json-streamer: Don't leak tokens on incomplete parse

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>
Message-Id: <1463608012-12760-1-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
(cherry picked from commit ba4dba54347d5062436a8553f527dbbed6dcf069)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/qobject/json-streamer.c b/qobject/json-streamer.c
index 02516853a13d50a1287af5e48d7774f80e945d19..7164390cf5a8ddaadd54e3bf2f15a15ecc52ae55 100644 (file)
--- 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;
     }