Subject: Re: [PATCH v7 4/5] format-patch: add commitListFormat config

From: Phillip Wood <[email-masked]>
Date: Tue, 10 Mar 2026 14:34:01 +0000

On 06/03/2026 23:34, Mirko Faina wrote:
> 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"

It is unusual for an empty config value to mean something different from 
it not being set. The reason for this is that it allows

     git -c config.key some-command

to act as though config.key was not set.

Perhaps we should use the value "default" to generate a default format. 
It would be nice to support a default format on the commandline as well.

>    - 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)"

Having the config value behave like --cover-letter-format=<value> is 
sensible

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

makes sense

Thanks

Phillip

> Signed-off-by: Mirko Faina <[email-masked]>
> ---
>   builtin/log.c           | 21 ++++++++++++++++
>   t/t4014-format-patch.sh | 53 +++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 74 insertions(+)
> 
> 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 &&