backport-native-handle-validation

Author: maxkatz6

src/Windows/Avalonia.Win32/Win32NativeControlHost.cs

@@ -94,6 +94,10 @@ public DumbWindow(bool layered = false, IntPtr? parent = null)
                     IntPtr.Zero,
                     IntPtr.Zero,
                     IntPtr.Zero);
+
+                if (Handle == IntPtr.Zero)
+                    throw new InvalidOperationException("Unable to create child window for native control host. Application manifest with supported OS list might be required.");
+
                 if (layered)
                     UnmanagedMethods.SetLayeredWindowAttributes(Handle, 0, 255,
                         UnmanagedMethods.LayeredWindowFlags.LWA_ALPHA);