From bae3220dd55e8a9812d5c356f4931a66015b9dd9 Mon Sep 17 00:00:00 2001
From: Moonchild <moonchild@palemoon.org>
Date: Fri, 17 Dec 2021 22:13:49 +0100
Subject: [PATCH] No issue - Fix a potential autocomplete issue.

Account for the case where we don't have a tree view in selectedIndex
setter which may break future autocompletes.
---
 toolkit/content/widgets/autocomplete.xml | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/toolkit/content/widgets/autocomplete.xml b/toolkit/content/widgets/autocomplete.xml
index da2bf678d4..885eb2eab4 100644
--- a/toolkit/content/widgets/autocomplete.xml
+++ b/toolkit/content/widgets/autocomplete.xml
@@ -780,7 +780,12 @@
                 onget="return this.tree.currentIndex;">
         <setter>
           <![CDATA[
-          this.tree.view.selection.select(val);
+          if (!this.tree.view) {
+            // We don't have a view? return "no selection".
+            val = -1;
+          } else {
+            this.tree.view.selection.select(val);
+          }
           if (this.tree.treeBoxObject.height > 0)
             this.tree.treeBoxObject.ensureRowIsVisible(val < 0 ? 0 : val);
           // Fire select event on xul:tree so that accessibility API