merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 321 insertions, 119 deletions

diff --git a/third_party/git/builtin/log.c b/third_party/git/builtin/log.c
index 44b10b341541..0a7ed4bef92b 100644
--- a/third_party/git/builtin/log.c
+++ b/third_party/git/builtin/log.c
@@ -33,10 +33,10 @@
 #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
 
 /* Set a default date-time format for git log ("log.date" config variable) */
 static const char *default_date_mode = NULL;
@@ -45,6 +45,7 @@ static int default_abbrev_commit;
 static int default_show_root = 1;
 static int default_follow;
 static int default_show_signature;
+static int default_encode_email_headers = 1;
 static int decoration_style;
 static int decoration_given;
 static int use_mailmap_config = 1;
@@ -150,6 +151,7 @@ static void cmd_log_init_defaults(struct rev_info *rev)
 	rev->show_root_diff = default_show_root;
 	rev->subject_prefix = fmt_patch_subject_prefix;
 	rev->show_signature = default_show_signature;
+	rev->encode_email_headers = default_encode_email_headers;
 	rev->diffopt.flags.allow_textconv = 1;
 
 	if (default_date_mode)
@@ -163,21 +165,24 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	int quiet = 0, source = 0, mailmap;
 	static struct line_opt_callback_data line_cb = {NULL, NULL, STRING_LIST_INIT_DUP};
 	static struct string_list decorate_refs_exclude = STRING_LIST_INIT_NODUP;
+	static struct string_list decorate_refs_exclude_config = STRING_LIST_INIT_NODUP;
 	static struct string_list decorate_refs_include = STRING_LIST_INIT_NODUP;
 	struct decoration_filter decoration_filter = {&decorate_refs_include,
-						      &decorate_refs_exclude};
+						      &decorate_refs_exclude,
+						      &decorate_refs_exclude_config};
 	static struct revision_sources revision_sources;
 
 	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_ALIAS(0, "mailmap", "use-mailmap"),
 		OPT_STRING_LIST(0, "decorate-refs", &decorate_refs_include,
 				N_("pattern"), N_("only decorate refs that match <pattern>")),
 		OPT_STRING_LIST(0, "decorate-refs-exclude", &decorate_refs_exclude,
 				N_("pattern"), N_("do not decorate refs that match <pattern>")),
-		{ OPTION_CALLBACK, 0, "decorate", NULL, NULL, N_("decorate options"),
-		  PARSE_OPT_OPTARG, decorate_callback},
+		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"),
 			     log_line_range_callback),
@@ -207,7 +212,7 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	if (!rev->show_notes_given && (!rev->pretty_given || w.notes))
 		rev->show_notes = 1;
 	if (rev->show_notes)
-		init_display_notes(&rev->notes_opt);
+		load_display_notes(&rev->notes_opt);
 
 	if ((rev->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
 	    rev->diffopt.filter || rev->diffopt.flags.follow_renames)
@@ -235,7 +240,19 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	}
 
 	if (decoration_style) {
+		const struct string_list *config_exclude =
+			repo_config_get_value_multi(the_repository,
+						    "log.excludeDecoration");
+
+		if (config_exclude) {
+			struct string_list_item *item;
+			for_each_string_list_item(item, config_exclude)
+				string_list_append(&decorate_refs_exclude_config,
+						   item->string);
+		}
+
 		rev->show_decorations = 1;
+
 		load_ref_decorations(&decoration_filter, decoration_style);
 	}
 
@@ -437,6 +454,10 @@ 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.encodeemailheaders")) {
+		default_encode_email_headers = git_config_bool(var, value);
+		return 0;
+	}
 	if (!strcmp(var, "log.abbrevcommit")) {
 		default_abbrev_commit = git_config_bool(var, value);
 		return 0;
@@ -577,8 +598,8 @@ 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 */
+	if (rev->ignore_merges < 0) {
+		/* There was no "-m" variant on the command line */
 		rev->ignore_merges = 0;
 		if (!rev->first_parent_only && !rev->combine_merges) {
 			/* No "--first-parent", "-c", or "--cc" */
@@ -627,6 +648,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 			break;
 		case OBJ_TAG: {
 			struct tag *t = (struct tag *)o;
+			struct object_id *oid = get_tagged_oid(t);
 
