 1;
+		else if (!strcmp(argv[1], "--ours"))
+			revs->max_count = 2;
+		else if (!strcmp(argv[1], "--theirs"))
+			revs->max_count = 3;
+		else if (!strcmp(argv[1], "-q"))
+			options |= DIFF_SILENT_ON_REMOVED;
+		else if (!strcmp(argv[1], "-h"))
+			usage(builtin_diff_usage);
+		else
+			return error(_("invalid option: %s"), argv[1]);
+		argv++; argc--;
+	}
+
+	/*
+	 * "diff --base" should not combine merges because it was not
+	 * asked to.  "diff -c" should not densify (if the user wants
+	 * dense one, --cc can be explicitly asked for, or just rely
+	 * on the default).
+	 */
+	if (revs->max_count == -1 && !revs->combine_merges &&
+	    (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
+		revs->combine_merges = revs->dense_combined_merges = 1;
+
+	setup_work_tree();
+	if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
+		perror("read_cache_preload");
+		return -1;
+	}
+	return run_diff_files(revs, options);
+}
+
+int cmd_diff(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	struct rev_info rev;
+	struct object_array_entry ent[100];
+	int ents = 0, blobs = 0, paths = 0;
+	const char *path = NULL;
+	struct blobinfo blob[2];
+	int nongit;
+	int result = 0;
+
+	/*
+	 * We could get N tree-ish in the rev.pending_objects list.
+	 * Also there could be M blobs there, and P pathspecs.
+	 *
+	 * N=0, M=0:
+	 *	cache vs files (diff-files)
+	 * N=0, M=2:
+	 *      compare two random blobs.  P must be zero.
+	 * N=0, M=1, P=1:
+	 *	compare a blob with a working tree file.
+	 *
+	 * N=1, M=0:
+	 *      tree vs cache (diff-index --cached)
+	 *
+	 * N=2, M=0:
+	 *      tree vs tree (diff-tree)
+	 *
+	 * N=0, M=0, P=2:
+	 *      compare two filesystem entities (aka --no-index).
+	 *
+	 * Other cases are errors.
+	 */
+
+	prefix = setup_git_directory_gently(&nongit);
+	gitmodules_config();
+	git_config(git_diff_ui_config, NULL);
+
+	init_revisions(&rev, prefix);
+
+	/* If this is a no-index diff, just run it and exit there. */
+	diff_no_index(&rev, argc, argv, nongit, prefix);
+
+	/* Otherwise, we are doing the usual "git" diff */
+	rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
+
+	/* Default to let external and textconv be used */
+	DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
+	DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
+
+	if (nongit)
+		die(_("Not a git repository"));
+	argc = setup_revisions(argc, argv, &rev, NULL);
+	if (!rev.diffopt.output_format) {
+		rev.diffopt.output_format = DIFF_FORMAT_PATCH;
+		if (diff_setup_done(&rev.diffopt) < 0)
+			die(_("diff_setup_done failed"));
+	}
+
+	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
+
+	/*
+	 * If the user asked for our exit code then don't start a
+	 * pager or we would end up reporting its exit code instead.
+	 */
+	if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
+	    check_pager_config("diff") != 0)
+		setup_pager();
+
+	/*
+	 * Do we have --cached and not have a pending object, then
+	 * default to HEAD by hand.  Eek.
+	 */
+	if (!rev.pending.nr) {
+		int i;
+		for (i = 1; i < argc; i++) {
+			const char *arg = argv[i];
+			if (!strcmp(arg, "--"))
+				break;
+			else if (!strcmp(arg, "--cached") ||
+				 !strcmp(arg, "--staged")) {
+				add_head_to_pending(&rev);
+				if (!rev.pending.nr) {
+					struct tree *tree;
+					tree = lookup_tree((const unsigned char*)EMPTY_TREE_SHA1_BIN);
+					add_pending_object(&rev, &tree->object, "HEAD");
+				}
+				break;
+			}
+		}
+	}
+
+	for (i = 0; i < rev.pending.nr; i++) {
+		struct object_array_entry *list = rev.pending.objects+i;
+		struct object *obj = list->item;
+		const char *name = list->name;
+		int flags = (obj->flags & UNINTERESTING);
+		if (!obj->parsed)
+			obj = parse_object(obj->sha1);
+		obj = deref_tag(obj, NULL, 0);
+		if (!obj)
+			die(_("invalid object '%s' given."), name);
+		if (obj->type == OBJ_COMMIT)
+			obj = &((struct commit *)obj)->tree->object;
+		if (obj->type == OBJ_TREE) {
+			if (ARRAY_SIZE(ent) <= ents)
+				die(_("more than %d trees given: '%s'"),
+				    (int) ARRAY_SIZE(ent), name);
+			obj->flags |= flags;
+			ent[ents].item = obj;
+			ent[ents].name = name;
+			ents++;
+			continue;
+		}
+		if (obj->type == OBJ_BLOB) {
+			if (2 <= blobs)
+				die(_("more than two blobs given: '%s'"), name);
+			hashcpy(blob[blobs].sha1, obj->sha1);
+			blob[blobs].name = name;
+			blob[blobs].mode = list->mode;
+			blobs++;
+			continue;
+
+		}
+		die(_("unhandled object '%s' given."), name);
+	}
+	if (rev.prune_data.nr) {
+		if (!path)
+			path = rev.prune_data.items[0].match;
+		paths += rev.prune_data.nr;
+	}
+
+	/*
+	 * Now, do the arguments look reasonable?
+	 */
+	if (!ents) {
+		switch (blobs) {
+		case 0:
+			result = builtin_diff_files(&rev, argc, argv);
+			break;
+		case 1:
+			if (paths != 1)
+				usage(builtin_diff_usage);
+			result = builtin_diff_b_f(&rev, argc, argv, blob, path);
+			break;
+		case 2:
+			if (paths)
+				usage(builtin_diff_usage);
+			result = builtin_diff_blobs(&rev, argc, argv, blob);
+			break;
+		default:
+			usage(builtin_diff_usage);
+		}
+	}
+	else if (blobs)
+		usage(builtin_diff_usage);
+	else if (ents == 1)
+		result = builtin_diff_index(&rev, argc, argv);
+	else if (ents == 2)
+		result = builtin_diff_tree(&rev, argc, argv, ent);
+	else if (ent[0].item->flags & UNINTERESTING) {
+		/*
+		 * diff A...B where there is at least one merge base
+		 * between A and B.  We have ent[0] == merge-base,
+		 * ent[ents-2] == A, and ent[ents-1] == B.  Show diff
+		 * between the base and B.  Note that we pick one
+		 * merge base at random if there are more than one.
+		 */
+		ent[1] = ent[ents-1];
+		result = builtin_diff_tree(&rev, argc, argv, ent);
+	} else
+		result = builtin_diff_combined(&rev, argc, argv,
+					       ent, ents);
+	result = diff_result_code(&rev.diffopt, result);
+	if (1 < rev.diffopt.skip_stat_unmatch)
+		refresh_index_quietly();
+	return result;
+}
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
new file mode 100644
index 0000000..9836e6b
--- /dev/null
+++ b/builtin/fast-export.c
@@ -0,0 +1,705 @@
+/*
+ * "git fast-export" builtin command
+ *
+ * Copyright (C) 2007 Johannes E. Schindelin
+ */
+#include "builtin.h"
+#include "cache.h"
+#include "commit.h"
+#include "object.h"
+#include "tag.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "log-tree.h"
+#include "revision.h"
+#include "decorate.h"
+#include "string-list.h"
+#include "utf8.h"
+#include "parse-options.h"
+#include "quote.h"
+
+static const char *fast_export_usage[] = {
+	"git fast-export [rev-list-opts]",
+	NULL
+};
+
+static int progress;
+static enum { ABORT, VERBATIM, WARN, STRIP } signed_tag_mode = ABORT;
+static enum { ERROR, DROP, REWRITE } tag_of_filtered_mode = ABORT;
+static int fake_missing_tagger;
+static int use_done_feature;
+static int no_data;
+static int full_tree;
+
+static int parse_opt_signed_tag_mode(const struct option *opt,
+				     const char *arg, int unset)
+{
+	if (unset || !strcmp(arg, "abort"))
+		signed_tag_mode = ABORT;
+	else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
+		signed_tag_mode = VERBATIM;
+	else if (!strcmp(arg, "warn"))
+		signed_tag_mode = WARN;
+	else if (!strcmp(arg, "strip"))
+		signed_tag_mode = STRIP;
+	else
+		return error("Unknown signed-tag mode: %s", arg);
+	return 0;
+}
+
+static int parse_opt_tag_of_filtered_mode(const struct option *opt,
+					  const char *arg, int unset)
+{
+	if (unset || !strcmp(arg, "abort"))
+		tag_of_filtered_mode = ABORT;
+	else if (!strcmp(arg, "drop"))
+		tag_of_filtered_mode = DROP;
+	else if (!strcmp(arg, "rewrite"))
+		tag_of_filtered_mode = REWRITE;
+	else
+		return error("Unknown tag-of-filtered mode: %s", arg);
+	return 0;
+}
+
+static struct decoration idnums;
+static uint32_t last_idnum;
+
+static int has_unshown_parent(struct commit *commit)
+{
+	struct commit_list *parent;
+
+	for (parent = commit->parents; parent; parent = parent->next)
+		if (!(parent->item->object.flags & SHOWN) &&
+		    !(parent->item->object.flags & UNINTERESTING))
+			return 1;
+	return 0;
+}
+
+/* Since intptr_t is C99, we do not use it here */
+static inline uint32_t *mark_to_ptr(uint32_t mark)
+{
+	return ((uint32_t *)NULL) + mark;
+}
+
+static inline uint32_t ptr_to_mark(void * mark)
+{
+	return (uint32_t *)mark - (uint32_t *)NULL;
+}
+
+static inline void mark_object(struct object *object, uint32_t mark)
+{
+	add_decoration(&idnums, object, mark_to_ptr(mark));
+}
+
+static inline void mark_next_object(struct object *object)
+{
+	mark_object(object, ++last_idnum);
+}
+
+static int get_object_mark(struct object *object)
+{
+	void *decoration = lookup_decoration(&idnums, object);
+	if (!decoration)
+		return 0;
+	return ptr_to_mark(decoration);
+}
+
+static void show_progress(void)
+{
+	static int counter = 0;
+	if (!progress)
+		return;
+	if ((++counter % progress) == 0)
+		printf("progress %d objects\n", counter);
+}
+
+static void handle_object(const unsigned char *sha1)
+{
+	unsigned long size;
+	enum object_type type;
+	char *buf;
+	struct object *object;
+
+	if (no_data)
+		return;
+
+	if (is_null_sha1(sha1))
+		return;
+
+	object = parse_object(sha1);
+	if (!object)
+		die ("Could not read blob %s", sha1_to_hex(sha1));
+
+	if (object->flags & SHOWN)
+		return;
+
+	buf = read_sha1_file(sha1, &type, &size);
+	if (!buf)
+		die ("Could not read blob %s", sha1_to_hex(sha1));
+
+	mark_next_object(object);
+
+	printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
+	if (size && fwrite(buf, size, 1, stdout) != 1)
+		die_errno ("Could not write blob '%s'", sha1_to_hex(sha1));
+	printf("\n");
+
+	show_progress();
+
+	object->flags |= SHOWN;
+	free(buf);
+}
+
+static int depth_first(const void *a_, const void *b_)
+{
+	const struct diff_filepair *a = *((const struct diff_filepair **)a_);
+	const struct diff_filepair *b = *((const struct diff_filepair **)b_);
+	const char *name_a, *name_b;
+	int len_a, len_b, len;
+	int cmp;
+
+	name_a = a->one ? a->one->path : a->two->path;
+	name_b = b->one ? b->one->path : b->two->path;
+
+	len_a = strlen(name_a);
+	len_b = strlen(name_b);
+	len = (len_a < len_b) ? len_a : len_b;
+
+	/* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
+	cmp = memcmp(name_a, name_b, len);
+	if (cmp)
+		return cmp;
+	cmp = len_b - len_a;
+	if (cmp)
+		return cmp;
+	/*
+	 * Move 'R'ename entries last so that all references of the file
+	 * appear in the output before it is renamed (e.g., when a file
+	 * was copied and renamed in the same commit).
+	 */
+	return (a->status == 'R') - (b->status == 'R');
+}
+
+static void print_path(const char *path)
+{
+	int need_quote = quote_c_style(path, NULL, NULL, 0);
+	if (need_quote)
+		quote_c_style(path, NULL, stdout, 0);
+	else
+		printf("%s", path);
+}
+
+static void show_filemodify(struct diff_queue_struct *q,
+			    struct diff_options *options, void *data)
+{
+	int i;
+
+	/*
+	 * Handle files below a directory first, in case they are all deleted
+	 * and the directory changes to a file or symlink.
+	 */
+	qsort(q->queue, q->nr, sizeof(q->queue[0]), depth_first);
+
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filespec *ospec = q->queue[i]->one;
+		struct diff_filespec *spec = q->queue[i]->two;
+
+		switch (q->queue[i]->status) {
+		case DIFF_STATUS_DELETED:
+			printf("D ");
+			print_path(spec->path);
+			putchar('\n');
+			break;
+
+		case DIFF_STATUS_COPIED:
+		case DIFF_STATUS_RENAMED:
+			printf("%c ", q->queue[i]->status);
+			print_path(ospec->path);
+			putchar(' ');
+			print_path(spec->path);
+			putchar('\n');
+
+			if (!hashcmp(ospec->sha1, spec->sha1) &&
+			    ospec->mode == spec->mode)
+				break;
+			/* fallthrough */
+
+		case DIFF_STATUS_TYPE_CHANGED:
+		case DIFF_STATUS_MODIFIED:
+		case DIFF_STATUS_ADDED:
+			/*
+			 * Links refer to objects in another repositories;
+			 * output the SHA-1 verbatim.
+			 */
+			if (no_data || S_ISGITLINK(spec->mode))
+				printf("M %06o %s ", spec->mode,
+				       sha1_to_hex(spec->sha1));
+			else {
+				struct object *object = lookup_object(spec->sha1);
+				printf("M %06o :%d ", spec->mode,
+				       get_object_mark(object));
+			}
+			print_path(spec->path);
+			putchar('\n');
+			break;
+
+		default:
+			die("Unexpected comparison status '%c' for %s, %s",
+				q->queue[i]->status,
+				ospec->path ? ospec->path : "none",
+				spec->path ? spec->path : "none");
+		}
+	}
+}
+
+static const char *find_encoding(const char *begin, const char *end)
+{
+	const char *needle = "\nencoding ";
+	char *bol, *eol;
+
+	bol = memmem(begin, end ? end - begin : strlen(begin),
+		     needle, strlen(needle));
+	if (!bol)
+		return git_commit_encoding;
+	bol += strlen(needle);
+	eol = strchrnul(bol, '\n');
+	*eol = '\0';
+	return bol;
+}
+
+static void handle_commit(struct commit *commit, struct rev_info *rev)
+{
+	int saved_output_format = rev->diffopt.output_format;
+	const char *author, *author_end, *committer, *committer_end;
+	const char *encoding, *message;
+	char *reencoded = NULL;
+	struct commit_list *p;
+	int i;
+
+	rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
+
+	parse_commit(commit);
+	author = strstr(commit->buffer, "\nauthor ");
+	if (!author)
+		die ("Could not find author in commit %s",
+		     sha1_to_hex(commit->object.sha1));
+	author++;
+	author_end = strchrnul(author, '\n');
+	committer = strstr(author_end, "\ncommitter ");
+	if (!committer)
+		die ("Could not find committer in commit %s",
+		     sha1_to_hex(commit->object.sha1));
+	committer++;
+	committer_end = strchrnul(committer, '\n');
+	message = strstr(committer_end, "\n\n");
+	encoding = find_encoding(committer_end, message);
+	if (message)
+		message += 2;
+
+	if (commit->parents &&
+	    get_object_mark(&commit->parents->item->object) != 0 &&
+	    !full_tree) {
+		parse_commit(commit->parents->item);
+		diff_tree_sha1(commit->parents->item->tree->object.sha1,
+			       commit->tree->object.sha1, "", &rev->diffopt);
+	}
+	else
+		diff_root_tree_sha1(commit->tree->object.sha1,
+				    "", &rev->diffopt);
+
+	/* Export the referenced blobs, and remember the marks. */
+	for (i = 0; i < diff_queued_diff.nr; i++)
+		if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
+			handle_object(diff_queued_diff.queue[i]->two->sha1);
+
+	mark_next_object(&commit->object);
+	if (!is_encoding_utf8(encoding))
+		reencoded = reencode_string(message, "UTF-8", encoding);
+	if (!commit->parents)
+		printf("reset %s\n", (const char*)commit->util);
+	printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
+	       (const char *)commit->util, last_idnum,
+	       (int)(author_end - author), author,
+	       (int)(committer_end - committer), committer,
+	       (unsigned)(reencoded
+			  ? strlen(reencoded) : message
+			  ? strlen(message) : 0),
+	       reencoded ? reencoded : message ? message : "");
+	free(reencoded);
+
+	for (i = 0, p = commit->parents; p; p = p->next) {
+		int mark = get_object_mark(&p->item->object);
+		if (!mark)
+			continue;
+		if (i == 0)
+			printf("from :%d\n", mark);
+		else
+			printf("merge :%d\n", mark);
+		i++;
+	}
+
+	if (full_tree)
+		printf("deleteall\n");
+	log_tree_diff_flush(rev);
+	rev->diffopt.output_format = saved_output_format;
+
+	printf("\n");
+
+	show_progress();
+}
+
+static void handle_tail(struct object_array *commits, struct rev_info *revs)
+{
+	struct commit *commit;
+	while (commits->nr) {
+		commit = (struct commit *)commits->objects[commits->nr - 1].item;
+		if (has_unshown_parent(commit))
+			return;
+		handle_commit(commit, revs);
+		commits->nr--;
+	}
+}
+
+static void handle_tag(const char *name, struct tag *tag)
+{
+	unsigned long size;
+	enum object_type type;
+	char *buf;
+	const char *tagger, *tagger_end, *message;
+	size_t message_size = 0;
+	struct object *tagged;
+	int tagged_mark;
+	struct commit *p;
+
+	/* Trees have no identifer in fast-export output, thus we have no way
+	 * to output tags of trees, tags of tags of trees, etc.  Simply omit
+	 * such tags.
