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[or-cvs] r15413: Update nsSessionStore.js and diff to firefox 2.0.0.14. Add n (torbutton/trunk/src/components)



Author: mikeperry
Date: 2008-06-22 05:39:28 -0400 (Sun, 22 Jun 2008)
New Revision: 15413

Added:
   torbutton/trunk/src/components/nsSessionStore2.js
   torbutton/trunk/src/components/nsSessionStore3.js
Removed:
   torbutton/trunk/src/components/nsSessionStore.js
Modified:
   torbutton/trunk/src/components/nsSessionStore.diff
Log:

Update nsSessionStore.js and diff to firefox 2.0.0.14. Add
nsSessionStore.js from FF3.0.



Modified: torbutton/trunk/src/components/nsSessionStore.diff
===================================================================
--- torbutton/trunk/src/components/nsSessionStore.diff	2008-06-22 09:35:24 UTC (rev 15412)
+++ torbutton/trunk/src/components/nsSessionStore.diff	2008-06-22 09:39:28 UTC (rev 15413)
@@ -1,27 +1,33 @@
---- /usr/lib/firefox-2.0.0.7/components/nsSessionStore.js	2007-09-18 11:08:22.000000000 -0700
-+++ ./nsSessionStore.js	2007-10-01 01:14:40.000000000 -0700
-@@ -777,11 +777,20 @@
+--- nsSessionStore2.js	2008-04-16 12:02:47.000000000 -0700
++++ nsSessionStore2.js	2008-06-22 02:34:05.000000000 -0700
+@@ -777,11 +777,26 @@
      var browsers = tabbrowser.browsers;
      var tabs = this._windows[aWindow.__SSi].tabs = [];
      this._windows[aWindow.__SSi].selected = 0;
 +    var prefs = Components.classes["@mozilla.org/preferences-service;1"]
 +        .getService(Components.interfaces.nsIPrefBranch);
 +    var bypass_tor = prefs.getBoolPref("extensions.torbutton.notor_sessionstore");
++    var bypass_nontor = prefs.getBoolPref("extensions.torbutton.nonontor_sessionstore");
      
      for (var i = 0; i < browsers.length; i++) {
        var tabData = { entries: [], index: 0 };
        
        var browser = browsers[i];
-+      if(bypass_tor && typeof(browser.__tb_js_state) != "undefined" && 
-+              !browser.__tb_js_state) {
++      if(bypass_tor && typeof(browser.__tb_tor_fetched) != "undefined" && 
++              browser.__tb_tor_fetched) {
 +          //dump("bypassing tor tab\n");
 +          //tabs.push(tabData);
 +          continue;
 +      }
++      if(bypass_nontor && typeof(browser.__tb_tor_fetched) != "undefined" &&
++              !browser.__tb_tor_fetched) {
++          continue;
++      }
++
        if (!browser || !browser.currentURI) {
          // can happen when calling this function right after .addTab()
          tabs.push(tabData);
-@@ -796,6 +805,7 @@
+@@ -801,6 +816,7 @@
        
        if (history && browser.parentNode.__SS_data && browser.parentNode.__SS_data.entries[history.index]) {
          tabData = browser.parentNode.__SS_data;
@@ -29,16 +35,16 @@
          tabData.index = history.index + 1;
        }
        else if (history && history.count > 0) {
-@@ -979,7 +989,7 @@
+@@ -991,7 +1007,7 @@
      Array.forEach(aWindow.getBrowser().browsers, function(aBrowser, aIx) {
        try {
          var tabData = this._windows[aWindow.__SSi].tabs[aIx];
--        if (tabData.entries.length == 0)
-+        if (!tabData || tabData.entries.length == 0)
+-        if (tabData.entries.length == 0 ||
++        if (!tabData || tabData.entries.length == 0 ||
+             aBrowser.parentNode.__SS_data && aBrowser.parentNode.__SS_data._tab)
            return; // ignore incompletely initialized tabs
          
-         var text = [];
-@@ -2146,6 +2156,23 @@
+@@ -2183,6 +2199,23 @@
    }
  };
  

Deleted: torbutton/trunk/src/components/nsSessionStore.js
===================================================================
--- torbutton/trunk/src/components/nsSessionStore.js	2008-06-22 09:35:24 UTC (rev 15412)
+++ torbutton/trunk/src/components/nsSessionStore.js	2008-06-22 09:39:28 UTC (rev 15413)
@@ -1,2184 +0,0 @@
-/* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is the nsSessionStore component.
- *
- * The Initial Developer of the Original Code is
- * Simon Bünzli <zeniko@xxxxxxxxx>
- *
- * Portions created by the Initial Developer are Copyright (C) 2006
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- * Dietrich Ayala <autonome@xxxxxxxxx>
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
-/**
- * Session Storage and Restoration
- * 
- * Overview
- * This service keeps track of a user's session, storing the various bits
- * required to return the browser to it's current state. The relevant data is 
- * stored in memory, and is periodically saved to disk in a file in the 
- * profile directory. The service is started at first window load, in
- * delayedStartup, and will restore the session from the data received from
- * the nsSessionStartup service.
- */
-
-/* :::::::: Constants and Helpers ::::::::::::::: */
-
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-const Cr = Components.results;
-
-const CID = Components.ID("{5280606b-2510-4fe0-97ef-9b5a22eafe6b}");
-const CONTRACT_ID = "@mozilla.org/browser/sessionstore;1";
-const CLASS_NAME = "Browser Session Store Service";
-
-const STATE_STOPPED = 0;
-const STATE_RUNNING = 1;
-const STATE_QUITTING = -1;
-
-const STATE_STOPPED_STR = "stopped";
-const STATE_RUNNING_STR = "running";
-
-const PRIVACY_NONE = 0;
-const PRIVACY_ENCRYPTED = 1;
-const PRIVACY_FULL = 2;
-
-/* :::::::: Pref Defaults :::::::::::::::::::: */
-
-// whether the service is enabled
-const DEFAULT_ENABLED = true;
-
-// minimal interval between two save operations (in milliseconds)
-const DEFAULT_INTERVAL = 10000;
-
-// maximum number of closed tabs remembered (per window)
-const DEFAULT_MAX_TABS_UNDO = 10;
-
-// maximal amount of POSTDATA to be stored (in bytes, -1 = all of it)
-const DEFAULT_POSTDATA = 0;
-
-// on which sites to save text data, POSTDATA and cookies
-// (0 = everywhere, 1 = unencrypted sites, 2 = nowhere)
-const DEFAULT_PRIVACY_LEVEL = PRIVACY_ENCRYPTED;
-
-// resume the current session at startup just this once
-const DEFAULT_RESUME_SESSION_ONCE = false;
-
-// resume the current session at startup if it had previously crashed
-const DEFAULT_RESUME_FROM_CRASH = true;
-
-// global notifications observed
-const OBSERVING = [
-  "domwindowopened", "domwindowclosed",
-  "quit-application-requested", "quit-application-granted",
-  "quit-application", "browser:purge-session-history"
-];
-
-/*
-XUL Window properties to (re)store
-Restored in restoreDimensions_proxy()
-*/
-const WINDOW_ATTRIBUTES = ["width", "height", "screenX", "screenY", "sizemode"];
-
-/* 
-Hideable window features to (re)store
-Restored in restoreWindowFeatures()
-*/
-const WINDOW_HIDEABLE_FEATURES = [
-  "menubar", "toolbar", "locationbar", 
-  "personalbar", "statusbar", "scrollbars"
-];
-
-/*
-docShell capabilities to (re)store
-Restored in restoreHistory()
-eg: browser.docShell["allow" + aCapability] = false;
-*/
-const CAPABILITIES = [
-  "Subframes", "Plugins", "Javascript", "MetaRedirects", "Images"
-];
-
-function debug(aMsg) {
-  aMsg = ("SessionStore: " + aMsg).replace(/\S{80}/g, "$&\n");
-  Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService)
-                                     .logStringMessage(aMsg);
-}
-
-/* :::::::: The Service ::::::::::::::: */
-
-function SessionStoreService() {
-}
-
-SessionStoreService.prototype = {
-
-  // xul:tab attributes to (re)store (extensions might want to hook in here)
-  xulAttributes: [],
-
-  // set default load state
-  _loadState: STATE_STOPPED,
-
-  // minimal interval between two save operations (in milliseconds)
-  _interval: DEFAULT_INTERVAL,
-
-  // when crash recovery is disabled, session data is not written to disk
-  _resume_from_crash: DEFAULT_RESUME_FROM_CRASH,
-
-  // time in milliseconds (Date.now()) when the session was last written to file
-  _lastSaveTime: 0, 
-
-  // states for all currently opened windows
-  _windows: {},
-
-  // in case the last closed window ain't a navigator:browser one
-  _lastWindowClosed: null,
-
-  // not-"dirty" windows usually don't need to have their data updated
-  _dirtyWindows: {},
-
-  // flag all windows as dirty
-  _dirty: false,
-
-/* ........ Global Event Handlers .............. */
-
-  /**
-   * Initialize the component
-   */
-  init: function sss_init(aWindow) {
-    if (!aWindow || this._loadState == STATE_RUNNING) {
-      // make sure that all browser windows which try to initialize
-      // SessionStore are really tracked by it
-      if (aWindow && (!aWindow.__SSi || !this._windows[aWindow.__SSi]))
-        this.onLoad(aWindow);
-      return;
-    }
-
-    this._prefBranch = Cc["@mozilla.org/preferences-service;1"].
-                       getService(Ci.nsIPrefService).getBranch("browser.");
-    this._prefBranch.QueryInterface(Ci.nsIPrefBranch2);
-
-    // if the service is disabled, do not init 
-    if (!this._getPref("sessionstore.enabled", DEFAULT_ENABLED))
-      return;
-
-    var observerService = Cc["@mozilla.org/observer-service;1"].
-                          getService(Ci.nsIObserverService);
-
-    OBSERVING.forEach(function(aTopic) {
-      observerService.addObserver(this, aTopic, true);
-    }, this);
-    
-    // get interval from prefs - used often, so caching/observing instead of fetching on-demand
-    this._interval = this._getPref("sessionstore.interval", DEFAULT_INTERVAL);
-    this._prefBranch.addObserver("sessionstore.interval", this, true);
-    
-    // get crash recovery state from prefs and allow for proper reaction to state changes
-    this._resume_from_crash = this._getPref("sessionstore.resume_from_crash", DEFAULT_RESUME_FROM_CRASH);
-    this._prefBranch.addObserver("sessionstore.resume_from_crash", this, true);
-    
-    // observe prefs changes so we can modify stored data to match
-    this._prefBranch.addObserver("sessionstore.max_tabs_undo", this, true);
-
-    // get file references
-    var dirService = Cc["@mozilla.org/file/directory_service;1"].
