Issue 6113 - Workaround buggy windows.create in Firefox 51

lib/filterComposer.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 206 matching lines @@
 {
   return browser.windows.create({
     url: browser.extension.getURL("composer.html"),
     left: 50,
     top: 50,
     width: 420,
     height: 200,
     type: "popup"
   }).then(window =>
   {
+    // The windows.create API with versions of Firefox < 52 doesn't seem to
+    // populate the tabs property reliably.
+    if ("tabs" in window)
+      return window;
+    else
+      return browser.windows.get(window.id, {populate: true});
+  }).then(window =>
+  {
     let popupPageId = window.tabs[0].id;
 
     let doInitAttempt = 0;
     let doInit = () =>
     {
       doInitAttempt += 1;
       if (doInitAttempt > 3)
         return;
 
       browser.tabs.sendMessage(popupPageId, {
@@ skipping 67 matching lines @@
 {
   return quoteCSS(message.CSS);
 });
 
 ext.pages.onLoading.addListener(page =>
 {
   // A newly opened tab that is still loading has its URL set to about:blank
   if (/^https?:/.test(page.url.protocol))
     page.sendMessage({type: "composer.content.finished"});
 });