Fixed a crash that would sometime occur when dragging a tab outside the app (#1941)

Author: gave92

Files/UserControls/MultitaskingControl/HorizontalMultitaskingControl.xaml.cs

@@ -328,7 +328,7 @@ private async void TabStrip_TabDroppedOutside(TabView sender, TabViewTabDroppedO
             }
 
             var indexOfTabViewItem = sender.TabItems.IndexOf(args.Tab);
-            var tabViewItemPath = ((((args.Item as TabItem).Content as Grid).Children[0] as Frame).Content as IShellPage).NavigationToolbar.PathControlDisplayText;
+            var tabViewItemPath = ((((args.Item as TabItem).Content as Grid).Children[0] as Frame).Tag as TabItemContent).NavigationArg;
             var selectedTabViewItemIndex = sender.SelectedIndex;
             RemoveTab(args.Item as TabItem);
             if (!await Interaction.OpenPathInNewWindow(tabViewItemPath))
@@ -338,17 +338,16 @@ private async void TabStrip_TabDroppedOutside(TabView sender, TabViewTabDroppedO
             }
         }
 
-        private async void RemoveTab(TabItem tabItem)
+        private void RemoveTab(TabItem tabItem)
         {
             if (Items.Count == 1)
             {
                 MainPage.AppInstances.Remove(tabItem);
-                await ApplicationView.GetForCurrentView().TryConsolidateAsync();
+                App.CloseApp();
             }
             else if (Items.Count > 1)
             {
                 Items.Remove(tabItem);
-                //App.InteractionViewModel.TabStripSelectedIndex = verticalTabView.SelectedIndex;
             }
         }
     }