-                     getService(Ci.nsIProperties);
-    this._sessionFile = dirService.get("ProfD", Ci.nsILocalFile);
-    this._sessionFileBackup = this._sessionFile.clone();
-    this._sessionFile.append("sessionstore.js");
-    this._sessionFileBackup.append("sessionstore.bak");
-   
-    // get string containing session state
-    var iniString;
-    try {
-      var ss = Cc["@mozilla.org/browser/sessionstartup;1"].
-               getService(Ci.nsISessionStartup);
-      if (ss.doRestore())
-        iniString = ss.state;
-    }
-    catch(ex) { dump(ex + "\n"); } // no state to restore, which is ok
-
-    if (iniString) {
-      try {
-        // parse the session state into JS objects
-        this._initialState = this._safeEval(iniString);
-        // set bool detecting crash
-        this._lastSessionCrashed =
-          this._initialState.session && this._initialState.session.state &&
-          this._initialState.session.state == STATE_RUNNING_STR;
-        
-        // restore the features of the first window from localstore.rdf
-        WINDOW_ATTRIBUTES.forEach(function(aAttr) {
-          delete this._initialState.windows[0][aAttr];
-        }, this);
-        delete this._initialState.windows[0].hidden;
-      }
-      catch (ex) { debug("The session file is invalid: " + ex); }
-    }
-    
-    // if last session crashed, backup the session
-    if (this._lastSessionCrashed) {
-      try {
-        this._writeFile(this._sessionFileBackup, iniString);
-      }
-      catch (ex) { } // nothing else we can do here
-    }
-
-    // remove the session data files if crash recovery is disabled
-    if (!this._resume_from_crash)
-      this._clearDisk();
-    
-    // As this is called at delayedStartup, restoration must be initiated here
-    this.onLoad(aWindow);
-  },
-
-  /**
-   * Called on application shutdown, after notifications:
-   * quit-application-granted, quit-application
-   */
-  _uninit: function sss_uninit() {
-    if (this._doResumeSession()) { // save all data for session resuming 
-      this.saveState(true);
-    }
-    else { // discard all session related data 
-      this._clearDisk();
-    }
-    // Make sure to break our cycle with the save timer
-    if (this._saveTimer) {
-      this._saveTimer.cancel();
-      this._saveTimer = null;
-    }
-  },
-
-  /**
-   * Handle notifications
-   */
-  observe: function sss_observe(aSubject, aTopic, aData) {
-    // for event listeners
-    var _this = this;
-
-    switch (aTopic) {
-    case "domwindowopened": // catch new windows
-      aSubject.addEventListener("load", function(aEvent) {
-        aEvent.currentTarget.removeEventListener("load", arguments.callee, false);
-        _this.onLoad(aEvent.currentTarget);
-        }, false);
-      break;
-    case "domwindowclosed": // catch closed windows
-      this.onClose(aSubject);
-      break;
-    case "quit-application-requested":
-      // get a current snapshot of all windows
-      this._forEachBrowserWindow(function(aWindow) {
-        this._collectWindowData(aWindow);
-      });
-      this._dirtyWindows = [];
-      this._dirty = false;
-      break;
-    case "quit-application-granted":
-      // freeze the data at what we've got (ignoring closing windows)
-      this._loadState = STATE_QUITTING;
-      break;
-    case "quit-application":
-      if (aData == "restart")
-        this._prefBranch.setBoolPref("sessionstore.resume_session_once", true);
-      this._loadState = STATE_QUITTING; // just to be sure
-      this._uninit();
-      break;
-    case "browser:purge-session-history": // catch sanitization 
-      this._forEachBrowserWindow(function(aWindow) {
-        Array.forEach(aWindow.getBrowser().browsers, function(aBrowser) {
-          delete aBrowser.parentNode.__SS_data;
-        });
-      });
-      this._lastWindowClosed = null;
-      this._clearDisk();
-      // also clear all data about closed tabs
-      for (ix in this._windows) {
-        this._windows[ix]._closedTabs = [];
-      }
-      // give the tabbrowsers a chance to clear their histories first
-      var win = this._getMostRecentBrowserWindow();
-      if (win)
-        win.setTimeout(function() { _this.saveState(true); }, 0);
-      else
-        this.saveState(true);
-      break;
-    case "nsPref:changed": // catch pref changes
-      switch (aData) {
-      // if the user decreases the max number of closed tabs they want
-      // preserved update our internal states to match that max
-      case "sessionstore.max_tabs_undo":
-        var ix;
-        for (ix in this._windows) {
-          this._windows[ix]._closedTabs.splice(this._getPref("sessionstore.max_tabs_undo", DEFAULT_MAX_TABS_UNDO));
-        }
-        break;
-      case "sessionstore.interval":
-        this._interval = this._getPref("sessionstore.interval", this._interval);
-        // reset timer and save
-        if (this._saveTimer) {
-          this._saveTimer.cancel();
-          this._saveTimer = null;
-        }
-        this.saveStateDelayed(null, -1);
-        break;
-      case "sessionstore.resume_from_crash":
-        this._resume_from_crash = this._getPref("sessionstore.resume_from_crash", this._resume_from_crash);
-        // either create the file with crash recovery information or remove it
-        // (when _loadState is not STATE_RUNNING, that file is used for session resuming instead)
-        if (this._resume_from_crash)
-          this.saveState(true);
-        else if (this._loadState == STATE_RUNNING)
-          this._clearDisk();
-        break;
-      }
-      break;
-    case "timer-callback": // timer call back for delayed saving
-      this._saveTimer = null;
-      this.saveState();
-      break;
-    }
-  },
-
-/* ........ Window Event Handlers .............. */
-
-  /**
-   * Implement nsIDOMEventListener for handling various window and tab events
-   */
-  handleEvent: function sss_handleEvent(aEvent) {
-    switch (aEvent.type) {
-      case "load":
-        this.onTabLoad(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
-        break;
-      case "pageshow":
-        this.onTabLoad(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
-        break;
-      case "input":
-        this.onTabInput(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
-        break;
-      case "DOMAutoComplete":
-        this.onTabInput(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
-        break;
-      case "TabOpen":
-      case "TabClose":
-        var panelID = aEvent.originalTarget.linkedPanel;
-        var tabpanel = aEvent.originalTarget.ownerDocument.getElementById(panelID);
-        if (aEvent.type == "TabOpen") {
-          this.onTabAdd(aEvent.currentTarget.ownerDocument.defaultView, tabpanel);
-        }
-        else {
-          this.onTabClose(aEvent.currentTarget.ownerDocument.defaultView, aEvent.originalTarget);
-          this.onTabRemove(aEvent.currentTarget.ownerDocument.defaultView, tabpanel);
-        }
-        break;
-      case "TabSelect":
-        var tabpanels = aEvent.currentTarget.mPanelContainer;
-        this.onTabSelect(aEvent.currentTarget.ownerDocument.defaultView, tabpanels);
-        break;
-    }
-  },
-
-  /**
-   * If it's the first window load since app start...
-   * - determine if we're reloading after a crash or a forced-restart
-   * - restore window state
-   * - restart downloads
-   * Set up event listeners for this window's tabs
-   * @param aWindow
-   *        Window reference
-   */
-  onLoad: function sss_onLoad(aWindow) {
-    // return if window has already been initialized
-    if (aWindow && aWindow.__SSi && this._windows[aWindow.__SSi])
-      return;
-
-    var _this = this;
-
-    // ignore non-browser windows and windows opened while shutting down
-    if (aWindow.document.documentElement.getAttribute("windowtype") != "navigator:browser" ||
-      this._loadState == STATE_QUITTING)
-      return;
-
-    // assign it a unique identifier (timestamp)
-    aWindow.__SSi = "window" + Date.now();
-
-    // and create its data object
-    this._windows[aWindow.__SSi] = { tabs: [], selected: 0, _closedTabs: [] };
-    
-    // perform additional initialization when the first window is loading
-    if (this._loadState == STATE_STOPPED) {
-      this._loadState = STATE_RUNNING;
-      this._lastSaveTime = Date.now();
-      
-      // don't save during the first five seconds
-      // (until most of the pages have been restored)
-      this.saveStateDelayed(aWindow, 10000);
-
-      // restore a crashed session resp. resume the last session if requested
-      if (this._initialState) {
-        // make sure that the restored tabs are first in the window
-        this._initialState._firstTabs = true;
-        this.restoreWindow(aWindow, this._initialState, this._isCmdLineEmpty(aWindow));
-        delete this._initialState;
-      }
-      
-      if (this._lastSessionCrashed) {
-        // restart any interrupted downloads
-        aWindow.setTimeout(function(){ _this.retryDownloads(aWindow); }, 0);
-      }
-    }
-    
-    var tabbrowser = aWindow.getBrowser();
-    var tabpanels = tabbrowser.mPanelContainer;
-    
-    // add tab change listeners to all already existing tabs
-    for (var i = 0; i < tabpanels.childNodes.length; i++) {
-      this.onTabAdd(aWindow, tabpanels.childNodes[i], true);
-    }
-    // notification of tab add/remove/selection
-    tabbrowser.addEventListener("TabOpen", this, true);
-    tabbrowser.addEventListener("TabClose", this, true);
-    tabbrowser.addEventListener("TabSelect", this, true);
-  },
-
-  /**
-   * On window close...
