Updated FormattedStringExtensions.cs (#25892)

src/Controls/src/Core/Platform/Android/Extensions/FormattedStringExtensions.cs

@@ -204,7 +204,8 @@ namespace Microsoft.Maui.Controls.Platform
 					var spanStartX = (int)layout.GetPrimaryHorizontal(startOffset);
 
 					var endOffset = (curLine == spanEndLine) ? spanEndOffset : lineVisibleEndOffset;
-					var spanEndX = (int)layout.GetSecondaryHorizontal(endOffset);
+					var validEndOffset = System.Math.Min(endOffset, layout.GetLineEnd(curLine));
+					var spanEndX = (int)layout.GetSecondaryHorizontal(validEndOffset);
 
 					var spanWidth = spanEndX - spanStartX;
 					var spanLeftX = spanStartX;

src/Controls/tests/TestCases.HostApp/Issues/Issue25836.cs

@@ -0,0 +1,40 @@
+using System.ComponentModel;
+using Microsoft.Maui.Controls.PlatformConfiguration;
+using Microsoft.Maui.Controls.PlatformConfiguration.iOSSpecific;
+using Entry = Microsoft.Maui.Controls.Entry;
+
+namespace Maui.Controls.Sample.Issues
+{
+
+	[Issue(IssueTracker.Github, 25836, "Span with tail truncation and paragraph breaks with exception", PlatformAffected.Android)]
+	public class Issue25836 : ContentPage
+	{
+		public Issue25836()
+		{
+			var span = new Span
+			{
+				Text =
+				" Mi augue molestie ligula lobortis enim Velit, in. \n Imperdiet eu dignissim odio. Massa erat Hac inceptos facilisis nibh " +
+				" Interdum massa Consectetuer risus sociis molestie facilisi enim. Class gravida. \n Gravida sociosqu cras Quam velit, suspendisse" +
+				"  leo auctor odio integer primis dui potenti dolor faucibus augue justo morbi ornare sem. "
+			};
+
+			var formattedString = new FormattedString();
+			formattedString.Spans.Add(span);
+
+			var label = new Label
+			{
+				AutomationId = "Label",
+				LineBreakMode = LineBreakMode.TailTruncation,
+				VerticalOptions = LayoutOptions.Start,
+				FormattedText = formattedString,
+				MaxLines = 3
+			};
+
+			var layout = new StackLayout();
+			layout.Children.Add(label);
+
+			Content = layout;
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue25836.cs

@@ -0,0 +1,22 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue25836 : _IssuesUITest
+	{
+		public Issue25836(TestDevice testDevice) : base(testDevice)
+		{
+		}
+
+		public override string Issue => "Span with tail truncation and paragraph breaks with exception";
+
+		[Test]
+		[Category(UITestCategories.Label)]
+		public void ExceptionShouldNotBeThrown()
+		{
+			App.WaitForElement("Label");
+		}
+	}
+}