-check connection state / rval

1 files changed, 6 insertions, 0 deletions

diff --git a/src/multicast/gnunet-service-multicast.c b/src/multicast/gnunet-service-multicast.c
index daaf242e8..4c1b3f1d7 100644
--- a/src/multicast/gnunet-service-multicast.c
+++ b/src/multicast/gnunet-service-multicast.c
@@ -898,6 +898,12 @@ client_recv_join_decision (void *cls, struct GNUNET_SERVER_Client *client,
   const struct MulticastJoinDecisionMessageHeader *
     hdcsn = (const struct MulticastJoinDecisionMessageHeader *) m;
 
+  if (NULL == grp)
+  {
+    GNUNET_break (0);
+    GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
+    return;
+  }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "%p Got join decision from client for group %s..\n",
               grp, GNUNET_h2s (&grp->pub_key_hash));