From 7ff0fe367e188ab73467cbfc12a1e11cdd7e71fb Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@users.noreply.github.com>
Date: Tue, 2 Jul 2024 15:21:01 +0200
Subject: [PATCH] Try to avoid NRE in TreeSelectedItemsBase.

---
 .../Selection/TreeSelectedItems.cs                           | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Avalonia.Controls.TreeDataGrid/Selection/TreeSelectedItems.cs b/src/Avalonia.Controls.TreeDataGrid/Selection/TreeSelectedItems.cs
index 19494388..ee25a7b3 100644
--- a/src/Avalonia.Controls.TreeDataGrid/Selection/TreeSelectedItems.cs
+++ b/src/Avalonia.Controls.TreeDataGrid/Selection/TreeSelectedItems.cs
@@ -56,7 +56,8 @@ public T? this[int index]
             {
                 for (var i = range.Begin; i <= range.End; ++i)
                 {
-                    yield return node.ItemsView![i];
+                    if (node.ItemsView is not null)
+                        yield return node.ItemsView[i];
                 }
             }
 
@@ -110,4 +111,4 @@ public TreeSelectedItems(TreeSelectionModelBase<T> root) : base(root) { }
                 yield return i;
         }
     }
-}
\ No newline at end of file
+}