format-patch: add commitListFormat config

Using "--cover-letter" we can tell format-patch to generate a cover
letter, in this cover letter there's a list of commits included in the
patch series and the format is specified by the "--cover-letter-format"
option. Would be useful if this format could be configured from the
config file instead of always needing to pass it from the command line.

Teach format-patch how to read the format spec for the cover letter from
the config files. The variable it should look for is called
format.commitListFormat.

Possible values:
  - commitListFormat is set but no string is passed: it will default to
    "[%(count)/%(total)] %s"

  - if a string is passed: will use it as a format spec. Note that this
    is either "shortlog" or a format spec prefixed by "log:"
    e.g."log:%s (%an)"

  - if commitListFormat is not set: it will default to the shortlog
    format.

Signed-off-by: Mirko Faina <mroik@delayed.space>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 74 insertions, 0 deletions

diff --git a/builtin/log.c b/builtin/log.c
index 95e5d9755f..5fec0ddaf9 100644
--- a/builtin/log.c
+++ b/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);
@@ -2329,6 +2344,12 @@ int cmd_format_patch(int argc,
 		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);
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 458da80721..4891389a53 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -428,6 +428,59 @@ test_expect_success 'cover letter no format' '
 	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 &&