From 8a5c3bc97b66e576e9fba4302e3d1f8c303d655c Mon Sep 17 00:00:00 2001
From: Alexander Batalov <alex.batalov@gmail.com>
Date: Wed, 5 Oct 2022 14:38:19 +0300
Subject: [PATCH] Fix obj_can_hear_obj implementation

---
 src/interpreter_extra.cc | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/interpreter_extra.cc b/src/interpreter_extra.cc
index b9970d7..ed35b0f 100644
--- a/src/interpreter_extra.cc
+++ b/src/interpreter_extra.cc
@@ -2622,9 +2622,10 @@ static void opObjectCanHearObject(Program* program)
 
     bool canHear = false;
 
-    // FIXME: This is clearly an error. If any of the object is NULL
-    // dereferencing will crash the game.
-    if (object2 == NULL || object1 == NULL) {
+    // SFALL: Fix broken implementation.
+    // CE: In Sfall this fix is available under "ObjCanHearObjFix" switch and
+    // it's not enabled by default. Probably needs testing.
+    if (object2 != nullptr && object1 != nullptr) {
         if (object2->elevation == object1->elevation) {
             if (object2->tile != -1 && object1->tile != -1) {
                 if (isWithinPerception(object2, object1)) {