From d8e1951698e6f9106b733354c39524dad91f427c Mon Sep 17 00:00:00 2001
From: Richard Pospesel <richard@torproject.org>
Date: Wed, 16 Oct 2019 15:06:54 -0700
Subject: [PATCH] Bug 31920: Fix Security Level panel when its toolbar button
 moves to overflow

Simply removed the 'clever' caching of the underlying toolbar button
element. Now, each time the button is needed it is queried from the
underlying document.

A correct, but more complicated, fix would be to determine when the
toolbar button had been moved to the overflow menu and then update our
cached reference. However, this would be super brittle and would
break once another way to move the toolbar button is added in the
future.

In the end, caching something so infrequently queried is not worth the
complexity.
---
 .../securitylevel/content/securityLevel.js    | 23 ++++---------------
 1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/browser/components/securitylevel/content/securityLevel.js b/browser/components/securitylevel/content/securityLevel.js
index e0fc64621b489..280a8c2156d14 100644
--- a/browser/components/securitylevel/content/securityLevel.js
+++ b/browser/components/securitylevel/content/securityLevel.js
@@ -62,8 +62,6 @@ const SecurityLevelPrefs = {
 
 const SecurityLevelButton = {
   _securityPrefsBranch : null,
-  _button : null,
-  _anchor : null,
 
   _populateXUL : function(securityLevelButton) {
     if (securityLevelButton != null) {
@@ -95,23 +93,14 @@ const SecurityLevelButton = {
   },
 
   get button() {
-    if (this._button) {
-      return this._button;
-    }
-
     let button = document.getElementById("security-level-button");
     if (!button) {
       return null;
     }
-
-    return this._button = button;
+    return button;
   },
 
   get anchor() {
-    if (this._anchor) {
-      return this._anchor;
-    }
-
     let anchor = document.getAnonymousElementByAttribute(this.button, "class",
                                                    "toolbarbutton-icon");
     if (!anchor) {
@@ -119,13 +108,14 @@ const SecurityLevelButton = {
     }
 
     anchor.setAttribute("consumeanchor", SecurityLevelButton.button.id);
-    return this._anchor = anchor;
+    return anchor;
   },
 
   init : function() {
     // set the initial class based off of the current pref
-    this._populateXUL(this.button);
-    this._configUIFromPrefs(this.button);
+    let button = this.button;
+    this._populateXUL(button);
+    this._configUIFromPrefs(button);
 
     this._securityPrefsBranch = Services.prefs.getBranch("extensions.torbutton.");
     this._securityPrefsBranch.addObserver("", this, false);
@@ -167,9 +157,6 @@ const SecurityLevelButton = {
     if (aNode.id == "security-level-button" && !aWasRemoval) {
       this._populateXUL(aNode);
       this._configUIFromPrefs(aNode);
-      // clear out our cached elements as they seem to be recreated when the UI is customized
-      delete this._button;
-      delete this._anchor;
     }
   },
 
-- 
GitLab