Prevent user editing the main right click context menu as if it were designable!

Author: tznind

src/MenuTracker.cs

@@ -3,6 +3,7 @@
 using Terminal.Gui;
 using Terminal.Gui.App;
 using Terminal.Gui.Views;
+using TerminalGuiDesigner.UI;
 
 namespace TerminalGuiDesigner;
 
@@ -295,6 +296,13 @@ private void ConvertEmptySubMenus(MenuItem menuItem)
     internal static MenuItem? GetFocusedMenuItemIfAny(IApplication app)
     {
         var m = app.Popovers?.Popovers?.FirstOrDefault(p => p.Visible) as PopoverMenu;
+        
+        // Don't let user edit the literal popup context menu in main app (that appears
+        // when right clicking in empty space).
+        if(m?.Data is string s && s == Editor.DesignerCorePopoverName)
+        {
+            return null;
+        }
 
         var focused = m?.Focused;
 

src/UI/Editor.cs

@@ -65,6 +65,11 @@ public class Editor : Runnable, IErrorReporter
     /// </summary>
     public const string Error = "Error";
 
+    /// <summary>
+    /// String to assign to popover data field so that we don't accidentally edit our own context menus!
+    /// </summary>
+    public const string? DesignerCorePopoverName = "CoreDesignerPopupMenu";
+
     /// <summary>
     /// Initializes a new instance of the <see cref="Editor"/> class.
     /// </summary>
@@ -1022,6 +1027,8 @@ private void CreateAndShowContextMenu(Mouse? m, Design? rightClicked)
         }
 
         var menu = new PopoverMenu(all.ToArray());
+        menu.Data = DesignerCorePopoverName;
+
         Point position;
         if (m != null && m.Position.HasValue)
         {