+	 */
+	tagged = tag->tagged;
+	while (tagged->type == OBJ_TAG) {
+		tagged = ((struct tag *)tagged)->tagged;
+	}
+	if (tagged->type == OBJ_TREE) {
+		warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
+			sha1_to_hex(tag->object.sha1));
+		return;
+	}
+
+	buf = read_sha1_file(tag->object.sha1, &type, &size);
+	if (!buf)
+		die ("Could not read tag %s", sha1_to_hex(tag->object.sha1));
+	message = memmem(buf, size, "\n\n", 2);
+	if (message) {
+		message += 2;
+		message_size = strlen(message);
+	}
+	tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
+	if (!tagger) {
+		if (fake_missing_tagger)
+			tagger = "tagger Unspecified Tagger "
+				"<unspecified-tagger> 0 +0000";
+		else
+			tagger = "";
+		tagger_end = tagger + strlen(tagger);
+	} else {
+		tagger++;
+		tagger_end = strchrnul(tagger, '\n');
+	}
+
+	/* handle signed tags */
+	if (message) {
+		const char *signature = strstr(message,
+					       "\n-----BEGIN PGP SIGNATURE-----\n");
+		if (signature)
+			switch(signed_tag_mode) {
+			case ABORT:
+				die ("Encountered signed tag %s; use "
+				     "--signed-tag=<mode> to handle it.",
+				     sha1_to_hex(tag->object.sha1));
+			case WARN:
+				warning ("Exporting signed tag %s",
+					 sha1_to_hex(tag->object.sha1));
+				/* fallthru */
+			case VERBATIM:
+				break;
+			case STRIP:
+				message_size = signature + 1 - message;
+				break;
+			}
+	}
+
+	/* handle tag->tagged having been filtered out due to paths specified */
+	tagged = tag->tagged;
+	tagged_mark = get_object_mark(tagged);
+	if (!tagged_mark) {
+		switch(tag_of_filtered_mode) {
+		case ABORT:
+			die ("Tag %s tags unexported object; use "
+			     "--tag-of-filtered-object=<mode> to handle it.",
+			     sha1_to_hex(tag->object.sha1));
+		case DROP:
+			/* Ignore this tag altogether */
+			return;
+		case REWRITE:
+			if (tagged->type != OBJ_COMMIT) {
+				die ("Tag %s tags unexported %s!",
+				     sha1_to_hex(tag->object.sha1),
+				     typename(tagged->type));
+			}
+			p = (struct commit *)tagged;
+			for (;;) {
+				if (p->parents && p->parents->next)
+					break;
+				if (p->object.flags & UNINTERESTING)
+					break;
+				if (!(p->object.flags & TREESAME))
+					break;
+				if (!p->parents)
+					die ("Can't find replacement commit for tag %s\n",
+					     sha1_to_hex(tag->object.sha1));
+				p = p->parents->item;
+			}
+			tagged_mark = get_object_mark(&p->object);
+		}
+	}
+
+	if (!prefixcmp(name, "refs/tags/"))
+		name += 10;
+	printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
+	       name, tagged_mark,
+	       (int)(tagger_end - tagger), tagger,
+	       tagger == tagger_end ? "" : "\n",
+	       (int)message_size, (int)message_size, message ? message : "");
+}
+
+static void get_tags_and_duplicates(struct object_array *pending,
+				    struct string_list *extra_refs)
+{
+	struct tag *tag;
+	int i;
+
+	for (i = 0; i < pending->nr; i++) {
+		struct object_array_entry *e = pending->objects + i;
+		unsigned char sha1[20];
+		struct commit *commit = commit;
+		char *full_name;
+
+		if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
+			continue;
+
+		switch (e->item->type) {
+		case OBJ_COMMIT:
+			commit = (struct commit *)e->item;
+			break;
+		case OBJ_TAG:
+			tag = (struct tag *)e->item;
+
+			/* handle nested tags */
+			while (tag && tag->object.type == OBJ_TAG) {
+				parse_object(tag->object.sha1);
+				string_list_append(extra_refs, full_name)->util = tag;
+				tag = (struct tag *)tag->tagged;
+			}
+			if (!tag)
+				die ("Tag %s points nowhere?", e->name);
+			switch(tag->object.type) {
+			case OBJ_COMMIT:
+				commit = (struct commit *)tag;
+				break;
+			case OBJ_BLOB:
+				handle_object(tag->object.sha1);
+				continue;
+			default: /* OBJ_TAG (nested tags) is already handled */
+				warning("Tag points to object of unexpected type %s, skipping.",
+					typename(tag->object.type));
+				continue;
+			}
+			break;
+		default:
+			warning("%s: Unexpected object of type %s, skipping.",
+				e->name,
+				typename(e->item->type));
+			continue;
+		}
+		if (commit->util)
+			/* more than one name for the same object */
+			string_list_append(extra_refs, full_name)->util = commit;
+		else
+			commit->util = full_name;
+	}
+}
+
+static void handle_tags_and_duplicates(struct string_list *extra_refs)
+{
+	struct commit *commit;
+	int i;
+
+	for (i = extra_refs->nr - 1; i >= 0; i--) {
+		const char *name = extra_refs->items[i].string;
+		struct object *object = extra_refs->items[i].util;
+		switch (object->type) {
+		case OBJ_TAG:
+			handle_tag(name, (struct tag *)object);
+			break;
+		case OBJ_COMMIT:
+			/* create refs pointing to already seen commits */
+			commit = (struct commit *)object;
+			printf("reset %s\nfrom :%d\n\n", name,
+			       get_object_mark(&commit->object));
+			show_progress();
+			break;
+		}
+	}
+}
+
+static void export_marks(char *file)
+{
+	unsigned int i;
+	uint32_t mark;
+	struct object_decoration *deco = idnums.hash;
+	FILE *f;
+	int e = 0;
+
+	f = fopen(file, "w");
+	if (!f)
+		die_errno("Unable to open marks file %s for writing.", file);
+
+	for (i = 0; i < idnums.size; i++) {
+		if (deco->base && deco->base->type == 1) {
+			mark = ptr_to_mark(deco->decoration);
+			if (fprintf(f, ":%"PRIu32" %s\n", mark,
+				sha1_to_hex(deco->base->sha1)) < 0) {
+			    e = 1;
+			    break;
+			}
+		}
+		deco++;
+	}
+
+	e |= ferror(f);
+	e |= fclose(f);
+	if (e)
+		error("Unable to write marks file %s.", file);
+}
+
+static void import_marks(char *input_file)
+{
+	char line[512];
+	FILE *f = fopen(input_file, "r");
+	if (!f)
+		die_errno("cannot read '%s'", input_file);
+
+	while (fgets(line, sizeof(line), f)) {
+		uint32_t mark;
+		char *line_end, *mark_end;
+		unsigned char sha1[20];
+		struct object *object;
+
+		line_end = strchr(line, '\n');
+		if (line[0] != ':' || !line_end)
+			die("corrupt mark line: %s", line);
+		*line_end = '\0';
+
+		mark = strtoumax(line + 1, &mark_end, 10);
+		if (!mark || mark_end == line + 1
+			|| *mark_end != ' ' || get_sha1(mark_end + 1, sha1))
+			die("corrupt mark line: %s", line);
+
+		object = parse_object(sha1);
+		if (!object)
+			die ("Could not read blob %s", sha1_to_hex(sha1));
+
+		if (object->flags & SHOWN)
+			error("Object %s already has a mark", sha1);
+
+		mark_object(object, mark);
+		if (last_idnum < mark)
+			last_idnum = mark;
+
+		object->flags |= SHOWN;
+	}
+	fclose(f);
+}
+
+int cmd_fast_export(int argc, const char **argv, const char *prefix)
+{
+	struct rev_info revs;
+	struct object_array commits = OBJECT_ARRAY_INIT;
+	struct string_list extra_refs = STRING_LIST_INIT_NODUP;
+	struct commit *commit;
+	char *export_filename = NULL, *import_filename = NULL;
+	struct option options[] = {
+		OPT_INTEGER(0, "progress", &progress,
+			    "show progress after <n> objects"),
+		OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, "mode",
+			     "select handling of signed tags",
+			     parse_opt_signed_tag_mode),
+		OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, "mode",
+			     "select handling of tags that tag filtered objects",
+			     parse_opt_tag_of_filtered_mode),
+		OPT_STRING(0, "export-marks", &export_filename, "file",
+			     "Dump marks to this file"),
+		OPT_STRING(0, "import-marks", &import_filename, "file",
+			     "Import marks from this file"),
+		OPT_BOOLEAN(0, "fake-missing-tagger", &fake_missing_tagger,
+			     "Fake a tagger when tags lack one"),
+		OPT_BOOLEAN(0, "full-tree", &full_tree,
+			     "Output full tree for each commit"),
+		OPT_BOOLEAN(0, "use-done-feature", &use_done_feature,
+			     "Use the done feature to terminate the stream"),
+		{ OPTION_NEGBIT, 0, "data", &no_data, NULL,
+			"Skip output of blob data",
+			PARSE_OPT_NOARG | PARSE_OPT_NEGHELP, NULL, 1 },
+		OPT_END()
+	};
+
+	if (argc == 1)
+		usage_with_options (fast_export_usage, options);
+
+	/* we handle encodings */
+	git_config(git_default_config, NULL);
+
+	init_revisions(&revs, prefix);
+	revs.topo_order = 1;
+	revs.show_source = 1;
+	revs.rewrite_parents = 1;
+	argc = setup_revisions(argc, argv, &revs, NULL);
+	argc = parse_options(argc, argv, prefix, options, fast_export_usage, 0);
+	if (argc > 1)
+		usage_with_options (fast_export_usage, options);
+
+	if (use_done_feature)
+		printf("feature done\n");
+
+	if (import_filename)
+		import_marks(import_filename);
+
+	if (import_filename && revs.prune_data.nr)
+		full_tree = 1;
+
+	get_tags_and_duplicates(&revs.pending, &extra_refs);
+
+	if (prepare_revision_walk(&revs))
+		die("revision walk setup failed");
+	revs.diffopt.format_callback = show_filemodify;
+	DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
+	while ((commit = get_revision(&revs))) {
+		if (has_unshown_parent(commit)) {
+			add_object_array(&commit->object, NULL, &commits);
+		}
+		else {
+			handle_commit(commit, &revs);
+			handle_tail(&commits, &revs);
+		}
+	}
+
+	handle_tags_and_duplicates(&extra_refs);
+
+	if (export_filename)
+		export_marks(export_filename);
+
+	if (use_done_feature)
+		printf("done\n");
+
+	return 0;
+}
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
new file mode 100644
index 0000000..412bd32
--- /dev/null
+++ b/builtin/fetch-pack.c
@@ -0,0 +1,1055 @@
+#include "builtin.h"
+#include "refs.h"
+#include "pkt-line.h"
+#include "commit.h"
+#include "tag.h"
+#include "exec_cmd.h"
+#include "pack.h"
+#include "sideband.h"
+#include "fetch-pack.h"
+#include "remote.h"
+#include "run-command.h"
+#include "transport.h"
+
+static int transfer_unpack_limit = -1;
+static int fetch_unpack_limit = -1;
+static int unpack_limit = 100;
+static int prefer_ofs_delta = 1;
+static int no_done = 0;
+static struct fetch_pack_args args = {
+	/* .uploadpack = */ "git-upload-pack",
+};
+
+static const char fetch_pack_usage[] =
+"git fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
+
+#define COMPLETE	(1U << 0)
+#define COMMON		(1U << 1)
+#define COMMON_REF	(1U << 2)
+#define SEEN		(1U << 3)
+#define POPPED		(1U << 4)
+
+static int marked;
+
+/*
+ * After sending this many "have"s if we do not get any new ACK , we
+ * give up traversing our history.
+ */
+#define MAX_IN_VAIN 256
+
+static struct commit_list *rev_list;
+static int non_common_revs, multi_ack, use_sideband;
+
+static void rev_list_push(struct commit *commit, int mark)
+{
+	if (!(commit->object.flags & mark)) {
+		commit->object.flags |= mark;
+
+		if (!(commit->object.parsed))
+			if (parse_commit(commit))
+				return;
+
+		commit_list_insert_by_date(commit, &rev_list);
+
+		if (!(commit->object.flags & COMMON))
+			non_common_revs++;
+	}
+}
+
+static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *o = deref_tag(parse_object(sha1), path, 0);
+
+	if (o && o->type == OBJ_COMMIT)
+		rev_list_push((struct commit *)o, SEEN);
+
+	return 0;
+}
+
+static int clear_marks(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *o = deref_tag(parse_object(sha1), path, 0);
+
+	if (o && o->type == OBJ_COMMIT)
+		clear_commit_marks((struct commit *)o,
+				   COMMON | COMMON_REF | SEEN | POPPED);
+	return 0;
+}
+
+/*
+   This function marks a rev and its ancestors as common.
+   In some cases, it is desirable to mark only the ancestors (for example
+   when only the server does not yet know that they are common).
+*/
+
+static void mark_common(struct commit *commit,
+		int ancestors_only, int dont_parse)
+{
+	if (commit != NULL && !(commit->object.flags & COMMON)) {
+		struct object *o = (struct object *)commit;
+
+		if (!ancestors_only)
+			o->flags |= COMMON;
+
+		if (!(o->flags & SEEN))
+			rev_list_push(commit, SEEN);
+		else {
+			struct commit_list *parents;
+
+			if (!ancestors_only && !(o->flags & POPPED))
+				non_common_revs--;
+			if (!o->parsed && !dont_parse)
+				if (parse_commit(commit))
+					return;
+
+			for (parents = commit->parents;
+					parents;
+					parents = parents->next)
+				mark_common(parents->item, 0, dont_parse);
+		}
+	}
+}
+
+/*
+  Get the next rev to send, ignoring the common.
+*/
+
+static const unsigned char *get_rev(void)
+{
+	struct commit *commit = NULL;
+
+	while (commit == NULL) {
+		unsigned int mark;
+		struct commit_list *parents;
+
+		if (rev_list == NULL || non_common_revs == 0)
+			return NULL;
+
+		commit = rev_list->item;
+		if (!commit->object.parsed)
+			parse_commit(commit);
+		parents = commit->parents;
+
+		commit->object.flags |= POPPED;
+		if (!(commit->object.flags & COMMON))
+			non_common_revs--;
+
+		if (commit->object.flags & COMMON) {
+			/* do not send "have", and ignore ancestors */
+			commit = NULL;
+			mark = COMMON | SEEN;
+		} else if (commit->object.flags & COMMON_REF)
+			/* send "have", and ignore ancestors */
+			mark = COMMON | SEEN;
+		else
+			/* send "have", also for its ancestors */
+			mark = SEEN;
+
+		while (parents) {
+			if (!(parents->item->object.flags & SEEN))
+				rev_list_push(parents->item, mark);
+			if (mark & COMMON)
+				mark_common(parents->item, 1, 0);
+			parents = parents->next;
+		}
+
+		rev_list = rev_list->next;
+	}
+
+	return commit->object.sha1;
+}
+
+enum ack_type {
+	NAK = 0,
+	ACK,
+	ACK_continue,
+	ACK_common,
+	ACK_ready
+};
+
+static void consume_shallow_list(int fd)
+{
+	if (args.stateless_rpc && args.depth > 0) {
+		/* If we sent a depth we will get back "duplicate"
+		 * shallow and unshallow commands every time there
+		 * is a block of have lines exchanged.
+		 */
+		char line[1000];
+		while (packet_read_line(fd, line, sizeof(line))) {
+			if (!prefixcmp(line, "shallow "))
+				continue;
+			if (!prefixcmp(line, "unshallow "))
+				continue;
+			die("git fetch-pack: expected shallow list");
+		}
+	}
+}
+
+struct write_shallow_data {
+	struct strbuf *out;
+	int use_pack_protocol;
+	int count;
+};
+
+static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
+{
+	struct write_shallow_data *data = cb_data;
+	const char *hex = sha1_to_hex(graft->sha1);
+	data->count++;
+	if (data->use_pack_protocol)
+		packet_buf_write(data->out, "shallow %s", hex);
+	else {
+		strbuf_addstr(data->out, hex);
+		strbuf_addch(data->out, '\n');
+	}
+	return 0;
+}
+
+static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
+{
+	struct write_shallow_data data;
+	data.out = out;
+	data.use_pack_protocol = use_pack_protocol;
+	data.count = 0;
+	for_each_commit_graft(write_one_shallow, &data);
+	return data.count;
+}
+
+static enum ack_type get_ack(int fd, unsigned char *result_sha1)
+{
+	static char line[1000];
+	int len = packet_read_line(fd, line, sizeof(line));
+
+	if (!len)
+		die("git fetch-pack: expected ACK/NAK, got EOF");
+	if (line[len-1] == '\n')
+		line[--len] = 0;
+	if (!strcmp(line, "NAK"))
+		return NAK;
+	if (!prefixcmp(line, "ACK ")) {
+		if (!get_sha1_hex(line+4, result_sha1)) {
+			if (strstr(line+45, "continue"))
+				return ACK_continue;
+			if (strstr(line+45, "common"))
+				return ACK_common;
+			if (strstr(line+45, "ready"))
+				return ACK_ready;
+			return ACK;
+		}
+	}
+	die("git fetch_pack: expected ACK/NAK, got '%s'", line);
+}
+
+static void send_request(int fd, struct strbuf *buf)
+{
+	if (args.stateless_rpc) {
+		send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
+		packet_flush(fd);
+	} else
+		safe_write(fd, buf->buf, buf->len);
+}
+
+static void insert_one_alternate_ref(const struct ref *ref, void *unused)
+{
+	rev_list_insert_ref(NULL, ref->old_sha1, 0, NULL);
+}
+
+static void insert_alternate_refs(void)
+{
+	for_each_alternate_ref(insert_one_alternate_ref, NULL);
+}
+
+#define INITIAL_FLUSH 16
+#define PIPESAFE_FLUSH 32
+#define LARGE_FLUSH 1024
+
+static int next_flush(int count)
+{
+	int flush_limit = args.stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
+
+	if (count < flush_limit)
+		count <<= 1;
+	else
+		count += flush_limit;
+	return count;
+}
+
+static int find_common(int fd[2], unsigned char *result_sha1,
+		       struct ref *refs)
+{
+	int fetching;
+	int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
+	const unsigned char *sha1;
+	unsigned in_vain = 0;
+	int got_continue = 0;
+	int got_ready = 0;
+	struct strbuf req_buf = STRBUF_INIT;
+	size_t state_len = 0;
+
+	if (args.stateless_rpc && multi_ack == 1)
+		die("--stateless-rpc requires multi_ack_detailed");
+	if (marked)
+		for_each_ref(clear_marks, NULL);
+	marked = 1;
+
+	for_each_ref(rev_list_insert_ref, NULL);
+	insert_alternate_refs();
+
+	fetching = 0;
+	for ( ; refs ; refs = refs->next) {
+		unsigned char *remote = refs->old_sha1;
+		const char *remote_hex;
+		struct object *o;
+
+		/*
+		 * If that object is complete (i.e. it is an ancestor of a
+		 * local ref), we tell them we have it but do not have to
+		 * tell them about its ancestors, which they already know
+		 * about.
+		 *
+		 * We use lookup_object here because we are only
+		 * interested in the case we *know* the object is
+		 * reachable and we have already scanned it.
+		 */
+		if (((o = lookup_object(remote)) != NULL) &&
+				(o->flags & COMPLETE)) {
+			continue;
+		}
+
+		remote_hex = sha1_to_hex(remote);
+		if (!fetching) {
+			struct strbuf c = STRBUF_INIT;
+			if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
+			if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
+			if (no_done)            strbuf_addstr(&c, " no-done");
+			if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
+			if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
+			if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
+			if (args.no_progress)   strbuf_addstr(&c, " no-progress");
+			if (args.include_tag)   strbuf_addstr(&c, " include-tag");
+			if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
+			packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
+			strbuf_release(&c);
+		} else
+			packet_buf_write(&req_buf, "want %s\n", remote_hex);
+		fetching++;
+	}
+
+	if (!fetching) {
+		strbuf_release(&req_buf);
+		packet_flush(fd[1]);
+		return 1;
+	}
+
+	if (is_repository_shallow())
+		write_shallow_commits(&req_buf, 1);
+	if (args.depth > 0)
+		packet_buf_write(&req_buf, "deepen %d", args.depth);
+	packet_buf_flush(&req_buf);
+	state_len = req_buf.len;
+
+	if (args.depth > 0) {
+		char line[1024];
+		unsigned char sha1[20];
+
+		send_request(fd[1], &req_buf);
+		while (packet_read_line(fd[0], line, sizeof(line))) {
+			if (!prefixcmp(line, "shallow ")) {
+				if (get_sha1_hex(line + 8, sha1))
+					die("invalid shallow line: %s", line);
+				register_shallow(sha1);
+				continue;
+			}
+			if (!prefixcmp(line, "unshallow ")) {
+				if (get_sha1_hex(line + 10, sha1))
+					die("invalid unshallow line: %s", line);
+				if (!lookup_object(sha1))
+					die("object not found: %s", line);
+				/* make sure that it is parsed as shallow */
+				if (!parse_object(sha1))
+					die("error in object: %s", line);
+				if (unregister_shallow(sha1))
+					die("no shallow found: %s", line);
+				continue;
+			}
+			die("expected shallow/unshallow, got %s", line);
+		}
+	} else if (!args.stateless_rpc)
+		send_request(fd[1], &req_buf);
+
+	if (!args.stateless_rpc) {
+		/* If we aren't using the stateless-rpc interface
+		 * we don't need to retain the headers.
+		 */
+		strbuf_setlen(&req_buf, 0);
+		state_len = 0;
+	}
+
+	flushes = 0;
+	retval = -1;
+	while ((sha1 = get_rev())) {
+		packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
+		if (args.verbose)
+			fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
+		in_vain++;
+		if (flush_at <= ++count) {
+			int ack;
+
+			packet_buf_flush(&req_buf);
+			send_request(fd[1], &req_buf);
+			strbuf_setlen(&req_buf, state_len);
+			flushes++;
+			flush_at = next_flush(count);
+
+			/*
+			 * We keep one window "ahead" of the other side, and
+			 * will wait for an ACK only on the next one
+			 */
+			if (!args.stateless_rpc && count == INITIAL_FLUSH)
+				continue;
+
+			consume_shallow_list(fd[0]);
+			do {
+				ack = get_ack(fd[0], result_sha1);
+				if (args.verbose && ack)
+					fprintf(stderr, "got ack %d %s\n", ack,
+							sha1_to_hex(result_sha1));
+				switch (ack) {
+				case ACK:
+					flushes = 0;
+					multi_ack = 0;
+					retval = 0;
+					goto done;
+				case ACK_common:
+				case ACK_ready:
+				case ACK_continue: {
+					struct commit *commit =
+						lookup_commit(result_sha1);
+					if (!commit)
+						die("invalid commit %s", sha1_to_hex(result_sha1));
+					if (args.stateless_rpc
+					 && ack == ACK_common
+					 && !(commit->object.flags & COMMON)) {
+						/* We need to replay the have for this object
+						 * on the next RPC request so the peer knows
+						 * it is in common with us.
