From 608efb11403be129f73ca0871aa348df1ad99c30 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 7 Apr 2020 15:06:28 +0200
Subject: [PATCH] Invalidate path on geometry change.

Fixes #2680.
---
 src/Avalonia.Controls/Shapes/Path.cs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/Avalonia.Controls/Shapes/Path.cs b/src/Avalonia.Controls/Shapes/Path.cs
index 84c3ededa5..3fd84c0c7b 100644
--- a/src/Avalonia.Controls/Shapes/Path.cs
+++ b/src/Avalonia.Controls/Shapes/Path.cs
@@ -1,3 +1,5 @@
+using System;
+using Avalonia.Data;
 using Avalonia.Media;
 
 namespace Avalonia.Controls.Shapes
@@ -10,6 +12,7 @@ namespace Avalonia.Controls.Shapes
         static Path()
         {
             AffectsGeometry<Path>(DataProperty);
+            DataProperty.Changed.AddClassHandler<Path>((o, e) => o.DataChanged(e));
         }
 
         public Geometry Data
@@ -19,5 +22,26 @@ namespace Avalonia.Controls.Shapes
         }
 
         protected override Geometry CreateDefiningGeometry() => Data;
+
+        private void DataChanged(AvaloniaPropertyChangedEventArgs e)
+        {
+            var oldGeometry = (Geometry)e.OldValue;
+            var newGeometry = (Geometry)e.NewValue;
+
+            if (oldGeometry is object)
+            {
+                oldGeometry.Changed -= GeometryChanged;
+            }
+
+            if (newGeometry is object)
+            {
+                newGeometry.Changed += GeometryChanged;
+            }
+        }
+
+        private void GeometryChanged(object sender, EventArgs e)
+        {
+            InvalidateGeometry();
+        }
     }
 }