builtin/commit: fix leaking change data contents

While we free the worktree change data, we never free its contents. Fix
this.

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

builtin/commit.c

@@ -728,6 +728,13 @@ static void prepare_amend_commit(struct commit *commit, struct strbuf *sb,
 	repo_unuse_commit_buffer(the_repository, commit, buffer);
 }
 
+static void change_data_free(void *util, const char *str UNUSED)
+{
+	struct wt_status_change_data *d = util;
+	free(d->rename_source);
+	free(d);
+}
+
 static int prepare_to_commit(const char *index_file, const char *prefix,
 			     struct commit *current_head,
 			     struct wt_status *s,
@@ -991,7 +998,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		s->use_color = 0;
 		committable = run_status(s->fp, index_file, prefix, 1, s);
 		s->use_color = saved_color_setting;
-		string_list_clear(&s->change, 1);
+		string_list_clear_func(&s->change, change_data_free);
 	} else {
 		struct object_id oid;
 		const char *parent = "HEAD";

t/t7500-commit-template-squash-signoff.sh

@@ -7,6 +7,7 @@ test_description='git commit
 
 Tests for template, signoff, squash and -F functions.'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-rebase.sh