1 files changed, 198 insertions, 98 deletions

diff --git a/builtin/log.c b/builtin/log.c
index d104d5c..f67b67d 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -12,6 +12,7 @@
 #include "color.h"
 #include "commit.h"
 #include "diff.h"
+#include "diff-merges.h"
 #include "revision.h"
 #include "log-tree.h"
 #include "builtin.h"
@@ -33,11 +34,11 @@
 #include "commit-slab.h"
 #include "repository.h"
 #include "commit-reach.h"
-#include "interdiff.h"
 #include "range-diff.h"
 
 #define MAIL_DEFAULT_WRAP 72
 #define COVER_FROM_AUTO_MAX_SUBJECT_LEN 100
+#define FORMAT_PATCH_NAME_MAX_DEFAULT 64
 
 /* Set a default date-time format for git log ("log.date" config variable) */
 static const char *default_date_mode = NULL;
@@ -51,6 +52,7 @@ static int decoration_style;
 static int decoration_given;
 static int use_mailmap_config = 1;
 static const char *fmt_patch_subject_prefix = "PATCH";
+static int fmt_patch_name_max = FORMAT_PATCH_NAME_MAX_DEFAULT;
 static const char *fmt_pretty;
 
 static const char * const builtin_log_usage[] = {
@@ -132,7 +134,6 @@ static int log_line_range_callback(const struct option *option, const char *arg,
 
 static void init_log_defaults(void)
 {
-	init_grep_defaults(the_repository);
 	init_diff_ui_defaults();
 
 	decoration_style = auto_decoration_style();
@@ -151,6 +152,7 @@ static void cmd_log_init_defaults(struct rev_info *rev)
 	rev->abbrev_commit = default_abbrev_commit;
 	rev->show_root_diff = default_show_root;
 	rev->subject_prefix = fmt_patch_subject_prefix;
+	rev->patch_name_max = fmt_patch_name_max;
 	rev->show_signature = default_show_signature;
 	rev->encode_email_headers = default_encode_email_headers;
 	rev->diffopt.flags.allow_textconv = 1;
@@ -176,7 +178,7 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	const struct option builtin_log_options[] = {
 		OPT__QUIET(&quiet, N_("suppress diff output")),
 		OPT_BOOL(0, "source", &source, N_("show source")),
-		OPT_BOOL(0, "use-mailmap", &mailmap, N_("Use mail map file")),
+		OPT_BOOL(0, "use-mailmap", &mailmap, N_("use mail map file")),
 		OPT_ALIAS(0, "mailmap", "use-mailmap"),
 		OPT_STRING_LIST(0, "decorate-refs", &decorate_refs_include,
 				N_("pattern"), N_("only decorate refs that match <pattern>")),
@@ -184,8 +186,8 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 				N_("pattern"), N_("do not decorate refs that match <pattern>")),
 		OPT_CALLBACK_F(0, "decorate", NULL, NULL, N_("decorate options"),
 			       PARSE_OPT_OPTARG, decorate_callback),
-		OPT_CALLBACK('L', NULL, &line_cb, "n,m:file",
-			     N_("Process line range n,m in file, counting from 1"),
+		OPT_CALLBACK('L', NULL, &line_cb, "range:file",
+			     N_("trace the evolution of line range <start>,<end> or function :<funcname> in <file>"),
 			     log_line_range_callback),
 		OPT_END()
 	};
@@ -207,6 +209,9 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	if (argc > 1)
 		die(_("unrecognized argument: %s"), argv[1]);
 
+	if (rev->line_level_traverse && rev->prune_data.nr)
+		die(_("-L<range>:<file> cannot be used with pathspec"));
+
 	memset(&w, 0, sizeof(w));
 	userformat_find_requirements(NULL, &w);
 