-   * - remove event listeners from tabs
-   * - save all window data
-   * @param aWindow
-   *        Window reference
-   */
-  onClose: function sss_onClose(aWindow) {
-    // ignore windows not tracked by SessionStore
-    if (!aWindow.__SSi || !this._windows[aWindow.__SSi]) {
-      return;
-    }
-    
-    var tabbrowser = aWindow.getBrowser();
-    var tabpanels = tabbrowser.mPanelContainer;
-
-    tabbrowser.removeEventListener("TabOpen", this, true);
-    tabbrowser.removeEventListener("TabClose", this, true);
-    tabbrowser.removeEventListener("TabSelect", this, true);
-    
-    for (var i = 0; i < tabpanels.childNodes.length; i++) {
-      this.onTabRemove(aWindow, tabpanels.childNodes[i], true);
-    }
-    
-    if (this._loadState == STATE_RUNNING) { // window not closed during a regular shut-down 
-      // update all window data for a last time
-      this._collectWindowData(aWindow);
-      
-      // preserve this window's data (in case it was the last navigator:browser)
-      this._lastWindowClosed = this._windows[aWindow.__SSi];
-      this._lastWindowClosed.title = aWindow.content.document.title;
-      this._updateCookies([this._lastWindowClosed]);
-      
-      // clear this window from the list
-      delete this._windows[aWindow.__SSi];
-      
-      // save the state without this window to disk
-      this.saveStateDelayed();
-    }
-    
-    delete aWindow.__SSi;
-  },
-
-  /**
-   * set up listeners for a new tab
-   * @param aWindow
-   *        Window reference
-   * @param aPanel
-   *        TabPanel reference
-   * @param aNoNotification
-   *        bool Do not save state if we're updating an existing tab
-   */
-  onTabAdd: function sss_onTabAdd(aWindow, aPanel, aNoNotification) {
-    aPanel.addEventListener("load", this, true);
-    aPanel.addEventListener("pageshow", this, true);
-    aPanel.addEventListener("input", this, true);
-    aPanel.addEventListener("DOMAutoComplete", this, true);
-    
-    if (!aNoNotification) {
-      this.saveStateDelayed(aWindow);
-    }
-  },
-
-  /**
-   * remove listeners for a tab
-   * @param aWindow
-   *        Window reference
-   * @param aPanel
-   *        TabPanel reference
-   * @param aNoNotification
-   *        bool Do not save state if we're updating an existing tab
-   */
-  onTabRemove: function sss_onTabRemove(aWindow, aPanel, aNoNotification) {
-    aPanel.removeEventListener("load", this, true);
-    aPanel.removeEventListener("pageshow", this, true);
-    aPanel.removeEventListener("input", this, true);
-    aPanel.removeEventListener("DOMAutoComplete", this, true);
-    
-    delete aPanel.__SS_data;
-    delete aPanel.__SS_text;
-    
-    if (!aNoNotification) {
-      this.saveStateDelayed(aWindow);
-    }
-  },
-
-  /**
-   * When a tab closes, collect it's properties
-   * @param aWindow
-   *        Window reference
-   * @param aTab
-   *        TabPanel reference
-   */
-  onTabClose: function sss_onTabClose(aWindow, aTab) {
-    // don't update our internal state if we don't have to
-    if (this._getPref("sessionstore.max_tabs_undo", DEFAULT_MAX_TABS_UNDO) == 0) {
-      return;
-    }
-    
-    // make sure that the tab related data is up-to-date
-    this._saveWindowHistory(aWindow);
-    this._updateTextAndScrollData(aWindow);
-    
-    // store closed-tab data for undo
-    var tabState = this._windows[aWindow.__SSi].tabs[aTab._tPos];
-    if (tabState && (tabState.entries.length > 1 ||
-        tabState.entries[0].url != "about:blank")) {
-      this._windows[aWindow.__SSi]._closedTabs.unshift({
-        state: tabState,
-        title: aTab.getAttribute("label"),
-        pos: aTab._tPos
-      });
-      var maxTabsUndo = this._getPref("sessionstore.max_tabs_undo", DEFAULT_MAX_TABS_UNDO);
-      var length = this._windows[aWindow.__SSi]._closedTabs.length;
-      if (length > maxTabsUndo)
-        this._windows[aWindow.__SSi]._closedTabs.splice(maxTabsUndo, length - maxTabsUndo);
-    }
-  },
-
-  /**
-   * When a tab loads, save state.
-   * @param aWindow
-   *        Window reference
-   * @param aPanel
-   *        TabPanel reference
-   * @param aEvent
-   *        Event obj
-   */
-  onTabLoad: function sss_onTabLoad(aWindow, aPanel, aEvent) { 
-    // react on "load" and solitary "pageshow" events (the first "pageshow"
-    // following "load" is too late for deleting the data caches)
-    if (aEvent.type != "load" && !aEvent.persisted) {
-      return;
-    }
-    
-    delete aPanel.__SS_data;
-    delete aPanel.__SS_text;
-    this.saveStateDelayed(aWindow);
-  },
-
-  /**
-   * Called when a tabpanel sends the "input" notification 
-   * stores textarea data
-   * @param aWindow
-   *        Window reference
-   * @param aPanel
-   *        TabPanel reference
-   * @param aEvent
-   *        Event obj
-   */
-  onTabInput: function sss_onTabInput(aWindow, aPanel, aEvent) {
-    if (this._saveTextData(aPanel, aEvent.originalTarget)) {
-      this.saveStateDelayed(aWindow, 3000);
-    }
-  },
-
-  /**
-   * When a tab is selected, save session data
-   * @param aWindow
-   *        Window reference
-   * @param aPanels
-   *        TabPanel reference
-   */
-  onTabSelect: function sss_onTabSelect(aWindow, aPanels) {
-    if (this._loadState == STATE_RUNNING) {
-      this._windows[aWindow.__SSi].selected = aPanels.selectedIndex;
-      this.saveStateDelayed(aWindow);
-    }
-  },
-
-/* ........ nsISessionStore API .............. */
-
-  getBrowserState: function sss_getBrowserState() {
-    return this._toJSONString(this._getCurrentState());
-  },
-
-  setBrowserState: function sss_setBrowserState(aState) {
-    var window = this._getMostRecentBrowserWindow();
-    if (!window) {
-      this._openWindowWithState("(" + aState + ")");
-      return;
-    }
-
-    // close all other browser windows
-    this._forEachBrowserWindow(function(aWindow) {
-      if (aWindow != window) {
-        aWindow.close();
-      }
-    });
-
-    // restore to the given state
-    this.restoreWindow(window, "(" + aState + ")", true);
-  },
-
-  getWindowState: function sss_getWindowState(aWindow) {
-    return this._toJSONString(this._getWindowState(aWindow));
-  },
-
-  setWindowState: function sss_setWindowState(aWindow, aState, aOverwrite) {
-    this.restoreWindow(aWindow, "(" + aState + ")", aOverwrite);
-  },
-
-  getClosedTabCount: function sss_getClosedTabCount(aWindow) {
-    return this._windows[aWindow.__SSi]._closedTabs.length;
-  },
-
-  closedTabNameAt: function sss_closedTabNameAt(aWindow, aIx) {
-    var tabs = this._windows[aWindow.__SSi]._closedTabs;
-    
-    return aIx in tabs ? tabs[aIx].title : null;
-  },
-
-  getClosedTabData: function sss_getClosedTabDataAt(aWindow) {
-    return this._toJSONString(this._windows[aWindow.__SSi]._closedTabs);
-  },
-
-  undoCloseTab: function sss_undoCloseTab(aWindow, aIndex) {
-    var closedTabs = this._windows[aWindow.__SSi]._closedTabs;
-
-    // default to the most-recently closed tab
-    aIndex = aIndex || 0;
-    
-    if (aIndex in closedTabs) {
-      var browser = aWindow.getBrowser();
-
-      // fetch the data of closed tab, while removing it from the array
-      var closedTab = closedTabs.splice(aIndex, 1).shift();
-      var closedTabState = closedTab.state;
-
-      // create a new tab
-      closedTabState._tab = browser.addTab();
-      
-      // restore the tab's position
-      browser.moveTabTo(closedTabState._tab, closedTab.pos);
-
-      // restore tab content
-      this.restoreHistoryPrecursor(aWindow, [closedTabState], 1, 0, 0);
-    }
-    else {
-      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
-    }
-  },
-
-  getWindowValue: function sss_getWindowValue(aWindow, aKey) {
-    if (aWindow.__SSi) {
-      var data = this._windows[aWindow.__SSi].extData || {};
-      return data[aKey] || "";
-    }
-    else {
-      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
-    }
-  },
-
-  setWindowValue: function sss_setWindowValue(aWindow, aKey, aStringValue) {
-    if (aWindow.__SSi) {
-      if (!this._windows[aWindow.__SSi].extData) {
-        this._windows[aWindow.__SSi].extData = {};
-      }
-      this._windows[aWindow.__SSi].extData[aKey] = aStringValue;
-      this.saveStateDelayed(aWindow);
-    }
-    else {
-      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
-    }
-  },
-
-  deleteWindowValue: function sss_deleteWindowValue(aWindow, aKey) {
-    if (this._windows[aWindow.__SSi].extData[aKey])
-      delete this._windows[aWindow.__SSi].extData[aKey];
-    else
-      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
-  },
-
-  getTabValue: function sss_getTabValue(aTab, aKey) {
-    var data = aTab.__SS_extdata || {};
-    return data[aKey] || "";
-  },
-
-  setTabValue: function sss_setTabValue(aTab, aKey, aStringValue) {
-    if (!aTab.__SS_extdata) {
-      aTab.__SS_extdata = {};
-    }
-    aTab.__SS_extdata[aKey] = aStringValue;
-    this.saveStateDelayed(aTab.ownerDocument.defaultView);
-  },
-
-  deleteTabValue: function sss_deleteTabValue(aTab, aKey) {
-    if (aTab.__SS_extdata[aKey])
-      delete aTab.__SS_extdata[aKey];
-    else
-      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
-  },
-
-
-  persistTabAttribute: function sss_persistTabAttribute(aName) {
-    this.xulAttributes.push(aName);
-    this.saveStateDelayed();
-  },
-
-/* ........ Saving Functionality .............. */
-
-  /**
-   * Store all session data for a window
-   * @param aWindow
-   *        Window reference
-   */
-  _saveWindowHistory: function sss_saveWindowHistory(aWindow) {
-    var tabbrowser = aWindow.getBrowser();
-    var browsers = tabbrowser.browsers;
-    var tabs = this._windows[aWindow.__SSi].tabs = [];
-    this._windows[aWindow.__SSi].selected = 0;
-    var prefs = Components.classes["@mozilla.org/preferences-service;1"]
-        .getService(Components.interfaces.nsIPrefBranch);
-    var bypass_tor = prefs.getBoolPref("extensions.torbutton.notor_sessionstore");
-    var bypass_nontor = prefs.getBoolPref("extensions.torbutton.nonontor_sessionstore");
-    
-    for (var i = 0; i < browsers.length; i++) {
-      var tabData = { entries: [], index: 0 };
-      
-      var browser = browsers[i];
-      if(bypass_tor && typeof(browser.__tb_tor_fetched) != "undefined" && 
-              browser.__tb_tor_fetched) {
-          //dump("bypassing tor tab\n");
-          //tabs.push(tabData);
-          continue;
-      }
-      if(bypass_nontor && typeof(browser.__tb_tor_fetched) != "undefined" &&
-              !browser.__tb_tor_fetched) {
-          continue;
-      }
-
-      if (!browser || !browser.currentURI) {
-        // can happen when calling this function right after .addTab()
-        tabs.push(tabData);
-        continue;
-      }
-      var history = null;
-      
-      try {
-        history = browser.sessionHistory;
-      }
-      catch (ex) { } // this could happen if we catch a tab during (de)initialization
-      
-      if (history && browser.parentNode.__SS_data && browser.parentNode.__SS_data.entries[history.index]) {
-        tabData = browser.parentNode.__SS_data;
-        if(!tabData) continue;
-        tabData.index = history.index + 1;
-      }
-      else if (history && history.count > 0) {
-        for (var j = 0; j < history.count; j++) {
-          tabData.entries.push(this._serializeHistoryEntry(history.getEntryAtIndex(j, false)));
-        }
-        tabData.index = history.index + 1;
-        
-        browser.parentNode.__SS_data = tabData;
-      }
-      else {
-        tabData.entries[0] = { url: browser.currentURI.spec };
-        tabData.index = 1;
-      }
-      tabData.zoom = browser.markupDocumentViewer.textZoom;
-      
-      var disallow = CAPABILITIES.filter(function(aCapability) {
-        return !browser.docShell["allow" + aCapability];
-      });
-      tabData.disallow = disallow.join(",");
-      
-      var _this = this;
-      var xulattr = Array.filter(tabbrowser.mTabs[i].attributes, function(aAttr) {
-        return (_this.xulAttributes.indexOf(aAttr.name) > -1);
-      }).map(function(aAttr) {
-        return aAttr.name + "=" + encodeURI(aAttr.value);
-      });
-      tabData.xultab = xulattr.join(" ");
-      
-      tabData.extData = tabbrowser.mTabs[i].__SS_extdata || null;
-      
-      tabs.push(tabData);
-      
-      if (browser == tabbrowser.selectedBrowser) {
-        this._windows[aWindow.__SSi].selected = i + 1;
-      }
-    }
-  },
-
-  /**
-   * Get an object that is a serialized representation of a History entry
-   * Used for data storage
-   * @param aEntry
-   *        nsISHEntry instance
-   * @returns object
-   */
-  _serializeHistoryEntry: function sss_serializeHistoryEntry(aEntry) {
-    var entry = { url: aEntry.URI.spec, children: [] };
-    
-    if (aEntry.title && aEntry.title != entry.url) {
-      entry.title = aEntry.title;
-    }
-    if (aEntry.isSubFrame) {
-      entry.subframe = true;
-    }
-    if (!(aEntry instanceof Ci.nsISHEntry)) {
-      return entry;
-    }
-    
-    var cacheKey = aEntry.cacheKey;
-    if (cacheKey && cacheKey instanceof Ci.nsISupportsPRUint32) {
-      entry.cacheKey = cacheKey.data;
-    }
-    entry.ID = aEntry.ID;
-    
-    var x = {}, y = {};
-    aEntry.getScrollPosition(x, y);
-    entry.scroll = x.value + "," + y.value;
-    
-    try {
-      var prefPostdata = this._getPref("sessionstore.postdata", DEFAULT_POSTDATA);
-      if (prefPostdata && aEntry.postData && this._checkPrivacyLevel(aEntry.URI.schemeIs("https"))) {
-        aEntry.postData.QueryInterface(Ci.nsISeekableStream).
