From 1a9ed2052aaeea6386a12523239d7d22aeb6dae3 Mon Sep 17 00:00:00 2001
From: John Boyer <git@johntboyer.com>
Date: Mon, 10 Oct 2022 18:04:54 +1100
Subject: [PATCH] Fixed DataGrid not properly removing multiple items on
 collection changed.

---
 .../Collections/DataGridCollectionView.cs            | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/Avalonia.Controls.DataGrid/Collections/DataGridCollectionView.cs b/src/Avalonia.Controls.DataGrid/Collections/DataGridCollectionView.cs
index 41d7883047..30517f4b00 100644
--- a/src/Avalonia.Controls.DataGrid/Collections/DataGridCollectionView.cs
+++ b/src/Avalonia.Controls.DataGrid/Collections/DataGridCollectionView.cs
@@ -3413,13 +3413,15 @@ namespace Avalonia.Collections
                 return;
             }
             
-            object removedItem = args.OldItems?[0];
-
             // fire notifications for removes
-            if (args.Action == NotifyCollectionChangedAction.Remove ||
-                args.Action == NotifyCollectionChangedAction.Replace)
+            if (args.OldItems != null && 
+                (args.Action == NotifyCollectionChangedAction.Remove ||
+                args.Action == NotifyCollectionChangedAction.Replace))
             {
-                ProcessRemoveEvent(removedItem, args.Action == NotifyCollectionChangedAction.Replace);
+                foreach (var removedItem in args.OldItems)
+                {
+                    ProcessRemoveEvent(removedItem, args.Action == NotifyCollectionChangedAction.Replace);
+                }
             }
 
             // fire notifications for adds