builtin/config: do not die in get_color()

When trying to parse an invalid color via `get_color()` we die. We're
about to introduce another caller in a subsequent commit though that has
its own error handling, so dying is a bit drastic there. Furthermore,
the only caller that we already have right now already knows to handle
errors in other branches that don't call `get_color()`.

Convert the function to instead return an error code to improve its
flexibility.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

builtin/config.c

@@ -547,24 +547,31 @@ static int git_get_color_config(const char *var, const char *value,
 	return 0;
 }
 
-static void get_color(const struct config_location_options *opts,
+static int get_color(const struct config_location_options *opts,
 		      const char *var, const char *def_color)
 {
 	struct get_color_config_data data = {
 		.get_color_slot = var,
 		.parsed_color[0] = '\0',
 	};
+	int ret;
 
 	config_with_options(git_get_color_config, &data,
 			    &opts->source, the_repository,
 			    &opts->options);
 
 	if (!data.get_color_found && def_color) {
-		if (color_parse(def_color, data.parsed_color) < 0)
-			die(_("unable to parse default color value"));
+		if (color_parse(def_color, data.parsed_color) < 0) {
+			ret = error(_("unable to parse default color value"));
+			goto out;
+		}
 	}
 
+	ret = 0;
+
+out:
 	fputs(data.parsed_color, stdout);
+	return ret;
 }
 
 struct get_colorbool_config_data {
@@ -1390,7 +1397,7 @@ static int cmd_config_actions(int argc, const char **argv, const char *prefix)
 	}
 	else if (actions == ACTION_GET_COLOR) {
 		check_argc(argc, 1, 2);
-		get_color(&location_opts, argv[0], argv[1]);
+		ret = get_color(&location_opts, argv[0], argv[1]);
 	}
 	else if (actions == ACTION_GET_COLORBOOL) {
 		check_argc(argc, 1, 2);