From 261e4775229d84bcee3a93ba51c38f21bdd5e2b2 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Thu, 9 Jan 2020 10:23:29 +0100
Subject: [PATCH] ItemsRepeater fix.

* Remove item from repeater children if there is no itemtemplate when being recycled.

Ported from https://github.com/microsoft/microsoft-ui-xaml/commit/c4d4d9995a0ee7df27aac11f875538dd4fbe14fb
---
 src/Avalonia.Controls/Repeater/ViewManager.cs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/Repeater/ViewManager.cs b/src/Avalonia.Controls/Repeater/ViewManager.cs
index e4fc1158ef..f4588787e8 100644
--- a/src/Avalonia.Controls/Repeater/ViewManager.cs
+++ b/src/Avalonia.Controls/Repeater/ViewManager.cs
@@ -110,7 +110,19 @@ namespace Avalonia.Controls
         public void ClearElementToElementFactory(IControl element)
         {
             _owner.OnElementClearing(element);
-            _owner.ItemTemplateShim?.RecycleElement(_owner, element);
+
+            if (_owner.ItemTemplateShim != null)
+            {
+                _owner.ItemTemplateShim.RecycleElement(_owner, element);
+            }
+            else
+            {
+                // No ItemTemplate to recycle to, remove the element from the children collection.
+                if (!_owner.Children.Remove(element))
+                {
+                    throw new InvalidOperationException("ItemsRepeater's child not found in its Children collection.");
+                }
+            }
 
             var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
             virtInfo.MoveOwnershipToElementFactory();