From b1d34acdc6d5f147dedfca202d424fa51235b348 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Mon, 11 May 2020 10:35:41 +0200
Subject: [PATCH] Handle requesting children of unrealized containers.

---
 src/Avalonia.Controls/TreeView.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/TreeView.cs b/src/Avalonia.Controls/TreeView.cs
index 4c45dbfbf7..165276c539 100644
--- a/src/Avalonia.Controls/TreeView.cs
+++ b/src/Avalonia.Controls/TreeView.cs
@@ -395,7 +395,7 @@ namespace Avalonia.Controls
         private void OnSelectionModelChildrenRequested(object sender, SelectionModelChildrenRequestedEventArgs e)
         {
             var container = ItemContainerGenerator.Index.ContainerFromItem(e.Source) as ItemsControl;
-            e.Children = container.GetObservable(ItemsProperty);
+            e.Children = container?.GetObservable(ItemsProperty);
         }
 
         private TreeViewItem GetContainerInDirection(