 			if (rev.shown_one)
 				putchar('\n');
@@ -638,10 +660,10 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 			rev.shown_one = 1;
 			if (ret)
 				break;
-			o = parse_object(the_repository, &t->tagged->oid);
+			o = parse_object(the_repository, oid);
 			if (!o)
 				ret = error(_("could not read object %s"),
-					    oid_to_hex(&t->tagged->oid));
+					    oid_to_hex(oid));
 			objects[i].item = o;
 			i--;
 			break;
@@ -709,8 +731,7 @@ static void log_setup_revisions_tweak(struct rev_info *rev,
 	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)
+	if (rev->first_parent_only && rev->ignore_merges < 0)
 		rev->ignore_merges = 0;
 }
 
@@ -764,28 +785,62 @@ static void add_header(const char *value)
 	item->string[len] = '\0';
 }
 
-#define THREAD_SHALLOW 1
-#define THREAD_DEEP 2
-static int thread;
+enum cover_setting {
+	COVER_UNSET,
+	COVER_OFF,
+	COVER_ON,
+	COVER_AUTO
+};
+
+enum thread_level {
+	THREAD_UNSET,
+	THREAD_SHALLOW,
+	THREAD_DEEP
+};
+
+enum cover_from_description {
+	COVER_FROM_NONE,
+	COVER_FROM_MESSAGE,
+	COVER_FROM_SUBJECT,
+	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;
-static int config_cover_letter;
+static enum cover_setting config_cover_letter;
 static const char *config_output_directory;
+static enum cover_from_description cover_from_description_mode = COVER_FROM_MESSAGE;
+static int show_notes;
+static struct display_notes_opt notes_opt;
 
-enum {
-	COVER_UNSET,
-	COVER_OFF,
-	COVER_ON,
-	COVER_AUTO
-};
+static enum cover_from_description parse_cover_from_description(const char *arg)
+{
+	if (!arg || !strcmp(arg, "default"))
+		return COVER_FROM_MESSAGE;
+	else if (!strcmp(arg, "none"))
+		return COVER_FROM_NONE;
+	else if (!strcmp(arg, "message"))
+		return COVER_FROM_MESSAGE;
+	else if (!strcmp(arg, "subject"))
+		return COVER_FROM_SUBJECT;
+	else if (!strcmp(arg, "auto"))
+		return COVER_FROM_AUTO;
+	else
+		die(_("%s: invalid cover from description mode"), arg);
+}
 
 static int git_format_config(const char *var, const char *value, void *cb)
 {
-	struct rev_info *rev = cb;
-
 	if (!strcmp(var, "format.headers")) {
 		if (!value)
 			die(_("format.headers without value"));
@@ -835,7 +890,7 @@ static int git_format_config(const char *var, const char *value, void *cb)
 			thread = THREAD_SHALLOW;
 			return 0;
 		}
-		thread = git_config_bool(var, value) && THREAD_SHALLOW;
+		thread = git_config_bool(var, value) ? THREAD_SHALLOW : THREAD_UNSET;
 		return 0;
 	}
 	if (!strcmp(var, "format.signoff")) {
@@ -857,7 +912,11 @@ 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")) {
@@ -872,19 +931,17 @@ static int git_format_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 	if (!strcmp(var, "format.notes")) {
-		struct strbuf buf = STRBUF_INIT;
 		int b = git_parse_maybe_bool(value);
-		if (!b)
-			return 0;
-		rev->show_notes = 1;
-		if (b < 0) {
-			strbuf_addstr(&buf, value);
-			expand_notes_ref(&buf);
-			string_list_append(&rev->notes_opt.extra_notes_refs,
-					strbuf_detach(&buf, NULL));
-		} else {
-			rev->notes_opt.use_default_notes = 1;
-		}
+		if (b < 0)
+			enable_ref_display_notes(&notes_opt, &show_notes, value);
+		else if (b)
+			enable_default_display_notes(&notes_opt, &show_notes);
+		else
+			disable_display_notes(&notes_opt, &show_notes);
+		return 0;
+	}
+	if (!strcmp(var, "format.coverfromdescription")) {
+		cover_from_description_mode = parse_cover_from_description(value);
 		return 0;
 	}
 
