Merge branch 'mf/format-patch-commit-list-format' into mf/format-patch-commit-list-format-doc

* mf/format-patch-commit-list-format:
  format-patch: --commit-list-format without prefix
  format-patch: add preset for --commit-list-format
  format-patch: wrap generate_commit_list_cover()
  format.commitListFormat: strip meaning from empty
  docs/pretty-formats: add %(count) and %(total)
  format-patch: rename --cover-letter-format option
  format-patch: refactor generate_commit_list_cover
  pretty.c: better die message %(count) and %(total)
  docs: add usage for the cover-letter fmt feature
  format-patch: add commitListFormat config
  format-patch: add ability to use alt cover format
  format-patch: move cover letter summary generation
  pretty.c: add %(count) and %(total) placeholders

6 files changed, 243 insertions, 14 deletions

diff --git a/Documentation/config/format.adoc b/Documentation/config/format.adoc
index ab0710e86a..ef1ed1d250 100644
--- a/Documentation/config/format.adoc
+++ b/Documentation/config/format.adoc
@@ -101,6 +101,11 @@ format.coverLetter::
 	generate a cover-letter only when there's more than one patch.
 	Default is false.
 
+format.commitListFormat::
+	When the `--cover-letter-format` option is not given, `format-patch`
+	uses the value of this variable to decide how to format the title of
+	each commit. Defaults to `shortlog`.
+
 format.outputDirectory::
 	Set a custom directory to store the resulting files instead of the
 	current working directory. All directory components will be created.
diff --git a/Documentation/git-format-patch.adoc b/Documentation/git-format-patch.adoc
index 36146006fa..c52dbcc170 100644
--- a/Documentation/git-format-patch.adoc
+++ b/Documentation/git-format-patch.adoc
@@ -24,6 +24,7 @@ SYNOPSIS
 		   [(--reroll-count|-v) <n>]
 		   [--to=<email>] [--cc=<email>]
 		   [--[no-]cover-letter] [--quiet]
+		   [--commit-list-format=<format-spec>]
 		   [--[no-]encode-email-headers]
 		   [--no-notes | --notes[=<ref>]]
 		   [--interdiff=<previous>]
@@ -322,6 +323,18 @@ feeding the result to `git send-email`.
 	containing the branch description, shortlog and the overall diffstat.  You can
 	fill in a description in the file before sending it out.
 
+--commit-list-format=<format-spec>::
+	Specify the format in which to generate the commit list of the patch
+	series. The accepted values for format-spec are `shortlog`, `modern` or a
+	format-string prefixed with `log:`.
+	e.g. `log: %s (%an)`
+	The user is allowed to drop the prefix if the format-string contains a
+	`%<placeholder>`.
+	If not given, defaults to the `format.commitListFormat` configuration
+	variable.
+	This option implies the use of `--cover-letter` unless
+	`--no-cover-letter` is given.
+
 --encode-email-headers::
 --no-encode-email-headers::
 	Encode email headers that have non-ASCII characters with
@@ -453,6 +466,7 @@ with configuration variables.
 	signOff = true
 	outputDirectory = <directory>
 	coverLetter = auto
+	commitListFormat = shortlog
 	coverFromDescription = auto
 ------------
 
diff --git a/Documentation/pretty-formats.adoc b/Documentation/pretty-formats.adoc
index 5405e57a60..2ae0eb11a9 100644
--- a/Documentation/pretty-formats.adoc
+++ b/Documentation/pretty-formats.adoc
@@ -253,6 +253,10 @@ The placeholders are:
 	linkgit:git-rev-list[1])
 +%d+:: ref names, like the --decorate option of linkgit:git-log[1]
 +%D+:: ref names without the " (", ")" wrapping.
++%(count)+:: the number of a patch within a patch series. Used only in
+	`--commit-list-format` in `format-patch`
++%(total)+:: the total number of patches in a patch series. Used only in
+	`--commit-list-format` in `format-patch`
 ++%(decorate++`[:<option>,...]`++)++::
 ref names with custom decorations. The `decorate` string may be followed by a
 colon and zero or more comma-separated options. Option values may contain
diff --git a/builtin/log.c b/builtin/log.c
index 89e8b8f011..ad7b7215fe 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -40,6 +40,7 @@
 #include "progress.h"
 #include "commit-slab.h"
 #include "advice.h"
+#include "utf8.h"
 
