1 files changed, 376 insertions, 0 deletions

diff --git a/builtin/reset.c b/builtin/reset.c
new file mode 100644
index 0000000..4cc34c9
--- /dev/null
+++ b/builtin/reset.c
@@ -0,0 +1,376 @@
+/*
+ * "git reset" builtin command
+ *
+ * Copyright (c) 2007 Carlos Rica
+ *
+ * Based on git-reset.sh, which is
+ *
+ * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
+ */
+#include "builtin.h"
+#include "tag.h"
+#include "object.h"
+#include "commit.h"
+#include "run-command.h"
+#include "refs.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "tree.h"
+#include "branch.h"
+#include "parse-options.h"
+#include "unpack-trees.h"
+#include "cache-tree.h"
+
+static const char * const git_reset_usage[] = {
+	"git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]",
+	"git reset [-q] <commit> [--] <paths>...",
+	"git reset --patch [<commit>] [--] [<paths>...]",
+	NULL
+};
+
+enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
+static const char *reset_type_names[] = {
+	N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
+};
+
+static inline int is_merge(void)
+{
+	return !access(git_path("MERGE_HEAD"), F_OK);
+}
+
+static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
+{
+	int nr = 1;
+	int newfd;
+	struct tree_desc desc[2];
+	struct tree *tree;
+	struct unpack_trees_options opts;
+	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
+
+	memset(&opts, 0, sizeof(opts));
+	opts.head_idx = 1;
+	opts.src_index = &the_index;
+	opts.dst_index = &the_index;
+	opts.fn = oneway_merge;
+	opts.merge = 1;
+	if (!quiet)
+		opts.verbose_update = 1;
+	switch (reset_type) {
+	case KEEP:
+	case MERGE:
+		opts.update = 1;
+		break;
+	case HARD:
+		opts.update = 1;
+		/* fallthrough */
+	default:
+		opts.reset = 1;
+	}
+
+	newfd = hold_locked_index(lock, 1);
+
+	read_cache_unmerged();
+
+	if (reset_type == KEEP) {
+		unsigned char head_sha1[20];
+		if (get_sha1("HEAD", head_sha1))
+			return error(_("You do not have a valid HEAD."));
+		if (!fill_tree_descriptor(desc, head_sha1))
+			return error(_("Failed to find tree of HEAD."));
+		nr++;
+		opts.fn = twoway_merge;
+	}
+
+	if (!fill_tree_descriptor(desc + nr - 1, sha1))
+		return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
+	if (unpack_trees(nr, desc, &opts))
+		return -1;
+
+	if (reset_type == MIXED || reset_type == HARD) {
+		tree = parse_tree_indirect(sha1);
+		prime_cache_tree(&active_cache_tree, tree);
+	}
+
+	if (write_cache(newfd, active_cache, active_nr) ||
+	    commit_locked_index(lock))
+		return error(_("Could not write new index file."));
+
+	return 0;
+}
+
+static void print_new_head_line(struct commit *commit)
+{
+	const char *hex, *body;
+
+	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
+	printf(_("HEAD is now at %s"), hex);
+	body = strstr(commit->buffer, "\n\n");
+	if (body) {
+		const char *eol;
+		size_t len;
+		body += 2;
+		eol = strchr(body, '\n');
+		len = eol ? eol - body : strlen(body);
+		printf(" %.*s\n", (int) len, body);
+	}
+	else
+		printf("\n");
+}
+
+static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
+{
+	int result;
+
+	if (!index_lock) {
+		index_lock = xcalloc(1, sizeof(struct lock_file));
+		fd = hold_locked_index(index_lock, 1);
+	}
+
+	if (read_cache() < 0)
+		return error(_("Could not read index"));
+
+	result = refresh_index(&the_index, (flags), NULL, NULL,
+			       _("Unstaged changes after reset:")) ? 1 : 0;
+	if (write_cache(fd, active_cache, active_nr) ||
+			commit_locked_index(index_lock))
+		return error ("Could not refresh index");
+	return result;
+}
+
