Issue 3780 - wait for the loading of filters and only afterwards start to fetch pages

lib/crawler.js

 /*
  * This Source Code is subject to the terms of the Mozilla Public License
  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/.
  */
 
 /**
  * @module crawler
  */
 
@@ skipping 193 matching lines @@
  *    Maximum number of tabs to be opened
  * @param {String} targetURL
  *    URL that should receive the results
  * @param {Function} onDone
  *    The callback which is called after finishing of crawling of all URLs.
  */
 function run(window, urls, timeout, maxtabs, targetURL, onDone)
 {
   new Promise((resolve, reject) =>
   {
-    if (FilterStorage.subscriptions.length > 0 && !FilterStorage._loading)
+    if (FilterStorage.subscriptions.length > 0)
     {
       resolve();
       return;
     }
-    FilterNotifier.addListener((action, item, newValue, oldValue) =>
+    let onFiltersLoaded = (action, item, newValue, oldValue) =>
     {
       if (action == "load")
       {
+        FilterNotifier.removeListener(onFiltersLoaded);
         resolve();
       }
-    });
-  }).then(() => crawl_urls(window, urls, timeout, maxtabs, targetURL, onDone)).catch(reportException);
+    };
+    FilterNotifier.addListener(onFiltersLoaded);
+  }).then(() => crawl_urls(window, urls, timeout, maxtabs, targetURL, onDone))
+  .catch(reportException);
 }
 exports.run = run;
 
 /**
  * Spawns a {Task} task to crawl each url from `urls` argument and calls
  * `onDone` when all tasks are finished.
  * @param {Window} window
  *   The browser window we're operating in
  * @param {String[]} urls
  *   URLs to be crawled
@@ skipping 116 matching lines @@
 
 function reportException(e)
 {
   let stack = "";
   if (e && typeof e == "object" && "stack" in e)
     stack = e.stack + "\n";
 
   Cu.reportError(e);
   dump(e + "\n" + stack + "\n");
 }