Merge pull request #9077 from mono/jstedfast-debugger-movetosuperview-crash-fix

[Debugger] When a CellView gets moved to a null Superview, don't Upda…

Author: jstedfast

main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/ObjectValue/Mac/MacDebuggerObjectCellViewBase.cs

@@ -64,7 +64,7 @@ public MacObjectValueTreeView TreeView {
 		public override NSObject ObjectValue {
 			get { return base.ObjectValue; }
 			set {
-				var target = ((MacObjectValueNode)value)?.Target;
+				var target = ((MacObjectValueNode) value)?.Target;
 
 				if (Node != target) {
 					if (target != null)
@@ -172,7 +172,9 @@ protected void UpdateFont (NSControl control, int sizeDelta = 0)
 		public override void ViewDidMoveToSuperview ()
 		{
 			base.ViewDidMoveToSuperview ();
-			UpdateContents ();
+
+			if (Superview != null)
+				UpdateContents ();
 		}
 
 		public override NSBackgroundStyle BackgroundStyle {