Merge pull request #97 from pmsanford/master

Handle case where there's no previous focus

Terminal.Gui/Views/ListView.cs

@@ -180,6 +180,8 @@ namespace Terminal.Gui {
 			if (source == null)
 				throw new ArgumentNullException (nameof (source));
 			Source = MakeWrapper (source);
+			((ListWrapper) Source).Container = this;
+			((ListWrapper) Source).Driver = Driver;
 		}
 
 		bool allowsMarking;

Terminal.Gui/Views/Menu.cs

@@ -382,7 +382,7 @@ namespace Terminal.Gui {
 			selected = -1;
 			SetNeedsDisplay ();
 			SuperView.Remove (openMenu);
-			previousFocused.SuperView.SetFocus (previousFocused);
+			previousFocused?.SuperView?.SetFocus (previousFocused);
 			openMenu = null;
 		}