-                        seek(Ci.nsISeekableStream.NS_SEEK_SET, 0);
-        var stream = Cc["@mozilla.org/scriptableinputstream;1"].
-                     createInstance(Ci.nsIScriptableInputStream);
-        stream.init(aEntry.postData);
-        var postdata = stream.read(stream.available());
-        if (prefPostdata == -1 || postdata.replace(/^(Content-.*\r\n)+(\r\n)*/, "").length <= prefPostdata) {
-          entry.postdata = postdata;
-        }
-      }
-    }
-    catch (ex) { debug(ex); } // POSTDATA is tricky - especially since some extensions don't get it right
-    
-    if (!(aEntry instanceof Ci.nsISHContainer)) {
-      return entry;
-    }
-    
-    for (var i = 0; i < aEntry.childCount; i++) {
-      var child = aEntry.GetChildAt(i);
-      if (child) {
-        entry.children.push(this._serializeHistoryEntry(child));
-      }
-      else { // to maintain the correct frame order, insert a dummy entry 
-        entry.children.push({ url: "about:blank" });
-      }
-    }
-    
-    return entry;
-  },
-
-  /**
-   * Updates the current document's cache of user entered text data
-   * @param aPanel
-   *        TabPanel reference
-   * @param aTextarea
-   *        HTML content element (without an XPCNativeWrapper applied)
-   * @returns bool
-   */
-  _saveTextData: function sss_saveTextData(aPanel, aTextarea) {
-    var wrappedTextarea = XPCNativeWrapper(aTextarea);
-    var id = wrappedTextarea.id ? "#" + wrappedTextarea.id :
-                                  wrappedTextarea.name;
-    if (!id
-      || !(wrappedTextarea instanceof Ci.nsIDOMHTMLTextAreaElement 
-      || wrappedTextarea instanceof Ci.nsIDOMHTMLInputElement)) {
-      return false; // nothing to save
-    }
-    
-    if (!aPanel.__SS_text) {
-      aPanel.__SS_text = [];
-      aPanel.__SS_text._refs = [];
-    }
-    
-    // get the index of the reference to the text element
-    var ix = aPanel.__SS_text._refs.indexOf(aTextarea);
-    if (ix == -1) {
-      // we haven't registered this text element yet - do so now
-      aPanel.__SS_text._refs.push(aTextarea);
-      ix = aPanel.__SS_text.length;
-    }
-    else if (!aPanel.__SS_text[ix].cache) {
-      // we've already marked this text element for saving (the cache is
-      // added during save operations and would have to be updated here)
-      return false;
-    }
-    
-    // determine the frame we're in and encode it into the textarea's ID
-    var content = wrappedTextarea.ownerDocument.defaultView;
-    while (content != content.top) {
-      var frames = content.parent.frames;
-      for (var i = 0; i < frames.length && frames[i] != content; i++);
-      id = i + "|" + id;
-      content = content.parent;
-    }
-    
-    // mark this element for saving
-    aPanel.__SS_text[ix] = { id: id, element: wrappedTextarea };
-    
-    return true;
-  },
-
-  /**
-   * go through all frames and store the current scroll positions
-   * and innerHTML content of WYSIWYG editors
-   * @param aWindow
-   *        Window reference
-   */
-  _updateTextAndScrollData: function sss_updateTextAndScrollData(aWindow) {
-    var _this = this;
-    function updateRecursively(aContent, aData) {
-      for (var i = 0; i < aContent.frames.length; i++) {
-        if (aData.children && aData.children[i]) {
-          updateRecursively(aContent.frames[i], aData.children[i]);
-        }
-      }
-      // designMode is undefined e.g. for XUL documents (as about:config)
-      var isHTTPS = _this._getURIFromString((aContent.parent || aContent).
-                                        document.location.href).schemeIs("https");
-      if ((aContent.document.designMode || "") == "on" && _this._checkPrivacyLevel(isHTTPS)) {
-        if (aData.innerHTML == undefined) {
-          // we get no "input" events from iframes - listen for keypress here
-          aContent.addEventListener("keypress", function(aEvent) { _this.saveStateDelayed(aWindow, 3000); }, true);
-        }
-        aData.innerHTML = aContent.document.body.innerHTML;
-      }
-      aData.scroll = aContent.scrollX + "," + aContent.scrollY;
-    }
-    
-    Array.forEach(aWindow.getBrowser().browsers, function(aBrowser, aIx) {
-      try {
-        var tabData = this._windows[aWindow.__SSi].tabs[aIx];
-        if (!tabData || tabData.entries.length == 0)
-          return; // ignore incompletely initialized tabs
-        
-        var text = [];
-        if (aBrowser.parentNode.__SS_text && this._checkPrivacyLevel(aBrowser.currentURI.schemeIs("https"))) {
-          for (var ix = aBrowser.parentNode.__SS_text.length - 1; ix >= 0; ix--) {
-            var data = aBrowser.parentNode.__SS_text[ix];
-            if (!data.cache) {
-              // update the text element's value before adding it to the data structure
-              data.cache = encodeURI(data.element.value);
-            }
-            text.push(data.id + "=" + data.cache);
-          }
-        }
-        if (aBrowser.currentURI.spec == "about:config") {
-          text = ["#textbox=" + encodeURI(aBrowser.contentDocument.getElementById("textbox").wrappedJSObject.value)];
-        }
-        tabData.text = text.join(" ");
-        
-        updateRecursively(XPCNativeWrapper(aBrowser.contentWindow), tabData.entries[tabData.index - 1]);
-      }
-      catch (ex) { debug(ex); } // get as much data as possible, ignore failures (might succeed the next time)
-    }, this);
-  },
-
-  /**
-   * store all hosts for a URL
-   * @param aWindow
-   *        Window reference
-   */
-  _updateCookieHosts: function sss_updateCookieHosts(aWindow) {
-    var hosts = this._windows[aWindow.__SSi]._hosts = {};
-    
-    // get all possible subdomain levels for a given URL
-    var _this = this;
-    function extractHosts(aEntry) {
-      if (/^https?:\/\/(?:[^@\/\s]+@)?([\w.-]+)/.test(aEntry.url) &&
-        !hosts[RegExp.$1] && _this._checkPrivacyLevel(_this._getURIFromString(aEntry.url).schemeIs("https"))) {
-        var host = RegExp.$1;
-        var ix;
-        for (ix = host.indexOf(".") + 1; ix; ix = host.indexOf(".", ix) + 1) {
-          hosts[host.substr(ix)] = true;
-        }
-        hosts[host] = true;
-      }
-      if (aEntry.children) {
-        aEntry.children.forEach(extractHosts);
-      }
-    }
-    
-    this._windows[aWindow.__SSi].tabs.forEach(function(aTabData) { aTabData.entries.forEach(extractHosts); });
-  },
-
-  /**
-   * Serialize cookie data
-   * @param aWindows
-   *        array of Window references
-   */
-  _updateCookies: function sss_updateCookies(aWindows) {
-    var cookiesEnum = Cc["@mozilla.org/cookiemanager;1"].
