gas cloud fix

remove_region() calls newsym() when removing gas clouds, but when
newsym() checked whether it was updating a gas cloud location it
always got a false 'yes' because the region hadn't been removed yet.
Fixing this didn't seem to make any observable difference so it must
be followed fairly rapidly by a full vision recalc.

diff --git a/src/region.c b/src/region.c
index 9422de20cf04a4dd4322c0f5f2d9fa39c4b378f8..fae8883ffb582fb532aadbbe9807fc68bbb00d79 100644 (file)
--- a/src/region.c
+++ b/src/region.c
@@ -1,4 +1,4 @@
-/* NetHack 3.6 region.c        $NHDT-Date: 1573933605 2019/11/16 19:46:45 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.44 $ */
+/* NetHack 3.6 region.c        $NHDT-Date: 1573957877 2019/11/17 02:31:17 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.45 $ */
 /* Copyright (c) 1996 by Jean-Christophe Collet  */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -340,6 +340,11 @@ NhRegion *reg;
     if (i == n_regions)
         return;
 
+    /* remove region before potential newsym() calls, but don't free it yet */
+    if (--n_regions != i)
+        regions[i] = regions[n_regions];
+    regions[n_regions] = (NhRegion *) 0;
+
     /* Update screen if necessary */
     reg->ttl = -2L; /* for visible_region_at */
     if (reg->visible)
@@ -349,9 +354,6 @@ NhRegion *reg;
                     newsym(x, y);
 
     free_region(reg);
-    regions[i] = regions[n_regions - 1];
-    regions[n_regions - 1] = (NhRegion *) 0;
-    n_regions--;
 }
 
 /*