+						 */
+						const char *hex = sha1_to_hex(result_sha1);
+						packet_buf_write(&req_buf, "have %s\n", hex);
+						state_len = req_buf.len;
+					}
+					mark_common(commit, 0, 1);
+					retval = 0;
+					in_vain = 0;
+					got_continue = 1;
+					if (ack == ACK_ready) {
+						rev_list = NULL;
+						got_ready = 1;
+					}
+					break;
+					}
+				}
+			} while (ack);
+			flushes--;
+			if (got_continue && MAX_IN_VAIN < in_vain) {
+				if (args.verbose)
+					fprintf(stderr, "giving up\n");
+				break; /* give up */
+			}
+		}
+	}
+done:
+	if (!got_ready || !no_done) {
+		packet_buf_write(&req_buf, "done\n");
+		send_request(fd[1], &req_buf);
+	}
+	if (args.verbose)
+		fprintf(stderr, "done\n");
+	if (retval != 0) {
+		multi_ack = 0;
+		flushes++;
+	}
+	strbuf_release(&req_buf);
+
+	consume_shallow_list(fd[0]);
+	while (flushes || multi_ack) {
+		int ack = get_ack(fd[0], result_sha1);
+		if (ack) {
+			if (args.verbose)
+				fprintf(stderr, "got ack (%d) %s\n", ack,
+					sha1_to_hex(result_sha1));
+			if (ack == ACK)
+				return 0;
+			multi_ack = 1;
+			continue;
+		}
+		flushes--;
+	}
+	/* it is no error to fetch into a completely empty repo */
+	return count ? retval : 0;
+}
+
+static struct commit_list *complete;
+
+static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *o = parse_object(sha1);
+
+	while (o && o->type == OBJ_TAG) {
+		struct tag *t = (struct tag *) o;
+		if (!t->tagged)
+			break; /* broken repository */
+		o->flags |= COMPLETE;
+		o = parse_object(t->tagged->sha1);
+	}
+	if (o && o->type == OBJ_COMMIT) {
+		struct commit *commit = (struct commit *)o;
+		if (!(commit->object.flags & COMPLETE)) {
+			commit->object.flags |= COMPLETE;
+			commit_list_insert_by_date(commit, &complete);
+		}
+	}
+	return 0;
+}
+
+static void mark_recent_complete_commits(unsigned long cutoff)
+{
+	while (complete && cutoff <= complete->item->date) {
+		if (args.verbose)
+			fprintf(stderr, "Marking %s as complete\n",
+				sha1_to_hex(complete->item->object.sha1));
+		pop_most_recent_commit(&complete, COMPLETE);
+	}
+}
+
+static void filter_refs(struct ref **refs, int nr_match, char **match)
+{
+	struct ref **return_refs;
+	struct ref *newlist = NULL;
+	struct ref **newtail = &newlist;
+	struct ref *ref, *next;
+	struct ref *fastarray[32];
+
+	if (nr_match && !args.fetch_all) {
+		if (ARRAY_SIZE(fastarray) < nr_match)
+			return_refs = xcalloc(nr_match, sizeof(struct ref *));
+		else {
+			return_refs = fastarray;
+			memset(return_refs, 0, sizeof(struct ref *) * nr_match);
+		}
+	}
+	else
+		return_refs = NULL;
+
+	for (ref = *refs; ref; ref = next) {
+		next = ref->next;
+		if (!memcmp(ref->name, "refs/", 5) &&
+		    check_ref_format(ref->name + 5))
+			; /* trash */
+		else if (args.fetch_all &&
+			 (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
+			*newtail = ref;
+			ref->next = NULL;
+			newtail = &ref->next;
+			continue;
+		}
+		else {
+			int order = path_match(ref->name, nr_match, match);
+			if (order) {
+				return_refs[order-1] = ref;
+				continue; /* we will link it later */
+			}
+		}
+		free(ref);
+	}
+
+	if (!args.fetch_all) {
+		int i;
+		for (i = 0; i < nr_match; i++) {
+			ref = return_refs[i];
+			if (ref) {
+				*newtail = ref;
+				ref->next = NULL;
+				newtail = &ref->next;
+			}
+		}
+		if (return_refs != fastarray)
+			free(return_refs);
+	}
+	*refs = newlist;
+}
+
+static int everything_local(struct ref **refs, int nr_match, char **match)
+{
+	struct ref *ref;
+	int retval;
+	unsigned long cutoff = 0;
+
+	save_commit_buffer = 0;
+
+	for (ref = *refs; ref; ref = ref->next) {
+		struct object *o;
+
+		o = parse_object(ref->old_sha1);
+		if (!o)
+			continue;
+
+		/* We already have it -- which may mean that we were
+		 * in sync with the other side at some time after
+		 * that (it is OK if we guess wrong here).
+		 */
+		if (o->type == OBJ_COMMIT) {
+			struct commit *commit = (struct commit *)o;
+			if (!cutoff || cutoff < commit->date)
+				cutoff = commit->date;
+		}
+	}
+
+	if (!args.depth) {
+		for_each_ref(mark_complete, NULL);
+		if (cutoff)
+			mark_recent_complete_commits(cutoff);
+	}
+
+	/*
+	 * Mark all complete remote refs as common refs.
+	 * Don't mark them common yet; the server has to be told so first.
+	 */
+	for (ref = *refs; ref; ref = ref->next) {
+		struct object *o = deref_tag(lookup_object(ref->old_sha1),
+					     NULL, 0);
+
+		if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
+			continue;
+
+		if (!(o->flags & SEEN)) {
+			rev_list_push((struct commit *)o, COMMON_REF | SEEN);
+
+			mark_common((struct commit *)o, 1, 1);
+		}
+	}
+
+	filter_refs(refs, nr_match, match);
+
+	for (retval = 1, ref = *refs; ref ; ref = ref->next) {
+		const unsigned char *remote = ref->old_sha1;
+		unsigned char local[20];
+		struct object *o;
+
+		o = lookup_object(remote);
+		if (!o || !(o->flags & COMPLETE)) {
+			retval = 0;
+			if (!args.verbose)
+				continue;
+			fprintf(stderr,
+				"want %s (%s)\n", sha1_to_hex(remote),
+				ref->name);
+			continue;
+		}
+
+		hashcpy(ref->new_sha1, local);
+		if (!args.verbose)
+			continue;
+		fprintf(stderr,
+			"already have %s (%s)\n", sha1_to_hex(remote),
+			ref->name);
+	}
+	return retval;
+}
+
+static int sideband_demux(int in, int out, void *data)
+{
+	int *xd = data;
+
+	int ret = recv_sideband("fetch-pack", xd[0], out);
+	close(out);
+	return ret;
+}
+
+static int get_pack(int xd[2], char **pack_lockfile)
+{
+	struct async demux;
+	const char *argv[20];
+	char keep_arg[256];
+	char hdr_arg[256];
+	const char **av;
+	int do_keep = args.keep_pack;
+	struct child_process cmd;
+
+	memset(&demux, 0, sizeof(demux));
+	if (use_sideband) {
+		/* xd[] is talking with upload-pack; subprocess reads from
+		 * xd[0], spits out band#2 to stderr, and feeds us band#1
+		 * through demux->out.
+		 */
+		demux.proc = sideband_demux;
+		demux.data = xd;
+		demux.out = -1;
+		if (start_async(&demux))
+			die("fetch-pack: unable to fork off sideband"
+			    " demultiplexer");
+	}
+	else
+		demux.out = xd[0];
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.argv = argv;
+	av = argv;
+	*hdr_arg = 0;
+	if (!args.keep_pack && unpack_limit) {
+		struct pack_header header;
+
+		if (read_pack_header(demux.out, &header))
+			die("protocol error: bad pack header");
+		snprintf(hdr_arg, sizeof(hdr_arg),
+			 "--pack_header=%"PRIu32",%"PRIu32,
+			 ntohl(header.hdr_version), ntohl(header.hdr_entries));
+		if (ntohl(header.hdr_entries) < unpack_limit)
+			do_keep = 0;
+		else
+			do_keep = 1;
+	}
+
+	if (do_keep) {
+		if (pack_lockfile)
+			cmd.out = -1;
+		*av++ = "index-pack";
+		*av++ = "--stdin";
+		if (!args.quiet && !args.no_progress)
+			*av++ = "-v";
+		if (args.use_thin_pack)
+			*av++ = "--fix-thin";
+		if (args.lock_pack || unpack_limit) {
+			int s = sprintf(keep_arg,
+					"--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
+			if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+				strcpy(keep_arg + s, "localhost");
+			*av++ = keep_arg;
+		}
+	}
+	else {
+		*av++ = "unpack-objects";
+		if (args.quiet)
+			*av++ = "-q";
+	}
+	if (*hdr_arg)
+		*av++ = hdr_arg;
+	*av++ = NULL;
+
+	cmd.in = demux.out;
+	cmd.git_cmd = 1;
+	if (start_command(&cmd))
+		die("fetch-pack: unable to fork off %s", argv[0]);
+	if (do_keep && pack_lockfile) {
+		*pack_lockfile = index_pack_lockfile(cmd.out);
+		close(cmd.out);
+	}
+
+	if (finish_command(&cmd))
+		die("%s failed", argv[0]);
+	if (use_sideband && finish_async(&demux))
+		die("error in sideband demultiplexer");
+	return 0;
+}
+
+static struct ref *do_fetch_pack(int fd[2],
+		const struct ref *orig_ref,
+		int nr_match,
+		char **match,
+		char **pack_lockfile)
+{
+	struct ref *ref = copy_ref_list(orig_ref);
+	unsigned char sha1[20];
+
+	if (is_repository_shallow() && !server_supports("shallow"))
+		die("Server does not support shallow clients");
+	if (server_supports("multi_ack_detailed")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports multi_ack_detailed\n");
+		multi_ack = 2;
+		if (server_supports("no-done")) {
+			if (args.verbose)
+				fprintf(stderr, "Server supports no-done\n");
+			if (args.stateless_rpc)
+				no_done = 1;
+		}
+	}
+	else if (server_supports("multi_ack")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports multi_ack\n");
+		multi_ack = 1;
+	}
+	if (server_supports("side-band-64k")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports side-band-64k\n");
+		use_sideband = 2;
+	}
+	else if (server_supports("side-band")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports side-band\n");
+		use_sideband = 1;
+	}
+	if (server_supports("ofs-delta")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports ofs-delta\n");
+	} else
+		prefer_ofs_delta = 0;
+	if (everything_local(&ref, nr_match, match)) {
+		packet_flush(fd[1]);
+		goto all_done;
+	}
+	if (find_common(fd, sha1, ref) < 0)
+		if (!args.keep_pack)
+			/* When cloning, it is not unusual to have
+			 * no common commit.
+			 */
+			warning("no common commits");
+
+	if (args.stateless_rpc)
+		packet_flush(fd[1]);
+	if (get_pack(fd, pack_lockfile))
+		die("git fetch-pack: fetch failed.");
+
+ all_done:
+	return ref;
+}
+
+static int remove_duplicates(int nr_heads, char **heads)
+{
+	int src, dst;
+
+	for (src = dst = 0; src < nr_heads; src++) {
+		/* If heads[src] is different from any of
+		 * heads[0..dst], push it in.
+		 */
+		int i;
+		for (i = 0; i < dst; i++) {
+			if (!strcmp(heads[i], heads[src]))
+				break;
+		}
+		if (i < dst)
+			continue;
+		if (src != dst)
+			heads[dst] = heads[src];
+		dst++;
+	}
+	return dst;
+}
+
+static int fetch_pack_config(const char *var, const char *value, void *cb)
+{
+	if (strcmp(var, "fetch.unpacklimit") == 0) {
+		fetch_unpack_limit = git_config_int(var, value);
+		return 0;
+	}
+
+	if (strcmp(var, "transfer.unpacklimit") == 0) {
+		transfer_unpack_limit = git_config_int(var, value);
+		return 0;
+	}
+
+	if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
+		prefer_ofs_delta = git_config_bool(var, value);
+		return 0;
+	}
+
+	return git_default_config(var, value, cb);
+}
+
+static struct lock_file lock;
+
+static void fetch_pack_setup(void)
+{
+	static int did_setup;
+	if (did_setup)
+		return;
+	git_config(fetch_pack_config, NULL);
+	if (0 <= transfer_unpack_limit)
+		unpack_limit = transfer_unpack_limit;
+	else if (0 <= fetch_unpack_limit)
+		unpack_limit = fetch_unpack_limit;
+	did_setup = 1;
+}
+
+int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
+{
+	int i, ret, nr_heads;
+	struct ref *ref = NULL;
+	char *dest = NULL, **heads;
+	int fd[2];
+	char *pack_lockfile = NULL;
+	char **pack_lockfile_ptr = NULL;
+	struct child_process *conn;
+
+	packet_trace_identity("fetch-pack");
+
+	nr_heads = 0;
+	heads = NULL;
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+
+		if (*arg == '-') {
+			if (!prefixcmp(arg, "--upload-pack=")) {
+				args.uploadpack = arg + 14;
+				continue;
+			}
+			if (!prefixcmp(arg, "--exec=")) {
+				args.uploadpack = arg + 7;
+				continue;
+			}
+			if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
+				args.quiet = 1;
+				continue;
+			}
+			if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
+				args.lock_pack = args.keep_pack;
+				args.keep_pack = 1;
+				continue;
+			}
+			if (!strcmp("--thin", arg)) {
+				args.use_thin_pack = 1;
+				continue;
+			}
+			if (!strcmp("--include-tag", arg)) {
+				args.include_tag = 1;
+				continue;
+			}
+			if (!strcmp("--all", arg)) {
+				args.fetch_all = 1;
+				continue;
+			}
+			if (!strcmp("-v", arg)) {
+				args.verbose = 1;
+				continue;
+			}
+			if (!prefixcmp(arg, "--depth=")) {
+				args.depth = strtol(arg + 8, NULL, 0);
+				continue;
+			}
+			if (!strcmp("--no-progress", arg)) {
+				args.no_progress = 1;
+				continue;
+			}
+			if (!strcmp("--stateless-rpc", arg)) {
+				args.stateless_rpc = 1;
+				continue;
+			}
+			if (!strcmp("--lock-pack", arg)) {
+				args.lock_pack = 1;
+				pack_lockfile_ptr = &pack_lockfile;
+				continue;
+			}
+			usage(fetch_pack_usage);
+		}
+		dest = (char *)arg;
+		heads = (char **)(argv + i + 1);
+		nr_heads = argc - i - 1;
+		break;
+	}
+	if (!dest)
+		usage(fetch_pack_usage);
+
+	if (args.stateless_rpc) {
+		conn = NULL;
+		fd[0] = 0;
+		fd[1] = 1;
+	} else {
+		conn = git_connect(fd, (char *)dest, args.uploadpack,
+				   args.verbose ? CONNECT_VERBOSE : 0);
+	}
+
+	get_remote_heads(fd[0], &ref, 0, NULL, 0, NULL);
+
+	ref = fetch_pack(&args, fd, conn, ref, dest,
+		nr_heads, heads, pack_lockfile_ptr);
+	if (pack_lockfile) {
+		printf("lock %s\n", pack_lockfile);
+		fflush(stdout);
+	}
+	close(fd[0]);
+	close(fd[1]);
+	if (finish_connect(conn))
+		ref = NULL;
+	ret = !ref;
+
+	if (!ret && nr_heads) {
+		/* If the heads to pull were given, we should have
+		 * consumed all of them by matching the remote.
+		 * Otherwise, 'git fetch remote no-such-ref' would
+		 * silently succeed without issuing an error.
+		 */
+		for (i = 0; i < nr_heads; i++)
+			if (heads[i] && heads[i][0]) {
+				error("no such remote ref %s", heads[i]);
+				ret = 1;
+			}
+	}
+	while (ref) {
+		printf("%s %s\n",
+		       sha1_to_hex(ref->old_sha1), ref->name);
+		ref = ref->next;
+	}
+
+	return ret;
+}
+
+struct ref *fetch_pack(struct fetch_pack_args *my_args,
+		       int fd[], struct child_process *conn,
+		       const struct ref *ref,
+		const char *dest,
+		int nr_heads,
+		char **heads,
+		char **pack_lockfile)
+{
+	struct stat st;
+	struct ref *ref_cpy;
+
+	fetch_pack_setup();
+	if (&args != my_args)
+		memcpy(&args, my_args, sizeof(args));
+	if (args.depth > 0) {
+		if (stat(git_path("shallow"), &st))
+			st.st_mtime = 0;
+	}
+
+	if (heads && nr_heads)
+		nr_heads = remove_duplicates(nr_heads, heads);
+	if (!ref) {
+		packet_flush(fd[1]);
+		die("no matching remote head");
+	}
+	ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
+
+	if (args.depth > 0) {
+		struct cache_time mtime;
+		struct strbuf sb = STRBUF_INIT;
+		char *shallow = git_path("shallow");
+		int fd;
+
+		mtime.sec = st.st_mtime;
+		mtime.nsec = ST_MTIME_NSEC(st);
+		if (stat(shallow, &st)) {
+			if (mtime.sec)
+				die("shallow file was removed during fetch");
+		} else if (st.st_mtime != mtime.sec
+#ifdef USE_NSEC
+				|| ST_MTIME_NSEC(st) != mtime.nsec
+#endif
+			  )
+			die("shallow file was changed during fetch");
+
+		fd = hold_lock_file_for_update(&lock, shallow,
+					       LOCK_DIE_ON_ERROR);
+		if (!write_shallow_commits(&sb, 0)
+		 || write_in_full(fd, sb.buf, sb.len) != sb.len) {
+			unlink_or_warn(shallow);
+			rollback_lock_file(&lock);
+		} else {
+			commit_lock_file(&lock);
+		}
+		strbuf_release(&sb);
+	}
+
+	reprepare_packed_git();
+	return ref_cpy;
+}
diff --git a/builtin/fetch.c b/builtin/fetch.c
new file mode 100644
index 0000000..9d481f8
--- /dev/null
+++ b/builtin/fetch.c
@@ -0,0 +1,1023 @@
+/*
+ * "git fetch"
+ */
+#include "cache.h"
+#include "refs.h"
+#include "commit.h"
+#include "builtin.h"
+#include "string-list.h"
+#include "remote.h"
+#include "transport.h"
+#include "run-command.h"
+#include "parse-options.h"
+#include "sigchain.h"
+#include "transport.h"
+#include "submodule.h"
+
+static const char * const builtin_fetch_usage[] = {
+	"git fetch [<options>] [<repository> [<refspec>...]]",
+	"git fetch [<options>] <group>",
+	"git fetch --multiple [<options>] [(<repository> | <group>)...]",
+	"git fetch --all [<options>]",
+	NULL
+};
+
+enum {
+	TAGS_UNSET = 0,
+	TAGS_DEFAULT = 1,
+	TAGS_SET = 2
+};
+
+static int all, append, dry_run, force, keep, multiple, prune, update_head_ok, verbosity;
+static int progress, recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
+static int tags = TAGS_DEFAULT;
+static const char *depth;
+static const char *upload_pack;
+static struct strbuf default_rla = STRBUF_INIT;
+static struct transport *transport;
+static const char *submodule_prefix = "";
+static const char *recurse_submodules_default;
+
+static int option_parse_recurse_submodules(const struct option *opt,
+				   const char *arg, int unset)
+{
+	if (unset) {
+		recurse_submodules = RECURSE_SUBMODULES_OFF;
+	} else {
+		if (arg)
+			recurse_submodules = parse_fetch_recurse_submodules_arg(opt->long_name, arg);
+		else
+			recurse_submodules = RECURSE_SUBMODULES_ON;
+	}
+	return 0;
+}
+
+static struct option builtin_fetch_options[] = {
+	OPT__VERBOSITY(&verbosity),
+	OPT_BOOLEAN(0, "all", &all,
+		    "fetch from all remotes"),
+	OPT_BOOLEAN('a', "append", &append,
+		    "append to .git/FETCH_HEAD instead of overwriting"),
+	OPT_STRING(0, "upload-pack", &upload_pack, "path",
+		   "path to upload pack on remote end"),
+	OPT__FORCE(&force, "force overwrite of local branch"),
+	OPT_BOOLEAN('m', "multiple", &multiple,
+		    "fetch from multiple remotes"),
+	OPT_SET_INT('t', "tags", &tags,
+		    "fetch all tags and associated objects", TAGS_SET),
+	OPT_SET_INT('n', NULL, &tags,
+		    "do not fetch all tags (--no-tags)", TAGS_UNSET),
+	OPT_BOOLEAN('p', "prune", &prune,
+		    "prune remote-tracking branches no longer on remote"),
+	{ OPTION_CALLBACK, 0, "recurse-submodules", NULL, "on-demand",
+		    "control recursive fetching of submodules",
+		    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
+	OPT_BOOLEAN(0, "dry-run", &dry_run,
+		    "dry run"),
+	OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
+	OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
+		    "allow updating of HEAD ref"),
+	OPT_BOOLEAN(0, "progress", &progress, "force progress reporting"),
+	OPT_STRING(0, "depth", &depth, "depth",
+		   "deepen history of shallow clone"),
+	{ OPTION_STRING, 0, "submodule-prefix", &submodule_prefix, "dir",
+		   "prepend this to submodule path output", PARSE_OPT_HIDDEN },
+	{ OPTION_STRING, 0, "recurse-submodules-default",
+		   &recurse_submodules_default, NULL,
+		   "default mode for recursion", PARSE_OPT_HIDDEN },
+	OPT_END()
+};
+
+static void unlock_pack(void)
+{
+	if (transport)
+		transport_unlock_pack(transport);
+}
+
+static void unlock_pack_on_signal(int signo)
+{
+	unlock_pack();
+	sigchain_pop(signo);
+	raise(signo);
+}
+
+static void add_merge_config(struct ref **head,
+			   const struct ref *remote_refs,
+		           struct branch *branch,
+		           struct ref ***tail)
+{
+	int i;
+
+	for (i = 0; i < branch->merge_nr; i++) {
+		struct ref *rm, **old_tail = *tail;
+		struct refspec refspec;
+
+		for (rm = *head; rm; rm = rm->next) {
+			if (branch_merge_matches(branch, i, rm->name)) {
+				rm->merge = 1;
+				break;
+			}
+		}
+		if (rm)
+			continue;
+
+		/*
+		 * Not fetched to a remote-tracking branch?  We need to fetch
+		 * it anyway to allow this branch's "branch.$name.merge"
+		 * to be honored by 'git pull', but we do not have to
+		 * fail if branch.$name.merge is misconfigured to point
+		 * at a nonexisting branch.  If we were indeed called by
+		 * 'git pull', it will notice the misconfiguration because
+		 * there is no entry in the resulting FETCH_HEAD marked
+		 * for merging.
+		 */
+		memset(&refspec, 0, sizeof(refspec));
+		refspec.src = branch->merge[i]->src;
+		get_fetch_map(remote_refs, &refspec, tail, 1);
+		for (rm = *old_tail; rm; rm = rm->next)
+			rm->merge = 1;
+	}
+}
+
+static void find_non_local_tags(struct transport *transport,
+			struct ref **head,
+			struct ref ***tail);
+
+static struct ref *get_ref_map(struct transport *transport,
+			       struct refspec *refs, int ref_count, int tags,
+			       int *autotags)
+{
+	int i;
+	struct ref *rm;
+	struct ref *ref_map = NULL;
+	struct ref **tail = &ref_map;
+
+	const struct ref *remote_refs = transport_get_remote_refs(transport);
+
+	if (ref_count || tags == TAGS_SET) {
+		for (i = 0; i < ref_count; i++) {
+			get_fetch_map(remote_refs, &refs[i], &tail, 0);
+			if (refs[i].dst && refs[i].dst[0])
+				*autotags = 1;
+		}
+		/* Merge everything on the command line, but not --tags */
+		for (rm = ref_map; rm; rm = rm->next)
+			rm->merge = 1;
+		if (tags == TAGS_SET)
+			get_fetch_map(remote_refs, tag_refspec, &tail, 0);
+	} else {
+		/* Use the defaults */
+		struct remote *remote = transport->remote;
+		struct branch *branch = branch_get(NULL);
+		int has_merge = branch_has_merge_config(branch);
+		if (remote &&
+		    (remote->fetch_refspec_nr ||
+		     /* Note: has_merge implies non-NULL branch->remote_name */
+		     (has_merge && !strcmp(branch->remote_name, remote->name)))) {
+			for (i = 0; i < remote->fetch_refspec_nr; i++) {
+				get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
+				if (remote->fetch[i].dst &&
+				    remote->fetch[i].dst[0])
+					*autotags = 1;
+				if (!i && !has_merge && ref_map &&
+				    !remote->fetch[0].pattern)
+					ref_map->merge = 1;
+			}
+			/*
+			 * if the remote we're fetching from is the same
+			 * as given in branch.<name>.remote, we add the
+			 * ref given in branch.<name>.merge, too.