 #include "commit-reach.h"
 #include "range-diff.h"
@@ -886,6 +887,7 @@ struct format_config {
 	char *signature;
 	char *signature_file;
 	enum cover_setting config_cover_letter;
+	char *fmt_cover_letter_commit_list;
 	char *config_output_directory;
 	enum cover_from_description cover_from_description_mode;
 	int show_notes;
@@ -930,6 +932,7 @@ static void format_config_release(struct format_config *cfg)
 	string_list_clear(&cfg->extra_cc, 0);
 	strbuf_release(&cfg->sprefix);
 	free(cfg->fmt_patch_suffix);
+	free(cfg->fmt_cover_letter_commit_list);
 }
 
 static enum cover_from_description parse_cover_from_description(const char *arg)
@@ -1052,6 +1055,10 @@ static int git_format_config(const char *var, const char *value,
 		cfg->config_cover_letter = git_config_bool(var, value) ? COVER_ON : COVER_OFF;
 		return 0;
 	}
+	if (!strcmp(var, "format.commitlistformat")) {
+		FREE_AND_NULL(cfg->fmt_cover_letter_commit_list);
+		return git_config_string(&cfg->fmt_cover_letter_commit_list, var, value);
+	}
 	if (!strcmp(var, "format.outputdirectory")) {
 		FREE_AND_NULL(cfg->config_output_directory);
 		return git_config_string(&cfg->config_output_directory, var, value);
@@ -1335,13 +1342,59 @@ static void get_notes_args(struct strvec *arg, struct rev_info *rev)
 	}
 }
 
+static void generate_shortlog_cover_letter(struct shortlog *log,
+					   struct rev_info *rev,
+					   struct commit **list,
+					   int nr)
+{
+	shortlog_init(log);
+	log->wrap_lines = 1;
+	log->wrap = MAIL_DEFAULT_WRAP;
+	log->in1 = 2;
+	log->in2 = 4;
+	log->file = rev->diffopt.file;
+	log->groups = SHORTLOG_GROUP_AUTHOR;
+	shortlog_finish_setup(log);
+	for (int i = 0; i < nr; i++)
+		shortlog_add_commit(log, list[i]);
+
+	shortlog_output(log);
+}
+
+static void generate_commit_list_cover(FILE *cover_file, const char *format,
+				       struct commit **list, int n)
+{
+	struct strbuf commit_line = STRBUF_INIT;
+	struct strbuf wrapped_line = STRBUF_INIT;
+	struct pretty_print_context ctx = {0};
+	struct rev_info rev = REV_INFO_INIT;
+
+	rev.total = n;
+	ctx.rev = &rev;
+	for (int i = 1; i <= n; i++) {
+		rev.nr = i;
+		repo_format_commit_message(the_repository, list[n - i], format,
+				&commit_line, &ctx);
+		strbuf_add_wrapped_text(&wrapped_line, commit_line.buf, 0, 0,
+					MAIL_DEFAULT_WRAP);
+		fprintf(cover_file, "%s\n", wrapped_line.buf);
+		strbuf_reset(&commit_line);
+		strbuf_reset(&wrapped_line);
+	}
+	fprintf(cover_file, "\n");
+
+	strbuf_release(&commit_line);
+	strbuf_release(&wrapped_line);
+}
+
 static void make_cover_letter(struct rev_info *rev, int use_separate_file,
 			      struct commit *origin,
 			      int nr, struct commit **list,
 			      const char *description_file,
 			      const char *branch_name,
 			      int quiet,
-			      const struct format_config *cfg)
+			      const struct format_config *cfg,
+			      const char *format)
 {
 	const char *from;
 	struct shortlog log;
@@ -1388,18 +1441,17 @@ static void make_cover_letter(struct rev_info *rev, int use_separate_file,
 	free(pp.after_subject);
 	strbuf_release(&sb);
 
-	shortlog_init(&log);
-	log.wrap_lines = 1;
-	log.wrap = MAIL_DEFAULT_WRAP;
-	log.in1 = 2;
-	log.in2 = 4;
-	log.file = rev->diffopt.file;
-	log.groups = SHORTLOG_GROUP_AUTHOR;
-	shortlog_finish_setup(&log);
-	for (i = 0; i < nr; i++)
-		shortlog_add_commit(&log, list[i]);
-
-	shortlog_output(&log);
+	if (skip_prefix(format, "log:", &format))
+		generate_commit_list_cover(rev->diffopt.file, format, list, nr);
+	else if (!strcmp(format, "shortlog"))
+		generate_shortlog_cover_letter(&log, rev, list, nr);
+	else if (!strcmp(format, "modern"))
+		generate_commit_list_cover(rev->diffopt.file, "[%(count)/%(total)] %s",
+					   list, nr);
+	else if (strchr(format, '%'))
+		generate_commit_list_cover(rev->diffopt.file, format, list, nr);
+	else
+		die(_("'%s' is not a valid format string"), format);
 
