use a flag to tell if a menu has been reparented.

native/Avalonia.Native/inc/avalonia-native.h

@@ -190,7 +190,7 @@ public:
     virtual HRESULT CreateCursorFactory(IAvnCursorFactory** ppv) = 0;
     virtual HRESULT ObtainGlDisplay(IAvnGlDisplay** ppv) = 0;
     virtual HRESULT SetAppMenu(IAvnMenu* menu) = 0;
-    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv, bool isTopLevel) = 0;
+    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv) = 0;
     virtual HRESULT CreateMenuItem (IAvnMenuItem** ppv) = 0;
     virtual HRESULT CreateMenuItemSeperator (IAvnMenuItem** ppv) = 0;
 };

native/Avalonia.Native/src/OSX/common.h

@@ -15,7 +15,7 @@ extern IAvnScreens* CreateScreens();
 extern IAvnClipboard* CreateClipboard();
 extern IAvnCursorFactory* CreateCursorFactory();
 extern IAvnGlDisplay* GetGlDisplay();
-extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* events, bool isTopLevel);
+extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* events);
 extern IAvnMenuItem* CreateAppMenuItem();
 extern IAvnMenuItem* CreateAppMenuItemSeperator();
 extern void SetAppMenu (NSString* appName, IAvnMenu* appMenu);

native/Avalonia.Native/src/OSX/main.mm

@@ -227,9 +227,9 @@ public:
         return S_OK;
     }
     
-    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv, bool isTopLevel) override
+    virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv) override
     {
-        *ppv = ::CreateAppMenu(cb, isTopLevel);
+        *ppv = ::CreateAppMenu(cb);
         return S_OK;
     }
     

native/Avalonia.Native/src/OSX/menu.h

@@ -16,6 +16,8 @@ class AvnAppMenu;
 
 @interface AvnMenu : NSMenu
 - (id) initWithDelegate: (NSObject<NSMenuDelegate>*) del;
+- (void) setIsReparented: (bool) value;
+- (bool) isReparented;
 @end
 
 @interface AvnMenuItem : NSMenuItem
@@ -59,12 +61,11 @@ class AvnAppMenu : public ComSingleObject<IAvnMenu, &IID_IAvnMenu>
 private:
     AvnMenu* _native;
     ComPtr<IAvnMenuEvents> _baseEvents;
-    bool _isTopLevel;
     
 public:
     FORWARD_IUNKNOWN()
     
-    AvnAppMenu(IAvnMenuEvents* events, bool isTopLevel);
+    AvnAppMenu(IAvnMenuEvents* events);
         
     AvnMenu* GetNative();
     

native/Avalonia.Native/src/OSX/menu.mm

@@ -5,16 +5,29 @@
 
 @implementation AvnMenu
 {
+    bool _isReparented;
     NSObject<NSMenuDelegate>* _wtf;
 }
+
 - (id) initWithDelegate: (NSObject<NSMenuDelegate>*)del
 {
     self = [super init];
     self.delegate = del;
     _wtf = del;
+    _isReparented = false;
     return self;
 }
 
+- (bool)isReparented
+{
+    return _isReparented;
+}
+
+- (void)setIsReparented:(bool)value
+{
+    _isReparented = value;
+}
+
 @end
 
 @implementation AvnMenuItem
@@ -169,18 +182,11 @@ void AvnAppMenuItem::RaiseOnClicked()
     }
 }
 
-AvnAppMenu::AvnAppMenu(IAvnMenuEvents* events, bool isTopLevel)
+AvnAppMenu::AvnAppMenu(IAvnMenuEvents* events)
 {
-    _isTopLevel = isTopLevel;
     _baseEvents = events;
     id del = [[AvnMenuDelegate alloc] initWithParent: this];
     _native = [[AvnMenu alloc] initWithDelegate: del];
-    
-    
-    if(_isTopLevel)
-    {
-        [_native insertItem: [NSMenuItem new] atIndex:0];
-    }
 }
 
 
@@ -201,7 +207,7 @@ HRESULT AvnAppMenu::InsertItem(int index, IAvnMenuItem *item)
 {
     @autoreleasepool
     {
-        if(_isTopLevel)
+        if([_native isReparented])
         {
             index++;
         }
@@ -284,11 +290,11 @@ HRESULT AvnAppMenu::Clear()
 
 @end
 
-extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* cb, bool isTopLevel)
+extern IAvnMenu* CreateAppMenu(IAvnMenuEvents* cb)
 {
     @autoreleasepool
     {
-        return new AvnAppMenu(cb, isTopLevel);
+        return new AvnAppMenu(cb);
     }
 }
 

native/Avalonia.Native/src/OSX/window.mm

@@ -1144,7 +1144,7 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     ComPtr<WindowBaseImpl> _parent;
     bool _canBecomeKeyAndMain;
     bool _closed;
-    NSMenu* _menu;
+    AvnMenu* _menu;
     double _lastScaling;
 }
 
@@ -1194,6 +1194,8 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
             [appMenu removeItem:appMenuItem];
             
             [_menu insertItem:appMenuItem atIndex:0];
+            
+            [_menu setIsReparented:true];
         }
         
         [NSApp setMenu:_menu];
@@ -1212,6 +1214,11 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
         
         [[appMenuItem menu] removeItem:appMenuItem];
         
+        if(_menu != nullptr)
+        {
+            [_menu setIsReparented:false];
+        }
+        
         [nativeAppMenu->GetNative() addItem:appMenuItem];
         
         [NSApp setMenu:nativeAppMenu->GetNative()];
@@ -1222,11 +1229,11 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     }
 }
 
--(void) applyMenu:(NSMenu *)menu
+-(void) applyMenu:(AvnMenu *)menu
 {
     if(menu == nullptr)
     {
-        menu = [NSMenu new];
+        menu = [AvnMenu new];
     }
     
     _menu = menu;