Merge pull request #9335 from mono/jstedfast-debugger-remove-value-nre-fix

[Debugger] Fixed an NRE exception in OVTVController.RemoveValue if no…

Author: slluis

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

@@ -828,6 +828,11 @@ protected void OnDelete ()
 			foreach (var row in selectedRows) {
 				var item = (MacObjectValueNode) ItemAtRow ((nint) row);
 
+				// The user is only allowed to delete top-level nodes. It doesn't make sense to allow
+				// deleting child nodes of anything else.
+				if (!(item.Target.Parent is RootObjectValueNode))
+					continue;
+
 				nodesToDelete.Add (item.Target);
 			}
 

main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/ObjectValue/ObjectValueTreeViewController.cs

@@ -299,12 +299,18 @@ void RemovePinnedWatch ()
 		void RemoveValue (ObjectValueNode node)
 		{
 			var toplevel = node.Parent is RootObjectValueNode;
-			int index = node.Parent.Children.IndexOf (node);
+			int index;
+
+			if (node.Parent != null) {
+				index = node.Parent.Children.IndexOf (node);
+			} else {
+				index = -1;
+			}
 
 			UnregisterNode (node);
 			OnEvaluationCompleted (node, new ObjectValueNode[0]);
 
-			if (AllowWatchExpressions && toplevel)
+			if (AllowWatchExpressions && toplevel && index != -1)
 				ExpressionRemoved?.Invoke (this, new ExpressionRemovedEventArgs (index, node.Name));
 		}