From f639cf2145ecfa35ea31b91c05774a74f40923fa Mon Sep 17 00:00:00 2001
From: YUKI Hiroshi <shimoda@clear-code.com>
Date: Tue, 17 Mar 2015 17:52:08 +0900
Subject: [PATCH] Don't update ensureElementIsVisible() twice

---
 content/treestyletab/windowHelper.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/content/treestyletab/windowHelper.js b/content/treestyletab/windowHelper.js
index 99efc4c2..60362a33 100644
--- a/content/treestyletab/windowHelper.js
+++ b/content/treestyletab/windowHelper.js
@@ -554,6 +554,7 @@ var TreeStyleTabWindowHelper = {
 		 */
 		{
 			let scrollbox = aTabBrowser.treeStyleTab.scrollBox;
+			if (!scrollbox.__treestyletab__ensureElementIsVisible) {
 			scrollbox.__treestyletab__ensureElementIsVisible = scrollbox.ensureElementIsVisible;
 			scrollbox.ensureElementIsVisible = function(...aArgs) {
 				var treeStyleTab = TreeStyleTabService.getTabBrowserFromChild(this).treeStyleTab;
@@ -568,6 +569,7 @@ var TreeStyleTabWindowHelper = {
 
 				this.__treestyletab__ensureElementIsVisible.apply(this, aArgs);
 			};
+			}
 		}
 
 		{