[Android] Fix WebView in a grid expands beyond it's cell

src/Controls/tests/TestCases.HostApp/Issues/Issue32030.cs

@@ -0,0 +1,58 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 32030, "Android - WebView in a grid expands beyond it's cell", PlatformAffected.Android)]
+
+public class Issue32030 : ContentPage
+{
+    WebView webView;
+
+    public Issue32030()
+    {
+        // Create Grid
+        var grid = new Grid
+        {
+            RowDefinitions = new RowDefinitionCollection
+            {
+                new RowDefinition { Height = new GridLength(50) },
+                new RowDefinition { Height = GridLength.Star },
+                new RowDefinition { Height = new GridLength(50) }
+            }
+        };
+
+        // Create "above webview" Label
+        var topLabel = new Label
+        {
+            Text = "Above webview",
+            AutomationId = "TopLabel",
+            HorizontalTextAlignment = TextAlignment.Center
+        };
+        grid.Add(topLabel);
+        Grid.SetRow(topLabel, 0);
+
+        // Create WebView
+        webView = new WebView
+        {
+            BackgroundColor = Colors.BurlyWood
+        };
+        webView.Navigated += WebView_Navigated;
+        grid.Add(webView);
+        Grid.SetRow(webView, 1);
+
+        // Create "below webview" Label
+        var bottomLabel = new Label
+        {
+            Text = "Below webview",
+            HorizontalTextAlignment = TextAlignment.Center
+        };
+        grid.Add(bottomLabel);
+        Grid.SetRow(bottomLabel, 2);
+
+        // Set the grid as the page content
+        Content = grid;
+    }
+
+    async void WebView_Navigated(object sender, WebNavigatedEventArgs e)
+    {
+        await DisplayAlert("Navigation Completed", $"WebView navigated to: {e.Url}", "OK");
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue32030.cs

@@ -0,0 +1,18 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+public class Issue32030 : _IssuesUITest
+{
+    public Issue32030(TestDevice device) : base(device) { }
+
+    public override string Issue => "Android - WebView in a grid expands beyond it's cell";
+    [Test]
+    [Category(UITestCategories.WebView)]
+    public void VerifyWebViewStaysWithinGridCell()
+    {
+        App.WaitForElement("TopLabel");
+        VerifyScreenshot();
+    }
+}

src/Core/src/Platform/Android/MauiWebViewClient.cs

@@ -57,7 +57,7 @@ public override void OnPageFinished(WebView? view, string? url)
 			bool navigate = _navigationResult != WebNavigationResult.Failure || !GetValidUrl(url).Equals(_lastUrlNavigatedCancel, StringComparison.OrdinalIgnoreCase);
 			_lastUrlNavigatedCancel = _navigationResult == WebNavigationResult.Cancel ? url : null;
 
-			if (navigate)
+			if (navigate && !IsBlankNavigation(url))
 				handler.VirtualView.Navigated(handler.CurrentNavigationEvent, GetValidUrl(url), _navigationResult);
 
 			handler.SyncPlatformCookiesToVirtualView(url);
@@ -96,6 +96,15 @@ public override bool OnRenderProcessGone(WebView? view, RenderProcessGoneDetail?
 		bool NavigatingCanceled(string? url) =>
 			!_handler.TryGetTarget(out var handler) || handler.NavigatingCanceled(url);
 
+		static bool IsBlankNavigation(string? url)
+		{
+			if (string.IsNullOrWhiteSpace(url))
+				return false;
+
+			// Check if URL is about:blank (case insensitive)
+			return string.Equals(url.Trim(), "about:blank", StringComparison.OrdinalIgnoreCase);
+		}
+
 		static string GetValidUrl(string? url)
 		{
 			if (string.IsNullOrEmpty(url))

src/Core/src/Platform/Android/WebViewExtensions.cs

@@ -25,6 +25,10 @@ public static void UpdateSource(this AWebView platformWebView, IWebView webView,
 					platformWebView.UpdateCanGoBackForward(webView);
 				}
 			}
+			else
+			{
+				platformWebView.LoadUrl("about:blank");
+			}
 		}
 
 		public static void UpdateSettings(this AWebView platformWebView, IWebView webView, bool javaScriptEnabled, bool domStorageEnabled)