@@ -993,20 +1050,6 @@ static void print_signature(FILE *file)
 	putc('\n', file);
 }
 
-static void add_branch_description(struct strbuf *buf, const char *branch_name)
-{
-	struct strbuf desc = STRBUF_INIT;
-	if (!branch_name || !*branch_name)
-		return;
-	read_branch_desc(&desc, branch_name);
-	if (desc.len) {
-		strbuf_addch(buf, '\n');
-		strbuf_addbuf(buf, &desc);
-		strbuf_addch(buf, '\n');
-	}
-	strbuf_release(&desc);
-}
-
 static char *find_branch_name(struct rev_info *rev)
 {
 	int i, positive = -1;
@@ -1027,7 +1070,7 @@ 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);
@@ -1053,6 +1096,63 @@ static void show_diffstat(struct rev_info *rev,
 	fprintf(rev->diffopt.file, "\n");
 }
 
+static void prepare_cover_text(struct pretty_print_context *pp,
+			       const char *branch_name,
+			       struct strbuf *sb,
+			       const char *encoding,
+			       int need_8bit_cte)
+{
+	const char *subject = "*** SUBJECT HERE ***";
+	const char *body = "*** BLURB HERE ***";
+	struct strbuf description_sb = STRBUF_INIT;
+	struct strbuf subject_sb = STRBUF_INIT;
+
+	if (cover_from_description_mode == COVER_FROM_NONE)
+		goto do_pp;
+
+	if (branch_name && *branch_name)
+		read_branch_desc(&description_sb, branch_name);
+	if (!description_sb.len)
+		goto do_pp;
+
+	if (cover_from_description_mode == COVER_FROM_SUBJECT ||
+			cover_from_description_mode == COVER_FROM_AUTO)
+		body = format_subject(&subject_sb, description_sb.buf, " ");
+
+	if (cover_from_description_mode == COVER_FROM_MESSAGE ||
+			(cover_from_description_mode == COVER_FROM_AUTO &&
+			 subject_sb.len > COVER_FROM_AUTO_MAX_SUBJECT_LEN))
+		body = description_sb.buf;
+	else
+		subject = subject_sb.buf;
+
+do_pp:
+	pp_title_line(pp, &subject, sb, encoding, need_8bit_cte);
+	pp_remainder(pp, &body, sb, 0);
+
+	strbuf_release(&description_sb);
+	strbuf_release(&subject_sb);
+}
+
+static int get_notes_refs(struct string_list_item *item, void *arg)
+{
+	strvec_pushf(arg, "--notes=%s", item->string);
+	return 0;
+}
+
+static void get_notes_args(struct strvec *arg, struct rev_info *rev)
+{
+	if (!rev->show_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)) {
+		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,
 			      struct commit *origin,
 			      int nr, struct commit **list,
@@ -1060,8 +1160,6 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 			      int quiet)
 {
 	const char *committer;
-	const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
-	const char *msg;
 	struct shortlog log;
 	struct strbuf sb = STRBUF_INIT;
 	int i;
@@ -1091,15 +1189,12 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 	if (!branch_name)
 		branch_name = find_branch_name(rev);
 
-	msg = body;
 	pp.fmt = CMIT_FMT_EMAIL;
 	pp.date_mode.type = DATE_RFC2822;
 	pp.rev = rev;
 	pp.print_email_subject = 1;
 	pp_user_info(&pp, NULL, &sb, committer, encoding);
-	pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
-	pp_remainder(&pp, &msg, &sb, 0);
-	add_branch_description(&sb, branch_name);
+	prepare_cover_text(&pp, branch_name, &sb, encoding, need_8bit_cte);
 	fprintf(rev->diffopt.file, "%s\n", sb.buf);
 
 	strbuf_release(&sb);
@@ -1110,6 +1205,7 @@ 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]);
 
@@ -1121,7 +1217,8 @@ 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) {
@@ -1130,13 +1227,16 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 		 * can be added later if deemed desirable.
 		 */
 		struct diff_options opts;
+		struct strvec other_arg = STRVEC_INIT;
 		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);
+				rev->creation_factor, 1, &opts, &other_arg);
+		strvec_clear(&other_arg);
 	}
 }
 