+			 *
+			 * Note: has_merge implies non-NULL branch->remote_name
+			 */
+			if (has_merge &&
+			    !strcmp(branch->remote_name, remote->name))
+				add_merge_config(&ref_map, remote_refs, branch, &tail);
+		} else {
+			ref_map = get_remote_ref(remote_refs, "HEAD");
+			if (!ref_map)
+				die(_("Couldn't find remote ref HEAD"));
+			ref_map->merge = 1;
+			tail = &ref_map->next;
+		}
+	}
+	if (tags == TAGS_DEFAULT && *autotags)
+		find_non_local_tags(transport, &ref_map, &tail);
+	ref_remove_duplicates(ref_map);
+
+	return ref_map;
+}
+
+#define STORE_REF_ERROR_OTHER 1
+#define STORE_REF_ERROR_DF_CONFLICT 2
+
+static int s_update_ref(const char *action,
+			struct ref *ref,
+			int check_old)
+{
+	char msg[1024];
+	char *rla = getenv("GIT_REFLOG_ACTION");
+	static struct ref_lock *lock;
+
+	if (dry_run)
+		return 0;
+	if (!rla)
+		rla = default_rla.buf;
+	snprintf(msg, sizeof(msg), "%s: %s", rla, action);
+	lock = lock_any_ref_for_update(ref->name,
+				       check_old ? ref->old_sha1 : NULL, 0);
+	if (!lock)
+		return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
+					  STORE_REF_ERROR_OTHER;
+	if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
+		return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
+					  STORE_REF_ERROR_OTHER;
+	return 0;
+}
+
+#define REFCOL_WIDTH  10
+
+static int update_local_ref(struct ref *ref,
+			    const char *remote,
+			    char *display)
+{
+	struct commit *current = NULL, *updated;
+	enum object_type type;
+	struct branch *current_branch = branch_get(NULL);
+	const char *pretty_ref = prettify_refname(ref->name);
+
+	*display = 0;
+	type = sha1_object_info(ref->new_sha1, NULL);
+	if (type < 0)
+		die(_("object %s not found"), sha1_to_hex(ref->new_sha1));
+
+	if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
+		if (verbosity > 0)
+			sprintf(display, "= %-*s %-*s -> %s", TRANSPORT_SUMMARY_WIDTH,
+				_("[up to date]"), REFCOL_WIDTH, remote,
+				pretty_ref);
+		return 0;
+	}
+
+	if (current_branch &&
+	    !strcmp(ref->name, current_branch->name) &&
+	    !(update_head_ok || is_bare_repository()) &&
+	    !is_null_sha1(ref->old_sha1)) {
+		/*
+		 * If this is the head, and it's not okay to update
+		 * the head, and the old value of the head isn't empty...
+		 */
+		sprintf(display, _("! %-*s %-*s -> %s  (can't fetch in current branch)"),
+			TRANSPORT_SUMMARY_WIDTH, _("[rejected]"), REFCOL_WIDTH, remote,
+			pretty_ref);
+		return 1;
+	}
+
+	if (!is_null_sha1(ref->old_sha1) &&
+	    !prefixcmp(ref->name, "refs/tags/")) {
+		int r;
+		r = s_update_ref("updating tag", ref, 0);
+		sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '-',
+			TRANSPORT_SUMMARY_WIDTH, _("[tag update]"), REFCOL_WIDTH, remote,
+			pretty_ref, r ? _("  (unable to update local ref)") : "");
+		return r;
+	}
+
+	current = lookup_commit_reference_gently(ref->old_sha1, 1);
+	updated = lookup_commit_reference_gently(ref->new_sha1, 1);
+	if (!current || !updated) {
+		const char *msg;
+		const char *what;
+		int r;
+		if (!strncmp(ref->name, "refs/tags/", 10)) {
+			msg = "storing tag";
+			what = _("[new tag]");
+		}
+		else {
+			msg = "storing head";
+			what = _("[new branch]");
+			if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
+			    (recurse_submodules != RECURSE_SUBMODULES_ON))
+				check_for_new_submodule_commits(ref->new_sha1);
+		}
+
+		r = s_update_ref(msg, ref, 0);
+		sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '*',
+			TRANSPORT_SUMMARY_WIDTH, what, REFCOL_WIDTH, remote, pretty_ref,
+			r ? _("  (unable to update local ref)") : "");
+		return r;
+	}
+
+	if (in_merge_bases(current, &updated, 1)) {
+		char quickref[83];
+		int r;
+		strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
+		strcat(quickref, "..");
+		strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
+		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
+		    (recurse_submodules != RECURSE_SUBMODULES_ON))
+			check_for_new_submodule_commits(ref->new_sha1);
+		r = s_update_ref("fast-forward", ref, 1);
+		sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : ' ',
+			TRANSPORT_SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
+			pretty_ref, r ? _("  (unable to update local ref)") : "");
+		return r;
+	} else if (force || ref->force) {
+		char quickref[84];
+		int r;
+		strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
+		strcat(quickref, "...");
+		strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
+		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
+		    (recurse_submodules != RECURSE_SUBMODULES_ON))
+			check_for_new_submodule_commits(ref->new_sha1);
+		r = s_update_ref("forced-update", ref, 1);
+		sprintf(display, "%c %-*s %-*s -> %s  (%s)", r ? '!' : '+',
+			TRANSPORT_SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
+			pretty_ref,
+			r ? _("unable to update local ref") : _("forced update"));
+		return r;
+	} else {
+		sprintf(display, "! %-*s %-*s -> %s  %s",
+			TRANSPORT_SUMMARY_WIDTH, _("[rejected]"), REFCOL_WIDTH, remote,
+			pretty_ref, _("(non-fast-forward)"));
+		return 1;
+	}
+}
+
+static int store_updated_refs(const char *raw_url, const char *remote_name,
+		struct ref *ref_map)
+{
+	FILE *fp;
+	struct commit *commit;
+	int url_len, i, note_len, shown_url = 0, rc = 0;
+	char note[1024];
+	const char *what, *kind;
+	struct ref *rm;
+	char *url, *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
+
+	fp = fopen(filename, "a");
+	if (!fp)
+		return error(_("cannot open %s: %s\n"), filename, strerror(errno));
+
+	if (raw_url)
+		url = transport_anonymize_url(raw_url);
+	else
+		url = xstrdup("foreign");
+	for (rm = ref_map; rm; rm = rm->next) {
+		struct ref *ref = NULL;
+
+		if (rm->peer_ref) {
+			ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
+			strcpy(ref->name, rm->peer_ref->name);
+			hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
+			hashcpy(ref->new_sha1, rm->old_sha1);
+			ref->force = rm->peer_ref->force;
+		}
+
+		commit = lookup_commit_reference_gently(rm->old_sha1, 1);
+		if (!commit)
+			rm->merge = 0;
+
+		if (!strcmp(rm->name, "HEAD")) {
+			kind = "";
+			what = "";
+		}
+		else if (!prefixcmp(rm->name, "refs/heads/")) {
+			kind = "branch";
+			what = rm->name + 11;
+		}
+		else if (!prefixcmp(rm->name, "refs/tags/")) {
+			kind = "tag";
+			what = rm->name + 10;
+		}
+		else if (!prefixcmp(rm->name, "refs/remotes/")) {
+			kind = "remote-tracking branch";
+			what = rm->name + 13;
+		}
+		else {
+			kind = "";
+			what = rm->name;
+		}
+
+		url_len = strlen(url);
+		for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
+			;
+		url_len = i + 1;
+		if (4 < i && !strncmp(".git", url + i - 3, 4))
+			url_len = i - 3;
+
+		note_len = 0;
+		if (*what) {
+			if (*kind)
+				note_len += sprintf(note + note_len, "%s ",
+						    kind);
+			note_len += sprintf(note + note_len, "'%s' of ", what);
+		}
+		note[note_len] = '\0';
+		fprintf(fp, "%s\t%s\t%s",
+			sha1_to_hex(commit ? commit->object.sha1 :
+				    rm->old_sha1),
+			rm->merge ? "" : "not-for-merge",
+			note);
+		for (i = 0; i < url_len; ++i)
+			if ('\n' == url[i])
+				fputs("\\n", fp);
+			else
+				fputc(url[i], fp);
+		fputc('\n', fp);
+
+		if (ref) {
+			rc |= update_local_ref(ref, what, note);
+			free(ref);
+		} else
+			sprintf(note, "* %-*s %-*s -> FETCH_HEAD",
+				TRANSPORT_SUMMARY_WIDTH, *kind ? kind : "branch",
+				 REFCOL_WIDTH, *what ? what : "HEAD");
+		if (*note) {
+			if (verbosity >= 0 && !shown_url) {
+				fprintf(stderr, _("From %.*s\n"),
+						url_len, url);
+				shown_url = 1;
+			}
+			if (verbosity >= 0)
+				fprintf(stderr, " %s\n", note);
+		}
+	}
+	free(url);
+	fclose(fp);
+	if (rc & STORE_REF_ERROR_DF_CONFLICT)
+		error(_("some local refs could not be updated; try running\n"
+		      " 'git remote prune %s' to remove any old, conflicting "
+		      "branches"), remote_name);
+	return rc;
+}
+
+/*
+ * We would want to bypass the object transfer altogether if
+ * everything we are going to fetch already exists and is connected
+ * locally.
+ *
+ * The refs we are going to fetch are in ref_map.  If running
+ *
+ *  $ git rev-list --objects --stdin --not --all
+ *
+ * (feeding all the refs in ref_map on its standard input)
+ * does not error out, that means everything reachable from the
+ * refs we are going to fetch exists and is connected to some of
+ * our existing refs.
+ */
+static int quickfetch(struct ref *ref_map)
+{
+	struct child_process revlist;
+	struct ref *ref;
+	int err;
+	const char *argv[] = {"rev-list",
+		"--quiet", "--objects", "--stdin", "--not", "--all", NULL};
+
+	/*
+	 * If we are deepening a shallow clone we already have these
+	 * objects reachable.  Running rev-list here will return with
+	 * a good (0) exit status and we'll bypass the fetch that we
+	 * really need to perform.  Claiming failure now will ensure
+	 * we perform the network exchange to deepen our history.
+	 */
+	if (depth)
+		return -1;
+
+	if (!ref_map)
+		return 0;
+
+	memset(&revlist, 0, sizeof(revlist));
+	revlist.argv = argv;
+	revlist.git_cmd = 1;
+	revlist.no_stdout = 1;
+	revlist.no_stderr = 1;
+	revlist.in = -1;
+
+	err = start_command(&revlist);
+	if (err) {
+		error(_("could not run rev-list"));
+		return err;
+	}
+
+	/*
+	 * If rev-list --stdin encounters an unknown commit, it terminates,
+	 * which will cause SIGPIPE in the write loop below.
+	 */
+	sigchain_push(SIGPIPE, SIG_IGN);
+
+	for (ref = ref_map; ref; ref = ref->next) {
+		if (write_in_full(revlist.in, sha1_to_hex(ref->old_sha1), 40) < 0 ||
+		    write_str_in_full(revlist.in, "\n") < 0) {
+			if (errno != EPIPE && errno != EINVAL)
+				error(_("failed write to rev-list: %s"), strerror(errno));
+			err = -1;
+			break;
+		}
+	}
+
+	if (close(revlist.in)) {
+		error(_("failed to close rev-list's stdin: %s"), strerror(errno));
+		err = -1;
+	}
+
+	sigchain_pop(SIGPIPE);
+
+	return finish_command(&revlist) || err;
+}
+
+static int fetch_refs(struct transport *transport, struct ref *ref_map)
+{
+	int ret = quickfetch(ref_map);
+	if (ret)
+		ret = transport_fetch_refs(transport, ref_map);
+	if (!ret)
+		ret |= store_updated_refs(transport->url,
+				transport->remote->name,
+				ref_map);
+	transport_unlock_pack(transport);
+	return ret;
+}
+
+static int prune_refs(struct refspec *refs, int ref_count, struct ref *ref_map)
+{
+	int result = 0;
+	struct ref *ref, *stale_refs = get_stale_heads(refs, ref_count, ref_map);
+	const char *dangling_msg = dry_run
+		? _("   (%s will become dangling)\n")
+		: _("   (%s has become dangling)\n");
+
+	for (ref = stale_refs; ref; ref = ref->next) {
+		if (!dry_run)
+			result |= delete_ref(ref->name, NULL, 0);
+		if (verbosity >= 0) {
+			fprintf(stderr, " x %-*s %-*s -> %s\n",
+				TRANSPORT_SUMMARY_WIDTH, _("[deleted]"),
+				REFCOL_WIDTH, _("(none)"), prettify_refname(ref->name));
+			warn_dangling_symref(stderr, dangling_msg, ref->name);
+		}
+	}
+	free_refs(stale_refs);
+	return result;
+}
+
+static int add_existing(const char *refname, const unsigned char *sha1,
+			int flag, void *cbdata)
+{
+	struct string_list *list = (struct string_list *)cbdata;
+	struct string_list_item *item = string_list_insert(list, refname);
+	item->util = (void *)sha1;
+	return 0;
+}
+
+static int will_fetch(struct ref **head, const unsigned char *sha1)
+{
+	struct ref *rm = *head;
+	while (rm) {
+		if (!hashcmp(rm->old_sha1, sha1))
+			return 1;
+		rm = rm->next;
+	}
+	return 0;
+}
+
+static void find_non_local_tags(struct transport *transport,
+			struct ref **head,
+			struct ref ***tail)
+{
+	struct string_list existing_refs = STRING_LIST_INIT_NODUP;
+	struct string_list remote_refs = STRING_LIST_INIT_NODUP;
+	const struct ref *ref;
+	struct string_list_item *item = NULL;
+
+	for_each_ref(add_existing, &existing_refs);
+	for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
+		if (prefixcmp(ref->name, "refs/tags"))
+			continue;
+
+		/*
+		 * The peeled ref always follows the matching base
+		 * ref, so if we see a peeled ref that we don't want
+		 * to fetch then we can mark the ref entry in the list
+		 * as one to ignore by setting util to NULL.
+		 */
+		if (!suffixcmp(ref->name, "^{}")) {
+			if (item && !has_sha1_file(ref->old_sha1) &&
+			    !will_fetch(head, ref->old_sha1) &&
+			    !has_sha1_file(item->util) &&
+			    !will_fetch(head, item->util))
+				item->util = NULL;
+			item = NULL;
+			continue;
+		}
+
+		/*
+		 * If item is non-NULL here, then we previously saw a
+		 * ref not followed by a peeled reference, so we need
+		 * to check if it is a lightweight tag that we want to
+		 * fetch.
+		 */
+		if (item && !has_sha1_file(item->util) &&
+		    !will_fetch(head, item->util))
+			item->util = NULL;
+
+		item = NULL;
+
+		/* skip duplicates and refs that we already have */
+		if (string_list_has_string(&remote_refs, ref->name) ||
+		    string_list_has_string(&existing_refs, ref->name))
+			continue;
+
+		item = string_list_insert(&remote_refs, ref->name);
+		item->util = (void *)ref->old_sha1;
+	}
+	string_list_clear(&existing_refs, 0);
+
+	/*
+	 * We may have a final lightweight tag that needs to be
+	 * checked to see if it needs fetching.
