From 7465a15f87303425a4d6a04eca86f55a99d99c19 Mon Sep 17 00:00:00 2001
From: Tim Taubert <ttaubert@mozilla.com>
Date: Wed, 13 Aug 2014 14:42:29 +0200
Subject: [PATCH] Bug 1052756 - Fix Toolbox.destroy() to properly clean up with
 add-on targets r=Mossop

---
 browser/devtools/framework/toolbox.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/browser/devtools/framework/toolbox.js b/browser/devtools/framework/toolbox.js
index 1d3c7deb4635..b4bb85dba1dd 100644
--- a/browser/devtools/framework/toolbox.js
+++ b/browser/devtools/framework/toolbox.js
@@ -1358,8 +1358,10 @@ Toolbox.prototype = {
     // Destroying the walker and inspector fronts
     outstanding.push(this.destroyInspector().then(() => {
       // Removing buttons
-      this._pickerButton.removeEventListener("command", this._togglePicker, false);
-      this._pickerButton = null;
+      if (this._pickerButton) {
+        this._pickerButton.removeEventListener("command", this._togglePicker, false);
+        this._pickerButton = null;
+      }
     }));
 
     // Remove the host UI