From 3e3f11d84f1d05fdf4ac4e9595648517b99438c5 Mon Sep 17 00:00:00 2001
From: Evan Ruiz <evan@musicalfluency.com>
Date: Wed, 29 Jan 2025 17:50:28 -0500
Subject: [PATCH] Path Geometry update fix for 4748 bug rerender on change for
 paths segments (#18025)

* Add failing Path Geometry update test

#4748 [BUG] Rerender on change for Paths, Segments and e.g.
Failing Test

* Fixes failing Path Geometry update test

Fixes #4748 [BUG] Rerender on change for Paths, Segments and e.g.
---
 src/Avalonia.Base/Media/PathGeometry.cs       |  2 +-
 .../Media/PathGeometryTests.cs                | 32 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 tests/Avalonia.Base.UnitTests/Media/PathGeometryTests.cs

diff --git a/src/Avalonia.Base/Media/PathGeometry.cs b/src/Avalonia.Base/Media/PathGeometry.cs
index bdfbfadce4..c07535c00b 100644
--- a/src/Avalonia.Base/Media/PathGeometry.cs
+++ b/src/Avalonia.Base/Media/PathGeometry.cs
@@ -35,7 +35,7 @@ namespace Avalonia.Media
         /// </summary>
         public PathGeometry()
         {
-            _figures = new PathFigures();
+            Figures = new PathFigures();
         }
 
         /// <summary>
diff --git a/tests/Avalonia.Base.UnitTests/Media/PathGeometryTests.cs b/tests/Avalonia.Base.UnitTests/Media/PathGeometryTests.cs
new file mode 100644
index 0000000000..9648187e61
--- /dev/null
+++ b/tests/Avalonia.Base.UnitTests/Media/PathGeometryTests.cs
@@ -0,0 +1,32 @@
+using Avalonia.Media;
+using Xunit;
+
+namespace Avalonia.Base.UnitTests.Media;
+
+public class PathGeometryTests
+{
+    [Fact]
+    public void PathGeometry_Triggers_Invalidation_On_Figures_Add()
+    {
+        var segment = new PolyLineSegment()
+        {
+            Points = [new Point(1, 1), new Point(2, 2)]
+        };
+
+        var figure = new PathFigure()
+        {
+            Segments = [segment],
+            IsClosed = false,
+            IsFilled = false,
+        };
+        
+        var target = new PathGeometry();
+
+        var changed = false;
+
+        target.Changed += (_, _) => { changed = true; };
+        
+        target.Figures?.Add(figure);
+        Assert.True(changed);
+    }
+}