Fix null derefernce when enumerating deleted objects (#2128)

Co-authored-by: wixoa <[email protected]>
OpenDreamProject · Dec 29, 2024 · f7b6d43 · f7b6d43
1 parent 7aff19a
commit f7b6d43
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/OpenDreamRuntime/Objects/DreamObject.cs b/OpenDreamRuntime/Objects/DreamObject.cs
@@ -145,6 +145,8 @@ public void Delete(bool possiblyThreaded = false) {
         }
 
         public bool IsSubtypeOf(TreeEntry ancestor) {
+            if(Deleted) //null deref protection, deleted objects don't have ObjectDefinition anymore
+                return false;
             return ObjectDefinition.IsSubtypeOf(ancestor);
         }
 

diff --git a/OpenDreamRuntime/Procs/DreamEnumerators.cs b/OpenDreamRuntime/Procs/DreamEnumerators.cs
@@ -47,8 +47,12 @@ public DreamObjectEnumerator(IEnumerable<DreamObject> dreamObjects, TreeEntry? f
 
     public bool Enumerate(DMProcState state, DreamReference? reference) {
         bool success = _dreamObjectEnumerator.MoveNext();
+
+        while(success && _dreamObjectEnumerator.Current.Deleted) //skip over deleted
+            success = _dreamObjectEnumerator.MoveNext();
+
         if (_filterType != null) {
-            while (success && !_dreamObjectEnumerator.Current.IsSubtypeOf(_filterType)) {
+            while (success && (_dreamObjectEnumerator.Current.Deleted || !_dreamObjectEnumerator.Current.IsSubtypeOf(_filterType))) {
                 success = _dreamObjectEnumerator.MoveNext();
             }
         }