oggstream: fix crash with 0 byte ogg packets

https://bugzilla.gnome.org/show_bug.cgi?id=687030

diff --git a/ext/ogg/gstoggstream.c b/ext/ogg/gstoggstream.c
index c79f088..fe28f2e 100644 (file)
--- a/ext/ogg/gstoggstream.c
+++ b/ext/ogg/gstoggstream.c
@@ -790,7 +790,7 @@ setup_vorbis_mapper (GstOggStream * pad, ogg_packet * packet)
 static gboolean
 is_header_vorbis (GstOggStream * pad, ogg_packet * packet)
 {
-  if (packet->bytes > 0 && (packet->packet[0] & 0x01) == 0)
+  if (packet->bytes == 0 || (packet->packet[0] & 0x01) == 0)
     return FALSE;
 
   if (packet->packet[0] == 5) {