From 776f3eaa2ecee22f825b12e4920b09d66222bf00 Mon Sep 17 00:00:00 2001
From: Max Katz <maxkatz6@outlook.com>
Date: Fri, 15 Oct 2021 03:55:58 -0400
Subject: [PATCH] Merge pull request #6732 from
 AvaloniaUI/fixes/6729-itemsrepeater-reassign-items

ItemsRepeater: unsubscribe from ItemsSourceView before disposing it.
---
 .../Repeater/ItemsRepeater.cs                 |  6 ++---
 .../ItemsRepeaterTests.cs                     | 24 +++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 tests/Avalonia.Controls.UnitTests/ItemsRepeaterTests.cs

diff --git a/src/Avalonia.Controls/Repeater/ItemsRepeater.cs b/src/Avalonia.Controls/Repeater/ItemsRepeater.cs
index 01200e87e3..0ff8fcbd28 100644
--- a/src/Avalonia.Controls/Repeater/ItemsRepeater.cs
+++ b/src/Avalonia.Controls/Repeater/ItemsRepeater.cs
@@ -588,14 +588,14 @@ namespace Avalonia.Controls
                 throw new AvaloniaInternalException("Cannot set ItemsSourceView during layout.");
             }
 
-            ItemsSourceView?.Dispose();
-            ItemsSourceView = newValue;
-
             if (oldValue != null)
             {
                 oldValue.CollectionChanged -= OnItemsSourceViewChanged;
             }
 
+            ItemsSourceView?.Dispose();
+            ItemsSourceView = newValue;
+
             if (newValue != null)
             {
                 newValue.CollectionChanged += OnItemsSourceViewChanged;
diff --git a/tests/Avalonia.Controls.UnitTests/ItemsRepeaterTests.cs b/tests/Avalonia.Controls.UnitTests/ItemsRepeaterTests.cs
new file mode 100644
index 0000000000..321676abc0
--- /dev/null
+++ b/tests/Avalonia.Controls.UnitTests/ItemsRepeaterTests.cs
@@ -0,0 +1,24 @@
+using System.Collections.ObjectModel;
+using Xunit;
+
+namespace Avalonia.Controls.UnitTests
+{
+    public class ItemsRepeaterTests
+    {
+        [Fact]
+        public void Can_Reassign_Items()
+        {
+            var target = new ItemsRepeater();
+            target.Items = new ObservableCollection<string>();
+            target.Items = new ObservableCollection<string>();
+        }
+
+        [Fact]
+        public void Can_Reassign_Items_To_Null()
+        {
+            var target = new ItemsRepeater();
+            target.Items = new ObservableCollection<string>();
+            target.Items = null;
+        }
+    }
+}