[iOS] Crash because of FontIconSource - fix

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue22682.cs

@@ -0,0 +1,23 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue22682 : _IssuesUITest
+	{
+		public override string Issue => "[iOS] FontIconSource crash";
+
+		public Issue22682(TestDevice device) : base(device)
+		{
+		}
+
+		[Test]
+		public void AppShouldNotCrash()
+		{
+			_ = App.WaitForElement("imageButton");
+
+			// The test passes if no crash is observed
+		}
+	}
+}

src/Controls/tests/TestCases/Issues/Issue22682.xaml

@@ -0,0 +1,10 @@
+<?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.Issue22682">
+    <ImageButton AutomationId="imageButton">
+        <ImageButton.Source>
+            <FontImageSource Size="24" Glyph="&#x00ad;"/>
+        </ImageButton.Source>
+    </ImageButton>
+</ContentPage>

src/Controls/tests/TestCases/Issues/Issue22682.xaml.cs

@@ -0,0 +1,15 @@
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 22682, "[iOS] FontIconSource crash", PlatformAffected.iOS)]
+	public partial class Issue22682 : ContentPage
+	{
+		public Issue22682()
+		{
+			InitializeComponent();
+		}
+	}
+}

src/Core/src/ImageSources/iOS/ImageSourceExtensions.cs

@@ -21,10 +21,20 @@ public static partial class ImageSourceExtensions
 			var font = fontManager.GetFont(imageSource.Font);
 			var color = (imageSource.Color ?? Colors.White).ToPlatform();
 			var glyph = (NSString)imageSource.Glyph;
-#pragma warning disable CS8604
+
+			if(string.IsNullOrWhiteSpace(imageSource.Glyph))
+			{
+				return null;
+			}
+
 			var attString = new NSAttributedString(glyph, font, color);
 			var imagesize = glyph.GetSizeUsingAttributes(attString.GetUIKitAttributes(0, out _)!);
-#pragma warning restore CS8604
+
+			if (imagesize.Width <= 0 || imagesize.Height <= 0)
+			{
+				return null;
+			}
+
 			UIGraphics.BeginImageContextWithOptions(imagesize, false, scale);
 			var ctx = new NSStringDrawingContext();