+	 */
+	if (item && !has_sha1_file(item->util) &&
+	    !will_fetch(head, item->util))
+		item->util = NULL;
+
+	/*
+	 * For all the tags in the remote_refs string list,
+	 * add them to the list of refs to be fetched
+	 */
+	for_each_string_list_item(item, &remote_refs) {
+		/* Unless we have already decided to ignore this item... */
+		if (item->util)
+		{
+			struct ref *rm = alloc_ref(item->string);
+			rm->peer_ref = alloc_ref(item->string);
+			hashcpy(rm->old_sha1, item->util);
+			**tail = rm;
+			*tail = &rm->next;
+		}
+	}
+
+	string_list_clear(&remote_refs, 0);
+}
+
+static void check_not_current_branch(struct ref *ref_map)
+{
+	struct branch *current_branch = branch_get(NULL);
+
+	if (is_bare_repository() || !current_branch)
+		return;
+
+	for (; ref_map; ref_map = ref_map->next)
+		if (ref_map->peer_ref && !strcmp(current_branch->refname,
+					ref_map->peer_ref->name))
+			die(_("Refusing to fetch into current branch %s "
+			    "of non-bare repository"), current_branch->refname);
+}
+
+static int truncate_fetch_head(void)
+{
+	char *filename = git_path("FETCH_HEAD");
+	FILE *fp = fopen(filename, "w");
+
+	if (!fp)
+		return error(_("cannot open %s: %s\n"), filename, strerror(errno));
+	fclose(fp);
+	return 0;
+}
+
+static int do_fetch(struct transport *transport,
+		    struct refspec *refs, int ref_count)
+{
+	struct string_list existing_refs = STRING_LIST_INIT_NODUP;
+	struct string_list_item *peer_item = NULL;
+	struct ref *ref_map;
+	struct ref *rm;
+	int autotags = (transport->remote->fetch_tags == 1);
+
+	for_each_ref(add_existing, &existing_refs);
+
+	if (tags == TAGS_DEFAULT) {
+		if (transport->remote->fetch_tags == 2)
+			tags = TAGS_SET;
+		if (transport->remote->fetch_tags == -1)
+			tags = TAGS_UNSET;
+	}
+
+	if (!transport->get_refs_list || !transport->fetch)
+		die(_("Don't know how to fetch from %s"), transport->url);
+
+	/* if not appending, truncate FETCH_HEAD */
+	if (!append && !dry_run) {
+		int errcode = truncate_fetch_head();
+		if (errcode)
+			return errcode;
+	}
+
+	ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
+	if (!update_head_ok)
+		check_not_current_branch(ref_map);
+
+	for (rm = ref_map; rm; rm = rm->next) {
+		if (rm->peer_ref) {
+			peer_item = string_list_lookup(&existing_refs,
+						       rm->peer_ref->name);
+			if (peer_item)
+				hashcpy(rm->peer_ref->old_sha1,
+					peer_item->util);
+		}
+	}
+
+	if (tags == TAGS_DEFAULT && autotags)
+		transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
+	if (fetch_refs(transport, ref_map)) {
+		free_refs(ref_map);
+		return 1;
+	}
+	if (prune) {
+		/* If --tags was specified, pretend the user gave us the canonical tags refspec */
+		if (tags == TAGS_SET) {
+			const char *tags_str = "refs/tags/*:refs/tags/*";
+			struct refspec *tags_refspec, *refspec;
+
+			/* Copy the refspec and add the tags to it */
+			refspec = xcalloc(ref_count + 1, sizeof(struct refspec));
+			tags_refspec = parse_fetch_refspec(1, &tags_str);
+			memcpy(refspec, refs, ref_count * sizeof(struct refspec));
+			memcpy(&refspec[ref_count], tags_refspec, sizeof(struct refspec));
+			ref_count++;
+
+			prune_refs(refspec, ref_count, ref_map);
+
+			ref_count--;
+			/* The rest of the strings belong to fetch_one */
+			free_refspec(1, tags_refspec);
+			free(refspec);
+		} else if (ref_count) {
+			prune_refs(refs, ref_count, ref_map);
+		} else {
+			prune_refs(transport->remote->fetch, transport->remote->fetch_refspec_nr, ref_map);
+		}
+	}
+	free_refs(ref_map);
+
+	/* if neither --no-tags nor --tags was specified, do automated tag
+	 * following ... */
+	if (tags == TAGS_DEFAULT && autotags) {
+		struct ref **tail = &ref_map;
+		ref_map = NULL;
+		find_non_local_tags(transport, &ref_map, &tail);
+		if (ref_map) {
+			transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
+			transport_set_option(transport, TRANS_OPT_DEPTH, "0");
+			fetch_refs(transport, ref_map);
+		}
+		free_refs(ref_map);
+	}
+
+	return 0;
+}
+
+static void set_option(const char *name, const char *value)
+{
+	int r = transport_set_option(transport, name, value);
+	if (r < 0)
+		die(_("Option \"%s\" value \"%s\" is not valid for %s"),
+			name, value, transport->url);
+	if (r > 0)
+		warning(_("Option \"%s\" is ignored for %s\n"),
+			name, transport->url);
+}
+
+static int get_one_remote_for_fetch(struct remote *remote, void *priv)
+{
+	struct string_list *list = priv;
+	if (!remote->skip_default_update)
+		string_list_append(list, remote->name);
+	return 0;
+}
+
+struct remote_group_data {
+	const char *name;
+	struct string_list *list;
+};
+
+static int get_remote_group(const char *key, const char *value, void *priv)
+{
+	struct remote_group_data *g = priv;
+
+	if (!prefixcmp(key, "remotes.") &&
+			!strcmp(key + 8, g->name)) {
+		/* split list by white space */
+		int space = strcspn(value, " \t\n");
+		while (*value) {
+			if (space > 1) {
+				string_list_append(g->list,
+						   xstrndup(value, space));
+			}
+			value += space + (value[space] != '\0');
+			space = strcspn(value, " \t\n");
+		}
+	}
+
+	return 0;
+}
+
+static int add_remote_or_group(const char *name, struct string_list *list)
+{
+	int prev_nr = list->nr;
+	struct remote_group_data g;
+	g.name = name; g.list = list;
+
+	git_config(get_remote_group, &g);
+	if (list->nr == prev_nr) {
+		struct remote *remote;
+		if (!remote_is_configured(name))
+			return 0;
+		remote = remote_get(name);
+		string_list_append(list, remote->name);
+	}
+	return 1;
+}
+
+static void add_options_to_argv(int *argc, const char **argv)
+{
+	if (dry_run)
+		argv[(*argc)++] = "--dry-run";
+	if (prune)
+		argv[(*argc)++] = "--prune";
+	if (update_head_ok)
+		argv[(*argc)++] = "--update-head-ok";
+	if (force)
+		argv[(*argc)++] = "--force";
+	if (keep)
+		argv[(*argc)++] = "--keep";
+	if (recurse_submodules == RECURSE_SUBMODULES_ON)
+		argv[(*argc)++] = "--recurse-submodules";
+	else if (recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND)
+		argv[(*argc)++] = "--recurse-submodules=on-demand";
+	if (verbosity >= 2)
+		argv[(*argc)++] = "-v";
+	if (verbosity >= 1)
+		argv[(*argc)++] = "-v";
+	else if (verbosity < 0)
+		argv[(*argc)++] = "-q";
+
+}
+
+static int fetch_multiple(struct string_list *list)
+{
+	int i, result = 0;
+	const char *argv[12] = { "fetch", "--append" };
+	int argc = 2;
+
+	add_options_to_argv(&argc, argv);
+
+	if (!append && !dry_run) {
+		int errcode = truncate_fetch_head();
+		if (errcode)
+			return errcode;
+	}
+
+	for (i = 0; i < list->nr; i++) {
+		const char *name = list->items[i].string;
+		argv[argc] = name;
+		argv[argc + 1] = NULL;
+		if (verbosity >= 0)
+			printf(_("Fetching %s\n"), name);
+		if (run_command_v_opt(argv, RUN_GIT_CMD)) {
+			error(_("Could not fetch %s"), name);
+			result = 1;
+		}
+	}
+
+	return result;
+}
+
+static int fetch_one(struct remote *remote, int argc, const char **argv)
+{
+	int i;
+	static const char **refs = NULL;
+	struct refspec *refspec;
+	int ref_nr = 0;
+	int exit_code;
+
+	if (!remote)
+		die(_("No remote repository specified.  Please, specify either a URL or a\n"
+		    "remote name from which new revisions should be fetched."));
+
+	transport = transport_get(remote, NULL);
+	transport_set_verbosity(transport, verbosity, progress);
+	if (upload_pack)
+		set_option(TRANS_OPT_UPLOADPACK, upload_pack);
+	if (keep)
+		set_option(TRANS_OPT_KEEP, "yes");
+	if (depth)
+		set_option(TRANS_OPT_DEPTH, depth);
+
+	if (argc > 0) {
+		int j = 0;
+		refs = xcalloc(argc + 1, sizeof(const char *));
+		for (i = 0; i < argc; i++) {
+			if (!strcmp(argv[i], "tag")) {
+				char *ref;
+				i++;
+				if (i >= argc)
+					die(_("You need to specify a tag name."));
+				ref = xmalloc(strlen(argv[i]) * 2 + 22);
+				strcpy(ref, "refs/tags/");
+				strcat(ref, argv[i]);
+				strcat(ref, ":refs/tags/");
+				strcat(ref, argv[i]);
+				refs[j++] = ref;
+			} else
+				refs[j++] = argv[i];
+		}
+		refs[j] = NULL;
+		ref_nr = j;
+	}
+
+	sigchain_push_common(unlock_pack_on_signal);
+	atexit(unlock_pack);
+	refspec = parse_fetch_refspec(ref_nr, refs);
+	exit_code = do_fetch(transport, refspec, ref_nr);
+	free_refspec(ref_nr, refspec);
+	transport_disconnect(transport);
+	transport = NULL;
+	return exit_code;
+}
+
+int cmd_fetch(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	struct string_list list = STRING_LIST_INIT_NODUP;
+	struct remote *remote;
+	int result = 0;
+
+	packet_trace_identity("fetch");
+
+	/* Record the command line for the reflog */
+	strbuf_addstr(&default_rla, "fetch");
+	for (i = 1; i < argc; i++)
+		strbuf_addf(&default_rla, " %s", argv[i]);
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_fetch_options, builtin_fetch_usage, 0);
+
+	if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
+		if (recurse_submodules_default) {
+			int arg = parse_fetch_recurse_submodules_arg("--recurse-submodules-default", recurse_submodules_default);
+			set_config_fetch_recurse_submodules(arg);
+		}
+		gitmodules_config();
+		git_config(submodule_config, NULL);
+	}
+
+	if (all) {
+		if (argc == 1)
+			die(_("fetch --all does not take a repository argument"));
+		else if (argc > 1)
+			die(_("fetch --all does not make sense with refspecs"));
+		(void) for_each_remote(get_one_remote_for_fetch, &list);
+		result = fetch_multiple(&list);
+	} else if (argc == 0) {
+		/* No arguments -- use default remote */
+		remote = remote_get(NULL);
+		result = fetch_one(remote, argc, argv);
+	} else if (multiple) {
+		/* All arguments are assumed to be remotes or groups */
+		for (i = 0; i < argc; i++)
+			if (!add_remote_or_group(argv[i], &list))
+				die(_("No such remote or remote group: %s"), argv[i]);
+		result = fetch_multiple(&list);
+	} else {
+		/* Single remote or group */
+		(void) add_remote_or_group(argv[0], &list);
+		if (list.nr > 1) {
+			/* More than one remote */
+			if (argc > 1)
+				die(_("Fetching a group and specifying refspecs does not make sense"));
+			result = fetch_multiple(&list);
+		} else {
+			/* Zero or one remotes */
+			remote = remote_get(argv[0]);
+			result = fetch_one(remote, argc-1, argv+1);
+		}
+	}
+
+	if (!result && (recurse_submodules != RECURSE_SUBMODULES_OFF)) {
+		const char *options[10];
+		int num_options = 0;
+		add_options_to_argv(&num_options, options);
+		result = fetch_populated_submodules(num_options, options,
+						    submodule_prefix,
+						    recurse_submodules,
+						    verbosity < 0);
+	}
+
+	/* All names were strdup()ed or strndup()ed */
+	list.strdup_strings = 1;
+	string_list_clear(&list, 0);
+
+	return result;
+}
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
new file mode 100644
index 0000000..7e2f225
--- /dev/null
+++ b/builtin/fmt-merge-msg.c
@@ -0,0 +1,372 @@
+#include "builtin.h"
+#include "cache.h"
+#include "commit.h"
+#include "diff.h"
+#include "revision.h"
+#include "tag.h"
+#include "string-list.h"
+
+static const char * const fmt_merge_msg_usage[] = {
+	"git fmt-merge-msg [-m <message>] [--log[=<n>]|--no-log] [--file <file>]",
+	NULL
+};
+
+static int shortlog_len;
+
+static int fmt_merge_msg_config(const char *key, const char *value, void *cb)
+{
+	if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
+		int is_bool;
+		shortlog_len = git_config_bool_or_int(key, value, &is_bool);
+		if (!is_bool && shortlog_len < 0)
+			return error("%s: negative length %s", key, value);
+		if (is_bool && shortlog_len)
+			shortlog_len = DEFAULT_MERGE_LOG_LEN;
+	}
+	return 0;
+}
+
+struct src_data {
+	struct string_list branch, tag, r_branch, generic;
+	int head_status;
+};
+
+static void init_src_data(struct src_data *data)
+{
+	data->branch.strdup_strings = 1;
+	data->tag.strdup_strings = 1;
+	data->r_branch.strdup_strings = 1;
+	data->generic.strdup_strings = 1;
+}
+
+static struct string_list srcs = STRING_LIST_INIT_DUP;
+static struct string_list origins = STRING_LIST_INIT_DUP;
+
+static int handle_line(char *line)
+{
+	int i, len = strlen(line);
+	unsigned char *sha1;
+	char *src, *origin;
+	struct src_data *src_data;
+	struct string_list_item *item;
+	int pulling_head = 0;
+
+	if (len < 43 || line[40] != '\t')
+		return 1;
+
+	if (!prefixcmp(line + 41, "not-for-merge"))
+		return 0;
+
+	if (line[41] != '\t')
+		return 2;
+
+	line[40] = 0;
+	sha1 = xmalloc(20);
+	i = get_sha1(line, sha1);
+	line[40] = '\t';
+	if (i)
+		return 3;
+
+	if (line[len - 1] == '\n')
+		line[len - 1] = 0;
+	line += 42;
+
+	src = strstr(line, " of ");
+	if (src) {
+		*src = 0;
+		src += 4;
+		pulling_head = 0;
+	} else {
+		src = line;
+		pulling_head = 1;
+	}
+
+	item = unsorted_string_list_lookup(&srcs, src);
+	if (!item) {
+		item = string_list_append(&srcs, src);
+		item->util = xcalloc(1, sizeof(struct src_data));
+		init_src_data(item->util);
+	}
+	src_data = item->util;
+
+	if (pulling_head) {
+		origin = src;
+		src_data->head_status |= 1;
+	} else if (!prefixcmp(line, "branch ")) {
+		origin = line + 7;
+		string_list_append(&src_data->branch, origin);
+		src_data->head_status |= 2;
+	} else if (!prefixcmp(line, "tag ")) {
+		origin = line;
+		string_list_append(&src_data->tag, origin + 4);
+		src_data->head_status |= 2;
+	} else if (!prefixcmp(line, "remote-tracking branch ")) {
+		origin = line + strlen("remote-tracking branch ");
+		string_list_append(&src_data->r_branch, origin);
+		src_data->head_status |= 2;
+	} else {
+		origin = src;
+		string_list_append(&src_data->generic, line);
+		src_data->head_status |= 2;
+	}
+
+	if (!strcmp(".", src) || !strcmp(src, origin)) {
+		int len = strlen(origin);
+		if (origin[0] == '\'' && origin[len - 1] == '\'')
+			origin = xmemdupz(origin + 1, len - 2);
+	} else {
+		char *new_origin = xmalloc(strlen(origin) + strlen(src) + 5);
+		sprintf(new_origin, "%s of %s", origin, src);
+		origin = new_origin;
+	}
+	string_list_append(&origins, origin)->util = sha1;
+	return 0;
+}
+
+static void print_joined(const char *singular, const char *plural,
+		struct string_list *list, struct strbuf *out)
+{
+	if (list->nr == 0)
+		return;
+	if (list->nr == 1) {
+		strbuf_addf(out, "%s%s", singular, list->items[0].string);
+	} else {
+		int i;
+		strbuf_addstr(out, plural);
+		for (i = 0; i < list->nr - 1; i++)
+			strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
+				    list->items[i].string);
+		strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
+	}
+}
+
+static void shortlog(const char *name, unsigned char *sha1,
+		struct commit *head, struct rev_info *rev, int limit,
+		struct strbuf *out)
+{
+	int i, count = 0;
+	struct commit *commit;
+	struct object *branch;
+	struct string_list subjects = STRING_LIST_INIT_DUP;
+	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
+	struct strbuf sb = STRBUF_INIT;
+
+	branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
+	if (!branch || branch->type != OBJ_COMMIT)
+		return;
+
+	setup_revisions(0, NULL, rev, NULL);
+	rev->ignore_merges = 1;
+	add_pending_object(rev, branch, name);
+	add_pending_object(rev, &head->object, "^HEAD");
+	head->object.flags |= UNINTERESTING;
+	if (prepare_revision_walk(rev))
+		die("revision walk setup failed");
+	while ((commit = get_revision(rev)) != NULL) {
+		struct pretty_print_context ctx = {0};
+
+		/* ignore merges */
+		if (commit->parents && commit->parents->next)
+			continue;
+
+		count++;
+		if (subjects.nr > limit)
+			continue;
+
+		format_commit_message(commit, "%s", &sb, &ctx);
+		strbuf_ltrim(&sb);
+
+		if (!sb.len)
+			string_list_append(&subjects,
+					   sha1_to_hex(commit->object.sha1));
+		else
+			string_list_append(&subjects, strbuf_detach(&sb, NULL));
+	}
+
+	if (count > limit)
+		strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
+	else
+		strbuf_addf(out, "\n* %s:\n", name);
+
+	for (i = 0; i < subjects.nr; i++)
+		if (i >= limit)
+			strbuf_addf(out, "  ...\n");
+		else
+			strbuf_addf(out, "  %s\n", subjects.items[i].string);
+
+	clear_commit_marks((struct commit *)branch, flags);
+	clear_commit_marks(head, flags);
+	free_commit_list(rev->commits);
+	rev->commits = NULL;
+	rev->pending.nr = 0;
+
+	string_list_clear(&subjects, 0);
+}
+
+static void do_fmt_merge_msg_title(struct strbuf *out,
+	const char *current_branch) {
+	int i = 0;
+	char *sep = "";
+
+	strbuf_addstr(out, "Merge ");
+	for (i = 0; i < srcs.nr; i++) {
+		struct src_data *src_data = srcs.items[i].util;
+		const char *subsep = "";
+
+		strbuf_addstr(out, sep);
+		sep = "; ";
+
+		if (src_data->head_status == 1) {
+			strbuf_addstr(out, srcs.items[i].string);
+			continue;
+		}
+		if (src_data->head_status == 3) {
+			subsep = ", ";
+			strbuf_addstr(out, "HEAD");
+		}
+		if (src_data->branch.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("branch ", "branches ", &src_data->branch,
+					out);
+		}
+		if (src_data->r_branch.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("remote-tracking branch ", "remote-tracking branches ",
+					&src_data->r_branch, out);
+		}
+		if (src_data->tag.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("tag ", "tags ", &src_data->tag, out);
+		}
+		if (src_data->generic.nr) {
+			strbuf_addstr(out, subsep);
+			print_joined("commit ", "commits ", &src_data->generic,
+					out);
+		}
+		if (strcmp(".", srcs.items[i].string))
+			strbuf_addf(out, " of %s", srcs.items[i].string);
+	}
+
+	if (!strcmp("master", current_branch))
+		strbuf_addch(out, '\n');
+	else
+		strbuf_addf(out, " into %s\n", current_branch);
+}
+
+static int do_fmt_merge_msg(int merge_title, struct strbuf *in,
+	struct strbuf *out, int shortlog_len) {
+	int i = 0, pos = 0;
+	unsigned char head_sha1[20];
+	const char *current_branch;
+
+	/* get current branch */
+	current_branch = resolve_ref("HEAD", head_sha1, 1, NULL);
+	if (!current_branch)
+		die("No current branch");
+	if (!prefixcmp(current_branch, "refs/heads/"))
+		current_branch += 11;
+
+	/* get a line */
+	while (pos < in->len) {
+		int len;
+		char *newline, *p = in->buf + pos;
+
+		newline = strchr(p, '\n');
+		len = newline ? newline - p : strlen(p);
+		pos += len + !!newline;
+		i++;
+		p[len] = 0;
+		if (handle_line(p))
+			die ("Error in line %d: %.*s", i, len, p);
+	}
+
+	if (!srcs.nr)
+		return 0;
+
+	if (merge_title)
+		do_fmt_merge_msg_title(out, current_branch);
+
+	if (shortlog_len) {
+		struct commit *head;
+		struct rev_info rev;
+
+		head = lookup_commit_or_die(head_sha1, "HEAD");
+		init_revisions(&rev, NULL);
+		rev.commit_format = CMIT_FMT_ONELINE;
+		rev.ignore_merges = 1;
+		rev.limited = 1;
+
+		if (suffixcmp(out->buf, "\n"))
+			strbuf_addch(out, '\n');
+
+		for (i = 0; i < origins.nr; i++)
+			shortlog(origins.items[i].string, origins.items[i].util,
+					head, &rev, shortlog_len, out);
+	}
+	return 0;
+}
+
+int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
+		  int merge_title, int shortlog_len) {
+	return do_fmt_merge_msg(merge_title, in, out, shortlog_len);
+}
+
+int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
+{
+	const char *inpath = NULL;
+	const char *message = NULL;
+	struct option options[] = {
+		{ OPTION_INTEGER, 0, "log", &shortlog_len, "n",
+		  "populate log with at most <n> entries from shortlog",
+		  PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
+		{ OPTION_INTEGER, 0, "summary", &shortlog_len, "n",
+		  "alias for --log (deprecated)",
+		  PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, NULL,
+		  DEFAULT_MERGE_LOG_LEN },
+		OPT_STRING('m', "message", &message, "text",
+			"use <text> as start of message"),
+		OPT_FILENAME('F', "file", &inpath, "file to read from"),
+		OPT_END()
+	};
+
+	FILE *in = stdin;
+	struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
+	int ret;
+
+	git_config(fmt_merge_msg_config, NULL);
+	argc = parse_options(argc, argv, prefix, options, fmt_merge_msg_usage,
+			     0);
+	if (argc > 0)
+		usage_with_options(fmt_merge_msg_usage, options);
+	if (message && !shortlog_len) {
+		char nl = '\n';
+		write_in_full(STDOUT_FILENO, message, strlen(message));
+		write_in_full(STDOUT_FILENO, &nl, 1);
+		return 0;
+	}
+	if (shortlog_len < 0)
+		die("Negative --log=%d", shortlog_len);
+
+	if (inpath && strcmp(inpath, "-")) {
+		in = fopen(inpath, "r");
+		if (!in)
+			die_errno("cannot open '%s'", inpath);
+	}
+
+	if (strbuf_read(&input, fileno(in), 0) < 0)
+		die_errno("could not read input file");
+
+	if (message)
+		strbuf_addstr(&output, message);
+	ret = fmt_merge_msg(&input, &output,
+			    message ? 0 : 1,
+			    shortlog_len);
+
+	if (ret)
+		return ret;
+	write_in_full(STDOUT_FILENO, output.buf, output.len);
+	return 0;
+}
diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
new file mode 100644
index 0000000..89e75c6
--- /dev/null
+++ b/builtin/for-each-ref.c
@@ -0,0 +1,1000 @@
+#include "builtin.h"
+#include "cache.h"
+#include "refs.h"
+#include "object.h"
+#include "tag.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "quote.h"
+#include "parse-options.h"
+#include "remote.h"
+
+/* Quoting styles */
+#define QUOTE_NONE 0
+#define QUOTE_SHELL 1
+#define QUOTE_PERL 2
+#define QUOTE_PYTHON 4
+#define QUOTE_TCL 8
+
+typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
+
+struct atom_value {
+	const char *s;
+	unsigned long ul; /* used for sorting when not FIELD_STR */
+};
+
+struct ref_sort {
+	struct ref_sort *next;
+	int atom; /* index into used_atom array */
+	unsigned reverse : 1;
+};
+
+struct refinfo {
+	char *refname;
+	unsigned char objectname[20];
+	int flag;
+	const char *symref;
+	struct atom_value *value;
+};
+
+static struct {
+	const char *name;
+	cmp_type cmp_type;
+} valid_atom[] = {
+	{ "refname" },
+	{ "objecttype" },
+	{ "objectsize", FIELD_ULONG },
+	{ "objectname" },
+	{ "tree" },
+	{ "parent" },
+	{ "numparent", FIELD_ULONG },
+	{ "object" },
+	{ "type" },
+	{ "tag" },
+	{ "author" },
+	{ "authorname" },
+	{ "authoremail" },
+	{ "authordate", FIELD_TIME },
+	{ "committer" },
+	{ "committername" },
+	{ "committeremail" },
+	{ "committerdate", FIELD_TIME },
+	{ "tagger" },
+	{ "taggername" },
+	{ "taggeremail" },
+	{ "taggerdate", FIELD_TIME },
+	{ "creator" },
+	{ "creatordate", FIELD_TIME },
+	{ "subject" },
+	{ "body" },
+	{ "contents" },
+	{ "upstream" },
+	{ "symref" },
+	{ "flag" },
+};
+
+/*
+ * An atom is a valid field atom listed above, possibly prefixed with
+ * a "*" to denote deref_tag().
+ *
+ * We parse given format string and sort specifiers, and make a list
+ * of properties that we need to extract out of objects.  refinfo
+ * structure will hold an array of values extracted that can be
+ * indexed with the "atom number", which is an index into this
+ * array.
+ */
+static const char **used_atom;
+static cmp_type *used_atom_type;
+static int used_atom_cnt, sort_atom_limit, need_tagged, need_symref;
+
+/*
+ * Used to parse format string and sort specifiers
+ */
+static int parse_atom(const char *atom, const char *ep)
+{
+	const char *sp;
+	int i, at;
+
+	sp = atom;
+	if (*sp == '*' && sp < ep)
+		sp++; /* deref */
+	if (ep <= sp)
+		die("malformed field name: %.*s", (int)(ep-atom), atom);
+
+	/* Do we have the atom already used elsewhere? */
+	for (i = 0; i < used_atom_cnt; i++) {
+		int len = strlen(used_atom[i]);
+		if (len == ep - atom && !memcmp(used_atom[i], atom, len))
+			return i;
+	}
+
+	/* Is the atom a valid one? */
+	for (i = 0; i < ARRAY_SIZE(valid_atom); i++) {
+		int len = strlen(valid_atom[i].name);
+		/*
+		 * If the atom name has a colon, strip it and everything after
+		 * it off - it specifies the format for this entry, and
+		 * shouldn't be used for checking against the valid_atom
+		 * table.
