Make sure we check for owner even after a queue frame

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@4854 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -1533,7 +1533,9 @@ static int attempt_transmit(void *data)
 							fr.frametype = AST_FRAME_CONTROL;
 							fr.subclass = AST_CONTROL_HANGUP;
 							iax2_queue_frame(f->callno, &fr);
-							iaxs[f->callno]->owner->hangupcause = AST_CAUSE_DESTINATION_OUT_OF_ORDER;
+							/* Remember, owner could disappear */
+							if (iaxs[f->callno]->owner)
+								iaxs[f->callno]->owner->hangupcause = AST_CAUSE_DESTINATION_OUT_OF_ORDER;
 						} else {
 							if (iaxs[f->callno]->reg) {
 								memset(&iaxs[f->callno]->reg->us, 0, sizeof(iaxs[f->callno]->reg->us));