From dda69255c4c3f667ec4025a038678f89111dcb41 Mon Sep 17 00:00:00 2001
From: Jay Wang <jay.wang@wisetechglobal.com>
Date: Fri, 28 Aug 2026 16:22:58 +0800
Subject: [PATCH 1/3] Handle disposed AsyncWaitHandle during BeginInvoke
 completion

---
 .../Windows/Forms/Control.ThreadMethodEntry.cs    |  9 ++++++++-
 .../System/Windows/Forms/ControlTests.Methods.cs  | 15 +++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms/System/Windows/Forms/Control.ThreadMethodEntry.cs b/src/System.Windows.Forms/System/Windows/Forms/Control.ThreadMethodEntry.cs
index 9d7acffbc59..1c90650afd5 100644
--- a/src/System.Windows.Forms/System/Windows/Forms/Control.ThreadMethodEntry.cs
+++ b/src/System.Windows.Forms/System/Windows/Forms/Control.ThreadMethodEntry.cs
@@ -76,7 +76,14 @@ internal void Complete()
             lock (_invokeSyncObject)
             {
                 IsCompleted = true;
-                _resetEvent?.Set();
+                try
+                {
+                    _resetEvent?.Set();
+                }
+                catch (ObjectDisposedException)
+                {
+                    // AsyncWaitHandle exposes the event and allows callers to dispose it before completion.
+                }
             }
         }
     }
diff --git a/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs b/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs
index b9f3ad3682b..ddb5e68978c 100644
--- a/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs
+++ b/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs
@@ -3850,6 +3850,21 @@ await Task.Run(() =>
         Assert.Equal(0, createdCallCount);
     }
 
+    [WinFormsFact]
+    public void Control_BeginInvoke_DisposedAsyncWaitHandle_CompletesCallback()
+    {
+        using Control control = new();
+        Assert.NotEqual(IntPtr.Zero, control.Handle);
+        bool callbackInvoked = false;
+        IAsyncResult asyncResult = control.BeginInvoke(() => callbackInvoked = true);
+        asyncResult.AsyncWaitHandle.Dispose();
+
+        control.TestAccessor.Dynamic.InvokeMarshaledCallbacks();
+
+        Assert.True(callbackInvoked);
+        Assert.True(asyncResult.IsCompleted);
+    }
+
     [WinFormsFact]
     public void Control_Invoke_Action_calls_correct_method()
     {

From 280bc58e42eb420b6134b33f23eb4d5de5b5284c Mon Sep 17 00:00:00 2001
From: Jay Wang <jay.wang@wisetechglobal.com>
Date: Mon, 31 Aug 2026 13:48:27 +0800
Subject: [PATCH 2/3] Adapt AsyncWaitHandle test to fork message loop

---
 .../System/Windows/Forms/ControlTests.Methods.cs                | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs b/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs
index ddb5e68978c..12fa688aaf2 100644
--- a/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs
+++ b/src/test/unit/System.Windows.Forms/System/Windows/Forms/ControlTests.Methods.cs
@@ -3859,7 +3859,7 @@ public void Control_BeginInvoke_DisposedAsyncWaitHandle_CompletesCallback()
         IAsyncResult asyncResult = control.BeginInvoke(() => callbackInvoked = true);
         asyncResult.AsyncWaitHandle.Dispose();
 
-        control.TestAccessor.Dynamic.InvokeMarshaledCallbacks();
+        Application.DoEvents();
 
         Assert.True(callbackInvoked);
         Assert.True(asyncResult.IsCompleted);

From 992027738851cf2de62838b3f1a5ac478295f3e0 Mon Sep 17 00:00:00 2001
From: Jay Wang <jay.wang@wisetechglobal.com>
Date: Mon, 31 Aug 2026 14:24:47 +0800
Subject: [PATCH 3/3] update the package description

---
 .../System.Windows.Forms.Package.csproj                         | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms.Legacy/System.Windows.Forms.Package/System.Windows.Forms.Package.csproj b/src/System.Windows.Forms.Legacy/System.Windows.Forms.Package/System.Windows.Forms.Package.csproj
index c7a32613da9..875d39dba57 100644
--- a/src/System.Windows.Forms.Legacy/System.Windows.Forms.Package/System.Windows.Forms.Package.csproj
+++ b/src/System.Windows.Forms.Legacy/System.Windows.Forms.Package/System.Windows.Forms.Package.csproj
@@ -10,7 +10,7 @@
     <WtgPackageVersionPrefix>0.1.0</WtgPackageVersionPrefix>
     <PackageVersion Condition="'$(PackageVersion)' == ''">$(WtgPackageVersionPrefix)-dev</PackageVersion>
     <PackageDescription>WiseTech Global forked version of System.Windows.Forms that includes controls that were deprecated in .NET Core 3.1 and .NET 5, like DataGrid, Menu, ToolBar and StatusBar.</PackageDescription>
-    <PackageReleaseNotes>Fix the accessibility access on DataGrid components, PR link: https://github.com/WiseTechGlobal/winforms/pull/41</PackageReleaseNotes>
+    <PackageReleaseNotes>Handle disposed AsyncWaitHandle during BeginInvoke completion, version 0.2.17, PR link: https://github.com/WiseTechGlobal/winforms/pull/42</PackageReleaseNotes>
     <Authors>WiseTech Global</Authors>
     <Copyright>© WiseTech Global Limited. All rights reserved.</Copyright>
     <PackageReadmeFile>README.md</PackageReadmeFile>