From fc33d6978caa52fbf543780ca94b71adcfa512d5 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 10 Sep 2019 00:39:01 +0200
Subject: [PATCH] Fix DevTools crash.

Make sure `HeaderPresenter` has its template applied before trying to get its child.
---
 src/Avalonia.Diagnostics/Views/TreePageView.xaml.cs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Diagnostics/Views/TreePageView.xaml.cs b/src/Avalonia.Diagnostics/Views/TreePageView.xaml.cs
index ddf1473b45..1326f718de 100644
--- a/src/Avalonia.Diagnostics/Views/TreePageView.xaml.cs
+++ b/src/Avalonia.Diagnostics/Views/TreePageView.xaml.cs
@@ -70,7 +70,10 @@ namespace Avalonia.Diagnostics.Views
         private void TreeViewItemTemplateApplied(object sender, TemplateAppliedEventArgs e)
         {
             var item = (TreeViewItem)sender;
-            var header = item.HeaderPresenter.Child;
+            var headerPresenter = item.HeaderPresenter;
+            headerPresenter.ApplyTemplate();
+
+            var header = headerPresenter.Child;
             header.PointerEnter += AddAdorner;
             header.PointerLeave += RemoveAdorner;
             item.TemplateApplied -= TreeViewItemTemplateApplied;