@@ -226,7 +231,7 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 
 	if (mailmap) {
 		rev->mailmap = xcalloc(1, sizeof(struct string_list));
-		read_mailmap(rev->mailmap, NULL);
+		read_mailmap(rev->mailmap);
 	}
 
 	if (rev->pretty_given && rev->commit_format == CMIT_FMT_RAW) {
@@ -302,10 +307,11 @@ static struct itimerval early_output_timer;
 
 static void log_show_early(struct rev_info *revs, struct commit_list *list)
 {
-	int i = revs->early_output, close_file = revs->diffopt.close_file;
+	int i = revs->early_output;
 	int show_header = 1;
+	int no_free = revs->diffopt.no_free;
 
-	revs->diffopt.close_file = 0;
+	revs->diffopt.no_free = 0;
 	sort_in_topological_order(&list, revs->sort_order);
 	while (list && i) {
 		struct commit *commit = list->item;
@@ -322,8 +328,8 @@ static void log_show_early(struct rev_info *revs, struct commit_list *list)
 		case commit_ignore:
 			break;
 		case commit_error:
-			if (close_file)
-				fclose(revs->diffopt.file);
+			revs->diffopt.no_free = no_free;
+			diff_free(&revs->diffopt);
 			return;
 		}
 		list = list->next;
@@ -331,8 +337,8 @@ static void log_show_early(struct rev_info *revs, struct commit_list *list)
 
 	/* Did we already get enough commits for the early output? */
 	if (!i) {
-		if (close_file)
-			fclose(revs->diffopt.file);
+		revs->diffopt.no_free = 0;
+		diff_free(&revs->diffopt);
 		return;
 	}
 
@@ -396,7 +402,7 @@ static int cmd_log_walk(struct rev_info *rev)
 {
 	struct commit *commit;
 	int saved_nrl = 0;
-	int saved_dcctc = 0, close_file = rev->diffopt.close_file;
+	int saved_dcctc = 0;
 
 	if (rev->early_output)
 		setup_early_output();
@@ -412,7 +418,7 @@ static int cmd_log_walk(struct rev_info *rev)
 	 * and HAS_CHANGES being accumulated in rev->diffopt, so be careful to
 	 * retain that state information if replacing rev->diffopt in this loop
 	 */
-	rev->diffopt.close_file = 0;
+	rev->diffopt.no_free = 1;
 	while ((commit = get_revision(rev)) != NULL) {
 		if (!log_tree_commit(rev, commit) && rev->max_count >= 0)
 			/*
@@ -437,8 +443,8 @@ static int cmd_log_walk(struct rev_info *rev)
 	}
 	rev->diffopt.degraded_cc_to_c = saved_dcctc;
 	rev->diffopt.needed_rename_limit = saved_nrl;
-	if (close_file)
-		fclose(rev->diffopt.file);
+	rev->diffopt.no_free = 0;
+	diff_free(&rev->diffopt);
 
 	if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
 	    rev->diffopt.flags.check_failed) {
@@ -455,6 +461,10 @@ static int git_log_config(const char *var, const char *value, void *cb)
 		return git_config_string(&fmt_pretty, var, value);
 	if (!strcmp(var, "format.subjectprefix"))
 		return git_config_string(&fmt_patch_subject_prefix, var, value);
+	if (!strcmp(var, "format.filenamemaxlength")) {
+		fmt_patch_name_max = git_config_int(var, value);
+		return 0;
+	}
 	if (!strcmp(var, "format.encodeemailheaders")) {
 		default_encode_email_headers = git_config_bool(var, value);
 		return 0;
@@ -599,15 +609,10 @@ static int show_tree_object(const struct object_id *oid,
 static void show_setup_revisions_tweak(struct rev_info *rev,
 				       struct setup_revision_opt *opt)
 {
-	if (rev->ignore_merges) {
-		/* There was no "-m" on the command line */
-		rev->ignore_merges = 0;
-		if (!rev->first_parent_only && !rev->combine_merges) {
-			/* No "--first-parent", "-c", or "--cc" */
-			rev->combine_merges = 1;
-			rev->dense_combined_merges = 1;
-		}
-	}
+	if (rev->first_parent_only)
+		diff_merges_default_to_first_parent(rev);
+	else
+		diff_merges_default_to_dense_combined(rev);
 	if (!rev->diffopt.output_format)
 		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 }
@@ -728,13 +733,8 @@ static void log_setup_revisions_tweak(struct rev_info *rev,
 	    rev->prune_data.nr == 1)
 		rev->diffopt.flags.follow_renames = 1;
 
