From a6c600fd6133293ae3905731872691b7ede72b2b Mon Sep 17 00:00:00 2001
From: Pasi Kallinen <paxed@alt.org>
Date: Wed, 11 Mar 2020 19:52:09 +0200
Subject: [PATCH] Handle gone portal for migrating monsters

If the quest portal was gone, due to hero expulsion, migrating monsters
caused an impossible.
---
 src/dog.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/dog.c b/src/dog.c
index 05f693390..cce4b1348 100644
--- a/src/dog.c
+++ b/src/dog.c
@@ -408,7 +408,8 @@ boolean with_you;
         if (t) {
             xlocale = t->tx, ylocale = t->ty;
             break;
-        } else {
+        } else if (!(u.uevent.qexpelled
+                     && (Is_qstart(&u.uz0) || Is_qstart(&u.uz)))) {
             impossible("mon_arrive: no corresponding portal?");
         } /*FALLTHRU*/
     default: