From 7890a16d275a84910733962bf6a5c10be67a4893 Mon Sep 17 00:00:00 2001
From: DizzyEggg <jajkodizzy@wp.pl>
Date: Sun, 2 Aug 2020 15:04:55 +0200
Subject: [PATCH] Fix UB in event_object_movement.c

---
 src/event_object_movement.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/event_object_movement.c b/src/event_object_movement.c
index 6c49b91151..ab2f4749f2 100644
--- a/src/event_object_movement.c
+++ b/src/event_object_movement.c
@@ -2340,7 +2340,13 @@ const u8 *GetObjectEventScriptPointerByObjectEventId(u8 objectEventId)
 
 static u16 GetObjectEventFlagIdByLocalIdAndMap(u8 localId, u8 mapNum, u8 mapGroup)
 {
-    return GetObjectEventTemplateByLocalIdAndMap(localId, mapNum, mapGroup)->flagId;
+    struct ObjectEventTemplate *obj = GetObjectEventTemplateByLocalIdAndMap(localId, mapNum, mapGroup);
+#if UBFIX
+    // BUG: The function may return NULL, and attempting to read from NULL may freeze the game using modern compilers.
+    if (obj == NULL)
+        return 0;
+#endif // UBFIX
+    return obj->flagId;
 }
 
 static u16 GetObjectEventFlagIdByObjectEventId(u8 objectEventId)