-	/* Turn --cc/-c into -p --cc/-c when -p was not given */
-	if (!rev->diffopt.output_format && rev->combine_merges)
-		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
-
-	/* Turn -m on when --cc/-c was given */
-	if (rev->combine_merges)
-		rev->ignore_merges = 0;
+	if (rev->first_parent_only)
+		diff_merges_default_to_first_parent(rev);
 }
 
 int cmd_log(int argc, const char **argv, const char *prefix)
@@ -807,9 +807,15 @@ enum cover_from_description {
 	COVER_FROM_AUTO
 };
 
+enum auto_base_setting {
+	AUTO_BASE_NEVER,
+	AUTO_BASE_ALWAYS,
+	AUTO_BASE_WHEN_ABLE
+};
+
 static enum thread_level thread;
 static int do_signoff;
-static int base_auto;
+static enum auto_base_setting auto_base;
 static char *from;
 static const char *signature = git_version_string;
 static const char *signature_file;
@@ -908,7 +914,11 @@ static int git_format_config(const char *var, const char *value, void *cb)
 	if (!strcmp(var, "format.outputdirectory"))
 		return git_config_string(&config_output_directory, var, value);
 	if (!strcmp(var, "format.useautobase")) {
-		base_auto = git_config_bool(var, value);
+		if (value && !strcasecmp(value, "whenAble")) {
+			auto_base = AUTO_BASE_WHEN_ABLE;
+			return 0;
+		}
+		auto_base = git_config_bool(var, value) ? AUTO_BASE_ALWAYS : AUTO_BASE_NEVER;
 		return 0;
 	}
 	if (!strcmp(var, "format.from")) {
@@ -947,15 +957,9 @@ static int open_next_file(struct commit *commit, const char *subject,
 			 struct rev_info *rev, int quiet)
 {
 	struct strbuf filename = STRBUF_INIT;
-	int suffix_len = strlen(rev->patch_suffix) + 1;
 
 	if (output_directory) {
 		strbuf_addstr(&filename, output_directory);
-		if (filename.len >=
-		    PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len) {
-			strbuf_release(&filename);
-			return error(_("name of output directory is too long"));
-		}
 		strbuf_complete(&filename, '/');
 	}
 
@@ -1062,7 +1066,7 @@ static char *find_branch_name(struct rev_info *rev)
 		return NULL;
 	ref = rev->cmdline.rev[positive].name;
 	tip_oid = &rev->cmdline.rev[positive].item->oid;
-	if (dwim_ref(ref, strlen(ref), &branch_oid, &full_ref) &&
+	if (dwim_ref(ref, strlen(ref), &branch_oid, &full_ref, 0) &&
 	    skip_prefix(full_ref, "refs/heads/", &v) &&
 	    oideq(tip_oid, &branch_oid))
 		branch = xstrdup(v);
@@ -1128,24 +1132,24 @@ do_pp:
 
 static int get_notes_refs(struct string_list_item *item, void *arg)
 {
-	argv_array_pushf(arg, "--notes=%s", item->string);
+	strvec_pushf(arg, "--notes=%s", item->string);
 	return 0;
 }
 
-static void get_notes_args(struct argv_array *arg, struct rev_info *rev)
+static void get_notes_args(struct strvec *arg, struct rev_info *rev)
 {
 	if (!rev->show_notes) {
-		argv_array_push(arg, "--no-notes");
+		strvec_push(arg, "--no-notes");
 	} else if (rev->notes_opt.use_default_notes > 0 ||
 		   (rev->notes_opt.use_default_notes == -1 &&
 		    !rev->notes_opt.extra_notes_refs.nr)) {
-		argv_array_push(arg, "--notes");
+		strvec_push(arg, "--notes");
 	} else {
 		for_each_string_list(&rev->notes_opt.extra_notes_refs, get_notes_refs, arg);
 	}
 }
 