-                      getService(Ci.nsICookieManager).enumerator;
-    // collect the cookies per window
-    for (var i = 0; i < aWindows.length; i++) {
-      aWindows[i].cookies = { count: 0 };
-    }
-    
-    var _this = this;
-    while (cookiesEnum.hasMoreElements()) {
-      var cookie = cookiesEnum.getNext().QueryInterface(Ci.nsICookie2);
-      if (cookie.isSession && cookie.host) {
-        var url = "", value = "";
-        aWindows.forEach(function(aWindow) {
-          if (aWindow._hosts && aWindow._hosts[cookie.rawHost]) {
-            // make sure to construct URL and value only once per cookie
-            if (!url) {
-              var url = "http" + (cookie.isSecure ? "s" : "") + "://" + cookie.host + (cookie.path || "").replace(/^(?!\/)/, "/");
-              if (_this._checkPrivacyLevel(cookie.isSecure)) {
-                value = (cookie.name || "name") + "=" + (cookie.value || "") + ";";
-                value += cookie.isDomain ? "domain=" + cookie.rawHost + ";" : "";
-                value += cookie.path ? "path=" + cookie.path + ";" : "";
-                value += cookie.isSecure ? "secure;" : "";
-              }
-            }
-            if (value) {
-              // in order to not unnecessarily bloat the session file,
-              // all window cookies are saved into one JS object
-              var cookies = aWindow.cookies;
-              cookies["domain" + ++cookies.count] = url;
-              cookies["value" + cookies.count] = value;
-            }
-          }
-        });
-      }
-    }
-    
-    // don't include empty cookie sections
-    for (i = 0; i < aWindows.length; i++) {
-      if (aWindows[i].cookies.count == 0) {
-        delete aWindows[i].cookies;
-      }
-    }
-  },
-
-  /**
-   * Store window dimensions, visibility, sidebar
-   * @param aWindow
-   *        Window reference
-   */
-  _updateWindowFeatures: function sss_updateWindowFeatures(aWindow) {
-    var winData = this._windows[aWindow.__SSi];
-    
-    WINDOW_ATTRIBUTES.forEach(function(aAttr) {
-      winData[aAttr] = this._getWindowDimension(aWindow, aAttr);
-    }, this);
-    
-    winData.hidden = WINDOW_HIDEABLE_FEATURES.filter(function(aItem) {
-      return aWindow[aItem] && !aWindow[aItem].visible;
-    }).join(",");
-    
-    winData.sidebar = aWindow.document.getElementById("sidebar-box").getAttribute("sidebarcommand");
-  },
-
-  /**
-   * serialize session data as Ini-formatted string
-   * @returns string
-   */
-  _getCurrentState: function sss_getCurrentState() {
-    var activeWindow = this._getMostRecentBrowserWindow();
-    
-    if (this._loadState == STATE_RUNNING) {
-      // update the data for all windows with activities since the last save operation
-      this._forEachBrowserWindow(function(aWindow) {
-        if (this._dirty || this._dirtyWindows[aWindow.__SSi] || aWindow == activeWindow) {
-          this._collectWindowData(aWindow);
-        }
-        else { // always update the window features (whose change alone never triggers a save operation)
-          this._updateWindowFeatures(aWindow);
-        }
-      }, this);
-      this._dirtyWindows = [];
-      this._dirty = false;
-    }
-    
-    // collect the data for all windows
-    var total = [], windows = [];
-    var ix;
-    for (ix in this._windows) {
-      total.push(this._windows[ix]);
-      windows.push(ix);
-    }
-    this._updateCookies(total);
-    
-    // make sure that the current window is restored first
-    var ix = activeWindow ? windows.indexOf(activeWindow.__SSi || "") : -1;
-    if (ix > 0) {
-      total.unshift(total.splice(ix, 1)[0]);
-    }
-
-    // if no browser window remains open, return the state of the last closed window
-    if (total.length == 0 && this._lastWindowClosed) {
-      total.push(this._lastWindowClosed);
-    }
-    
-    return { windows: total };
-  },
-
-  /**
-   * serialize session data for a window 
-   * @param aWindow
-   *        Window reference
-   * @returns string
-   */
-  _getWindowState: function sss_getWindowState(aWindow) {
-    if (this._loadState == STATE_RUNNING) {
-      this._collectWindowData(aWindow);
-    }
-    
-    var total = [this._windows[aWindow.__SSi]];
-    this._updateCookies(total);
-    
-    return { windows: total };
-  },
-
-  _collectWindowData: function sss_collectWindowData(aWindow) {
-    // update the internal state data for this window
-    this._saveWindowHistory(aWindow);
-    this._updateTextAndScrollData(aWindow);
-    this._updateCookieHosts(aWindow);
-    this._updateWindowFeatures(aWindow);
-    
-    this._dirtyWindows[aWindow.__SSi] = false;
-  },
-
-/* ........ Restoring Functionality .............. */
-
-  /**
-   * restore features to a single window
-   * @param aWindow
-   *        Window reference
-   * @param aState
-   *        JS object or its eval'able source
-   * @param aOverwriteTabs
-   *        bool overwrite existing tabs w/ new ones
-   */
-  restoreWindow: function sss_restoreWindow(aWindow, aState, aOverwriteTabs) {
-    // initialize window if necessary
-    if (aWindow && (!aWindow.__SSi || !this._windows[aWindow.__SSi]))
-      this.onLoad(aWindow);
-
-    try {
-      var root = typeof aState == "string" ? this._safeEval(aState) : aState;
-      if (!root.windows[0]) {
-        return; // nothing to restore
-      }
-    }
-    catch (ex) { // invalid state object - don't restore anything 
-      debug(ex);
-      return;
-    }
-    
-    var winData;
-    // open new windows for all further window entries of a multi-window session
-    // (unless they don't contain any tab data)
-    for (var w = 1; w < root.windows.length; w++) {
-      winData = root.windows[w];
-      if (winData && winData.tabs && winData.tabs[0]) {
-        this._openWindowWithState({ windows: [winData], opener: aWindow });
-      }
-    }
-    
-    winData = root.windows[0];
-    if (!winData.tabs) {
-      winData.tabs = [];
-    }
-    
-    var tabbrowser = aWindow.getBrowser();
-    var openTabCount = aOverwriteTabs ? tabbrowser.browsers.length : -1;
-    var newTabCount = winData.tabs.length;
-    
-    for (var t = 0; t < newTabCount; t++) {
-      winData.tabs[t]._tab = t < openTabCount ? tabbrowser.mTabs[t] : tabbrowser.addTab();
-      // when resuming at startup: add additionally requested pages to the end
-      if (!aOverwriteTabs && root._firstTabs) {
-        tabbrowser.moveTabTo(winData.tabs[t]._tab, t);
-      }
-    }
-
-    // when overwriting tabs, remove all superflous ones
-    for (t = openTabCount - 1; t >= newTabCount; t--) {
-      tabbrowser.removeTab(tabbrowser.mTabs[t]);
-    }
-    
-    if (aOverwriteTabs) {
-      this.restoreWindowFeatures(aWindow, winData, root.opener || null);
-    }
-    if (winData.cookies) {
-      this.restoreCookies(winData.cookies);
-    }
-    if (winData.extData) {
-      if (!this._windows[aWindow.__SSi].extData) {
-        this._windows[aWindow.__SSi].extData = {}
-      }
-      for (var key in winData.extData) {
-        this._windows[aWindow.__SSi].extData[key] = winData.extData[key];
-      }
-    }
-    if (winData._closedTabs && (root._firstTabs || aOverwriteTabs)) {
-      //XXXzeniko remove the slice call as soon as _closedTabs instanceof Array
-      this._windows[aWindow.__SSi]._closedTabs = winData._closedTabs.slice();
-    }
-    
-    this.restoreHistoryPrecursor(aWindow, winData.tabs, (aOverwriteTabs ?
-      (parseInt(winData.selected) || 1) : 0), 0, 0);
-  },
-
-  /**
-   * Manage history restoration for a window
-   * @param aTabs
-   *        Array of tab data
-   * @param aCurrentTabs
-   *        Array of tab references
-   * @param aSelectTab
-   *        Index of selected tab
-   * @param aCount
-   *        Counter for number of times delaying b/c browser or history aren't ready
-   */
-  restoreHistoryPrecursor: function sss_restoreHistoryPrecursor(aWindow, aTabs, aSelectTab, aIx, aCount) {
-    var tabbrowser = aWindow.getBrowser();
-    
-    // make sure that all browsers and their histories are available
-    // - if one's not, resume this check in 100ms (repeat at most 10 times)
-    for (var t = aIx; t < aTabs.length; t++) {
-      try {
-        if (!tabbrowser.getBrowserForTab(aTabs[t]._tab).webNavigation.sessionHistory) {
-          throw new Error();
-        }
-      }
-      catch (ex) { // in case browser or history aren't ready yet 
-        if (aCount < 10) {
-          var restoreHistoryFunc = function(self) {
-            self.restoreHistoryPrecursor(aWindow, aTabs, aSelectTab, aIx, aCount + 1);
-          }
-          aWindow.setTimeout(restoreHistoryFunc, 100, this);
-          return;
-        }
-      }
-    }
-    
-    // mark the tabs as loading (at this point about:blank
-    // has completed loading in all tabs, so it won't interfere)
-    for (t = 0; t < aTabs.length; t++) {
-      var tab = aTabs[t]._tab;
-      tab.setAttribute("busy", "true");
-      tabbrowser.updateIcon(tab);
-      tabbrowser.setTabTitleLoading(tab);
-    }
-    
-    // make sure to restore the selected tab first (if any)
-    if (aSelectTab-- && aTabs[aSelectTab]) {
-        aTabs.unshift(aTabs.splice(aSelectTab, 1)[0]);
-        tabbrowser.selectedTab = aTabs[0]._tab;
-    }
-    
-    this.restoreHistory(aWindow, aTabs);
-  },
-
-  /**
-   * Restory history for a window
-   * @param aWindow
-   *        Window reference
-   * @param aTabs
-   *        Array of tab data
-   * @param aCurrentTabs
-   *        Array of tab references
-   * @param aSelectTab
-   *        Index of selected tab
-   */
-  restoreHistory: function sss_restoreHistory(aWindow, aTabs, aIdMap) {
-    var _this = this;
-    while (aTabs.length > 0 && (!aTabs[0]._tab || !aTabs[0]._tab.parentNode)) {
-      aTabs.shift(); // this tab got removed before being completely restored
-    }
-    if (aTabs.length == 0) {
-      return; // no more tabs to restore
-    }
-    
-    var tabData = aTabs.shift();
-
-    // helper hash for ensuring unique frame IDs
-    var idMap = { used: {} };
-    
-    var tab = tabData._tab;
-    var browser = aWindow.getBrowser().getBrowserForTab(tab);
-    var history = browser.webNavigation.sessionHistory;
-    
-    if (history.count > 0) {
-      history.PurgeHistory(history.count);
-    }
-    history.QueryInterface(Ci.nsISHistoryInternal);
-    
-    if (!tabData.entries) {
-      tabData.entries = [];
-    }
-    if (tabData.extData) {
-      tab.__SS_extdata = tabData.extData;
-    }
-    
-    browser.markupDocumentViewer.textZoom = parseFloat(tabData.zoom || 1);
-    
-    for (var i = 0; i < tabData.entries.length; i++) {
-      history.addEntry(this._deserializeHistoryEntry(tabData.entries[i], idMap), true);
-    }
-    
-    // make sure to reset the capabilities and attributes, in case this tab gets reused
-    var disallow = (tabData.disallow)?tabData.disallow.split(","):[];
-    CAPABILITIES.forEach(function(aCapability) {
-      browser.docShell["allow" + aCapability] = disallow.indexOf(aCapability) == -1;
-    });
-    Array.filter(tab.attributes, function(aAttr) {
-      return (_this.xulAttributes.indexOf(aAttr.name) > -1);
-    }).forEach(tab.removeAttribute, tab);
-    if (tabData.xultab) {
-      tabData.xultab.split(" ").forEach(function(aAttr) {
-        if (/^([^\s=]+)=(.*)/.test(aAttr)) {
-          tab.setAttribute(RegExp.$1, decodeURI(RegExp.$2));
-        }
-      });
-    }
-    
-    // notify the tabbrowser that the tab chrome has been restored
-    var event = aWindow.document.createEvent("Events");
-    event.initEvent("SSTabRestoring", true, false);
-    tab.dispatchEvent(event);
-    
-    var activeIndex = (tabData.index || tabData.entries.length) - 1;
-    try {
-      browser.webNavigation.gotoIndex(activeIndex);
-    }
-    catch (ex) { } // ignore an invalid tabData.index
-    
-    // restore those aspects of the currently active documents
-    // which are not preserved in the plain history entries
-    // (mainly scroll state and text data)
-    browser.__SS_restore_data = tabData.entries[activeIndex] || {};
-    browser.__SS_restore_text = tabData.text || "";
-    browser.__SS_restore_tab = tab;
-    browser.__SS_restore = this.restoreDocument_proxy;
-    browser.addEventListener("load", browser.__SS_restore, true);
-    
-    aWindow.setTimeout(function(){ _this.restoreHistory(aWindow, aTabs, aIdMap); }, 0);
-  },
-
-  /**
-   * expands serialized history data into a session-history-entry instance
-   * @param aEntry
-   *        Object containing serialized history data for a URL
-   * @param aIdMap
-   *        Hash for ensuring unique frame IDs
-   * @returns nsISHEntry
-   */
-  _deserializeHistoryEntry: function sss_deserializeHistoryEntry(aEntry, aIdMap) {
-    var shEntry = Cc["@mozilla.org/browser/session-history-entry;1"].
