From: Pasi Kallinen <paxed@alt.org>
Date: Sat, 5 Mar 2022 08:06:01 +0000 (+0200)
Subject: Fix segfault with uball
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=fab1048f2fb2b44bc5fdf00bedfd5afe33b37127;p=nethack

Fix segfault with uball

Drowning in a pool while punished and carrying the ball,
and the only available space to crawl back on dry land
has a magic trap, which unpunishes you.
---

diff --git a/src/teleport.c b/src/teleport.c
index baae6f350..37bbcdef9 100644
--- a/src/teleport.c
+++ b/src/teleport.c
@@ -365,8 +365,14 @@ teleds(int nux, int nuy, int teleds_flags)
         if (drag_ball(nux, nuy, &bc_control, &ballx, &bally, &chainx,
                       &chainy, &cause_delay, allow_drag))
             move_bc(0, bc_control, ballx, bally, chainx, chainy);
-        else /* dragging fails if hero is encumbered beyond 'burdened' */
-            unplacebc(); /* to match placebc() below */
+        else {
+            /* dragging fails if hero is encumbered beyond 'burdened' */
+            /* uball might've been cleared via drag_ball -> spoteffects ->
+               dotrap -> magic trap unpunishment */
+            ball_active = (Punished && uball->where != OBJ_FREE);
+            if (ball_active)
+                unplacebc(); /* to match placebc() below */
+        }
     }
 
     /* must set u.ux, u.uy after drag_ball(), which may need to know