+		 */
+		const char *formatp = strchr(sp, ':');
+		if (!formatp || ep < formatp)
+			formatp = ep;
+		if (len == formatp - sp && !memcmp(valid_atom[i].name, sp, len))
+			break;
+	}
+
+	if (ARRAY_SIZE(valid_atom) <= i)
+		die("unknown field name: %.*s", (int)(ep-atom), atom);
+
+	/* Add it in, including the deref prefix */
+	at = used_atom_cnt;
+	used_atom_cnt++;
+	used_atom = xrealloc(used_atom,
+			     (sizeof *used_atom) * used_atom_cnt);
+	used_atom_type = xrealloc(used_atom_type,
+				  (sizeof(*used_atom_type) * used_atom_cnt));
+	used_atom[at] = xmemdupz(atom, ep - atom);
+	used_atom_type[at] = valid_atom[i].cmp_type;
+	if (*atom == '*')
+		need_tagged = 1;
+	if (!strcmp(used_atom[at], "symref"))
+		need_symref = 1;
+	return at;
+}
+
+/*
+ * In a format string, find the next occurrence of %(atom).
+ */
+static const char *find_next(const char *cp)
+{
+	while (*cp) {
+		if (*cp == '%') {
+			/*
+			 * %( is the start of an atom;
+			 * %% is a quoted per-cent.
+			 */
+			if (cp[1] == '(')
+				return cp;
+			else if (cp[1] == '%')
+				cp++; /* skip over two % */
+			/* otherwise this is a singleton, literal % */
+		}
+		cp++;
+	}
+	return NULL;
+}
+
+/*
+ * Make sure the format string is well formed, and parse out
+ * the used atoms.
+ */
+static int verify_format(const char *format)
+{
+	const char *cp, *sp;
+	for (cp = format; *cp && (sp = find_next(cp)); ) {
+		const char *ep = strchr(sp, ')');
+		if (!ep)
+			return error("malformed format string %s", sp);
+		/* sp points at "%(" and ep points at the closing ")" */
+		parse_atom(sp + 2, ep);
+		cp = ep + 1;
+	}
+	return 0;
+}
+
+/*
+ * Given an object name, read the object data and size, and return a
+ * "struct object".  If the object data we are returning is also borrowed
+ * by the "struct object" representation, set *eaten as well---it is a
+ * signal from parse_object_buffer to us not to free the buffer.
+ */
+static void *get_obj(const unsigned char *sha1, struct object **obj, unsigned long *sz, int *eaten)
+{
+	enum object_type type;
+	void *buf = read_sha1_file(sha1, &type, sz);
+
+	if (buf)
+		*obj = parse_object_buffer(sha1, type, *sz, buf, eaten);
+	else
+		*obj = NULL;
+	return buf;
+}
+
+/* See grab_values */
+static void grab_common_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
+{
+	int i;
+
+	for (i = 0; i < used_atom_cnt; i++) {
+		const char *name = used_atom[i];
+		struct atom_value *v = &val[i];
+		if (!!deref != (*name == '*'))
+			continue;
+		if (deref)
+			name++;
+		if (!strcmp(name, "objecttype"))
+			v->s = typename(obj->type);
+		else if (!strcmp(name, "objectsize")) {
+			char *s = xmalloc(40);
+			sprintf(s, "%lu", sz);
+			v->ul = sz;
+			v->s = s;
+		}
+		else if (!strcmp(name, "objectname")) {
+			char *s = xmalloc(41);
+			strcpy(s, sha1_to_hex(obj->sha1));
+			v->s = s;
+		}
+		else if (!strcmp(name, "objectname:short")) {
+			v->s = xstrdup(find_unique_abbrev(obj->sha1,
+							  DEFAULT_ABBREV));
+		}
+	}
+}
+
+/* See grab_values */
+static void grab_tag_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
+{
+	int i;
+	struct tag *tag = (struct tag *) obj;
+
+	for (i = 0; i < used_atom_cnt; i++) {
+		const char *name = used_atom[i];
+		struct atom_value *v = &val[i];
+		if (!!deref != (*name == '*'))
+			continue;
+		if (deref)
+			name++;
+		if (!strcmp(name, "tag"))
+			v->s = tag->tag;
+		else if (!strcmp(name, "type") && tag->tagged)
+			v->s = typename(tag->tagged->type);
+		else if (!strcmp(name, "object") && tag->tagged) {
+			char *s = xmalloc(41);
+			strcpy(s, sha1_to_hex(tag->tagged->sha1));
+			v->s = s;
+		}
+	}
+}
+
+static int num_parents(struct commit *commit)
+{
+	struct commit_list *parents;
+	int i;
+
+	for (i = 0, parents = commit->parents;
+	     parents;
+	     parents = parents->next)
+		i++;
+	return i;
+}
+
+/* See grab_values */
+static void grab_commit_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
+{
+	int i;
+	struct commit *commit = (struct commit *) obj;
+
+	for (i = 0; i < used_atom_cnt; i++) {
+		const char *name = used_atom[i];
+		struct atom_value *v = &val[i];
+		if (!!deref != (*name == '*'))
+			continue;
+		if (deref)
+			name++;
+		if (!strcmp(name, "tree")) {
+			char *s = xmalloc(41);
+			strcpy(s, sha1_to_hex(commit->tree->object.sha1));
+			v->s = s;
+		}
+		if (!strcmp(name, "numparent")) {
+			char *s = xmalloc(40);
+			v->ul = num_parents(commit);
+			sprintf(s, "%lu", v->ul);
+			v->s = s;
+		}
+		else if (!strcmp(name, "parent")) {
+			int num = num_parents(commit);
+			int i;
+			struct commit_list *parents;
+			char *s = xmalloc(41 * num + 1);
+			v->s = s;
+			for (i = 0, parents = commit->parents;
+			     parents;
+			     parents = parents->next, i = i + 41) {
+				struct commit *parent = parents->item;
+				strcpy(s+i, sha1_to_hex(parent->object.sha1));
+				if (parents->next)
+					s[i+40] = ' ';
+			}
+			if (!i)
+				*s = '\0';
+		}
+	}
+}
+
+static const char *find_wholine(const char *who, int wholen, const char *buf, unsigned long sz)
+{
+	const char *eol;
+	while (*buf) {
+		if (!strncmp(buf, who, wholen) &&
+		    buf[wholen] == ' ')
+			return buf + wholen + 1;
+		eol = strchr(buf, '\n');
+		if (!eol)
+			return "";
+		eol++;
+		if (*eol == '\n')
+			return ""; /* end of header */
+		buf = eol;
+	}
+	return "";
+}
+
+static const char *copy_line(const char *buf)
+{
+	const char *eol = strchrnul(buf, '\n');
+	return xmemdupz(buf, eol - buf);
+}
+
+static const char *copy_name(const char *buf)
+{
+	const char *cp;
+	for (cp = buf; *cp && *cp != '\n'; cp++) {
+		if (!strncmp(cp, " <", 2))
+			return xmemdupz(buf, cp - buf);
+	}
+	return "";
+}
+
+static const char *copy_email(const char *buf)
+{
+	const char *email = strchr(buf, '<');
+	const char *eoemail;
+	if (!email)
+		return "";
+	eoemail = strchr(email, '>');
+	if (!eoemail)
+		return "";
+	return xmemdupz(email, eoemail + 1 - email);
+}
+
+static void grab_date(const char *buf, struct atom_value *v, const char *atomname)
+{
+	const char *eoemail = strstr(buf, "> ");
+	char *zone;
+	unsigned long timestamp;
+	long tz;
+	enum date_mode date_mode = DATE_NORMAL;
+	const char *formatp;
+
+	/*
+	 * We got here because atomname ends in "date" or "date<something>";
+	 * it's not possible that <something> is not ":<format>" because
+	 * parse_atom() wouldn't have allowed it, so we can assume that no
+	 * ":" means no format is specified, and use the default.
+	 */
+	formatp = strchr(atomname, ':');
+	if (formatp != NULL) {
+		formatp++;
+		date_mode = parse_date_format(formatp);
+	}
+
+	if (!eoemail)
+		goto bad;
+	timestamp = strtoul(eoemail + 2, &zone, 10);
+	if (timestamp == ULONG_MAX)
+		goto bad;
+	tz = strtol(zone, NULL, 10);
+	if ((tz == LONG_MIN || tz == LONG_MAX) && errno == ERANGE)
+		goto bad;
+	v->s = xstrdup(show_date(timestamp, tz, date_mode));
+	v->ul = timestamp;
+	return;
+ bad:
+	v->s = "";
+	v->ul = 0;
+}
+
+/* See grab_values */
+static void grab_person(const char *who, struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
+{
+	int i;
+	int wholen = strlen(who);
+	const char *wholine = NULL;
+
+	for (i = 0; i < used_atom_cnt; i++) {
+		const char *name = used_atom[i];
+		struct atom_value *v = &val[i];
+		if (!!deref != (*name == '*'))
+			continue;
+		if (deref)
+			name++;
+		if (strncmp(who, name, wholen))
+			continue;
+		if (name[wholen] != 0 &&
+		    strcmp(name + wholen, "name") &&
+		    strcmp(name + wholen, "email") &&
+		    prefixcmp(name + wholen, "date"))
+			continue;
+		if (!wholine)
+			wholine = find_wholine(who, wholen, buf, sz);
+		if (!wholine)
+			return; /* no point looking for it */
+		if (name[wholen] == 0)
+			v->s = copy_line(wholine);
+		else if (!strcmp(name + wholen, "name"))
+			v->s = copy_name(wholine);
+		else if (!strcmp(name + wholen, "email"))
+			v->s = copy_email(wholine);
+		else if (!prefixcmp(name + wholen, "date"))
+			grab_date(wholine, v, name);
+	}
+
+	/*
+	 * For a tag or a commit object, if "creator" or "creatordate" is
+	 * requested, do something special.
+	 */
+	if (strcmp(who, "tagger") && strcmp(who, "committer"))
+		return; /* "author" for commit object is not wanted */
+	if (!wholine)
+		wholine = find_wholine(who, wholen, buf, sz);
+	if (!wholine)
+		return;
+	for (i = 0; i < used_atom_cnt; i++) {
+		const char *name = used_atom[i];
+		struct atom_value *v = &val[i];
+		if (!!deref != (*name == '*'))
+			continue;
+		if (deref)
+			name++;
+
+		if (!prefixcmp(name, "creatordate"))
+			grab_date(wholine, v, name);
+		else if (!strcmp(name, "creator"))
+			v->s = copy_line(wholine);
+	}
+}
+
+static void find_subpos(const char *buf, unsigned long sz, const char **sub, const char **body)
+{
+	while (*buf) {
+		const char *eol = strchr(buf, '\n');
+		if (!eol)
+			return;
+		if (eol[1] == '\n') {
+			buf = eol + 1;
+			break; /* found end of header */
+		}
+		buf = eol + 1;
+	}
+	while (*buf == '\n')
+		buf++;
+	if (!*buf)
+		return;
+	*sub = buf; /* first non-empty line */
+	buf = strchr(buf, '\n');
+	if (!buf) {
+		*body = "";
+		return; /* no body */
+	}
+	while (*buf == '\n')
+		buf++; /* skip blank between subject and body */
+	*body = buf;
+}
+
+/* See grab_values */
+static void grab_sub_body_contents(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
+{
+	int i;
+	const char *subpos = NULL, *bodypos = NULL;
+
+	for (i = 0; i < used_atom_cnt; i++) {
+		const char *name = used_atom[i];
+		struct atom_value *v = &val[i];
+		if (!!deref != (*name == '*'))
+			continue;
+		if (deref)
+			name++;
+		if (strcmp(name, "subject") &&
+		    strcmp(name, "body") &&
+		    strcmp(name, "contents"))
+			continue;
+		if (!subpos)
+			find_subpos(buf, sz, &subpos, &bodypos);
+		if (!subpos)
+			return;
+
+		if (!strcmp(name, "subject"))
+			v->s = copy_line(subpos);
+		else if (!strcmp(name, "body"))
+			v->s = xstrdup(bodypos);
+		else if (!strcmp(name, "contents"))
+			v->s = xstrdup(subpos);
+	}
+}
+
+/*
+ * We want to have empty print-string for field requests
+ * that do not apply (e.g. "authordate" for a tag object)
+ */
+static void fill_missing_values(struct atom_value *val)
+{
+	int i;
+	for (i = 0; i < used_atom_cnt; i++) {
+		struct atom_value *v = &val[i];
+		if (v->s == NULL)
+			v->s = "";
+	}
+}
+
+/*
+ * val is a list of atom_value to hold returned values.  Extract
+ * the values for atoms in used_atom array out of (obj, buf, sz).
+ * when deref is false, (obj, buf, sz) is the object that is
+ * pointed at by the ref itself; otherwise it is the object the
+ * ref (which is a tag) refers to.
+ */
+static void grab_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
+{
+	grab_common_values(val, deref, obj, buf, sz);
+	switch (obj->type) {
+	case OBJ_TAG:
+		grab_tag_values(val, deref, obj, buf, sz);
+		grab_sub_body_contents(val, deref, obj, buf, sz);
+		grab_person("tagger", val, deref, obj, buf, sz);
+		break;
+	case OBJ_COMMIT:
+		grab_commit_values(val, deref, obj, buf, sz);
+		grab_sub_body_contents(val, deref, obj, buf, sz);
+		grab_person("author", val, deref, obj, buf, sz);
+		grab_person("committer", val, deref, obj, buf, sz);
+		break;
+	case OBJ_TREE:
+		/* grab_tree_values(val, deref, obj, buf, sz); */
+		break;
+	case OBJ_BLOB:
+		/* grab_blob_values(val, deref, obj, buf, sz); */
+		break;
+	default:
+		die("Eh?  Object of type %d?", obj->type);
+	}
+}
+
+static inline char *copy_advance(char *dst, const char *src)
+{
+	while (*src)
+		*dst++ = *src++;
+	return dst;
+}
+
+/*
+ * Parse the object referred by ref, and grab needed value.
+ */
+static void populate_value(struct refinfo *ref)
+{
+	void *buf;
+	struct object *obj;
+	int eaten, i;
+	unsigned long size;
+	const unsigned char *tagged;
+
+	ref->value = xcalloc(sizeof(struct atom_value), used_atom_cnt);
+
+	if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
+		unsigned char unused1[20];
+		const char *symref;
+		symref = resolve_ref(ref->refname, unused1, 1, NULL);
+		if (symref)
+			ref->symref = xstrdup(symref);
+		else
+			ref->symref = "";
+	}
+
+	/* Fill in specials first */
+	for (i = 0; i < used_atom_cnt; i++) {
+		const char *name = used_atom[i];
+		struct atom_value *v = &ref->value[i];
+		int deref = 0;
+		const char *refname;
+		const char *formatp;
+
+		if (*name == '*') {
+			deref = 1;
+			name++;
+		}
+
+		if (!prefixcmp(name, "refname"))
+			refname = ref->refname;
+		else if (!prefixcmp(name, "symref"))
+			refname = ref->symref ? ref->symref : "";
+		else if (!prefixcmp(name, "upstream")) {
+			struct branch *branch;
+			/* only local branches may have an upstream */
+			if (prefixcmp(ref->refname, "refs/heads/"))
+				continue;
+			branch = branch_get(ref->refname + 11);
+
+			if (!branch || !branch->merge || !branch->merge[0] ||
+			    !branch->merge[0]->dst)
+				continue;
+			refname = branch->merge[0]->dst;
+		}
+		else if (!strcmp(name, "flag")) {
+			char buf[256], *cp = buf;
+			if (ref->flag & REF_ISSYMREF)
+				cp = copy_advance(cp, ",symref");
+			if (ref->flag & REF_ISPACKED)
+				cp = copy_advance(cp, ",packed");
+			if (cp == buf)
+				v->s = "";
+			else {
+				*cp = '\0';
+				v->s = xstrdup(buf + 1);
+			}
+			continue;
+		}
+		else
+			continue;
+
+		formatp = strchr(name, ':');
+		/* look for "short" refname format */
+		if (formatp) {
+			formatp++;
+			if (!strcmp(formatp, "short"))
+				refname = shorten_unambiguous_ref(refname,
+						      warn_ambiguous_refs);
+			else
+				die("unknown %.*s format %s",
+				    (int)(formatp - name), name, formatp);
+		}
+
+		if (!deref)
+			v->s = refname;
+		else {
+			int len = strlen(refname);
+			char *s = xmalloc(len + 4);
+			sprintf(s, "%s^{}", refname);
+			v->s = s;
+		}
+	}
+
+	for (i = 0; i < used_atom_cnt; i++) {
+		struct atom_value *v = &ref->value[i];
+		if (v->s == NULL)
+			goto need_obj;
+	}
+	return;
+
+ need_obj:
+	buf = get_obj(ref->objectname, &obj, &size, &eaten);
+	if (!buf)
+		die("missing object %s for %s",
+		    sha1_to_hex(ref->objectname), ref->refname);
+	if (!obj)
+		die("parse_object_buffer failed on %s for %s",
+		    sha1_to_hex(ref->objectname), ref->refname);
+
+	grab_values(ref->value, 0, obj, buf, size);
+	if (!eaten)
+		free(buf);
+
+	/*
+	 * If there is no atom that wants to know about tagged
+	 * object, we are done.
+	 */
+	if (!need_tagged || (obj->type != OBJ_TAG))
+		return;
+
+	/*
+	 * If it is a tag object, see if we use a value that derefs
+	 * the object, and if we do grab the object it refers to.
+	 */
+	tagged = ((struct tag *)obj)->tagged->sha1;
+
+	/*
+	 * NEEDSWORK: This derefs tag only once, which
+	 * is good to deal with chains of trust, but
+	 * is not consistent with what deref_tag() does
+	 * which peels the onion to the core.
+	 */
+	buf = get_obj(tagged, &obj, &size, &eaten);
+	if (!buf)
+		die("missing object %s for %s",
+		    sha1_to_hex(tagged), ref->refname);
+	if (!obj)
+		die("parse_object_buffer failed on %s for %s",
+		    sha1_to_hex(tagged), ref->refname);
+	grab_values(ref->value, 1, obj, buf, size);
+	if (!eaten)
+		free(buf);
+}
+
+/*
+ * Given a ref, return the value for the atom.  This lazily gets value
+ * out of the object by calling populate value.
+ */
+static void get_value(struct refinfo *ref, int atom, struct atom_value **v)
+{
+	if (!ref->value) {
+		populate_value(ref);
+		fill_missing_values(ref->value);
+	}
+	*v = &ref->value[atom];
+}
+
+struct grab_ref_cbdata {
+	struct refinfo **grab_array;
+	const char **grab_pattern;
+	int grab_cnt;
+};
+
+/*
+ * A call-back given to for_each_ref().  Filter refs and keep them for
+ * later object processing.
+ */
+static int grab_single_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct grab_ref_cbdata *cb = cb_data;
+	struct refinfo *ref;
+	int cnt;
+
+	if (*cb->grab_pattern) {
+		const char **pattern;
+		int namelen = strlen(refname);
+		for (pattern = cb->grab_pattern; *pattern; pattern++) {
+			const char *p = *pattern;
+			int plen = strlen(p);
+
+			if ((plen <= namelen) &&
+			    !strncmp(refname, p, plen) &&
+			    (refname[plen] == '\0' ||
+			     refname[plen] == '/' ||
+			     p[plen-1] == '/'))
+				break;
+			if (!fnmatch(p, refname, FNM_PATHNAME))
+				break;
+		}
+		if (!*pattern)
+			return 0;
+	}
+
+	/*
+	 * We do not open the object yet; sort may only need refname
+	 * to do its job and the resulting list may yet to be pruned
+	 * by maxcount logic.
+	 */
+	ref = xcalloc(1, sizeof(*ref));
+	ref->refname = xstrdup(refname);
+	hashcpy(ref->objectname, sha1);
+	ref->flag = flag;
+
+	cnt = cb->grab_cnt;
+	cb->grab_array = xrealloc(cb->grab_array,
+				  sizeof(*cb->grab_array) * (cnt + 1));
+	cb->grab_array[cnt++] = ref;
+	cb->grab_cnt = cnt;
+	return 0;
+}
+
+static int cmp_ref_sort(struct ref_sort *s, struct refinfo *a, struct refinfo *b)
+{
+	struct atom_value *va, *vb;
+	int cmp;
+	cmp_type cmp_type = used_atom_type[s->atom];
+
+	get_value(a, s->atom, &va);
+	get_value(b, s->atom, &vb);
+	switch (cmp_type) {
+	case FIELD_STR:
+		cmp = strcmp(va->s, vb->s);
+		break;
+	default:
+		if (va->ul < vb->ul)
+			cmp = -1;
+		else if (va->ul == vb->ul)
+			cmp = 0;
+		else
+			cmp = 1;
+		break;
+	}
+	return (s->reverse) ? -cmp : cmp;
+}
+
+static struct ref_sort *ref_sort;
+static int compare_refs(const void *a_, const void *b_)
+{
+	struct refinfo *a = *((struct refinfo **)a_);
+	struct refinfo *b = *((struct refinfo **)b_);
+	struct ref_sort *s;
+
+	for (s = ref_sort; s; s = s->next) {
+		int cmp = cmp_ref_sort(s, a, b);
+		if (cmp)
+			return cmp;
+	}
+	return 0;
+}
+
+static void sort_refs(struct ref_sort *sort, struct refinfo **refs, int num_refs)
+{
+	ref_sort = sort;
+	qsort(refs, num_refs, sizeof(struct refinfo *), compare_refs);
+}
+
+static void print_value(struct refinfo *ref, int atom, int quote_style)
+{
+	struct atom_value *v;
+	get_value(ref, atom, &v);
+	switch (quote_style) {
+	case QUOTE_NONE:
+		fputs(v->s, stdout);
+		break;
+	case QUOTE_SHELL:
+		sq_quote_print(stdout, v->s);
+		break;
+	case QUOTE_PERL:
+		perl_quote_print(stdout, v->s);
+		break;
+	case QUOTE_PYTHON:
+		python_quote_print(stdout, v->s);
+		break;
+	case QUOTE_TCL:
+		tcl_quote_print(stdout, v->s);
+		break;
+	}
+}
+
+static int hex1(char ch)
+{
+	if ('0' <= ch && ch <= '9')
+		return ch - '0';
+	else if ('a' <= ch && ch <= 'f')
+		return ch - 'a' + 10;
+	else if ('A' <= ch && ch <= 'F')
+		return ch - 'A' + 10;
+	return -1;
+}
+static int hex2(const char *cp)
+{
+	if (cp[0] && cp[1])
+		return (hex1(cp[0]) << 4) | hex1(cp[1]);
+	else
+		return -1;
+}
+
+static void emit(const char *cp, const char *ep)
+{
+	while (*cp && (!ep || cp < ep)) {
+		if (*cp == '%') {
+			if (cp[1] == '%')
+				cp++;
+			else {
+				int ch = hex2(cp + 1);
+				if (0 <= ch) {
+					putchar(ch);
+					cp += 3;
+					continue;
+				}
+			}
+		}
+		putchar(*cp);
+		cp++;
+	}
+}
+
+static void show_ref(struct refinfo *info, const char *format, int quote_style)
+{
+	const char *cp, *sp, *ep;
+
+	for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
+		ep = strchr(sp, ')');
+		if (cp < sp)
+			emit(cp, sp);
+		print_value(info, parse_atom(sp + 2, ep), quote_style);
+	}
+	if (*cp) {
+		sp = cp + strlen(cp);
+		emit(cp, sp);
+	}
+	putchar('\n');
+}
+
+static struct ref_sort *default_sort(void)
+{
+	static const char cstr_name[] = "refname";
+
+	struct ref_sort *sort = xcalloc(1, sizeof(*sort));
+
+	sort->next = NULL;
+	sort->atom = parse_atom(cstr_name, cstr_name + strlen(cstr_name));
+	return sort;
+}
+
+static int opt_parse_sort(const struct option *opt, const char *arg, int unset)
+{
+	struct ref_sort **sort_tail = opt->value;
+	struct ref_sort *s;
+	int len;
+
+	if (!arg) /* should --no-sort void the list ? */
+		return -1;
+
+	*sort_tail = s = xcalloc(1, sizeof(*s));
+
+	if (*arg == '-') {
+		s->reverse = 1;
+		arg++;
+	}
+	len = strlen(arg);
+	s->atom = parse_atom(arg, arg+len);
+	return 0;
+}
+
+static char const * const for_each_ref_usage[] = {
+	"git for-each-ref [options] [<pattern>]",
+	NULL
+};
+
+int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
+{
+	int i, num_refs;
+	const char *format = "%(objectname) %(objecttype)\t%(refname)";
+	struct ref_sort *sort = NULL, **sort_tail = &sort;
+	int maxcount = 0, quote_style = 0;
+	struct refinfo **refs;
+	struct grab_ref_cbdata cbdata;
+
+	struct option opts[] = {
+		OPT_BIT('s', "shell", &quote_style,
+		        "quote placeholders suitably for shells", QUOTE_SHELL),
+		OPT_BIT('p', "perl",  &quote_style,
+		        "quote placeholders suitably for perl", QUOTE_PERL),
+		OPT_BIT(0 , "python", &quote_style,
+		        "quote placeholders suitably for python", QUOTE_PYTHON),
+		OPT_BIT(0 , "tcl",  &quote_style,
+		        "quote placeholders suitably for tcl", QUOTE_TCL),
+
+		OPT_GROUP(""),
+		OPT_INTEGER( 0 , "count", &maxcount, "show only <n> matched refs"),
+		OPT_STRING(  0 , "format", &format, "format", "format to use for the output"),
+		OPT_CALLBACK(0 , "sort", sort_tail, "key",
+		            "field name to sort on", &opt_parse_sort),
+		OPT_END(),
+	};
+
+	parse_options(argc, argv, prefix, opts, for_each_ref_usage, 0);
+	if (maxcount < 0) {
+		error("invalid --count argument: `%d'", maxcount);
+		usage_with_options(for_each_ref_usage, opts);
+	}
+	if (HAS_MULTI_BITS(quote_style)) {
+		error("more than one quoting style?");
+		usage_with_options(for_each_ref_usage, opts);
+	}
+	if (verify_format(format))
+		usage_with_options(for_each_ref_usage, opts);
+
+	if (!sort)
+		sort = default_sort();
+	sort_atom_limit = used_atom_cnt;
+
+	/* for warn_ambiguous_refs */
+	git_config(git_default_config, NULL);
+
+	memset(&cbdata, 0, sizeof(cbdata));
+	cbdata.grab_pattern = argv;
+	for_each_rawref(grab_single_ref, &cbdata);
+	refs = cbdata.grab_array;
+	num_refs = cbdata.grab_cnt;
+
+	sort_refs(sort, refs, num_refs);
+
+	if (!maxcount || num_refs < maxcount)
+		maxcount = num_refs;
+	for (i = 0; i < maxcount; i++)
+		show_ref(refs[i], format, quote_style);
+	return 0;
+}
diff --git a/builtin/fsck.c b/builtin/fsck.c
new file mode 100644
index 0000000..df1a88b
--- /dev/null
+++ b/builtin/fsck.c
@@ -0,0 +1,693 @@
+#include "builtin.h"
+#include "cache.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "tag.h"
+#include "refs.h"
+#include "pack.h"
+#include "cache-tree.h"
+#include "tree-walk.h"
+#include "fsck.h"
+#include "parse-options.h"
+#include "dir.h"
+
+#define REACHABLE 0x0001
+#define SEEN      0x0002
+
+static int show_root;
+static int show_tags;
+static int show_unreachable;
+static int include_reflogs = 1;
+static int check_full = 1;
+static int check_strict;
+static int keep_cache_objects;
+static unsigned char head_sha1[20];
+static const char *head_points_at;
+static int errors_found;
+static int write_lost_and_found;
+static int verbose;
+#define ERROR_OBJECT 01
+#define ERROR_REACHABLE 02
+
+#ifdef NO_D_INO_IN_DIRENT
+#define SORT_DIRENT 0
+#define DIRENT_SORT_HINT(de) 0
+#else
+#define SORT_DIRENT 1
+#define DIRENT_SORT_HINT(de) ((de)->d_ino)
+#endif
+
+static void objreport(struct object *obj, const char *severity,
+                      const char *err, va_list params)
+{
+	fprintf(stderr, "%s in %s %s: ",
+	        severity, typename(obj->type), sha1_to_hex(obj->sha1));
+	vfprintf(stderr, err, params);
+	fputs("\n", stderr);
+}
+
+__attribute__((format (printf, 2, 3)))
+static int objerror(struct object *obj, const char *err, ...)
+{
+	va_list params;
+	va_start(params, err);
+	errors_found |= ERROR_OBJECT;
+	objreport(obj, "error", err, params);
+	va_end(params);
+	return -1;
+}
+
+__attribute__((format (printf, 3, 4)))
+static int fsck_error_func(struct object *obj, int type, const char *err, ...)
+{
+	va_list params;
+	va_start(params, err);
+	objreport(obj, (type == FSCK_WARN) ? "warning" : "error", err, params);
+	va_end(params);
+	return (type == FSCK_WARN) ? 0 : 1;
+}
+
+static struct object_array pending;
+
+static int mark_object(struct object *obj, int type, void *data)
+{
+	struct object *parent = data;
+
+	/*
+	 * The only case data is NULL or type is OBJ_ANY is when
+	 * mark_object_reachable() calls us.  All the callers of
+	 * that function has non-NULL obj hence ...
+	 */
+	if (!obj) {
+		/* ... these references to parent->fld are safe here */
+		printf("broken link from %7s %s\n",
+			   typename(parent->type), sha1_to_hex(parent->sha1));
+		printf("broken link from %7s %s\n",
+			   (type == OBJ_ANY ? "unknown" : typename(type)), "unknown");
+		errors_found |= ERROR_REACHABLE;
+		return 1;
+	}
+
+	if (type != OBJ_ANY && obj->type != type)
+		/* ... and the reference to parent is safe here */
+		objerror(parent, "wrong object type in link");
+
+	if (obj->flags & REACHABLE)
+		return 0;
+	obj->flags |= REACHABLE;
+	if (!obj->parsed) {
+		if (parent && !has_sha1_file(obj->sha1)) {
+			printf("broken link from %7s %s\n",
+				 typename(parent->type), sha1_to_hex(parent->sha1));
+			printf("              to %7s %s\n",
+				 typename(obj->type), sha1_to_hex(obj->sha1));
+			errors_found |= ERROR_REACHABLE;
+		}
+		return 1;
+	}
+
+	add_object_array(obj, (void *) parent, &pending);
+	return 0;
+}
+
+static void mark_object_reachable(struct object *obj)
+{
+	mark_object(obj, OBJ_ANY, NULL);
+}
+
+static int traverse_one_object(struct object *obj)
+{
+	int result;
+	struct tree *tree = NULL;
+
+	if (obj->type == OBJ_TREE) {
+		obj->parsed = 0;
+		tree = (struct tree *)obj;
+		if (parse_tree(tree) < 0)
+			return 1; /* error already displayed */
+	}
+	result = fsck_walk(obj, mark_object, obj);
+	if (tree) {
+		free(tree->buffer);
+		tree->buffer = NULL;
+	}
+	return result;
+}
+
+static int traverse_reachable(void)
+{
+	int result = 0;
+	while (pending.nr) {
+		struct object_array_entry *entry;
+		struct object *obj;
+
+		entry = pending.objects + --pending.nr;
+		obj = entry->item;
+		result |= traverse_one_object(obj);
+	}
+	return !!result;
+}
+
+static int mark_used(struct object *obj, int type, void *data)
+{
+	if (!obj)
+		return 1;
+	obj->used = 1;
+	return 0;
+}
+
+/*
+ * Check a single reachable object
+ */
+static void check_reachable_object(struct object *obj)
+{
+	/*
+	 * We obviously want the object to be parsed,
+	 * except if it was in a pack-file and we didn't
+	 * do a full fsck
+	 */
+	if (!obj->parsed) {
+		if (has_sha1_pack(obj->sha1))
+			return; /* it is in pack - forget about it */
+		printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
+		errors_found |= ERROR_REACHABLE;
+		return;
+	}
+}
+
+/*
+ * Check a single unreachable object
+ */
+static void check_unreachable_object(struct object *obj)
+{
+	/*
+	 * Missing unreachable object? Ignore it. It's not like
+	 * we miss it (since it can't be reached), nor do we want
+	 * to complain about it being unreachable (since it does
+	 * not exist).
+	 */
+	if (!obj->parsed)
+		return;
+
+	/*
+	 * Unreachable object that exists? Show it if asked to,
+	 * since this is something that is prunable.
+	 */
+	if (show_unreachable) {
+		printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
+		return;
+	}
+
+	/*
+	 * "!used" means that nothing at all points to it, including
+	 * other unreachable objects. In other words, it's the "tip"
+	 * of some set of unreachable objects, usually a commit that
+	 * got dropped.
+	 *
+	 * Such starting points are more interesting than some random
+	 * set of unreachable objects, so we show them even if the user
+	 * hasn't asked for _all_ unreachable objects. If you have
+	 * deleted a branch by mistake, this is a prime candidate to
+	 * start looking at, for example.
+	 */
+	if (!obj->used) {
+		printf("dangling %s %s\n", typename(obj->type),
+		       sha1_to_hex(obj->sha1));
+		if (write_lost_and_found) {
+			char *filename = git_path("lost-found/%s/%s",
+				obj->type == OBJ_COMMIT ? "commit" : "other",
+				sha1_to_hex(obj->sha1));
+			FILE *f;
+
+			if (safe_create_leading_directories(filename)) {
+				error("Could not create lost-found");
+				return;
+			}
+			if (!(f = fopen(filename, "w")))
+				die_errno("Could not open '%s'", filename);
+			if (obj->type == OBJ_BLOB) {
+				enum object_type type;
+				unsigned long size;
+				char *buf = read_sha1_file(obj->sha1,
+						&type, &size);
+				if (buf && fwrite(buf, 1, size, f) != size)
+					die_errno("Could not write '%s'", filename);
+				free(buf);
+			} else
+				fprintf(f, "%s\n", sha1_to_hex(obj->sha1));
+			if (fclose(f))
+				die_errno("Could not finish '%s'",
+					  filename);
+		}
+		return;
+	}
+
+	/*
+	 * Otherwise? It's there, it's unreachable, and some other unreachable
+	 * object points to it. Ignore it - it's not interesting, and we showed
+	 * all the interesting cases above.
+	 */
+}
+
+static void check_object(struct object *obj)
+{
+	if (verbose)
+		fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1));
+
+	if (obj->flags & REACHABLE)
+		check_reachable_object(obj);
+	else
+		check_unreachable_object(obj);
+}
+
+static void check_connectivity(void)
+{
+	int i, max;
+
+	/* Traverse the pending reachable objects */
+	traverse_reachable();
+
+	/* Look up all the requirements, warn about missing objects.. */
+	max = get_max_object_index();
+	if (verbose)
+		fprintf(stderr, "Checking connectivity (%d objects)\n", max);
+
+	for (i = 0; i < max; i++) {
+		struct object *obj = get_indexed_object(i);
+
+		if (obj)
+			check_object(obj);
+	}
+}
+
+static int fsck_sha1(const unsigned char *sha1)
+{
+	struct object *obj = parse_object(sha1);
+	if (!obj) {
+		errors_found |= ERROR_OBJECT;
+		return error("%s: object corrupt or missing",
+			     sha1_to_hex(sha1));
+	}
+	if (obj->flags & SEEN)
+		return 0;
+	obj->flags |= SEEN;
+
+	if (verbose)
+		fprintf(stderr, "Checking %s %s\n",
+			typename(obj->type), sha1_to_hex(obj->sha1));
+
+	if (fsck_walk(obj, mark_used, NULL))
+		objerror(obj, "broken links");
+	if (fsck_object(obj, check_strict, fsck_error_func))
+		return -1;
+
+	if (obj->type == OBJ_TREE) {
+		struct tree *item = (struct tree *) obj;
+
+		free(item->buffer);
+		item->buffer = NULL;
+	}
+
+	if (obj->type == OBJ_COMMIT) {
+		struct commit *commit = (struct commit *) obj;
+
+		free(commit->buffer);
+		commit->buffer = NULL;
+
+		if (!commit->parents && show_root)
+			printf("root %s\n", sha1_to_hex(commit->object.sha1));
+	}
+
+	if (obj->type == OBJ_TAG) {
+		struct tag *tag = (struct tag *) obj;
+
+		if (show_tags && tag->tagged) {
+			printf("tagged %s %s", typename(tag->tagged->type), sha1_to_hex(tag->tagged->sha1));
+			printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * This is the sorting chunk size: make it reasonably
+ * big so that we can sort well..
+ */
+#define MAX_SHA1_ENTRIES (1024)
+
+struct sha1_entry {
+	unsigned long ino;
+	unsigned char sha1[20];
+};
+
+static struct {
+	unsigned long nr;
+	struct sha1_entry *entry[MAX_SHA1_ENTRIES];
+} sha1_list;
+
+static int ino_compare(const void *_a, const void *_b)
+{
+	const struct sha1_entry *a = _a, *b = _b;
+	unsigned long ino1 = a->ino, ino2 = b->ino;
+	return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
+}
+
+static void fsck_sha1_list(void)
+{
+	int i, nr = sha1_list.nr;
+
+	if (SORT_DIRENT)
+		qsort(sha1_list.entry, nr,
+		      sizeof(struct sha1_entry *), ino_compare);
+	for (i = 0; i < nr; i++) {
+		struct sha1_entry *entry = sha1_list.entry[i];
+		unsigned char *sha1 = entry->sha1;
+
+		sha1_list.entry[i] = NULL;
+		fsck_sha1(sha1);
+		free(entry);
+	}
+	sha1_list.nr = 0;
+}
+
+static void add_sha1_list(unsigned char *sha1, unsigned long ino)
+{
+	struct sha1_entry *entry = xmalloc(sizeof(*entry));
+	int nr;
+
+	entry->ino = ino;
+	hashcpy(entry->sha1, sha1);
+	nr = sha1_list.nr;
+	if (nr == MAX_SHA1_ENTRIES) {
+		fsck_sha1_list();
+		nr = 0;
+	}
+	sha1_list.entry[nr] = entry;
+	sha1_list.nr = ++nr;
+}
+
+static inline int is_loose_object_file(struct dirent *de,
+				       char *name, unsigned char *sha1)
+{
+	if (strlen(de->d_name) != 38)
+		return 0;
+	memcpy(name + 2, de->d_name, 39);
+	return !get_sha1_hex(name, sha1);
+}
+
+static void fsck_dir(int i, char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *de;
+	char name[100];
+
+	if (!dir)
+		return;
+
+	if (verbose)
+		fprintf(stderr, "Checking directory %s\n", path);
+
+	sprintf(name, "%02x", i);
+	while ((de = readdir(dir)) != NULL) {
+		unsigned char sha1[20];
+
+		if (is_dot_or_dotdot(de->d_name))
+			continue;
+		if (is_loose_object_file(de, name, sha1)) {
+			add_sha1_list(sha1, DIRENT_SORT_HINT(de));
+			continue;
+		}
+		if (!prefixcmp(de->d_name, "tmp_obj_"))
+			continue;
+		fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
+	}
+	closedir(dir);
+}
+
+static int default_refs;
+
+static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+		const char *email, unsigned long timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct object *obj;
+
+	if (verbose)
+		fprintf(stderr, "Checking reflog %s->%s\n",
+			sha1_to_hex(osha1), sha1_to_hex(nsha1));
+
+	if (!is_null_sha1(osha1)) {
+		obj = lookup_object(osha1);
+		if (obj) {
+			obj->used = 1;
+			mark_object_reachable(obj);
+		}
+	}
+	obj = lookup_object(nsha1);
+	if (obj) {
+		obj->used = 1;
+		mark_object_reachable(obj);
+	}
+	return 0;
+}
+
+static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data)
+{
+	for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL);
+	return 0;
+}
+
+static int is_branch(const char *refname)
+{
+	return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
+}
+
+static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *obj;
+
+	obj = parse_object(sha1);
+	if (!obj) {
+		error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
+		/* We'll continue with the rest despite the error.. */
+		return 0;
+	}
+	if (obj->type != OBJ_COMMIT && is_branch(refname))
+		error("%s: not a commit", refname);
+	default_refs++;
+	obj->used = 1;
+	mark_object_reachable(obj);
+
+	return 0;
+}
+
+static void get_default_heads(void)
+{
+	if (head_points_at && !is_null_sha1(head_sha1))
+		fsck_handle_ref("HEAD", head_sha1, 0, NULL);
+	for_each_ref(fsck_handle_ref, NULL);
+	if (include_reflogs)
+		for_each_reflog(fsck_handle_reflog, NULL);
+
+	/*
+	 * Not having any default heads isn't really fatal, but
+	 * it does mean that "--unreachable" no longer makes any
+	 * sense (since in this case everything will obviously
+	 * be unreachable by definition.
+	 *
+	 * Showing dangling objects is valid, though (as those
+	 * dangling objects are likely lost heads).
+	 *
+	 * So we just print a warning about it, and clear the
+	 * "show_unreachable" flag.
+	 */
+	if (!default_refs) {
+		fprintf(stderr, "notice: No default references\n");
+		show_unreachable = 0;
+	}
+}
+
+static void fsck_object_dir(const char *path)
+{
+	int i;
+
+	if (verbose)
+		fprintf(stderr, "Checking object directory\n");
+
+	for (i = 0; i < 256; i++) {
+		static char dir[4096];
+		sprintf(dir, "%s/%02x", path, i);
+		fsck_dir(i, dir);
+	}
+	fsck_sha1_list();
+}
+
+static int fsck_head_link(void)
+{
+	int flag;
+	int null_is_error = 0;
+
+	if (verbose)
+		fprintf(stderr, "Checking HEAD link\n");
+
+	head_points_at = resolve_ref("HEAD", head_sha1, 0, &flag);
+	if (!head_points_at)
+		return error("Invalid HEAD");
+	if (!strcmp(head_points_at, "HEAD"))
+		/* detached HEAD */
+		null_is_error = 1;
+	else if (prefixcmp(head_points_at, "refs/heads/"))
+		return error("HEAD points to something strange (%s)",
+			     head_points_at);
+	if (is_null_sha1(head_sha1)) {
+		if (null_is_error)
+			return error("HEAD: detached HEAD points at nothing");
+		fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n",
+			head_points_at + 11);
+	}
+	return 0;
+}
+
+static int fsck_cache_tree(struct cache_tree *it)
+{
+	int i;
+	int err = 0;
+
+	if (verbose)
+		fprintf(stderr, "Checking cache tree\n");
+
+	if (0 <= it->entry_count) {
+		struct object *obj = parse_object(it->sha1);
+		if (!obj) {
+			error("%s: invalid sha1 pointer in cache-tree",
+			      sha1_to_hex(it->sha1));
+			return 1;
+		}
+		obj->used = 1;
+		mark_object_reachable(obj);
+		if (obj->type != OBJ_TREE)
+			err |= objerror(obj, "non-tree in cache-tree");
+	}
+	for (i = 0; i < it->subtree_nr; i++)
+		err |= fsck_cache_tree(it->down[i]->cache_tree);
+	return err;
+}
+
+static char const * const fsck_usage[] = {
+	"git fsck [options] [<object>...]",
+	NULL
+};
+
+static struct option fsck_opts[] = {
+	OPT__VERBOSE(&verbose, "be verbose"),
+	OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"),
+	OPT_BOOLEAN(0, "tags", &show_tags, "report tags"),
+	OPT_BOOLEAN(0, "root", &show_root, "report root nodes"),
+	OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"),
+	OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"),
+	OPT_BOOLEAN(0, "full", &check_full, "also consider packs and alternate objects"),
+	OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"),
+	OPT_BOOLEAN(0, "lost-found", &write_lost_and_found,
+				"write dangling objects in .git/lost-found"),
+	OPT_END(),
+};
+
+int cmd_fsck(int argc, const char **argv, const char *prefix)
+{
+	int i, heads;
+	struct alternate_object_database *alt;
+
+	errors_found = 0;
+	read_replace_refs = 0;
+
+	argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
+	if (write_lost_and_found) {
+		check_full = 1;
+		include_reflogs = 0;
+	}
+
+	fsck_head_link();
+	fsck_object_dir(get_object_directory());
+
+	prepare_alt_odb();
+	for (alt = alt_odb_list; alt; alt = alt->next) {
+		char namebuf[PATH_MAX];
+		int namelen = alt->name - alt->base;
+		memcpy(namebuf, alt->base, namelen);
+		namebuf[namelen - 1] = 0;
+		fsck_object_dir(namebuf);
+	}
+
+	if (check_full) {
+		struct packed_git *p;
+
+		prepare_packed_git();
+		for (p = packed_git; p; p = p->next)
+			/* verify gives error messages itself */
+			verify_pack(p);
+
+		for (p = packed_git; p; p = p->next) {
+			uint32_t j, num;
+			if (open_pack_index(p))
+				continue;
+			num = p->num_objects;
+			for (j = 0; j < num; j++)
+				fsck_sha1(nth_packed_object_sha1(p, j));
+		}
+	}
+
+	heads = 0;
+	for (i = 0; i < argc; i++) {
+		const char *arg = argv[i];
+		unsigned char sha1[20];
+		if (!get_sha1(arg, sha1)) {
+			struct object *obj = lookup_object(sha1);
+
+			/* Error is printed by lookup_object(). */
+			if (!obj)
+				continue;
+
+			obj->used = 1;
+			mark_object_reachable(obj);
+			heads++;
+			continue;
+		}
+		error("invalid parameter: expected sha1, got '%s'", arg);
+	}
+
+	/*
+	 * If we've not been given any explicit head information, do the
+	 * default ones from .git/refs. We also consider the index file
+	 * in this case (ie this implies --cache).