-static void make_cover_letter(struct rev_info *rev, int use_stdout,
+static void make_cover_letter(struct rev_info *rev, int use_separate_file,
 			      struct commit *origin,
 			      int nr, struct commit **list,
 			      const char *branch_name,
@@ -1165,7 +1169,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 
 	committer = git_committer_info(0);
 
-	if (!use_stdout &&
+	if (use_separate_file &&
 	    open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
 		die(_("failed to create cover-letter file"));
 
@@ -1197,6 +1201,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 	log.in1 = 2;
 	log.in2 = 4;
 	log.file = rev->diffopt.file;
+	log.groups = SHORTLOG_GROUP_AUTHOR;
 	for (i = 0; i < nr; i++)
 		shortlog_add_commit(&log, list[i]);
 
@@ -1208,7 +1213,8 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 
 	if (rev->idiff_oid1) {
 		fprintf_ln(rev->diffopt.file, "%s", rev->idiff_title);
-		show_interdiff(rev, 0);
+		show_interdiff(rev->idiff_oid1, rev->idiff_oid2, 0,
+			       &rev->diffopt);
 	}
 
 	if (rev->rdiff1) {
@@ -1217,16 +1223,22 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 		 * can be added later if deemed desirable.
 		 */
 		struct diff_options opts;
-		struct argv_array other_arg = ARGV_ARRAY_INIT;
+		struct strvec other_arg = STRVEC_INIT;
+		struct range_diff_options range_diff_opts = {
+			.creation_factor = rev->creation_factor,
+			.dual_color = 1,
+			.diffopt = &opts,
+			.other_arg = &other_arg
+		};
+
 		diff_setup(&opts);
 		opts.file = rev->diffopt.file;
 		opts.use_color = rev->diffopt.use_color;
 		diff_setup_done(&opts);
 		fprintf_ln(rev->diffopt.file, "%s", rev->rdiff_title);
 		get_notes_args(&other_arg, rev);
-		show_range_diff(rev->rdiff1, rev->rdiff2,
-				rev->creation_factor, 1, &opts, &other_arg);
-		argv_array_clear(&other_arg);
+		show_range_diff(rev->rdiff1, rev->rdiff2, &range_diff_opts);
+		strvec_clear(&other_arg);
 	}
 }
 
@@ -1425,6 +1437,23 @@ static int from_callback(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+static int base_callback(const struct option *opt, const char *arg, int unset)
+{
+	const char **base_commit = opt->value;
+
+	if (unset) {
+		auto_base = AUTO_BASE_NEVER;
+		*base_commit = NULL;
+	} else if (!strcmp(arg, "auto")) {
+		auto_base = AUTO_BASE_ALWAYS;
+		*base_commit = NULL;
+	} else {
+		auto_base = AUTO_BASE_NEVER;
+		*base_commit = arg;
+	}
+	return 0;
+}
+
 struct base_tree_info {
 	struct object_id base_commit;
 	int nr_patch_id, alloc_patch_id;
@@ -1437,13 +1466,36 @@ static struct commit *get_base_commit(const char *base_commit,
 {
 	struct commit *base = NULL;
 	struct commit **rev;
-	int i = 0, rev_nr = 0;
+	int i = 0, rev_nr = 0, auto_select, die_on_failure;
+
+	switch (auto_base) {
+	case AUTO_BASE_NEVER:
+		if (base_commit) {
+			auto_select = 0;
+			die_on_failure = 1;
+		} else {
+			/* no base information is requested */
+			return NULL;
+		}
+		break;
+	case AUTO_BASE_ALWAYS:
+	case AUTO_BASE_WHEN_ABLE:
+		if (base_commit) {
+			BUG("requested automatic base selection but a commit was provided");
+		} else {
+			auto_select = 1;
+			die_on_failure = auto_base == AUTO_BASE_ALWAYS;
+		}
+		break;
+	default:
+		BUG("unexpected automatic base selection method");
+	}
 
