github PR #787 - segfault for wizterrain wish

Pull request from entrez:  the change to show the result of a wish in
its gamelog/livelog event resulted in a segfault if that result was
&zeroobj.  It occurs for wizard mode wishes producing terrain changes
instead of objects.

Closes #787

src/zap.c

@@ -5674,6 +5674,9 @@ makewish(void)
            to retain wishless conduct */
         livelog_printf(LL_WISH, "declined to make a wish");
         return;
+    } else if (otmp == &cg.zeroobj) {
+        /* wizard mode terrain wish: skip livelogging, etc */
+        return;
     }
 
     if (otmp->oartifact) {
@@ -5696,9 +5699,7 @@ makewish(void)
     /* TODO? maybe generate a second event decribing what was received since
        those just echo player's request rather than show actual result */
 
-    if (otmp != &cg.zeroobj) {
+    const char *verb = ((Is_airlevel(&u.uz) || u.uinwater) ? "slip" : "drop"),
-        const char
-            *verb = ((Is_airlevel(&u.uz) || u.uinwater) ? "slip" : "drop"),
                *oops_msg = (u.uswallow
                             ? "Oops!  %s out of your reach!"
                             : (Is_airlevel(&u.uz) || Is_waterlevel(&u.uz)
@@ -5708,11 +5709,9 @@ makewish(void)
                                : "Oops!  %s to the floor!");
 
     /* The(aobjnam()) is safe since otmp is unidentified -dlc */
-        (void) hold_another_object(otmp, oops_msg,
+    (void) hold_another_object(otmp, oops_msg, The(aobjnam(otmp, verb)),
-                                   The(aobjnam(otmp, verb)),
                                (const char *) 0);
     u.ublesscnt += rn1(100, 50); /* the gods take notice */
-    }
 }
 
 /* Fills buf with the appropriate string for this ray.