Detect and handle the case of our own typo correction extension being installed in parallel

lib/typoFixer.js

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 let {Prefs} = require("prefs");
 let {WindowObserver} = require("windowObserver");
 let {getSchemeCorrection, isKnownScheme, getDomainCorrection, getDomainReferral, onWhitelistEntryAdded} = require("typoRules");
 let {processTypedDomain, processDomainCorrection, processFalsePositive} = require("typoCollector");
 let appIntegration = require("typoAppIntegration");
 let netError = require("typoNetError");
 
-
 let typoWindowObserver = null;
 
 exports.attachWindowObserver = attachWindowObserver;
 function attachWindowObserver()
 {

[Wladimir Palant, 2012/11/19 07:30:02]

Please check whether the observer is already attached:

if (typoWindowObserver)
  return;

+  if (typoWindowObserver)
+    return;
+  
   // Attach our handlers to all browser windows
   typoWindowObserver = new WindowObserver(
   {
     applyToWindow: function(window)
     {
       if (!appIntegration.isKnownWindow(window))
         return;
       
       netError.applyToWindow(window);
       appIntegration.applyToWindow(window, correctURL);
     },
 
     removeFromWindow: function(window)
     {
       if (!appIntegration.isKnownWindow(window))
         return;
       
       netError.removeFromWindow(window);
       appIntegration.removeFromWindow(window);
     }
   });
 }
 attachWindowObserver();
 
 exports.detachWindowObserver = detachWindowObserver;
 function detachWindowObserver()
 {

[Wladimir Palant, 2012/11/19 07:30:02]

Please check whether the observer is already detached:

if (!typoWindowObserver)
  return;

+  if (!typoWindowObserver)
+    return;
+  
   // Detach our handlers from all browser windows
   typoWindowObserver.shutdown();
   typoWindowObserver = null;
 }
 
 function parseURL(url)
 {
   if (/^\s*((?:\w+:)?\/*(?:[^\/#]*@)?)([^\/:#]*)/.test(url))
     return [RegExp.$1, RegExp.$2.toLowerCase(), RegExp.rightContext];
   else
@@ skipping 147 matching lines @@
     stringBundle = Services.strings.createBundle("chrome://" + require("info").addonName + "/locale/typo.properties?" + Math.random());
   let result = [
     stringBundle.GetStringFromName("urlfixer.isItCorrect"),
     stringBundle.GetStringFromName("urlfixer.yes"),
     stringBundle.GetStringFromName("urlfixer.no")
   ];
 
   getInfobarTexts = function() result;
   return getInfobarTexts();
 }