-	if (base_commit && strcmp(base_commit, "auto")) {
+	if (!auto_select) {
 		base = lookup_commit_reference_by_name(base_commit);
 		if (!base)
 			die(_("unknown commit %s"), base_commit);
-	} else if ((base_commit && !strcmp(base_commit, "auto"))) {
+	} else {
 		struct branch *curr_branch = branch_get(NULL);
 		const char *upstream = branch_get_upstream(curr_branch, NULL);
 		if (upstream) {
@@ -1451,19 +1503,32 @@ static struct commit *get_base_commit(const char *base_commit,
 			struct commit *commit;
 			struct object_id oid;
 
-			if (get_oid(upstream, &oid))
-				die(_("failed to resolve '%s' as a valid ref"), upstream);
+			if (get_oid(upstream, &oid)) {
+				if (die_on_failure)
+					die(_("failed to resolve '%s' as a valid ref"), upstream);
+				else
+					return NULL;
+			}
 			commit = lookup_commit_or_die(&oid, "upstream base");
 			base_list = get_merge_bases_many(commit, total, list);
 			/* There should be one and only one merge base. */
-			if (!base_list || base_list->next)
-				die(_("could not find exact merge base"));
+			if (!base_list || base_list->next) {
+				if (die_on_failure) {
+					die(_("could not find exact merge base"));
+				} else {
+					free_commit_list(base_list);
+					return NULL;
+				}
+			}
 			base = base_list->item;
 			free_commit_list(base_list);
 		} else {
-			die(_("failed to get upstream, if you want to record base commit automatically,\n"
-			      "please use git branch --set-upstream-to to track a remote branch.\n"
-			      "Or you could specify base commit by --base=<base-commit-id> manually"));
+			if (die_on_failure)
+				die(_("failed to get upstream, if you want to record base commit automatically,\n"
+				      "please use git branch --set-upstream-to to track a remote branch.\n"
+				      "Or you could specify base commit by --base=<base-commit-id> manually"));
+			else
+				return NULL;
 		}
 	}
 
@@ -1480,8 +1545,14 @@ static struct commit *get_base_commit(const char *base_commit,
 		for (i = 0; i < rev_nr / 2; i++) {
 			struct commit_list *merge_base;
 			merge_base = get_merge_bases(rev[2 * i], rev[2 * i + 1]);
-			if (!merge_base || merge_base->next)
-				die(_("failed to find exact merge base"));
+			if (!merge_base || merge_base->next) {
+				if (die_on_failure) {
+					die(_("failed to find exact merge base"));
+				} else {
+					free(rev);
+					return NULL;
+				}
+			}
 
 			rev[i] = merge_base->item;
 		}
@@ -1491,12 +1562,24 @@ static struct commit *get_base_commit(const char *base_commit,
 		rev_nr = DIV_ROUND_UP(rev_nr, 2);
 	}
 
-	if (!in_merge_bases(base, rev[0]))
-		die(_("base commit should be the ancestor of revision list"));
+	if (!in_merge_bases(base, rev[0])) {
+		if (die_on_failure) {
+			die(_("base commit should be the ancestor of revision list"));
+		} else {
+			free(rev);
+			return NULL;
+		}
+	}
 
 	for (i = 0; i < total; i++) {
-		if (base == list[i])
-			die(_("base commit shouldn't be in revision list"));
+		if (base == list[i]) {
+			if (die_on_failure) {
+				die(_("base commit shouldn't be in revision list"));
+			} else {
+				free(rev);
+				return NULL;
+			}
+		}
 	}
 
 	free(rev);
@@ -1596,16 +1679,20 @@ static void infer_range_diff_ranges(struct strbuf *r1,
 				    struct commit *head)
 {
 	const char *head_oid = oid_to_hex(&head->object.oid);
+	int prev_is_range = is_range_diff_range(prev);
 