-                  createInstance(Ci.nsISHEntry);
-    
-    var ioService = Cc["@mozilla.org/network/io-service;1"].
-                    getService(Ci.nsIIOService);
-    shEntry.setURI(ioService.newURI(aEntry.url, null, null));
-    shEntry.setTitle(aEntry.title || aEntry.url);
-    shEntry.setIsSubFrame(aEntry.subframe || false);
-    shEntry.loadType = Ci.nsIDocShellLoadInfo.loadHistory;
-    
-    if (aEntry.cacheKey) {
-      var cacheKey = Cc["@mozilla.org/supports-PRUint32;1"].
-                     createInstance(Ci.nsISupportsPRUint32);
-      cacheKey.data = aEntry.cacheKey;
-      shEntry.cacheKey = cacheKey;
-    }
-    if (aEntry.ID) {
-      // get a new unique ID for this frame (since the one from the last
-      // start might already be in use)
-      var id = aIdMap[aEntry.ID] || 0;
-      if (!id) {
-        for (id = Date.now(); aIdMap.used[id]; id++);
-        aIdMap[aEntry.ID] = id;
-        aIdMap.used[id] = true;
-      }
-      shEntry.ID = id;
-    }
-    
-    var scrollPos = (aEntry.scroll || "0,0").split(",");
-    scrollPos = [parseInt(scrollPos[0]) || 0, parseInt(scrollPos[1]) || 0];
-    shEntry.setScrollPosition(scrollPos[0], scrollPos[1]);
-    
-    if (aEntry.postdata) {
-      var stream = Cc["@mozilla.org/io/string-input-stream;1"].
-                   createInstance(Ci.nsIStringInputStream);
-      stream.setData(aEntry.postdata, -1);
-      shEntry.postData = stream;
-    }
-    
-    if (aEntry.children && shEntry instanceof Ci.nsISHContainer) {
-      for (var i = 0; i < aEntry.children.length; i++) {
-        shEntry.AddChild(this._deserializeHistoryEntry(aEntry.children[i], aIdMap), i);
-      }
-    }
-    
-    return shEntry;
-  },
-
-  /**
-   * Restore properties to a loaded document
-   */
-  restoreDocument_proxy: function sss_restoreDocument_proxy(aEvent) {
-    // wait for the top frame to be loaded completely
-    if (!aEvent || !aEvent.originalTarget || !aEvent.originalTarget.defaultView || aEvent.originalTarget.defaultView != aEvent.originalTarget.defaultView.top) {
-      return;
-    }
-    
-    var textArray = this.__SS_restore_text ? this.__SS_restore_text.split(" ") : [];
-    function restoreTextData(aContent, aPrefix) {
-      textArray.forEach(function(aEntry) {
-        if (/^((?:\d+\|)*)(#?)([^\s=]+)=(.*)$/.test(aEntry) && (!RegExp.$1 || RegExp.$1 == aPrefix)) {
-          var document = aContent.document;
-          var node = RegExp.$2 ? document.getElementById(RegExp.$3) : document.getElementsByName(RegExp.$3)[0] || null;
-          if (node && "value" in node) {
-            node.value = decodeURI(RegExp.$4);
-            
-            var event = document.createEvent("UIEvents");
-            event.initUIEvent("input", true, true, aContent, 0);
-            node.dispatchEvent(event);
-          }
-        }
-      });
-    }
-    
-    function restoreTextDataAndScrolling(aContent, aData, aPrefix) {
-      restoreTextData(aContent, aPrefix);
-      if (aData.innerHTML) {
-        aContent.setTimeout(function(aHTML) { if (this.document.designMode == "on") { this.document.body.innerHTML = aHTML; } }, 0, aData.innerHTML);
-      }
-      if (aData.scroll && /(\d+),(\d+)/.test(aData.scroll)) {
-        aContent.scrollTo(RegExp.$1, RegExp.$2);
-      }
-      for (var i = 0; i < aContent.frames.length; i++) {
-        if (aData.children && aData.children[i]) {
-          restoreTextDataAndScrolling(aContent.frames[i], aData.children[i], i + "|" + aPrefix);
-        }
-      }
-    }
-    
-    var content = XPCNativeWrapper(aEvent.originalTarget).defaultView;
-    if (this.currentURI.spec == "about:config") {
-      // unwrap the document for about:config because otherwise the properties
-      // of the XBL bindings - as the textbox - aren't accessible (see bug 350718)
-      content = content.wrappedJSObject;
-    }
-    restoreTextDataAndScrolling(content, this.__SS_restore_data, "");
-    
-    // notify the tabbrowser that this document has been completely restored
-    var event = this.ownerDocument.createEvent("Events");
-    event.initEvent("SSTabRestored", true, false);
-    this.__SS_restore_tab.dispatchEvent(event);
-    
-    this.removeEventListener("load", this.__SS_restore, true);
-    delete this.__SS_restore_data;
-    delete this.__SS_restore_text;
-    delete this.__SS_restore_tab;
-    delete this.__SS_restore;
-  },
-
-  /**
-   * Restore visibility and dimension features to a window
-   * @param aWindow
-   *        Window reference
-   * @param aWinData
-   *        Object containing session data for the window
-   * @param aOpener
-   *        Opening window, for refocusing
-   */
-  restoreWindowFeatures: function sss_restoreWindowFeatures(aWindow, aWinData, aOpener) {
-    var hidden = (aWinData.hidden)?aWinData.hidden.split(","):[];
-    WINDOW_HIDEABLE_FEATURES.forEach(function(aItem) {
-      aWindow[aItem].visible = hidden.indexOf(aItem) == -1;
-    });
-    
-    var _this = this;
-    aWindow.setTimeout(function() {
-      _this.restoreDimensions_proxy.apply(_this, [aWindow, aOpener, aWinData.width || 0, 
-        aWinData.height || 0, "screenX" in aWinData ? aWinData.screenX : NaN,
-        "screenY" in aWinData ? aWinData.screenY : NaN,
-        aWinData.sizemode || "", aWinData.sidebar || ""]);
-    }, 0);
-  },
-
-  /**
-   * Restore a window's dimensions
-   * @param aOpener
-   *        Opening window, for refocusing
-   * @param aWidth
-   *        Window width
-   * @param aHeight
-   *        Window height
-   * @param aLeft
-   *        Window left
-   * @param aTop
-   *        Window top
-   * @param aSizeMode
-   *        Window size mode (eg: maximized)
-   * @param aSidebar
-   *        Sidebar command
-   */
-  restoreDimensions_proxy: function sss_restoreDimensions_proxy(aWindow, aOpener, aWidth, aHeight, aLeft, aTop, aSizeMode, aSidebar) {
-    var win = aWindow;
-    var _this = this;
-    function win_(aName) { return _this._getWindowDimension(win, aName); }
-    
-    // only modify those aspects which aren't correct yet
-    if (aWidth && aHeight && (aWidth != win_("width") || aHeight != win_("height"))) {
-      aWindow.resizeTo(aWidth, aHeight);
-    }
-    if (!isNaN(aLeft) && !isNaN(aTop) && (aLeft != win_("screenX") || aTop != win_("screenY"))) {
-      aWindow.moveTo(aLeft, aTop);
-    }
-    if (aSizeMode == "maximized" && win_("sizemode") != "maximized") {
-      aWindow.maximize();
-    }
-    else if (aSizeMode && aSizeMode != "maximized" && win_("sizemode") != "normal") {
-      aWindow.restore();
-    }
-    var sidebar = aWindow.document.getElementById("sidebar-box");
-    if (sidebar.getAttribute("sidebarcommand") != aSidebar) {
-      aWindow.toggleSidebar(aSidebar);
-    }
-    // since resizing/moving a window brings it to the foreground,
-    // we might want to re-focus the window which created this one
-    if (aOpener) {
-      aOpener.focus();
-    }
-  },
-
-  /**
-   * Restores cookies to cookie service
-   * @param aCookies
-   *        Array of cookie data
-   */
-  restoreCookies: function sss_restoreCookies(aCookies) {
-    var cookieService = Cc["@mozilla.org/cookieService;1"].
-                        getService(Ci.nsICookieService);
-    var ioService = Cc["@mozilla.org/network/io-service;1"].
-                    getService(Ci.nsIIOService);
-    
-    for (var i = 1; i <= aCookies.count; i++) {
-      try {
-        cookieService.setCookieString(ioService.newURI(aCookies["domain" + i], null, null), null, aCookies["value" + i] + "expires=0;", null);
-      }
-      catch (ex) { debug(ex); } // don't let a single cookie stop recovering (might happen if a user tried to edit the session file)
-    }
-  },
-
-  /**
-   * Restart incomplete downloads
-   * @param aWindow
-   *        Window reference
-   */
-  retryDownloads: function sss_retryDownloads(aWindow) {
-    var downloadManager = Cc["@mozilla.org/download-manager;1"].
