[iOS] Fix crash closing Popup with WebView

src/Controls/samples/Controls.Sample.UITests/Issues/Issue21846.xaml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue21846"
+             xmlns:ns="clr-namespace:Maui.Controls.Sample.Issues">
+  <ScrollView>
+    <VerticalStackLayout
+      Padding="30,0"
+      Spacing="25">
+      <Button
+        x:Name="TestButton"
+        AutomationId="OpenModalButton"
+        Text="Open"
+        Clicked="OnButtonClicked" />
+    </VerticalStackLayout>
+  </ScrollView>
+</ContentPage>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue21846.xaml.cs

@@ -0,0 +1,22 @@
+using System;
+using Microsoft.Maui;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 21846, "Fix crash closing Popup with WebView", PlatformAffected.iOS)]
+	public partial class Issue21846 : ContentPage
+	{
+		public Issue21846()
+		{
+			InitializeComponent();
+		}
+
+		async void OnButtonClicked(object sender, System.EventArgs e)
+		{
+			await Navigation.PushModalAsync(new Issue21846Modal());
+		}
+	}
+}

src/Controls/samples/Controls.Sample.UITests/Issues/Issue21846Modal.xaml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue21846Modal"
+             xmlns:ns="clr-namespace:Maui.Controls.Sample.Issues">
+  <ScrollView>
+    <Grid
+      RowDefinitions="*, Auto"
+      Padding="30,0">
+      <WebView 
+        x:Name="TestWebView"
+        Source="https://www.microsoft.com"/>
+      <Button
+        Grid.Row="1"
+        AutomationId="CloseModalButton"
+        Text="Close"
+        Clicked="OnButtonClicked" />
+    </Grid>
+  </ScrollView>
+</ContentPage>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue21846Modal.xaml.cs

@@ -0,0 +1,34 @@
+using System;
+using Microsoft.Maui;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	public partial class Issue21846Modal : ContentPage
+	{
+		public Issue21846Modal()
+		{
+			InitializeComponent();
+
+			BindingContext = this;
+		}
+
+		async void OnButtonClicked(object sender, System.EventArgs e)
+		{
+			if (TestWebView is IElement visualElement)
+			{
+				if (visualElement.Handler != null)
+				{
+					if (visualElement.Handler is IDisposable disposableHandler)
+						disposableHandler.Dispose();
+
+					visualElement.Handler.DisconnectHandler();
+				}
+			}
+
+			await Navigation.PopModalAsync();
+		}
+	}
+}

src/Controls/tests/UITests/Tests/Issues/Issue21846.cs

@@ -0,0 +1,28 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.AppiumTests.Issues
+{
+	public class Issue21846 : _IssuesUITest
+	{
+		public Issue21846(TestDevice device) : base(device)
+		{
+		}
+
+		public override string Issue => "Fix crash closing Popup with WebView";
+
+		[Test]
+		[Category(UITestCategories.WebView)]
+		public void WebViewNoCrashPopup()
+		{
+			this.IgnoreIfPlatforms([TestDevice.Android, TestDevice.Windows]);
+
+			App.WaitForElement("OpenModalButton");
+			App.Click("OpenModalButton");
+
+			App.WaitForElement("CloseModalButton");
+			App.Click("CloseModalButton");
+		}
+	}
+}

src/Core/src/Platform/iOS/MauiWebViewNavigationDelegate.cs

@@ -26,12 +26,17 @@ public MauiWebViewNavigationDelegate(IWebViewHandler handler)
 		public void DidFinishNavigation(WKWebView webView, WKNavigation navigation)
 		{
 			var handler = Handler;
+
+			if (handler is null || !handler.IsConnected())
+				return;
+
+			var platformView = handler?.PlatformView;
 			var virtualView = handler?.VirtualView;
 
-			if (handler == null || virtualView == null)
+			if (platformView is null || virtualView is null)
 				return;
 
-			handler.PlatformView?.UpdateCanGoBackForward(handler.VirtualView);
+			platformView.UpdateCanGoBackForward(virtualView);
 
 			if (webView.IsLoading)
 				return;
@@ -47,49 +52,67 @@ public void DidFinishNavigation(WKWebView webView, WKNavigation navigation)
 			if (handler is WebViewHandler webViewHandler)
 				webViewHandler.ProcessNavigatedAsync(url).FireAndForget();
 			else
-				handler.PlatformView?.UpdateCanGoBackForward(virtualView);
+				platformView.UpdateCanGoBackForward(virtualView);
 		}
 
 		[Export("webView:didFailNavigation:withError:")]
 		public void DidFailNavigation(WKWebView webView, WKNavigation navigation, NSError error)
 		{
 			var handler = Handler;
+
+			if (handler is null || !handler.IsConnected())
+				return;
+
+			var platformView = handler?.PlatformView;
 			var virtualView = handler?.VirtualView;
 
-			if (handler == null || virtualView == null)
+			if (platformView is null || virtualView is null)
 				return;
 
 			var url = GetCurrentUrl();
 
 			virtualView.Navigated(_lastEvent, url, WebNavigationResult.Failure);
 
-			handler.PlatformView?.UpdateCanGoBackForward(virtualView);
+			platformView.UpdateCanGoBackForward(virtualView);
 		}
 
 		[Export("webView:didFailProvisionalNavigation:withError:")]
 		public void DidFailProvisionalNavigation(WKWebView webView, WKNavigation navigation, NSError error)
 		{
 			var handler = Handler;
+
+			if (handler is null || !handler.IsConnected())
+				return;
+
+			var platformView = handler?.PlatformView;
 			var virtualView = handler?.VirtualView;
 
-			if (handler == null || virtualView == null)
+			if (platformView is null || virtualView is null)
 				return;
 
 			var url = GetCurrentUrl();
 
 			virtualView.Navigated(_lastEvent, url, WebNavigationResult.Failure);
 
-			handler.PlatformView?.UpdateCanGoBackForward(virtualView);
+			platformView.UpdateCanGoBackForward(virtualView);
 		}
 
 		// https://stackoverflow.com/questions/37509990/migrating-from-uiwebview-to-wkwebview
 		[Export("webView:decidePolicyForNavigationAction:decisionHandler:")]
 		public void DecidePolicy(WKWebView webView, WKNavigationAction navigationAction, Action<WKNavigationActionPolicy> decisionHandler)
 		{
 			var handler = Handler;
+
+			if (handler is null || !handler.IsConnected())
+			{
+				decisionHandler.Invoke(WKNavigationActionPolicy.Cancel);
+				return;
+			}
+
+			var platformView = handler?.PlatformView;
 			var virtualView = handler?.VirtualView;
 
-			if (handler == null || virtualView == null)
+			if (platformView is null || virtualView is null)
 			{
 				decisionHandler.Invoke(WKNavigationActionPolicy.Cancel);
 				return;
@@ -130,7 +153,7 @@ public void DecidePolicy(WKWebView webView, WKNavigationAction navigationAction,
 			var lastUrl = request.Url.ToString();
 
 			bool cancel = virtualView.Navigating(navEvent, lastUrl);
-			handler.PlatformView?.UpdateCanGoBackForward(virtualView);
+			platformView.UpdateCanGoBackForward(virtualView);
 			decisionHandler(cancel ? WKNavigationActionPolicy.Cancel : WKNavigationActionPolicy.Allow);
 		}