From 404bcf72c142357bea658ce845d5ff426a19a723 Mon Sep 17 00:00:00 2001
From: haolink <5476865+haolink@users.noreply.github.com>
Date: Fri, 29 Aug 2025 19:17:07 +0200
Subject: [PATCH 1/3] Adds a Garbage Collector Handle fallback for Unity
 2021.2.x

---
 .../Runtime/ClassInjectorBase.cs              | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs b/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
index 1fc35b5f..d15bca85 100644
--- a/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
+++ b/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
@@ -13,9 +13,33 @@ public static class ClassInjectorBase
     public static object GetMonoObjectFromIl2CppPointer(IntPtr pointer)
     {
         var gcHandle = GetGcHandlePtrFromIl2CppObject(pointer);
+
+        if (gcHandle == IntPtr.Zero) // The Garbage collector handle might return a null pointer
+        {
+            gcHandle = FallbackGetGcHandlePtrFromIl2CppDelegateMTarget(pointer);
+        }
+
         return GCHandle.FromIntPtr(gcHandle).Target;
     }
 
+    /// <summary>
+    /// Tries to get the Garbage collector pointer from the m_target object from the m_target of the delegate.
+    /// Fixes Harmony in Unity 2021.2.x .
+    /// </summary>
+    /// <param name="pointer"></param>
+    /// <returns></returns>
+    private unsafe static IntPtr FallbackGetGcHandlePtrFromIl2CppDelegateMTarget(IntPtr pointer)
+    {
+        if (IL2CPP.il2cpp_class_is_assignable_from(Il2CppClassPointerStore<Il2CppSystem.MulticastDelegate>.NativeClassPtr, IL2CPP.il2cpp_object_get_class(pointer)))
+        {
+            var delegateObject = new Il2CppSystem.Delegate(pointer);
+            if (delegateObject.m_target != null && delegateObject.m_target.Pointer != IntPtr.Zero) {
+                return GetGcHandlePtrFromIl2CppObject(delegateObject.m_target.Pointer);
+            }
+        }
+        return IntPtr.Zero;
+    }
+
     public static unsafe IntPtr GetGcHandlePtrFromIl2CppObject(IntPtr pointer)
     {
         return GetInjectedData(pointer)->managedGcHandle;

From 7fc1cbc71788a590b632e6b17b725698607443eb Mon Sep 17 00:00:00 2001
From: haolink <5476865+haolink@users.noreply.github.com>
Date: Mon, 1 Sep 2025 17:48:45 +0200
Subject: [PATCH 2/3] Fix formatting.

---
 Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs b/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
index d15bca85..1b4c6f77 100644
--- a/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
+++ b/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
@@ -28,14 +28,13 @@ public static object GetMonoObjectFromIl2CppPointer(IntPtr pointer)
     /// </summary>
     /// <param name="pointer"></param>
     /// <returns></returns>
-    private unsafe static IntPtr FallbackGetGcHandlePtrFromIl2CppDelegateMTarget(IntPtr pointer)
+    private static IntPtr FallbackGetGcHandlePtrFromIl2CppDelegateMTarget(IntPtr pointer)
     {
         if (IL2CPP.il2cpp_class_is_assignable_from(Il2CppClassPointerStore<Il2CppSystem.MulticastDelegate>.NativeClassPtr, IL2CPP.il2cpp_object_get_class(pointer)))
         {
             var delegateObject = new Il2CppSystem.Delegate(pointer);
-            if (delegateObject.m_target != null && delegateObject.m_target.Pointer != IntPtr.Zero) {
+            if (delegateObject.m_target != null && delegateObject.m_target.Pointer != IntPtr.Zero)
                 return GetGcHandlePtrFromIl2CppObject(delegateObject.m_target.Pointer);
-            }
         }
         return IntPtr.Zero;
     }

From fba494ad26da56a8f57244a3f6c0af8d1488b7d3 Mon Sep 17 00:00:00 2001
From: ManlyMarco <39247311+ManlyMarco@users.noreply.github.com>
Date: Tue, 2 Sep 2025 08:52:27 +0200
Subject: [PATCH 3/3] Update Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs

---
 Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs b/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
index 1b4c6f77..96ea8d05 100644
--- a/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
+++ b/Il2CppInterop.Runtime/Runtime/ClassInjectorBase.cs
@@ -26,8 +26,6 @@ public static object GetMonoObjectFromIl2CppPointer(IntPtr pointer)
     /// Tries to get the Garbage collector pointer from the m_target object from the m_target of the delegate.
     /// Fixes Harmony in Unity 2021.2.x .
     /// </summary>
-    /// <param name="pointer"></param>
-    /// <returns></returns>
     private static IntPtr FallbackGetGcHandlePtrFromIl2CppDelegateMTarget(IntPtr pointer)
     {
         if (IL2CPP.il2cpp_class_is_assignable_from(Il2CppClassPointerStore<Il2CppSystem.MulticastDelegate>.NativeClassPtr, IL2CPP.il2cpp_object_get_class(pointer)))