From f97792f2ca6249f6d7131fd11ff6cf0e860e52ce Mon Sep 17 00:00:00 2001
From: Carti <carti_it@proton.me>
Date: Tue, 3 Feb 2026 08:10:32 +0100
Subject: [PATCH] Throw useful exception when handler is null

---
 src/Avalonia.X11/Dispatching/X11EventDispatcher.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/Avalonia.X11/Dispatching/X11EventDispatcher.cs b/src/Avalonia.X11/Dispatching/X11EventDispatcher.cs
index 36625a61cd..59560e4ecb 100644
--- a/src/Avalonia.X11/Dispatching/X11EventDispatcher.cs
+++ b/src/Avalonia.X11/Dispatching/X11EventDispatcher.cs
@@ -47,7 +47,12 @@ internal class X11EventDispatcher
                     }
                 }
                 else if (_eventHandlers.TryGetValue(xev.AnyEvent.window, out var handler))
+                {
+                    if (handler is null)
+                        throw new NullReferenceException($"Event handler for event '{xev.AnyEvent}' and window '{xev.AnyEvent.window}' is null");
+
                     handler(ref xev);
+                }
             }
             finally
             {