+static void update_index_from_diff(struct diff_queue_struct *q,
+		struct diff_options *opt, void *data)
+{
+	int i;
+	int *discard_flag = data;
+
+	/* do_diff_cache() mangled the index */
+	discard_cache();
+	*discard_flag = 1;
+	read_cache();
+
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filespec *one = q->queue[i]->one;
+		if (one->mode && !is_null_sha1(one->sha1)) {
+			struct cache_entry *ce;
+			ce = make_cache_entry(one->mode, one->sha1, one->path,
+				0, 0);
+			if (!ce)
+				die(_("make_cache_entry failed for path '%s'"),
+				    one->path);
+			add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
+				ADD_CACHE_OK_TO_REPLACE);
+		} else
+			remove_file_from_cache(one->path);
+	}
+}
+
+static int interactive_reset(const char *revision, const char **argv,
+			     const char *prefix)
+{
+	const char **pathspec = NULL;
+
+	if (*argv)
+		pathspec = get_pathspec(prefix, argv);
+
+	return run_add_interactive(revision, "--patch=reset", pathspec);
+}
+
+static int read_from_tree(const char *prefix, const char **argv,
+		unsigned char *tree_sha1, int refresh_flags)
+{
+	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
+	int index_fd, index_was_discarded = 0;
+	struct diff_options opt;
+
+	memset(&opt, 0, sizeof(opt));
+	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
+	opt.output_format = DIFF_FORMAT_CALLBACK;
+	opt.format_callback = update_index_from_diff;
+	opt.format_callback_data = &index_was_discarded;
+
+	index_fd = hold_locked_index(lock, 1);
+	index_was_discarded = 0;
+	read_cache();
+	if (do_diff_cache(tree_sha1, &opt))
+		return 1;
+	diffcore_std(&opt);
+	diff_flush(&opt);
+	diff_tree_release_paths(&opt);
+
+	if (!index_was_discarded)
+		/* The index is still clobbered from do_diff_cache() */
+		discard_cache();
+	return update_index_refresh(index_fd, lock, refresh_flags);
+}
+
+static void set_reflog_message(struct strbuf *sb, const char *action,
+			       const char *rev)
+{
+	const char *rla = getenv("GIT_REFLOG_ACTION");
+
+	strbuf_reset(sb);
+	if (rla)
+		strbuf_addf(sb, "%s: %s", rla, action);
+	else if (rev)
+		strbuf_addf(sb, "reset: moving to %s", rev);
+	else
+		strbuf_addf(sb, "reset: %s", action);
+}
+
+static void die_if_unmerged_cache(int reset_type)
+{
+	if (is_merge() || read_cache() < 0 || unmerged_cache())
+		die(_("Cannot do a %s reset in the middle of a merge."),
+		    _(reset_type_names[reset_type]));
+
+}
+
+int cmd_reset(int argc, const char **argv, const char *prefix)
+{
+	int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
+	int patch_mode = 0;
+	const char *rev = "HEAD";
+	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
+				*old_orig = NULL, sha1_old_orig[20];
+	struct commit *commit;
+	struct strbuf msg = STRBUF_INIT;
+	const struct option options[] = {
+		OPT__QUIET(&quiet, "be quiet, only report errors"),
+		OPT_SET_INT(0, "mixed", &reset_type,
+						"reset HEAD and index", MIXED),
+		OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
+		OPT_SET_INT(0, "hard", &reset_type,
+				"reset HEAD, index and working tree", HARD),
+		OPT_SET_INT(0, "merge", &reset_type,
+				"reset HEAD, index and working tree", MERGE),
+		OPT_SET_INT(0, "keep", &reset_type,
+				"reset HEAD but keep local changes", KEEP),
+		OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
+		OPT_END()
+	};
+
+	git_config(git_default_config, NULL);
+
+	argc = parse_options(argc, argv, prefix, options, git_reset_usage,
+						PARSE_OPT_KEEP_DASHDASH);
+
+	/*
+	 * Possible arguments are:
+	 *
+	 * git reset [-opts] <rev> <paths>...
