[Qemu-devel] [PATCH] json-streamer: Don't leak tokens on incomplete parse

[Eric Blake <eblake@redhat.com>]

Valgrind complained about a number of leaks in
tests/check-qobject-json:

==12657==    definitely lost: 17,247 bytes in 1,234 blocks

All of which had the same root cause: on an incomplete parse,
we were abandoning the token queue without cleaning up the
allocated data within each queue element.  Introduced in
commit 95385fe, when we switched from QList (which recursively
frees contents) to g_queue (which does not).

We don't yet require glib 2.32 with its g_queue_free_full(),
so open-code it instead.

CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 qobject/json-streamer.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/qobject/json-streamer.c b/qobject/json-streamer.c
index 0251685..7164390 100644
--- a/qobject/json-streamer.c
+++ b/qobject/json-streamer.c
@@ -20,9 +20,15 @@
 #define MAX_TOKEN_COUNT (2ULL << 20)
 #define MAX_NESTING (1ULL << 10)

+static void json_message_free_token(void *token, void *opaque)
+{
+    g_free(token);
+}
+
 static void json_message_free_tokens(JSONMessageParser *parser)
 {
     if (parser->tokens) {
+        g_queue_foreach(parser->tokens, json_message_free_token, NULL);
         g_queue_free(parser->tokens);
         parser->tokens = NULL;
     }
-- 
2.5.5