Fix firing modal from appearing ios14 (#14240)

* Call Complete Pending Navigation

* - add additional check so we don't call complete too many times

src/Controls/src/Core/Compatibility/Handlers/NavigationPage/iOS/NavigationRenderer.cs

@@ -44,6 +44,7 @@ public class NavigationRenderer : UINavigationController, IPlatformViewHandler
 		bool _navigating = false;
 		VisualElement _element;
 		bool _uiRequestedPop; // User tapped the back button or swiped to navigate back
+		MauiNavigationDelegate NavigationDelegate => Delegate as MauiNavigationDelegate;
 
 		[Internals.Preserve(Conditional = true)]
 		public NavigationRenderer() : base(typeof(MauiControlsNavigationBar), null)
@@ -425,10 +426,19 @@ Task<bool> GetAppearedOrDisappearedTask(Page page)
 				CompletePendingNavigation(false);
 			};
 
+			if (NavigationDelegate is not null)
+				NavigationDelegate.WaitingForNavigationToFinish = true;
+
 			_removeLifecycleEvents = new ActionDisposable(() =>
 			{
+				// This ensures that we don't cause multiple calls to CompletePendingNavigation.
+				// Depending on circumstances (covered by modal page) CompletePendingNavigation 
+				// might get called from the Delegate vs the DidAppear/DidDisappear methods
+				// on the ParentingViewController.
 				parentViewController.Appearing -= appearing;
 				parentViewController.Disappearing -= disappearing;
+				if (NavigationDelegate is not null)
+					NavigationDelegate.WaitingForNavigationToFinish = false;
 			});
 
 			parentViewController.Appearing += appearing;
@@ -1008,6 +1018,8 @@ class MauiNavigationDelegate : UINavigationControllerDelegate
 			bool _finishedWithInitialNavigation;
 			readonly WeakReference<NavigationRenderer> _navigation;
 
+			public bool WaitingForNavigationToFinish { get; internal set; }
+
 			public MauiNavigationDelegate(NavigationRenderer navigationRenderer)
 			{
 				_navigation = new WeakReference<NavigationRenderer>(navigationRenderer);
@@ -1028,6 +1040,9 @@ public override void DidShowViewController(UINavigationController navigationCont
 						_finishedWithInitialNavigation = true;
 						np.SendNavigatedFromHandler(null);
 					}
+
+					if (WaitingForNavigationToFinish)
+						r.CompletePendingNavigation(true);
 				}
 			}
 

src/Controls/tests/DeviceTests/ControlsHandlerTestBase.cs

@@ -101,11 +101,13 @@ protected Task<TValue> GetValueAsync<TValue>(IElement view, Func<IPlatformViewHa
 		}
 
 		static SemaphoreSlim _takeOverMainContentSempahore = new SemaphoreSlim(1);
-		protected Task CreateHandlerAndAddToWindow<THandler>(IElement view, Func<THandler, Task> action, IMauiContext mauiContext = null)
+		protected Task CreateHandlerAndAddToWindow<THandler>(IElement view, Func<THandler, Task> action, IMauiContext mauiContext = null, TimeSpan? timeOut = null)
 			where THandler : class, IElementHandler
 		{
 			mauiContext ??= MauiContext;
 
+			timeOut ??= TimeSpan.FromSeconds(15);
+
 			return InvokeOnMainThreadAsync(async () =>
 			{
 				IWindow window = null;
@@ -180,15 +182,20 @@ await SetupWindowForTests<THandler>(window, async () =>
 #if WINDOWS
 						await Task.Delay(10);
 #endif
+
+						THandler handler;
+
 						if (typeof(THandler).IsAssignableFrom(window.Handler.GetType()))
-							await action((THandler)window.Handler);
+							handler = (THandler)window.Handler;
 						else if (typeof(THandler).IsAssignableFrom(window.Content.Handler.GetType()))
-							await action((THandler)window.Content.Handler);
+							handler = (THandler)window.Content.Handler;
 						else if (window.Content is ContentPage cp && typeof(THandler).IsAssignableFrom(cp.Content.Handler.GetType()))
-							await action((THandler)cp.Content.Handler);
+							handler = (THandler)cp.Content.Handler;
 						else
 							throw new Exception($"I can't work with {typeof(THandler)}");
 
+						await action(handler).WaitAsync(timeOut.Value);
+
 
 #if !WINDOWS
 						bool isActivated = controlsWindow?.IsActivated ?? false;