-                          getService(Ci.nsIDownloadManager);
-    var rdfService = Cc["@mozilla.org/rdf/rdf-service;1"].
-                     getService(Ci.nsIRDFService);
-    var ioService = Cc["@mozilla.org/network/io-service;1"].
-                    getService(Ci.nsIIOService);
-    
-    var rdfContainer = Cc["@mozilla.org/rdf/container;1"].
-                       createInstance(Ci.nsIRDFContainer);
-    var datasource = downloadManager.datasource;
-    
-    try {
-      rdfContainer.Init(datasource, rdfService.GetResource("NC:DownloadsRoot"));
-    }
-    catch (ex) { // missing downloads datasource
-      return;
-    }
-    
-    // iterate through all downloads currently available in the RDF store
-    // and restart the ones which were in progress before the crash
-    var downloads = rdfContainer.GetElements();
-    while (downloads.hasMoreElements()) {
-      var download = downloads.getNext().QueryInterface(Ci.nsIRDFResource);
-
-      // restart only if the download's in progress
-      var node = datasource.GetTarget(download, rdfService.GetResource("http://home.netscape.com/NC-rdf#DownloadState";), true);
-      if (node) {
-        node.QueryInterface(Ci.nsIRDFInt);
-      }
-      if (!node || node.Value != Ci.nsIDownloadManager.DOWNLOAD_DOWNLOADING) {
-        continue;
-      }
-
-      // URL being downloaded
-      node = datasource.GetTarget(download, rdfService.GetResource("http://home.netscape.com/NC-rdf#URL";), true);
-      var url = node.QueryInterface(Ci.nsIRDFResource).Value;
-      
-      // location where download's being saved
-      node = datasource.GetTarget(download, rdfService.GetResource("http://home.netscape.com/NC-rdf#File";), true);
-
-      // nsIRDFResource.Value is a string that's a URI; the downloads.rdf from
-      // which this was created will have a string in one of the following two
-      // forms, depending on platform:
-      //
-      //    /home/lumpy/dogtreat.txt
-      //    C:\lumpy\dogtreat.txt
-      //
-      // During RDF loading, the string *appears* to be converted to a URL if
-      // necessary.  Strings in the first form are not URLs and are converted to
-      // file: URLs; strings in the latter form seem to be treated as if they
-      // already are URLs and thus are not modified.  Consequently, on platforms
-      // where paths aren't URLs, we need to extract the path from the file:
-      // URL.
-      //
-      // See also bug 335725, bug 239948, and bug 349971.
-      var savedTo = node.QueryInterface(Ci.nsIRDFResource).Value;
-      try {
-        var savedToURI = Cc["@mozilla.org/network/io-service;1"].
-                         getService(Ci.nsIIOService).
-                         newURI(savedTo, null, null);
-        if (savedToURI.schemeIs("file"))
-          savedTo = savedToURI.path;
-      }
-      catch (e) { /* not a URI, assume it was a string of form #1 */ }
-
-      var linkChecker = Cc["@mozilla.org/network/urichecker;1"].
-                        createInstance(Ci.nsIURIChecker);
-      linkChecker.init(ioService.newURI(url, null, null));
-      linkChecker.loadFlags = Ci.nsIRequest.LOAD_BACKGROUND;
-      linkChecker.asyncCheck(new AutoDownloader(url, savedTo, aWindow), null);
-    }
-  },
-
-/* ........ Disk Access .............. */
-
-  /**
-   * save state delayed by N ms
-   * marks window as dirty (i.e. data update can't be skipped)
-   * @param aWindow
-   *        Window reference
-   * @param aDelay
-   *        Milliseconds to delay
-   */
-  saveStateDelayed: function sss_saveStateDelayed(aWindow, aDelay) {
-    if (aWindow) {
-      this._dirtyWindows[aWindow.__SSi] = true;
-    }
-
-    if (!this._saveTimer && this._resume_from_crash) {
-      // interval until the next disk operation is allowed
-      var minimalDelay = this._lastSaveTime + this._interval - Date.now();
-      
-      // if we have to wait, set a timer, otherwise saveState directly
-      aDelay = Math.max(minimalDelay, aDelay || 2000);
-      if (aDelay > 0) {
-        this._saveTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
-        this._saveTimer.init(this, aDelay, Ci.nsITimer.TYPE_ONE_SHOT);
-      }
-      else {
-        this.saveState();
-      }
-    }
-  },
-
-  /**
-   * save state to disk
-   * @param aUpdateAll
-   *        Bool update all windows 
-   */
-  saveState: function sss_saveState(aUpdateAll) {
-    // if crash recovery is disabled, only save session resuming information
-    if (!this._resume_from_crash && this._loadState == STATE_RUNNING)
-      return;
-    
-    this._dirty = aUpdateAll;
-    var oState = this._getCurrentState();
-    oState.session = { state: ((this._loadState == STATE_RUNNING) ? STATE_RUNNING_STR : STATE_STOPPED_STR) };
-    this._writeFile(this._sessionFile, oState.toSource());
-    this._lastSaveTime = Date.now();
-  },
-
-  /**
-   * delete session datafile and backup
-   */
-  _clearDisk: function sss_clearDisk() {
-    if (this._sessionFile.exists()) {
-      try {
-        this._sessionFile.remove(false);
-      }
-      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
-    }
-    if (this._sessionFileBackup.exists()) {
-      try {
-        this._sessionFileBackup.remove(false);
-      }
-      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
-    }
-  },
-
-/* ........ Auxiliary Functions .............. */
-
-  /**
-   * call a callback for all currently opened browser windows
-   * (might miss the most recent one)
-   * @param aFunc
-   *        Callback each window is passed to
-   */
-  _forEachBrowserWindow: function sss_forEachBrowserWindow(aFunc) {
-    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
-                         getService(Ci.nsIWindowMediator);
-    var windowsEnum = windowMediator.getEnumerator("navigator:browser");
-    
-    while (windowsEnum.hasMoreElements()) {
-      var window = windowsEnum.getNext();
-      if (window.__SSi) {
-        aFunc.call(this, window);
-      }
-    }
-  },
-
-  /**
-   * Returns most recent window
-   * @returns Window reference
-   */
-  _getMostRecentBrowserWindow: function sss_getMostRecentBrowserWindow() {
-    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
-                         getService(Ci.nsIWindowMediator);
-    return windowMediator.getMostRecentWindow("navigator:browser");
-  },
-
-  /**
-   * open a new browser window for a given session state
-   * called when restoring a multi-window session
-   * @param aState
-   *        Object containing session data
-   */
-  _openWindowWithState: function sss_openWindowWithState(aState) {
-    
-    var argString = Cc["@mozilla.org/supports-string;1"].
-                    createInstance(Ci.nsISupportsString);
-    argString.data = "";
-
-    //XXXzeniko shouldn't it be possible to set the window's dimensions here (as feature)?
-    var window = Cc["@mozilla.org/embedcomp/window-watcher;1"].
-                 getService(Ci.nsIWindowWatcher).
-                 openWindow(null, this._getPref("chromeURL", null), "_blank", "chrome,dialog=no,all", argString);
-    
-    window.__SS_state = aState;
-    var _this = this;
-    window.addEventListener("load", function(aEvent) {
-      aEvent.currentTarget.removeEventListener("load", arguments.callee, true);
-      _this.restoreWindow(aEvent.currentTarget, aEvent.currentTarget.__SS_state, true, true);
-      delete aEvent.currentTarget.__SS_state;
-    }, true);
-  },
-
-  /**
-   * Whether or not to resume session, if not recovering from a crash.
-   * @returns bool
-   */
-  _doResumeSession: function sss_doResumeSession() {
-    return this._getPref("startup.page", 1) == 3 ||
-      this._getPref("sessionstore.resume_session_once", DEFAULT_RESUME_SESSION_ONCE);
-  },
-
-  /**
-   * whether the user wants to load any other page at startup
-   * (except the homepage) - needed for determining whether to overwrite the current tabs
-   * @returns bool
-   */
-  _isCmdLineEmpty: function sss_isCmdLineEmpty(aWindow) {
-    var defaultArgs = Cc["@mozilla.org/browser/clh;1"].
-                      getService(Ci.nsIBrowserHandler).defaultArgs;
-    if (aWindow.arguments && aWindow.arguments[0] &&
-        aWindow.arguments[0] == defaultArgs)
-      aWindow.arguments[0] = null;
-
-    return !aWindow.arguments || !aWindow.arguments[0];
-  },
-
-  /**
-   * don't save sensitive data if the user doesn't want to
-   * (distinguishes between encrypted and non-encrypted sites)
-   * @param aIsHTTPS
-   *        Bool is encrypted
-   * @returns bool
-   */
-  _checkPrivacyLevel: function sss_checkPrivacyLevel(aIsHTTPS) {
-    return this._getPref("sessionstore.privacy_level", DEFAULT_PRIVACY_LEVEL) < (aIsHTTPS ? PRIVACY_ENCRYPTED : PRIVACY_FULL);
-  },
-
-  /**
-   * on popup windows, the XULWindow's attributes seem not to be set correctly
-   * we use thus JSDOMWindow attributes for sizemode and normal window attributes
-   * (and hope for reasonable values when maximized/minimized - since then
-   * outerWidth/outerHeight aren't the dimensions of the restored window)
-   * @param aWindow
-   *        Window reference
-   * @param aAttribute
-   *        String sizemode | width | height | other window attribute
-   * @returns string
-   */
-  _getWindowDimension: function sss_getWindowDimension(aWindow, aAttribute) {
-    if (aAttribute == "sizemode") {
-      switch (aWindow.windowState) {
-      case aWindow.STATE_MAXIMIZED:
-        return "maximized";
-      case aWindow.STATE_MINIMIZED:
-        return "minimized";
-      default:
-        return "normal";
-      }
-    }
-    
-    var dimension;
-    switch (aAttribute) {
-    case "width":
-      dimension = aWindow.outerWidth;
-      break;
-    case "height":
-      dimension = aWindow.outerHeight;
-      break;
-    default:
-      dimension = aAttribute in aWindow ? aWindow[aAttribute] : "";
-      break;
-    }
-    
-    if (aWindow.windowState == aWindow.STATE_NORMAL) {
-      return dimension;
-    }
-    return aWindow.document.documentElement.getAttribute(aAttribute) || dimension;
-  },
-
-  /**
-   * Convenience method to get localized string bundles
-   * @param aURI
-   * @returns nsIStringBundle
-   */
-  _getStringBundle: function sss_getStringBundle(aURI) {
-     var bundleService = Cc["@mozilla.org/intl/stringbundle;1"].