@@ -1248,9 +1348,9 @@ static int output_directory_callback(const struct option *opt, const char *arg,
 
 static int thread_callback(const struct option *opt, const char *arg, int unset)
 {
-	int *thread = (int *)opt->value;
+	enum thread_level *thread = (enum thread_level *)opt->value;
 	if (unset)
-		*thread = 0;
+		*thread = THREAD_UNSET;
 	else if (!arg || !strcmp(arg, "shallow"))
 		*thread = THREAD_SHALLOW;
 	else if (!strcmp(arg, "deep"))
@@ -1297,7 +1397,7 @@ static int header_callback(const struct option *opt, const char *arg, int unset)
 		string_list_clear(&extra_to, 0);
 		string_list_clear(&extra_cc, 0);
 	} else {
-	    add_header(arg);
+		add_header(arg);
 	}
 	return 0;
 }
@@ -1335,6 +1435,23 @@ 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;
@@ -1347,13 +1464,36 @@ 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")) || base_auto) {
+	} else {
 		struct branch *curr_branch = branch_get(NULL);
 		const char *upstream = branch_get_upstream(curr_branch, NULL);
 		if (upstream) {
@@ -1361,19 +1501,32 @@ 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;
 		}
 	}
 
@@ -1390,8 +1543,14 @@ 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;
 		}
@@ -1401,12 +1560,24 @@ 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);
@@ -1506,16 +1677,20 @@ 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 = !!strstr(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);
 	}
 }
 
@@ -1541,9 +1716,11 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	int use_patch_format = 0;
 	int quiet = 0;
 	int reroll_count = -1;
+	char *cover_from_description_arg = NULL;
 	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;
@@ -1555,12 +1732,12 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	int creation_factor = -1;
 