 	/* We can only do diffstat with a unique reference point */
 	if (origin)
@@ -1917,6 +1969,7 @@ int cmd_format_patch(int argc,
 	int just_numbers = 0;
 	int ignore_if_in_upstream = 0;
 	int cover_letter = -1;
+	const char *cover_letter_fmt = NULL;
 	int boundary_count = 0;
 	int no_binary_diff = 0;
 	int zero_commit = 0;
@@ -1963,6 +2016,8 @@ int cmd_format_patch(int argc,
 			    N_("print patches to standard out")),
 		OPT_BOOL(0, "cover-letter", &cover_letter,
 			    N_("generate a cover letter")),
+		OPT_STRING(0, "commit-list-format", &cover_letter_fmt, N_("format-spec"),
+			    N_("format spec used for the commit list in the cover letter")),
 		OPT_BOOL(0, "numbered-files", &just_numbers,
 			    N_("use simple number sequence for output file names")),
 		OPT_STRING(0, "suffix", &fmt_patch_suffix, N_("sfx"),
@@ -2300,6 +2355,15 @@ int cmd_format_patch(int argc,
 		/* nothing to do */
 		goto done;
 	total = list.nr;
+
+	if (!cover_letter_fmt) {
+		cover_letter_fmt = cfg.fmt_cover_letter_commit_list;
+		if (!cover_letter_fmt)
+			cover_letter_fmt = "shortlog";
+	} else if (cover_letter == -1) {
+		cover_letter = 1;
+	}
+
 	if (cover_letter == -1) {
 		if (cfg.config_cover_letter == COVER_AUTO)
 			cover_letter = (total > 1);
@@ -2386,12 +2450,14 @@ int cmd_format_patch(int argc,
 	}
 	rev.numbered_files = just_numbers;
 	rev.patch_suffix = fmt_patch_suffix;
+
 	if (cover_letter) {
 		if (cfg.thread)
 			gen_message_id(&rev, "cover");
 		make_cover_letter(&rev, !!output_directory,
 				  origin, list.nr, list.items,
-				  description_file, branch_name, quiet, &cfg);
+				  description_file, branch_name, quiet, &cfg,
+				  cover_letter_fmt);
 		print_bases(&bases, rev.diffopt.file);
 		print_signature(signature, rev.diffopt.file);
 		total++;
diff --git a/pretty.c b/pretty.c
index ebf4da4834..814803980b 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1549,6 +1549,21 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 	if (!commit->object.parsed)
 		parse_object(the_repository, &commit->object.oid);
 
+	if (starts_with(placeholder, "(count)")) {
+		if (!c->pretty_ctx->rev)
+			die(_("%s is not supported by this command"), "%(count)");
+		strbuf_addf(sb, "%0*d", decimal_width(c->pretty_ctx->rev->total),
+			    c->pretty_ctx->rev->nr);
+		return 7;
+	}
+
+	if (starts_with(placeholder, "(total)")) {
+		if (!c->pretty_ctx->rev)
+			die(_("%s is not supported by this command"), "%(total)");
+		strbuf_addf(sb, "%d", c->pretty_ctx->rev->total);
+		return 7;
+	}
+
 	switch (placeholder[0]) {
 	case 'H':		/* commit hash */
 		strbuf_addstr(sb, diff_get_color(c->auto_color, DIFF_COMMIT));
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index bcdb944017..7517094bd6 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -380,6 +380,131 @@ test_expect_success 'filename limit applies only to basename' '
 	done
 '
 