-	if (!strstr(prev, "..")) {
+	if (prev_is_range)
+		strbuf_addstr(r1, prev);
+	else
 		strbuf_addf(r1, "%s..%s", head_oid, prev);
+
+	if (origin)
+		strbuf_addf(r2, "%s..%s", oid_to_hex(&origin->object.oid), head_oid);
+	else if (prev_is_range)
+		die(_("failed to infer range-diff origin of current series"));
+	else {
+		warning(_("using '%s' as range-diff origin of current series"), prev);
 		strbuf_addf(r2, "%s..%s", prev, head_oid);
-	} else if (!origin) {
-		die(_("failed to infer range-diff ranges"));
-	} else {
-		strbuf_addstr(r1, prev);
-		strbuf_addf(r2, "%s..%s",
-			    oid_to_hex(&origin->object.oid), head_oid);
 	}
 }
 
@@ -1635,6 +1722,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	char *branch_name = NULL;
 	char *base_commit = NULL;
 	struct base_tree_info bases;
+	struct commit *base;
 	int show_progress = 0;
 	struct progress *progress = NULL;
 	struct oid_array idiff_prev = OID_ARRAY_INIT;
@@ -1652,7 +1740,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		OPT_CALLBACK_F('N', "no-numbered", &numbered, NULL,
 			    N_("use [PATCH] even with multiple patches"),
 			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, no_numbered_callback),
-		OPT_BOOL('s', "signoff", &do_signoff, N_("add Signed-off-by:")),
+		OPT_BOOL('s', "signoff", &do_signoff, N_("add a Signed-off-by trailer")),
 		OPT_BOOL(0, "stdout", &use_stdout,
 			    N_("print patches to standard out")),
 		OPT_BOOL(0, "cover-letter", &cover_letter,
@@ -1665,14 +1753,16 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			    N_("start numbering patches at <n> instead of 1")),
 		OPT_INTEGER('v', "reroll-count", &reroll_count,
 			    N_("mark the series as Nth re-roll")),
+		OPT_INTEGER(0, "filename-max-length", &fmt_patch_name_max,
+			    N_("max length of output filename")),
 		OPT_CALLBACK_F(0, "rfc", &rev, NULL,
-			    N_("Use [RFC PATCH] instead of [PATCH]"),
+			    N_("use [RFC PATCH] instead of [PATCH]"),
 			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, rfc_callback),
 		OPT_STRING(0, "cover-from-description", &cover_from_description_arg,
 			    N_("cover-from-description-mode"),
 			    N_("generate parts of a cover letter based on a branch's description")),
 		OPT_CALLBACK_F(0, "subject-prefix", &rev, N_("prefix"),
-			    N_("Use [<prefix>] instead of [PATCH]"),
+			    N_("use [<prefix>] instead of [PATCH]"),
 			    PARSE_OPT_NONEG, subject_prefix_callback),
 		OPT_CALLBACK_F('o', "output-directory", &output_directory,
 			    N_("dir"), N_("store resulting files in <dir>"),
@@ -1711,8 +1801,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			    PARSE_OPT_OPTARG, thread_callback),
 		OPT_STRING(0, "signature", &signature, N_("signature"),
 			    N_("add a signature")),
-		OPT_STRING(0, "base", &base_commit, N_("base-commit"),
-			   N_("add prerequisite tree info to the patch series")),
+		OPT_CALLBACK_F(0, "base", &base_commit, N_("base-commit"),
+			       N_("add prerequisite tree info to the patch series"),
+			       0, base_callback),
 		OPT_FILENAME(0, "signature-file", &signature_file,
 				N_("add a signature from a file")),
 		OPT__QUIET(&quiet, N_("don't print the patch filenames")),
@@ -1749,9 +1840,6 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	s_r_opt.def = "HEAD";
 	s_r_opt.revarg_opt = REVARG_COMMITTISH;
 
