Merge branch 'mf/format-patch-cover-letter-format' into jch

"git format-patch --cover-letter" learns to use a simpler format
instead of the traditional shortlog format to list its commits with
a new --cover-letter-format option and format.commitListFormat
configuration variable.

* mf/format-patch-cover-letter-format:
  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

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. Default 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.

Documentation/git-format-patch.adoc

@@ -24,6 +24,7 @@ SYNOPSIS
 		   [(--reroll-count|-v) <n>]
 		   [--to=<email>] [--cc=<email>]
 		   [--[no-]cover-letter] [--quiet]
+		   [--cover-letter-format=<format-spec>]
 		   [--[no-]encode-email-headers]
 		   [--no-notes | --notes[=<ref>]]
 		   [--interdiff=<previous>]
@@ -322,6 +323,17 @@ 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.
 
+--cover-letter-format=<format-spec>::
+	Specify the format in which to generate the commit list of the
+	patch series. This option is available if the user wants to use
+	an alternative to the default `shortlog` format. The accepted
+	values for format-spec are "shortlog" or a format string
+	prefixed with `log:`.
+	e.g. `log: %s (%an)`
+	If defined, defaults to the `format.commitListFormat` configuration
+	variable.
+	This option is relevant only if a cover letter is generated.
+
 --encode-email-headers::
 --no-encode-email-headers::
 	Encode email headers that have non-ASCII characters with
@@ -453,6 +465,7 @@ with configuration variables.
 	signOff = true
 	outputDirectory = <directory>
 	coverLetter = auto
+	commitListFormat = shortlog
 	coverFromDescription = auto
 ------------
 

builtin/log.c

@@ -886,6 +886,7 @@ 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 +931,7 @@ 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 +1054,19 @@ 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")) {
+		struct strbuf tmp = STRBUF_INIT;
+		strbuf_init(&tmp, 0);
+		if (value)
+			strbuf_addstr(&tmp, value);
+		else
+			strbuf_addstr(&tmp, "log:[%(count)/%(total)] %s");
+
+		FREE_AND_NULL(cfg->fmt_cover_letter_commit_list);
+		git_config_string(&cfg->fmt_cover_letter_commit_list, var, tmp.buf);
+		strbuf_release(&tmp);
+		return 0;
+	}
 	if (!strcmp(var, "format.outputdirectory")) {
 		FREE_AND_NULL(cfg->config_output_directory);
 		return git_config_string(&cfg->config_output_directory, var, value);
@@ -1335,13 +1350,55 @@ 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 pretty_print_context ctx = {0};
+	struct rev_info rev = REV_INFO_INIT;
+
+	strbuf_init(&commit_line, 0);
+	rev.total = n;
+	ctx.rev = &rev;
+	for (int i = n - 1; i >= 0; i--) {
+		rev.nr = n - i;
+		repo_format_commit_message(the_repository, list[i], format,
+				&commit_line, &ctx);
+		fprintf(cover_file, "%s\n", commit_line.buf);
+		strbuf_reset(&commit_line);
+	}
+	fprintf(cover_file, "\n");
+
+	strbuf_release(&commit_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 +1445,12 @@ 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
+		die(_("'%s' is not a valid format string"), format);
 
 	/* We can only do diffstat with a unique reference point */
 	if (origin)
@@ -1917,6 +1968,7 @@ 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 +2015,8 @@ 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, "cover-letter-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 +2354,13 @@ 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";
+	}
+
 	if (cover_letter == -1) {
 		if (cfg.config_cover_letter == COVER_AUTO)
 			cover_letter = (total > 1);
@@ -2386,12 +2447,14 @@ 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++;

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(_("this format specifier can't be used with this command"));
+		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(_("this format specifier can't be used with this command"));
+		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));

t/t4014-format-patch.sh

@@ -380,6 +380,107 @@ 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 result test_file" &&
+	touch test_file &&
+	git add test_file &&
+	git commit -m "This is a subject" &&
+	git format-patch --cover-letter \
+	--cover-letter-format="log:[%(count)/%(total)] %s (%an)" -o patches HEAD~1 &&
+	grep "^\[1/1\] This is a subject (A U Thor)$" patches/0000-cover-letter.patch >result &&
+	test_line_count = 1 result
+'
+
+test_expected_success 'cover letter with author and count' '
+	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 --cover-letter \
+	--cover-letter-format="log:[%(count)/%(total)] %an" -o patches HEAD~1 &&
+	grep "^\[1/1\] A U Thor$" patches/0000-cover-letter.patch >result &&
+	test_line_count = 1 result
+'
+
+test_expect_success 'cover letter shortlog' '
+	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 --cover-letter --cover-letter-format=shortlog \
+	-o patches HEAD~1 &&
+	sed -n -e "/^A U Thor/p;" patches/0000-cover-letter.patch >result &&
+	test_line_count = 1 result
+'
+
+test_expect_success 'cover letter no format' '
+	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 --cover-letter -o patches HEAD~1 &&
+	sed -n -e "/^A U Thor/p;" patches/0000-cover-letter.patch >result &&
+	test_line_count = 1 result
+'
+
+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 but no format' '
+	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 &&
+	printf "\tcommitlistformat" >> .git/config &&
+	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 &&

t/t9902-completion.sh

@@ -2775,6 +2775,7 @@ test_expect_success PERL 'send-email' '
 	test_completion "git send-email --cov" <<-\EOF &&
 	--cover-from-description=Z
 	--cover-letter Z
+	--cover-letter-format=Z
 	EOF
 	test_completion "git send-email --val" <<-\EOF &&
 	--validate Z