builtin/grep: fix leak with --max-count=0

When executing with `--max-count=0` we'll return early from git-grep(1)
without performing any cleanup, which causes memory leaks. Plug these.

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

builtin/grep.c

@@ -906,6 +906,7 @@ int cmd_grep(int argc,
 	int dummy;
 	int use_index = 1;
 	int allow_revs;
+	int ret;
 
 	struct option options[] = {
 		OPT_BOOL(0, "cached", &cached,
@@ -1172,8 +1173,10 @@ int cmd_grep(int argc,
 	 * Optimize out the case where the amount of matches is limited to zero.
 	 * We do this to keep results consistent with GNU grep(1).
 	 */
-	if (opt.max_count == 0)
-		return 1;
+	if (opt.max_count == 0) {
+		ret = 1;
+		goto out;
+	}
 
 	if (show_in_pager) {
 		if (num_threads > 1)
@@ -1267,10 +1270,14 @@ int cmd_grep(int argc,
 		hit |= wait_all();
 	if (hit && show_in_pager)
 		run_pager(&opt, prefix);
+
+	ret = !hit;
+
+out:
 	clear_pathspec(&pathspec);
 	string_list_clear(&path_list, 0);
 	free_grep_patterns(&opt);
 	object_array_clear(&list);
 	free_repos();
-	return !hit;
+	return ret;
 }

t/t7810-grep.sh

@@ -9,6 +9,7 @@ test_description='git grep various.
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_invalid_grep_expression() {