 	const struct option builtin_format_patch_options[] = {
-		{ OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
+		OPT_CALLBACK_F('n', "numbered", &numbered, NULL,
 			    N_("use [PATCH n/m] even with a single patch"),
-			    PARSE_OPT_NOARG, numbered_callback },
-		{ OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
+			    PARSE_OPT_NOARG, numbered_callback),
+		OPT_CALLBACK_F('N', "no-numbered", &numbered, NULL,
 			    N_("use [PATCH] even with multiple patches"),
-			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, no_numbered_callback },
+			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, no_numbered_callback),
 		OPT_BOOL('s', "signoff", &do_signoff, N_("add Signed-off-by:")),
 		OPT_BOOL(0, "stdout", &use_stdout,
 			    N_("print patches to standard out")),
@@ -1574,18 +1751,21 @@ 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")),
-		{ OPTION_CALLBACK, 0, "rfc", &rev, NULL,
+		OPT_CALLBACK_F(0, "rfc", &rev, NULL,
 			    N_("Use [RFC PATCH] instead of [PATCH]"),
-			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, rfc_callback },
-		{ OPTION_CALLBACK, 0, "subject-prefix", &rev, N_("prefix"),
+			    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]"),
-			    PARSE_OPT_NONEG, subject_prefix_callback },
-		{ OPTION_CALLBACK, 'o', "output-directory", &output_directory,
+			    PARSE_OPT_NONEG, subject_prefix_callback),
+		OPT_CALLBACK_F('o', "output-directory", &output_directory,
 			    N_("dir"), N_("store resulting files in <dir>"),
-			    PARSE_OPT_NONEG, output_directory_callback },
-		{ OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
+			    PARSE_OPT_NONEG, output_directory_callback),
+		OPT_CALLBACK_F('k', "keep-subject", &rev, NULL,
 			    N_("don't strip/add [PATCH]"),
-			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
+			    PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback),
 		OPT_BOOL(0, "no-binary", &no_binary_diff,
 			 N_("don't output binary diffs")),
 		OPT_BOOL(0, "zero-commit", &zero_commit,
@@ -1596,31 +1776,30 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			      N_("show patch format instead of default (patch + stat)"),
 			      1, PARSE_OPT_NONEG),
 		OPT_GROUP(N_("Messaging")),
-		{ OPTION_CALLBACK, 0, "add-header", NULL, N_("header"),
-			    N_("add email header"), 0, header_callback },
-		{ OPTION_CALLBACK, 0, "to", NULL, N_("email"), N_("add To: header"),
-			    0, to_callback },
-		{ OPTION_CALLBACK, 0, "cc", NULL, N_("email"), N_("add Cc: header"),
-			    0, cc_callback },
-		{ OPTION_CALLBACK, 0, "from", &from, N_("ident"),
+		OPT_CALLBACK(0, "add-header", NULL, N_("header"),
+			    N_("add email header"), header_callback),
+		OPT_CALLBACK(0, "to", NULL, N_("email"), N_("add To: header"), to_callback),
+		OPT_CALLBACK(0, "cc", NULL, N_("email"), N_("add Cc: header"), cc_callback),
+		OPT_CALLBACK_F(0, "from", &from, N_("ident"),
 			    N_("set From address to <ident> (or committer ident if absent)"),
-			    PARSE_OPT_OPTARG, from_callback },
+			    PARSE_OPT_OPTARG, from_callback),
 		OPT_STRING(0, "in-reply-to", &in_reply_to, N_("message-id"),
 			    N_("make first mail a reply to <message-id>")),
-		{ OPTION_CALLBACK, 0, "attach", &rev, N_("boundary"),
+		OPT_CALLBACK_F(0, "attach", &rev, N_("boundary"),
 			    N_("attach the patch"), PARSE_OPT_OPTARG,
-			    attach_callback },
-		{ OPTION_CALLBACK, 0, "inline", &rev, N_("boundary"),
+			    attach_callback),
+		OPT_CALLBACK_F(0, "inline", &rev, N_("boundary"),
 			    N_("inline the patch"),
 			    PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
-			    inline_callback },
-		{ OPTION_CALLBACK, 0, "thread", &thread, N_("style"),
+			    inline_callback),
+		OPT_CALLBACK_F(0, "thread", &thread, N_("style"),
 			    N_("enable message threading, styles: shallow, deep"),
-			    PARSE_OPT_OPTARG, thread_callback },
+			    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")),
@@ -1640,9 +1819,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	extra_to.strdup_strings = 1;
 	extra_cc.strdup_strings = 1;
 	init_log_defaults();
+	init_display_notes(&notes_opt);
+	git_config(git_format_config, NULL);
 	repo_init_revisions(the_repository, &rev, prefix);
-	git_config(git_format_config, &rev);
+	rev.show_notes = show_notes;
+	memcpy(&rev.notes_opt, &notes_opt, sizeof(notes_opt));
 	rev.commit_format = CMIT_FMT_EMAIL;
+	rev.encode_email_headers = default_encode_email_headers;
 	rev.expand_tabs_in_log_default = 0;
 	rev.verbose_header = 1;
 	rev.diff = 1;
@@ -1668,6 +1851,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			     PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 			     PARSE_OPT_KEEP_DASHDASH);
 
+	if (cover_from_description_arg)
+		cover_from_description_mode = parse_cover_from_description(cover_from_description_arg);
+
 	if (0 < reroll_count) {
 		struct strbuf sprefix = STRBUF_INIT;
 		strbuf_addf(&sprefix, "%s v%d",
@@ -1754,7 +1940,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		rev.diffopt.flags.binary = 1;
 
 	if (rev.show_notes)
-		init_display_notes(&rev.notes_opt);
+		load_display_notes(&rev.notes_opt);
 
 	if (!output_directory && !use_stdout)
 		output_directory = config_output_directory;
@@ -1765,10 +1951,26 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		setup_pager();
 
 	if (output_directory) {
+		int saved;
 		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.
+		 */
+		saved = get_shared_repository();
+		set_shared_repository(0);
+		switch (safe_create_leading_directories_const(output_directory)) {
+		case SCLD_OK:
+		case SCLD_EXISTS:
+			break;
+		default:
+			die(_("could not create leading directories "
+			      "of '%s'"), output_directory);
+		}
+		set_shared_repository(saved);
 		if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
 			die_errno(_("could not create directory '%s'"),
 				  output_directory);
@@ -1897,8 +2099,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	}
 
 	memset(&bases, 0, sizeof(bases));
-	if (base_commit || base_auto) {
-		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);