remote: fix leaking push reports

The push reports that report failures to the user when pushing a
reference leak in several places. Plug these leaks by introducing a new
function `ref_push_report_free()` that frees the list of reports and
call it as required. While at it, fix a trivially leaking error string
in the vicinity.

These leaks get hit in t5411, but plugging them does not make the whole
test suite pass.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

builtin/receive-pack.c

@@ -374,6 +374,7 @@ static void write_head_info(void)
 struct command {
 	struct command *next;
 	const char *error_string;
+	char *error_string_owned;
 	struct ref_push_report *report;
 	unsigned int skip_update:1,
 		     did_not_exist:1,
@@ -1083,7 +1084,7 @@ static int read_proc_receive_report(struct packet_reader *reader,
 		hint->run_proc_receive |= RUN_PROC_RECEIVE_RETURNED;
 		if (!strcmp(head, "ng")) {
 			if (p)
-				hint->error_string = xstrdup(p);
+				hint->error_string = hint->error_string_owned = xstrdup(p);
 			else
 				hint->error_string = "failed";
 			code = -1;
@@ -2054,6 +2055,8 @@ static void free_commands(struct command *commands)
 	while (commands) {
 		struct command *next = commands->next;
 
+		ref_push_report_free(commands->report);
+		free(commands->error_string_owned);
 		free(commands);
 		commands = next;
 	}

remote.c

@@ -868,6 +868,20 @@ struct strvec *push_url_of_remote(struct remote *remote)
 	return remote->pushurl.nr ? &remote->pushurl : &remote->url;
 }
 
+void ref_push_report_free(struct ref_push_report *report)
+{
+	while (report) {
+		struct ref_push_report *next = report->next;
+
+		free(report->ref_name);
+		free(report->old_oid);
+		free(report->new_oid);
+		free(report);
+
+		report = next;
+	}
+}
+
 static int match_name_with_pattern(const char *key, const char *name,
 				   const char *value, char **result)
 {
@@ -1122,6 +1136,7 @@ void free_one_ref(struct ref *ref)
 	if (!ref)
 		return;
 	free_one_ref(ref->peer_ref);
+	ref_push_report_free(ref->report);
 	free(ref->remote_status);
 	free(ref->tracking_ref);
 	free(ref->symref);

remote.h

@@ -126,13 +126,15 @@ int remote_has_url(struct remote *remote, const char *url);
 struct strvec *push_url_of_remote(struct remote *remote);
 
 struct ref_push_report {
-	const char *ref_name;
+	char *ref_name;
 	struct object_id *old_oid;
 	struct object_id *new_oid;
 	unsigned int forced_update:1;
 	struct ref_push_report *next;
 };
 
+void ref_push_report_free(struct ref_push_report *);
+
 struct ref {
 	struct ref *next;
 	struct object_id old_oid;