+test_expect_success 'cover letter with subject, author and count' '
+	rm -rf patches &&
+	test_when_finished "git reset --hard HEAD~1" &&
+	test_when_finished "rm -rf patches test_file" &&
+	touch test_file &&
+	git add test_file &&
+	git commit -m "This is a subject" &&
+	git format-patch --commit-list-format="log:[%(count)/%(total)] %s (%an)" \
+	-o patches HEAD~1 &&
+	test_grep "^\[1/1\] This is a subject (A U Thor)$" patches/0000-cover-letter.patch
+'
+
+test_expect_success 'cover letter with custom format no prefix' '
+	rm -rf patches &&
+	test_when_finished "git reset --hard HEAD~1" &&
+	test_when_finished "rm -rf patches test_file" &&
+	touch test_file &&
+	git add test_file &&
+	git commit -m "This is a subject" &&
+	git format-patch --commit-list-format="[%(count)/%(total)] %s (%an)" \
+	-o patches HEAD~1 &&
+	test_grep "^\[1/1\] This is a subject (A U Thor)$" patches/0000-cover-letter.patch
+'
+
+test_expect_success 'cover letter fail when no prefix and no placeholder' '
+	rm -rf patches &&
+	test_when_finished "git reset --hard HEAD~1" &&
+	test_when_finished "rm -rf patches test_file err" &&
+	touch test_file &&
+	git add test_file &&
+	git commit -m "This is a subject" &&
+	test_must_fail git format-patch --commit-list-format="this should fail" \
+	-o patches HEAD~1 2>err &&
+	test_grep "is not a valid format string" err
+'
+
+test_expect_success 'cover letter modern format' '
+	test_when_finished "git reset --hard HEAD~1" &&
+	test_when_finished "rm -rf patches test_file" &&
+	touch test_file &&
+	git add test_file &&
+	git commit -m "This is a subject" &&
+	git format-patch --commit-list-format="modern" -o patches HEAD~1 &&
+	test_grep "^\[1/1\] This is a subject$" patches/0000-cover-letter.patch
+'
+
+test_expect_success 'cover letter shortlog format' '
+	test_when_finished "git reset --hard HEAD~1" &&
+	test_when_finished "rm -rf expect patches result test_file" &&
+	cat >expect <<-"EOF" &&
+	A U Thor (1):
+	  This is a subject
+	EOF
+	touch test_file &&
+	git add test_file &&
+	git commit -m "This is a subject" &&
+	git format-patch --commit-list-format=shortlog -o patches HEAD~1 &&
+	grep -E -A 1 "^A U Thor \([[:digit:]]+\):$" patches/0000-cover-letter.patch >result &&
+	cat result &&
+	test_cmp expect result
+'
+
+test_expect_success 'no cover letter but with format specified' '
+	test_when_finished "git reset --hard HEAD~1" &&
+	test_when_finished "rm -rf patches result test_file" &&
+	touch test_file &&
+	git add test_file &&
+	git commit -m "This is a subject" &&
+	git format-patch --no-cover-letter --commit-list-format="[%(count)] %s" -o patches HEAD~1 &&
+	test_path_is_missing patches/0000-cover-letter.patch
+'
+
+test_expect_success 'cover letter config with count, subject and author' '
+	test_when_finished "rm -rf patches result" &&
+	test_when_finished "git config unset format.coverletter" &&
+	test_when_finished "git config unset format.commitlistformat" &&
+	git config set format.coverletter true &&
+	git config set format.commitlistformat "log:[%(count)/%(total)] %s (%an)" &&
+	git format-patch -o patches HEAD~2 &&
+	grep -E "^[[[:digit:]]+/[[:digit:]]+] .* \(A U Thor\)" patches/0000-cover-letter.patch >result &&
+	test_line_count = 2 result
+'
+
+test_expect_success 'cover letter config with count and author' '
+	test_when_finished "rm -rf patches result" &&
+	test_when_finished "git config unset format.coverletter" &&
+	test_when_finished "git config unset format.commitlistformat" &&
+	git config set format.coverletter true &&
+	git config set format.commitlistformat "log:[%(count)/%(total)] (%an)" &&
+	git format-patch -o patches HEAD~2 &&
+	grep -E "^[[[:digit:]]+/[[:digit:]]+] \(A U Thor\)" patches/0000-cover-letter.patch >result &&
+	test_line_count = 2 result
+'
+
+test_expect_success 'cover letter config commitlistformat set to modern' '
+	test_when_finished "rm -rf patches result" &&
+	test_when_finished "git config unset format.coverletter" &&
+	test_when_finished "git config unset format.commitlistformat" &&
+	git config set format.coverletter true &&
+	git config set format.commitlistformat modern &&
+	git format-patch -o patches HEAD~2 &&
+	grep -E "^[[[:digit:]]+/[[:digit:]]+] .*$" patches/0000-cover-letter.patch >result &&
+	test_line_count = 2 result
+'
+
+test_expect_success 'cover letter config commitlistformat set to shortlog' '
+	test_when_finished "rm -rf patches result" &&
+	test_when_finished "git config unset format.coverletter" &&
+	test_when_finished "git config unset format.commitlistformat" &&
+	git config set format.coverletter true &&
+	git config set format.commitlistformat shortlog &&
+	git format-patch -o patches HEAD~2 &&
+	grep -E "^A U Thor \([[:digit:]]+\)" patches/0000-cover-letter.patch >result &&
+	test_line_count = 1 result
+'
+
+test_expect_success 'cover letter config commitlistformat not set' '
+	test_when_finished "rm -rf patches result" &&
+	test_when_finished "git config unset format.coverletter" &&
+	git config set format.coverletter true &&
+	git format-patch -o patches HEAD~2 &&
+	grep -E "^A U Thor \([[:digit:]]+\)" patches/0000-cover-letter.patch >result &&
+	test_line_count = 1 result
+'
+
 test_expect_success 'reroll count' '
 	rm -fr patches &&
 	git format-patch -o patches --cover-letter --reroll-count 4 main..side >list &&