--- a/jingle/register.c	Sun Jul 25 01:42:33 2010 +0200
+++ b/jingle/register.c	Sun Jul 25 02:03:58 2010 +0200
@@ -124,7 +124,8 @@
     thistransport = (TransportHandlerEntry *) entry->data;
     
     // Look if it's forbidden
-    if (g_slist_find_custom(*forbid, thistransport->xmlns, cmp_forbid))
+    if (forbid != NULL &&
+        g_slist_find_custom(*forbid, thistransport->xmlns, cmp_forbid))
       continue;
     
     if (thistransport->transtype == requestedtype &&
@@ -133,7 +134,10 @@
       besttransport = thistransport;
     }
   }
-  *forbid = g_slist_append(*forbid, besttransport->xmlns);
+  
+  if (forbid != NULL)
+    *forbid = g_slist_append(*forbid, besttransport->xmlns);
+  
   return besttransport->funcs;
 }