From 5765c869c5cbca4cf69a669d1b76e7971d4239a1 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Mon, 13 Apr 2020 12:09:01 -0300
Subject: [PATCH] allow setting submenu to null.

---
 native/Avalonia.Native/src/OSX/menu.mm | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/native/Avalonia.Native/src/OSX/menu.mm b/native/Avalonia.Native/src/OSX/menu.mm
index 2abee42e11..2e94de7207 100644
--- a/native/Avalonia.Native/src/OSX/menu.mm
+++ b/native/Avalonia.Native/src/OSX/menu.mm
@@ -67,9 +67,16 @@ NSMenuItem* AvnAppMenuItem::GetNative()
 
 HRESULT AvnAppMenuItem::SetSubMenu (IAvnAppMenu* menu)
 {
-    auto nsMenu = dynamic_cast<AvnAppMenu*>(menu)->GetNative();
-    
-    [_native setSubmenu: nsMenu];
+    if(menu != nullptr)
+    {
+        auto nsMenu = dynamic_cast<AvnAppMenu*>(menu)->GetNative();
+        
+        [_native setSubmenu: nsMenu];
+    }
+    else
+    {
+        [_native setSubmenu: nullptr];
+    }
     
     return S_OK;
 }