format.commitListFormat: strip meaning from empty

The configuration variable format.commitListFormat allows for an empty
value. This is unusual and can create issues when interacting with this
configuration variable through the CLI.

Strip meaning to format.commitListFormat with an empty value.

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

Author: Mroik

builtin/log.c

@@ -1055,17 +1055,8 @@ static int git_format_config(const char *var, const char *value,
 		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;
+		return git_config_string(&cfg->fmt_cover_letter_commit_list, var, value);
 	}
 	if (!strcmp(var, "format.outputdirectory")) {
 		FREE_AND_NULL(cfg->config_output_directory);

t/t4014-format-patch.sh

@@ -451,17 +451,6 @@ test_expect_success 'cover letter config with count and author' '
 	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" &&