From 2bd2bd508122a9a8ef76606abc700b5cdbafead8 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Fri, 30 Jun 2023 11:02:58 +0200
Subject: [PATCH] Fix crash when modifying animated model skeleton pose from
 gameplay code during update event

---
 Source/Engine/Level/Actors/AnimatedModel.cpp | 8 +++++++-
 Source/Engine/Level/Actors/AnimatedModel.h   | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Source/Engine/Level/Actors/AnimatedModel.cpp b/Source/Engine/Level/Actors/AnimatedModel.cpp
index 882026db7..148b57682 100644
--- a/Source/Engine/Level/Actors/AnimatedModel.cpp
+++ b/Source/Engine/Level/Actors/AnimatedModel.cpp
@@ -603,7 +603,13 @@ void AnimatedModel::OnAnimationUpdated_Sync()
     // Update synchronous stuff
     UpdateSockets();
     ApplyRootMotion(GraphInstance.RootMotion);
-    AnimationUpdated();
+    if (!_isDuringUpdateEvent)
+    {
+        // Prevent stack-overflow when gameplay modifies the pose within the event
+        _isDuringUpdateEvent = true;
+        AnimationUpdated();
+        _isDuringUpdateEvent = false;
+    }
 }
 
 void AnimatedModel::OnAnimationUpdated()
diff --git a/Source/Engine/Level/Actors/AnimatedModel.h b/Source/Engine/Level/Actors/AnimatedModel.h
index ccd0ee3b5..33f206580 100644
--- a/Source/Engine/Level/Actors/AnimatedModel.h
+++ b/Source/Engine/Level/Actors/AnimatedModel.h
@@ -60,6 +60,7 @@ private:
     AnimationUpdateMode _actualMode;
     uint32 _counter;
     Real _lastMinDstSqr;
+    bool _isDuringUpdateEvent = false;
     uint64 _lastUpdateFrame;
     BlendShapesInstance _blendShapes;
     ScriptingObjectReference<AnimatedModel> _masterPose;