From 55640f0c2bc8a49ba385f376db6bdbaf64cc795b Mon Sep 17 00:00:00 2001
From: Max Katz <maxkatz6@outlook.com>
Date: Mon, 3 Apr 2023 19:35:32 -0400
Subject: [PATCH] (hack?) Fix stackoverflow

---
 .../Controls/ResourceDictionary.cs            | 26 +++++++++++++++----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/Avalonia.Base/Controls/ResourceDictionary.cs b/src/Avalonia.Base/Controls/ResourceDictionary.cs
index 5123803f6e..878797d9b6 100644
--- a/src/Avalonia.Base/Controls/ResourceDictionary.cs
+++ b/src/Avalonia.Base/Controls/ResourceDictionary.cs
@@ -15,6 +15,7 @@ namespace Avalonia.Controls
     /// </summary>
     public class ResourceDictionary : IResourceDictionary
     {
+        private DeferredItem? s_lastDeferredItem;
         private Dictionary<object, object?>? _inner;
         private IResourceHost? _owner;
         private AvaloniaList<IResourceProvider>? _mergedDictionaries;
@@ -241,12 +242,27 @@ namespace Avalonia.Controls
             {
                 if (value is DeferredItem deffered)
                 {
-                    _inner[key] = value = deffered.Factory(null) switch
+                    // Avoid simple reentrancy, which could commonly occur on redefining the resource.
+                    if (s_lastDeferredItem == deffered)
                     {
-                        ITemplateResult t => t.Result,
-                        object v => v,
-                        _ => null,
-                    };
+                        value = null;
+                        return false;
+                    }
+
+                    try
+                    {
+                        s_lastDeferredItem = deffered;
+                        _inner[key] = value = deffered.Factory(null) switch
+                        {
+                            ITemplateResult t => t.Result,
+                            { } v => v,
+                            _ => null,
+                        };
+                    }
+                    finally
+                    {
+                        s_lastDeferredItem = null;
+                    }
                 }
                 return true;
             }