+	 */
+	if (!heads) {
+		get_default_heads();
+		keep_cache_objects = 1;
+	}
+
+	if (keep_cache_objects) {
+		read_cache();
+		for (i = 0; i < active_nr; i++) {
+			unsigned int mode;
+			struct blob *blob;
+			struct object *obj;
+
+			mode = active_cache[i]->ce_mode;
+			if (S_ISGITLINK(mode))
+				continue;
+			blob = lookup_blob(active_cache[i]->sha1);
+			if (!blob)
+				continue;
+			obj = &blob->object;
+			obj->used = 1;
+			mark_object_reachable(obj);
+		}
+		if (active_cache_tree)
+			fsck_cache_tree(active_cache_tree);
+	}
+
+	check_connectivity();
+	return errors_found;
+}
diff --git a/builtin/gc.c b/builtin/gc.c
new file mode 100644
index 0000000..0498094
--- /dev/null
+++ b/builtin/gc.c
@@ -0,0 +1,258 @@
+/*
+ * git gc builtin command
+ *
+ * Cleanup unreachable files and optimize the repository.
+ *
+ * Copyright (c) 2007 James Bowes
+ *
+ * Based on git-gc.sh, which is
+ *
+ * Copyright (c) 2006 Shawn O. Pearce
+ */
+
+#include "builtin.h"
+#include "cache.h"
+#include "parse-options.h"
+#include "run-command.h"
+
+#define FAILED_RUN "failed to run %s"
+
+static const char * const builtin_gc_usage[] = {
+	"git gc [options]",
+	NULL
+};
+
+static int pack_refs = 1;
+static int aggressive_window = 250;
+static int gc_auto_threshold = 6700;
+static int gc_auto_pack_limit = 50;
+static const char *prune_expire = "2.weeks.ago";
+
+#define MAX_ADD 10
+static const char *argv_pack_refs[] = {"pack-refs", "--all", "--prune", NULL};
+static const char *argv_reflog[] = {"reflog", "expire", "--all", NULL};
+static const char *argv_repack[MAX_ADD] = {"repack", "-d", "-l", NULL};
+static const char *argv_prune[] = {"prune", "--expire", NULL, NULL};
+static const char *argv_rerere[] = {"rerere", "gc", NULL};
+
+static int gc_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "gc.packrefs")) {
+		if (value && !strcmp(value, "notbare"))
+			pack_refs = -1;
+		else
+			pack_refs = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "gc.aggressivewindow")) {
+		aggressive_window = git_config_int(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "gc.auto")) {
+		gc_auto_threshold = git_config_int(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "gc.autopacklimit")) {
+		gc_auto_pack_limit = git_config_int(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "gc.pruneexpire")) {
+		if (value && strcmp(value, "now")) {
+			unsigned long now = approxidate("now");
+			if (approxidate(value) >= now)
+				return error(_("Invalid %s: '%s'"), var, value);
+		}
+		return git_config_string(&prune_expire, var, value);
+	}
+	return git_default_config(var, value, cb);
+}
+
+static void append_option(const char **cmd, const char *opt, int max_length)
+{
+	int i;
+
+	for (i = 0; cmd[i]; i++)
+		;
+
+	if (i + 2 >= max_length)
+		die(_("Too many options specified"));
+	cmd[i++] = opt;
+	cmd[i] = NULL;
+}
+
+static int too_many_loose_objects(void)
+{
+	/*
+	 * Quickly check if a "gc" is needed, by estimating how
+	 * many loose objects there are.  Because SHA-1 is evenly
+	 * distributed, we can check only one and get a reasonable
+	 * estimate.
+	 */
+	char path[PATH_MAX];
+	const char *objdir = get_object_directory();
+	DIR *dir;
+	struct dirent *ent;
+	int auto_threshold;
+	int num_loose = 0;
+	int needed = 0;
+
+	if (gc_auto_threshold <= 0)
+		return 0;
+
+	if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
+		warning(_("insanely long object directory %.*s"), 50, objdir);
+		return 0;
+	}
+	dir = opendir(path);
+	if (!dir)
+		return 0;
+
+	auto_threshold = (gc_auto_threshold + 255) / 256;
+	while ((ent = readdir(dir)) != NULL) {
+		if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
+		    ent->d_name[38] != '\0')
+			continue;
+		if (++num_loose > auto_threshold) {
+			needed = 1;
+			break;
+		}
+	}
+	closedir(dir);
+	return needed;
+}
+
+static int too_many_packs(void)
+{
+	struct packed_git *p;
+	int cnt;
+
+	if (gc_auto_pack_limit <= 0)
+		return 0;
+
+	prepare_packed_git();
+	for (cnt = 0, p = packed_git; p; p = p->next) {
+		if (!p->pack_local)
+			continue;
+		if (p->pack_keep)
+			continue;
+		/*
+		 * Perhaps check the size of the pack and count only
+		 * very small ones here?
+		 */
+		cnt++;
+	}
+	return gc_auto_pack_limit <= cnt;
+}
+
+static int need_to_gc(void)
+{
+	/*
+	 * Setting gc.auto to 0 or negative can disable the
+	 * automatic gc.
+	 */
+	if (gc_auto_threshold <= 0)
+		return 0;
+
+	/*
+	 * If there are too many loose objects, but not too many
+	 * packs, we run "repack -d -l".  If there are too many packs,
+	 * we run "repack -A -d -l".  Otherwise we tell the caller
+	 * there is no need.
+	 */
+	if (too_many_packs())
+		append_option(argv_repack,
+			      prune_expire && !strcmp(prune_expire, "now") ?
+			      "-a" : "-A",
+			      MAX_ADD);
+	else if (!too_many_loose_objects())
+		return 0;
+
+	if (run_hook(NULL, "pre-auto-gc", NULL))
+		return 0;
+	return 1;
+}
+
+int cmd_gc(int argc, const char **argv, const char *prefix)
+{
+	int aggressive = 0;
+	int auto_gc = 0;
+	int quiet = 0;
+	char buf[80];
+
+	struct option builtin_gc_options[] = {
+		OPT__QUIET(&quiet, "suppress progress reporting"),
+		{ OPTION_STRING, 0, "prune", &prune_expire, "date",
+			"prune unreferenced objects",
+			PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
+		OPT_BOOLEAN(0, "aggressive", &aggressive, "be more thorough (increased runtime)"),
+		OPT_BOOLEAN(0, "auto", &auto_gc, "enable auto-gc mode"),
+		OPT_END()
+	};
+
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(builtin_gc_usage, builtin_gc_options);
+
+	git_config(gc_config, NULL);
+
+	if (pack_refs < 0)
+		pack_refs = !is_bare_repository();
+
+	argc = parse_options(argc, argv, prefix, builtin_gc_options,
+			     builtin_gc_usage, 0);
+	if (argc > 0)
+		usage_with_options(builtin_gc_usage, builtin_gc_options);
+
+	if (aggressive) {
+		append_option(argv_repack, "-f", MAX_ADD);
+		append_option(argv_repack, "--depth=250", MAX_ADD);
+		if (aggressive_window > 0) {
+			sprintf(buf, "--window=%d", aggressive_window);
+			append_option(argv_repack, buf, MAX_ADD);
+		}
+	}
+	if (quiet)
+		append_option(argv_repack, "-q", MAX_ADD);
+
+	if (auto_gc) {
+		/*
+		 * Auto-gc should be least intrusive as possible.
+		 */
+		if (!need_to_gc())
+			return 0;
+		if (quiet)
+			fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
+		else
+			fprintf(stderr,
+					_("Auto packing the repository for optimum performance. You may also\n"
+					"run \"git gc\" manually. See "
+					"\"git help gc\" for more information.\n"));
+	} else
+		append_option(argv_repack,
+			      prune_expire && !strcmp(prune_expire, "now")
+			      ? "-a" : "-A",
+			      MAX_ADD);
+
+	if (pack_refs && run_command_v_opt(argv_pack_refs, RUN_GIT_CMD))
+		return error(FAILED_RUN, argv_pack_refs[0]);
+
+	if (run_command_v_opt(argv_reflog, RUN_GIT_CMD))
+		return error(FAILED_RUN, argv_reflog[0]);
+
+	if (run_command_v_opt(argv_repack, RUN_GIT_CMD))
+		return error(FAILED_RUN, argv_repack[0]);
+
+	if (prune_expire) {
+		argv_prune[2] = prune_expire;
+		if (run_command_v_opt(argv_prune, RUN_GIT_CMD))
+			return error(FAILED_RUN, argv_prune[0]);
+	}
+
+	if (run_command_v_opt(argv_rerere, RUN_GIT_CMD))
+		return error(FAILED_RUN, argv_rerere[0]);
+
+	if (auto_gc && too_many_loose_objects())
+		warning(_("There are too many unreachable loose objects; "
+			"run 'git prune' to remove them."));
+
+	return 0;
+}
diff --git a/builtin/grep.c b/builtin/grep.c
new file mode 100644
index 0000000..a286692
--- /dev/null
+++ b/builtin/grep.c
@@ -0,0 +1,1075 @@
+/*
+ * Builtin "git grep"
+ *
+ * Copyright (c) 2006 Junio C Hamano
+ */
+#include "cache.h"
+#include "blob.h"
+#include "tree.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree-walk.h"
+#include "builtin.h"
+#include "parse-options.h"
+#include "string-list.h"
+#include "run-command.h"
+#include "userdiff.h"
+#include "grep.h"
+#include "quote.h"
+#include "dir.h"
+#include "thread-utils.h"
+
+static char const * const grep_usage[] = {
+	"git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]",
+	NULL
+};
+
+static int use_threads = 1;
+
+#ifndef NO_PTHREADS
+#define THREADS 8
+static pthread_t threads[THREADS];
+
+static void *load_sha1(const unsigned char *sha1, unsigned long *size,
+		       const char *name);
+static void *load_file(const char *filename, size_t *sz);
+
+enum work_type {WORK_SHA1, WORK_FILE};
+
+/* We use one producer thread and THREADS consumer
+ * threads. The producer adds struct work_items to 'todo' and the
+ * consumers pick work items from the same array.
+ */
+struct work_item {
+	enum work_type type;
+	char *name;
+
+	/* if type == WORK_SHA1, then 'identifier' is a SHA1,
+	 * otherwise type == WORK_FILE, and 'identifier' is a NUL
+	 * terminated filename.
+	 */
+	void *identifier;
+	char done;
+	struct strbuf out;
+};
+
+/* In the range [todo_done, todo_start) in 'todo' we have work_items
+ * that have been or are processed by a consumer thread. We haven't
+ * written the result for these to stdout yet.
+ *
+ * The work_items in [todo_start, todo_end) are waiting to be picked
+ * up by a consumer thread.
+ *
+ * The ranges are modulo TODO_SIZE.
+ */
+#define TODO_SIZE 128
+static struct work_item todo[TODO_SIZE];
+static int todo_start;
+static int todo_end;
+static int todo_done;
+
+/* Has all work items been added? */
+static int all_work_added;
+
+/* This lock protects all the variables above. */
+static pthread_mutex_t grep_mutex;
+
+/* Used to serialize calls to read_sha1_file. */
+static pthread_mutex_t read_sha1_mutex;
+
+#define grep_lock() pthread_mutex_lock(&grep_mutex)
+#define grep_unlock() pthread_mutex_unlock(&grep_mutex)
+#define read_sha1_lock() pthread_mutex_lock(&read_sha1_mutex)
+#define read_sha1_unlock() pthread_mutex_unlock(&read_sha1_mutex)
+
+/* Signalled when a new work_item is added to todo. */
+static pthread_cond_t cond_add;
+
+/* Signalled when the result from one work_item is written to
+ * stdout.
+ */
+static pthread_cond_t cond_write;
+
+/* Signalled when we are finished with everything. */
+static pthread_cond_t cond_result;
+
+static int skip_first_line;
+
+static void add_work(enum work_type type, char *name, void *id)
+{
+	grep_lock();
+
+	while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
+		pthread_cond_wait(&cond_write, &grep_mutex);
+	}
+
+	todo[todo_end].type = type;
+	todo[todo_end].name = name;
+	todo[todo_end].identifier = id;
+	todo[todo_end].done = 0;
+	strbuf_reset(&todo[todo_end].out);
+	todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
+
+	pthread_cond_signal(&cond_add);
+	grep_unlock();
+}
+
+static struct work_item *get_work(void)
+{
+	struct work_item *ret;
+
+	grep_lock();
+	while (todo_start == todo_end && !all_work_added) {
+		pthread_cond_wait(&cond_add, &grep_mutex);
+	}
+
+	if (todo_start == todo_end && all_work_added) {
+		ret = NULL;
+	} else {
+		ret = &todo[todo_start];
+		todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
+	}
+	grep_unlock();
+	return ret;
+}
+
+static void grep_sha1_async(struct grep_opt *opt, char *name,
+			    const unsigned char *sha1)
+{
+	unsigned char *s;
+	s = xmalloc(20);
+	memcpy(s, sha1, 20);
+	add_work(WORK_SHA1, name, s);
+}
+
+static void grep_file_async(struct grep_opt *opt, char *name,
+			    const char *filename)
+{
+	add_work(WORK_FILE, name, xstrdup(filename));
+}
+
+static void work_done(struct work_item *w)
+{
+	int old_done;
+
+	grep_lock();
+	w->done = 1;
+	old_done = todo_done;
+	for(; todo[todo_done].done && todo_done != todo_start;
+	    todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
+		w = &todo[todo_done];
+		if (w->out.len) {
+			const char *p = w->out.buf;
+			size_t len = w->out.len;
+
+			/* Skip the leading hunk mark of the first file. */
+			if (skip_first_line) {
+				while (len) {
+					len--;
+					if (*p++ == '\n')
+						break;
+				}
+				skip_first_line = 0;
+			}
+
+			write_or_die(1, p, len);
+		}
+		free(w->name);
+		free(w->identifier);
+	}
+
+	if (old_done != todo_done)
+		pthread_cond_signal(&cond_write);
+
+	if (all_work_added && todo_done == todo_end)
+		pthread_cond_signal(&cond_result);
+
+	grep_unlock();
+}
+
+static void *run(void *arg)
+{
+	int hit = 0;
+	struct grep_opt *opt = arg;
+
+	while (1) {
+		struct work_item *w = get_work();
+		if (!w)
+			break;
+
+		opt->output_priv = w;
+		if (w->type == WORK_SHA1) {
+			unsigned long sz;
+			void* data = load_sha1(w->identifier, &sz, w->name);
+
+			if (data) {
+				hit |= grep_buffer(opt, w->name, data, sz);
+				free(data);
+			}
+		} else if (w->type == WORK_FILE) {
+			size_t sz;
+			void* data = load_file(w->identifier, &sz);
+			if (data) {
+				hit |= grep_buffer(opt, w->name, data, sz);
+				free(data);
+			}
+		} else {
+			assert(0);
+		}
+
+		work_done(w);
+	}
+	free_grep_patterns(arg);
+	free(arg);
+
+	return (void*) (intptr_t) hit;
+}
+
+static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
+{
+	struct work_item *w = opt->output_priv;
+	strbuf_add(&w->out, buf, size);
+}
+
+static void start_threads(struct grep_opt *opt)
+{
+	int i;
+
+	pthread_mutex_init(&grep_mutex, NULL);
+	pthread_mutex_init(&read_sha1_mutex, NULL);
+	pthread_cond_init(&cond_add, NULL);
+	pthread_cond_init(&cond_write, NULL);
+	pthread_cond_init(&cond_result, NULL);
+
+	for (i = 0; i < ARRAY_SIZE(todo); i++) {
+		strbuf_init(&todo[i].out, 0);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(threads); i++) {
+		int err;
+		struct grep_opt *o = grep_opt_dup(opt);
+		o->output = strbuf_out;
+		compile_grep_patterns(o);
+		err = pthread_create(&threads[i], NULL, run, o);
+
+		if (err)
+			die(_("grep: failed to create thread: %s"),
+			    strerror(err));
+	}
+}
+
+static int wait_all(void)
+{
+	int hit = 0;
+	int i;
+
+	grep_lock();
+	all_work_added = 1;
+
+	/* Wait until all work is done. */
+	while (todo_done != todo_end)
+		pthread_cond_wait(&cond_result, &grep_mutex);
+
+	/* Wake up all the consumer threads so they can see that there
+	 * is no more work to do.
+	 */
+	pthread_cond_broadcast(&cond_add);
+	grep_unlock();
+
+	for (i = 0; i < ARRAY_SIZE(threads); i++) {
+		void *h;
+		pthread_join(threads[i], &h);
+		hit |= (int) (intptr_t) h;
+	}
+
+	pthread_mutex_destroy(&grep_mutex);
+	pthread_mutex_destroy(&read_sha1_mutex);
+	pthread_cond_destroy(&cond_add);
+	pthread_cond_destroy(&cond_write);
+	pthread_cond_destroy(&cond_result);
+
+	return hit;
+}
+#else /* !NO_PTHREADS */
+#define read_sha1_lock()
+#define read_sha1_unlock()
+
+static int wait_all(void)
+{
+	return 0;
+}
+#endif
+
+static int grep_config(const char *var, const char *value, void *cb)
+{
+	struct grep_opt *opt = cb;
+	char *color = NULL;
+
+	switch (userdiff_config(var, value)) {
+	case 0: break;
+	case -1: return -1;
+	default: return 0;
+	}
+
+	if (!strcmp(var, "grep.extendedregexp")) {
+		if (git_config_bool(var, value))
+			opt->regflags |= REG_EXTENDED;
+		else
+			opt->regflags &= ~REG_EXTENDED;
+		return 0;
+	}
+
+	if (!strcmp(var, "grep.linenumber")) {
+		opt->linenum = git_config_bool(var, value);
+		return 0;
+	}
+
+	if (!strcmp(var, "color.grep"))
+		opt->color = git_config_colorbool(var, value);
+	else if (!strcmp(var, "color.grep.context"))
+		color = opt->color_context;
+	else if (!strcmp(var, "color.grep.filename"))
+		color = opt->color_filename;
+	else if (!strcmp(var, "color.grep.function"))
+		color = opt->color_function;
+	else if (!strcmp(var, "color.grep.linenumber"))
+		color = opt->color_lineno;
+	else if (!strcmp(var, "color.grep.match"))
+		color = opt->color_match;
+	else if (!strcmp(var, "color.grep.selected"))
+		color = opt->color_selected;
+	else if (!strcmp(var, "color.grep.separator"))
+		color = opt->color_sep;
+	else
+		return git_color_default_config(var, value, cb);
+	if (color) {
+		if (!value)
+			return config_error_nonbool(var);
+		color_parse(value, var, color);
+	}
+	return 0;
+}
+
+static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
+{
+	void *data;
+
+	if (use_threads) {
+		read_sha1_lock();
+		data = read_sha1_file(sha1, type, size);
+		read_sha1_unlock();
+	} else {
+		data = read_sha1_file(sha1, type, size);
+	}
+	return data;
+}
+
+static void *load_sha1(const unsigned char *sha1, unsigned long *size,
+		       const char *name)
+{
+	enum object_type type;
+	void *data = lock_and_read_sha1_file(sha1, &type, size);
+
+	if (!data)
+		error(_("'%s': unable to read %s"), name, sha1_to_hex(sha1));
+
+	return data;
+}
+
+static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
+		     const char *filename, int tree_name_len)
+{
+	struct strbuf pathbuf = STRBUF_INIT;
+	char *name;
+
+	if (opt->relative && opt->prefix_length) {
+		quote_path_relative(filename + tree_name_len, -1, &pathbuf,
+				    opt->prefix);
+		strbuf_insert(&pathbuf, 0, filename, tree_name_len);
+	} else {
+		strbuf_addstr(&pathbuf, filename);
+	}
+
+	name = strbuf_detach(&pathbuf, NULL);
+
+#ifndef NO_PTHREADS
+	if (use_threads) {
+		grep_sha1_async(opt, name, sh