Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 368927)
+++ channels/chan_sip.c	(working copy)
@@ -10659,7 +10659,7 @@
 	 */
 	if (sipmethod == SIP_CANCEL ||
 			(sipmethod == SIP_ACK && (p->invitestate == INV_COMPLETED || p->invitestate == INV_CANCELLED))) {
-		set_destination(p, ast_strdupa(p->uri));
+		/* Purposely do nothing in this case */
 	} else if (p->route) {
 		set_destination(p, p->route->hop);
 		add_route(req, is_strict ? p->route->next : p->route);