+	 * git reset [-opts] <rev> -- <paths>...
+	 * git reset [-opts] -- <paths>...
+	 * git reset [-opts] <paths>...
+	 *
+	 * At this point, argv[i] points immediately after [-opts].
+	 */
+
+	if (i < argc) {
+		if (!strcmp(argv[i], "--")) {
+			i++; /* reset to HEAD, possibly with paths */
+		} else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
+			rev = argv[i];
+			i += 2;
+		}
+		/*
+		 * Otherwise, argv[i] could be either <rev> or <paths> and
+		 * has to be unambiguous.
+		 */
+		else if (!get_sha1(argv[i], sha1)) {
+			/*
+			 * Ok, argv[i] looks like a rev; it should not
+			 * be a filename.
+			 */
+			verify_non_filename(prefix, argv[i]);
+			rev = argv[i++];
+		} else {
+			/* Otherwise we treat this as a filename */
+			verify_filename(prefix, argv[i], 1);
+		}
+	}
+
+	if (get_sha1(rev, sha1))
+		die(_("Failed to resolve '%s' as a valid ref."), rev);
+
+	commit = lookup_commit_reference(sha1);
+	if (!commit)
+		die(_("Could not parse object '%s'."), rev);
+	hashcpy(sha1, commit->object.sha1);
+
+	if (patch_mode) {
+		if (reset_type != NONE)
+			die(_("--patch is incompatible with --{hard,mixed,soft}"));
+		return interactive_reset(rev, argv + i, prefix);
+	}
+
+	/* git reset tree [--] paths... can be used to
+	 * load chosen paths from the tree into the index without
+	 * affecting the working tree nor HEAD. */
+	if (i < argc) {
+		if (reset_type == MIXED)
+			warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
+		else if (reset_type != NONE)
+			die(_("Cannot do %s reset with paths."),
+					_(reset_type_names[reset_type]));
+		return read_from_tree(prefix, argv + i, sha1,
+				quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
+	}
+	if (reset_type == NONE)
+		reset_type = MIXED; /* by default */
+
+	if (reset_type != SOFT && reset_type != MIXED)
+		setup_work_tree();
+
+	if (reset_type == MIXED && is_bare_repository())
+		die(_("%s reset is not allowed in a bare repository"),
+		    _(reset_type_names[reset_type]));
+
+	/* Soft reset does not touch the index file nor the working tree
+	 * at all, but requires them in a good order.  Other resets reset
+	 * the index file to the tree object we are switching to. */
+	if (reset_type == SOFT)
+		die_if_unmerged_cache(reset_type);
+	else {
+		int err;
+		if (reset_type == KEEP)
+			die_if_unmerged_cache(reset_type);
+		err = reset_index_file(sha1, reset_type, quiet);
+		if (reset_type == KEEP)
+			err = err || reset_index_file(sha1, MIXED, quiet);
+		if (err)
+			die(_("Could not reset index file to revision '%s'."), rev);
+	}
+
+	/* Any resets update HEAD to the head being switched to,
+	 * saving the previous head in ORIG_HEAD before. */
+	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
+		old_orig = sha1_old_orig;
+	if (!get_sha1("HEAD", sha1_orig)) {
+		orig = sha1_orig;
+		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
+		update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
+	}
+	else if (old_orig)
+		delete_ref("ORIG_HEAD", old_orig, 0);
+	set_reflog_message(&msg, "updating HEAD", rev);
+	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
+
+	switch (reset_type) {
+	case HARD:
+		if (!update_ref_status && !quiet)
+			print_new_head_line(commit);
+		break;
+	case SOFT: /* Nothing else to do. */
+		break;
+	case MIXED: /* Report what has not been updated. */
+		update_index_refresh(0, NULL,
+				quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
+		break;
+	}
+
+	remove_branch_state();
+
+	strbuf_release(&msg);
+
+	return update_ref_status;
+}