When the window will close, set appkit host view's layout manager to …

…nil.

lib/UIKit/TUINSView.m

@@ -100,6 +100,7 @@ - (CALayer *)focusRingLayerForView:(NSView *)view;
  */
 - (void)setUp;
 
+- (void)windowWillClose:(NSNotification *)notification;
 - (void)windowDidResignKey:(NSNotification *)notification;
 - (void)windowDidBecomeKey:(NSNotification *)notification;
 - (void)screenProfileOrBackingPropertiesDidChange:(NSNotification *)notification;
@@ -651,13 +652,20 @@ - (void)setUp {
 	// set up masking on the AppKit host view, and make ourselves the layout
 	// manager, so that we'll know when new sublayers are added
 	self.appKitHostView.layer.layoutManager = self;
+	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(windowWillClose:) name:NSWindowWillCloseNotification object:self.window];
 
 	#if ENABLE_NSVIEW_CLIPPING
 	self.appKitHostView.layer.mask = self.maskLayer;
 	[self recalculateNSViewClipping];
 	#endif
 }
 
+- (void)windowWillClose:(NSNotification *)notification {
+	// since the layer retains the layoutManger, we need to set it to nil to
+	// make sure TUINSView will be deallocated
+	self.appKitHostView.layer.layoutManager = nil;
+}
+
 - (void)didAddSubview:(NSView *)view {
 	NSAssert(view == self || view == self.appKitHostView, @"Subviews should not be added to TUINSView %@: %@", self, view);
 	[super didAddSubview:view];