Merge pull request #2230 from BDisp/menubar-without-menuitems-fix-2228

Fixes #2228. Crash when attempting to open menu bar item with action but no menu items assigned.

Terminal.Gui/Views/Menu.cs

@@ -1182,7 +1182,9 @@ namespace Terminal.Gui {
 		public virtual void OnMenuOpened ()
 		{
 			MenuItem mi = null;
-			if (openCurrentMenu.barItems.Children != null && openCurrentMenu?.current > -1) {
+			if (openCurrentMenu.barItems.Children != null && openCurrentMenu.barItems.Children.Length > 0
+				&& openCurrentMenu?.current > -1) {
+
 				mi = openCurrentMenu.barItems.Children [openCurrentMenu.current];
 			} else if (openCurrentMenu.barItems.IsTopLevel) {
 				mi = openCurrentMenu.barItems;

UnitTests/MenuTests.cs

@@ -1498,7 +1498,7 @@ Edit
 			Assert.True (menu.IsMenuOpen);
 			Assert.False (tf.HasFocus);
 			Application.Top.Redraw (Application.Top.Bounds);
-			TestHelpers.AssertDriverContentsAre (expectedMenu.expectedSubMenuOpen(0), output);
+			TestHelpers.AssertDriverContentsAre (expectedMenu.expectedSubMenuOpen (0), output);
 
 			// Right - Edit has no sub menu; this tests that no sub menu shows
 			Assert.True (menu.openMenu.ProcessKey (new KeyEvent (Key.CursorRight, new KeyModifiers ())));
@@ -1636,5 +1636,23 @@ Edit
 00000000000000
 00000000000000", attributes);
 		}
+
+		[Fact, AutoInitShutdown]
+		public void MenuBar_With_Action_But_Without_MenuItems_Not_Throw ()
+		{
+			var menu = new MenuBar (
+			    menus: new []
+			    {
+				new MenuBarItem { Title = "Test 1", Action = () => { } },
+				new MenuBarItem { Title = "Test 2", Action = () => { } },
+			    });
+
+			Application.Top.Add (menu);
+			Application.Begin (Application.Top);
+
+			Assert.False (Application.Top.OnKeyDown (new KeyEvent (Key.AltMask, new KeyModifiers { Alt = true })));
+			Assert.True (menu.ProcessKey (new KeyEvent (Key.CursorRight, new KeyModifiers ())));
+			Assert.True (menu.ProcessKey (new KeyEvent (Key.CursorRight, new KeyModifiers ())));
+		}
 	}
 }