-	if (base_auto)
-		base_commit = "auto";
-
 	if (default_attach) {
 		rev.mime_boundary = default_attach;
 		rev.no_inline = 1;
@@ -1767,6 +1855,10 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			     PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 			     PARSE_OPT_KEEP_DASHDASH);
 
+	/* Make sure "0000-$sub.patch" gives non-negative length for $sub */
+	if (fmt_patch_name_max <= strlen("0000-") + strlen(fmt_patch_suffix))
+		fmt_patch_name_max = strlen("0000-") + strlen(fmt_patch_suffix);
+
 	if (cover_from_description_arg)
 		cover_from_description_mode = parse_cover_from_description(cover_from_description_arg);
 
@@ -1851,6 +1943,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
 
 	rev.zero_commit = zero_commit;
+	rev.patch_name_max = fmt_patch_name_max;
 
 	if (!rev.diffopt.flags.text && !no_binary_diff)
 		rev.diffopt.flags.binary = 1;
@@ -1858,20 +1951,27 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (rev.show_notes)
 		load_display_notes(&rev.notes_opt);
 
-	if (!output_directory && !use_stdout)
-		output_directory = config_output_directory;
+	if (use_stdout + rev.diffopt.close_file + !!output_directory > 1)
+		die(_("--stdout, --output, and --output-directory are mutually exclusive"));
 
-	if (!use_stdout)
-		output_directory = set_outdir(prefix, output_directory);
-	else
+	if (use_stdout) {
 		setup_pager();
-
-	if (output_directory) {
+	} else if (rev.diffopt.close_file) {
+		/*
+		 * The diff code parsed --output; it has already opened the
+		 * file, but but we must instruct it not to close after each
+		 * diff.
+		 */
+		rev.diffopt.no_free = 1;
+	} else {
 		int saved;
+
+		if (!output_directory)
+			output_directory = config_output_directory;
+		output_directory = set_outdir(prefix, output_directory);
+
 		if (rev.diffopt.use_color != GIT_COLOR_ALWAYS)
 			rev.diffopt.use_color = GIT_COLOR_NEVER;
-		if (use_stdout)
-			die(_("standard output, or directory, which one?"));
 		/*
 		 * We consider <outdir> as 'outside of gitdir', therefore avoid
 		 * applying adjust_shared_perm in s-c-l-d.
@@ -2015,8 +2115,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	}
 
 	memset(&bases, 0, sizeof(bases));
-	if (base_commit) {
-		struct commit *base = get_base_commit(base_commit, list, nr);
+	base = get_base_commit(base_commit, list, nr);
+	if (base) {
 		reset_revision_walk();
 		clear_object_flags(UNINTERESTING);
 		prepare_bases(&bases, base, list, nr);
@@ -2033,7 +2133,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (cover_letter) {
 		if (thread)
 			gen_message_id(&rev, "cover");
-		make_cover_letter(&rev, use_stdout,
+		make_cover_letter(&rev, !!output_directory,
 				  origin, nr, list, branch_name, quiet);
 		print_bases(&bases, rev.diffopt.file);
 		print_signature(rev.diffopt.file);
@@ -2088,7 +2188,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			gen_message_id(&rev, oid_to_hex(&commit->object.oid));
 		}
 
-		if (!use_stdout &&
+		if (output_directory &&
 		    open_next_file(rev.numbered_files ? NULL : commit, NULL, &rev, quiet))
 			die(_("failed to create output files"));
 		shown = log_tree_commit(&rev, commit);
@@ -2101,7 +2201,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		 * the log; when using one file per patch, we do
 		 * not want the extra blank line.
 		 */
-		if (!use_stdout)
+		if (output_directory)
 			rev.shown_one = 0;
 		if (shown) {
 			print_bases(&bases, rev.diffopt.file);
@@ -2112,7 +2212,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			else
 				print_signature(rev.diffopt.file);
 		}
-		if (!use_stdout)
+		if (output_directory)
 			fclose(rev.diffopt.file);
 	}
 	stop_progress(&progress);