Index: channels/chan_zap.c
===================================================================
--- channels/chan_zap.c (revision 4239)
+++ channels/chan_zap.c (working copy)
@@ -2115,7 +2115,7 @@
                                swap_subs(p, SUB_CALLWAIT, SUB_REAL);
                                unalloc_sub(p, SUB_CALLWAIT);
                                p->owner = p->subs[SUB_REAL].owner;
-                               if (p->owner->_state != AST_STATE_UP)
+                               if (p->owner && p->owner->_state != AST_STATE_UP)
                                        p->subs[SUB_REAL].needanswer = 1;
                                if (p->subs[SUB_REAL].owner->bridge)
                                        ast_moh_stop(p->subs[SUB_REAL].owner->bridge);