-                         getService(Ci.nsIStringBundleService);
-     var appLocale = Cc["@mozilla.org/intl/nslocaleservice;1"].
-                     getService(Ci.nsILocaleService).getApplicationLocale();
-     return bundleService.createBundle(aURI, appLocale);
-  },
-
-  /**
-   * Get nsIURI from string
-   * @param string
-   * @returns nsIURI
-   */
-   _getURIFromString: function sss_getURIFromString(aString) {
-     var ioService = Cc["@mozilla.org/network/io-service;1"].
-                     getService(Ci.nsIIOService);
-     return ioService.newURI(aString, null, null);
-   },
-
-  /**
-   * safe eval'ing
-   */
-  _safeEval: function sss_safeEval(aStr) {
-    var s = new Components.utils.Sandbox("about:blank");
-    return Components.utils.evalInSandbox(aStr, s);
-  },
-
-  /**
-   * Converts a JavaScript object into a JSON string
-   * (see http://www.json.org/ for the full grammar).
-   *
-   * The inverse operation consists of eval("(" + JSON_string + ")");
-   * and should be provably safe.
-   *
-   * @param aJSObject is the object to be converted
-   * @return the object's JSON representation
-   */
-  _toJSONString: function sss_toJSONString(aJSObject) {
-    // these characters have a special escape notation
-    const charMap = { "\b": "\\b", "\t": "\\t", "\n": "\\n", "\f": "\\f",
-                      "\r": "\\r", '"': '\\"', "\\": "\\\\" };
-    // we use a single string builder for efficiency reasons
-    var parts = [];
-    
-    // this recursive function walks through all objects and appends their
-    // JSON representation to the string builder
-    function jsonIfy(aObj) {
-      if (typeof aObj == "boolean") {
-        parts.push(aObj ? "true" : "false");
-      }
-      else if (typeof aObj == "number" && isFinite(aObj)) {
-        // there is no representation for infinite numbers or for NaN!
-        parts.push(aObj.toString());
-      }
-      else if (typeof aObj == "string") {
-        aObj = aObj.replace(/[\\"\x00-\x1F\u0080-\uFFFF]/g, function($0) {
-          // use the special escape notation if one exists, otherwise
-          // produce a general unicode escape sequence
-          return charMap[$0] ||
-            "\\u" + ("0000" + $0.charCodeAt(0).toString(16)).slice(-4);
-        });
-        parts.push('"' + aObj + '"')
-      }
-      else if (aObj == null) {
-        parts.push("null");
-      }
-      else if (aObj instanceof Array) {
-        parts.push("[");
-        for (var i = 0; i < aObj.length; i++) {
-          jsonIfy(aObj[i]);
-          parts.push(",");
-        }
-        if (parts[parts.length - 1] == ",")
-          parts.pop(); // drop the trailing colon
-        parts.push("]");
-      }
-      else if (typeof aObj == "object") {
-        parts.push("{");
-        for (var key in aObj) {
-          jsonIfy(key.toString());
-          parts.push(":");
-          jsonIfy(aObj[key]);
-          parts.push(",");
-        }
-        if (parts[parts.length - 1] == ",")
-          parts.pop(); // drop the trailing colon
-        parts.push("}");
-      }
-      else {
-        throw new Error("No JSON representation for this object!");
-      }
-    }
-    jsonIfy(aJSObject);
-    
-    var newJSONString = parts.join(" ");
-    // sanity check - so that API consumers can just eval this string
-    if (/[^,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t]/.test(
-      newJSONString.replace(/"(\\.|[^"\\])*"/g, "")
-    ))
-      throw new Error("JSON conversion failed unexpectedly!");
-    
-    return newJSONString;
-  },
-
-/* ........ Storage API .............. */
-
-  /**
-   * basic pref reader
-   * @param aName
-   * @param aDefault
-   * @param aUseRootBranch
-   */
-  _getPref: function sss_getPref(aName, aDefault) {
-    var pb = this._prefBranch;
-    try {
-      switch (pb.getPrefType(aName)) {
-      case pb.PREF_STRING:
-        return pb.getCharPref(aName);
-      case pb.PREF_BOOL:
-        return pb.getBoolPref(aName);
-      case pb.PREF_INT:
-        return pb.getIntPref(aName);
-      default:
-        return aDefault;
-      }
-    }
-    catch(ex) {
-      return aDefault;
-    }
-  },
-
-  /**
-   * write file to disk
-   * @param aFile
-   *        nsIFile
-   * @param aData
-   *        String data
-   */
-  _writeFile: function sss_writeFile(aFile, aData) {
-    // init stream
-    var stream = Cc["@mozilla.org/network/safe-file-output-stream;1"].
-                 createInstance(Ci.nsIFileOutputStream);
-    stream.init(aFile, 0x02 | 0x08 | 0x20, 0600, 0);
-
-    // convert to UTF-8
-    var converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"].
-                    createInstance(Ci.nsIScriptableUnicodeConverter);
-    converter.charset = "UTF-8";
-    var convertedData = converter.ConvertFromUnicode(aData);
-    convertedData += converter.Finish();
-
-    // write and close stream
-    stream.write(convertedData, convertedData.length);
-    if (stream instanceof Ci.nsISafeOutputStream) {
-      stream.finish();
-    } else {
-      stream.close();
-    }
-  },
-
-/* ........ QueryInterface .............. */
-
-  QueryInterface: function(aIID) {
-    if (!aIID.equals(Ci.nsISupports) && 
-      !aIID.equals(Ci.nsIObserver) && 
-      !aIID.equals(Ci.nsISupportsWeakReference) && 
-      !aIID.equals(Ci.nsIDOMEventListener) &&
-      !aIID.equals(Ci.nsISessionStore)) {
-      Components.returnCode = Cr.NS_ERROR_NO_INTERFACE;
-      return null;
-    }
-    
-    return this;
-  }
-};
-
-/* :::::::::: Asynchronous File Downloader :::::::::::::: */
-
-function AutoDownloader(aURL, aFilename, aWindow) {
-   this._URL = aURL;
-   this._filename = aFilename;
-   this._window = aWindow;
-}
-
-AutoDownloader.prototype = {
-  onStartRequest: function(aRequest, aContext) { },
-  onStopRequest: function(aRequest, aContext, aStatus) {
-    if (Components.isSuccessCode(aStatus)) {
-      var file =
-        Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsILocalFile);
-      file.initWithPath(this._filename);
-      if (file.exists()) {
-        file.remove(false);
-      }
-      
-      this._window.saveURL(this._URL, this._filename, null, true, true, null);
-    }
-  }
-};
-
-/* :::::::: Service Registration & Initialization ::::::::::::::: */
-
-/* ........ nsIModule .............. */
-
-const SessionStoreModule = {
-
-  getClassObject: function(aCompMgr, aCID, aIID) {
-    if (aCID.equals(CID)) {
-      return SessionStoreFactory;
-    }
-    
-    Components.returnCode = Cr.NS_ERROR_NOT_REGISTERED;
-    return null;
-  },
-
-  registerSelf: function(aCompMgr, aFileSpec, aLocation, aType) {
-    aCompMgr.QueryInterface(Ci.nsIComponentRegistrar);
-    aCompMgr.registerFactoryLocation(CID, CLASS_NAME, CONTRACT_ID, aFileSpec, aLocation, aType);
-
-    var catMan = Cc["@mozilla.org/categorymanager;1"].
-                 getService(Ci.nsICategoryManager);
-    catMan.addCategoryEntry("app-startup", CLASS_NAME, "service," + CONTRACT_ID, true, true);
-  },
-
-  unregisterSelf: function(aCompMgr, aLocation, aType) {
-    aCompMgr.QueryInterface(Ci.nsIComponentRegistrar);
-    aCompMgr.unregisterFactoryLocation(CID, aLocation);
-
-    var catMan = Cc["@mozilla.org/categorymanager;1"].
-                 getService(Ci.nsICategoryManager);
-    catMan.deleteCategoryEntry( "app-startup", "service," + CONTRACT_ID, true);
-  },
-
-  canUnload: function(aCompMgr) {
-    return true;
-  }
-}
-
-/* ........ nsIFactory .............. */
-
-const SessionStoreFactory = {
-
-  createInstance: function(aOuter, aIID) {
-    if (aOuter != null) {
-      Components.returnCode = Cr.NS_ERROR_NO_AGGREGATION;
-      return null;
-    }
-    
-    return (new SessionStoreService()).QueryInterface(aIID);
-  },
-
-  lockFactory: function(aLock) { },
-
-  QueryInterface: function(aIID) {
-    if (!aIID.equals(Ci.nsISupports) && !aIID.equals(Ci.nsIModule) &&
-        !aIID.equals(Ci.nsIFactory) && !aIID.equals(Ci.nsISessionStore)) {
-      Components.returnCode = Cr.NS_ERROR_NO_INTERFACE;
-      return null;
-    }
-    
-    return this;
-  }
-};
-
-const NoModule = {
-  getClassObject: function(aCompMgr, aCID, aIID) {
-    Components.returnCode = Cr.NS_ERROR_NOT_REGISTERED;
-    return null;
-  },
-  registerSelf: function(aCompMgr, aFileSpec, aLocation, aType) { return; },
-  unregisterSelf: function(aCompMgr, aLocation, aType) { return; },
-  canUnload: function(aCompMgr) { return true; }
-};
-
-
-function NSGetModule(aComMgr, aFileSpec) {
-  var prefs = Components.classes["@mozilla.org/preferences-service;1"]
-        .getService(Components.interfaces.nsIPrefBranch);
-  if(prefs.getBoolPref("extensions.torbutton.notor_sessionstore")) {
-    return SessionStoreModule;
-  } else {
-    return NoModule;
-  }
-}

Copied: torbutton/trunk/src/components/nsSessionStore2.js (from rev 15381, torbutton/trunk/src/components/nsSessionStore.js)
===================================================================
--- torbutton/trunk/src/components/nsSessionStore2.js	                        (rev 0)
+++ torbutton/trunk/src/components/nsSessionStore2.js	2008-06-22 09:39:28 UTC (rev 15413)
@@ -0,0 +1,2221 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the nsSessionStore component.
+ *
+ * The Initial Developer of the Original Code is
+ * Simon Bünzli <zeniko@xxxxxxxxx>
+ *
+ * Portions created by the Initial Developer are Copyright (C) 2006
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ * Dietrich Ayala <autonome@xxxxxxxxx>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/**
+ * Session Storage and Restoration
+ * 
+ * Overview
+ * This service keeps track of a user's session, storing the various bits
+ * required to return the browser to it's current state. The relevant data is 
+ * stored in memory, and is periodically saved to disk in a file in the 
+ * profile directory. The service is started at first window load, in
+ * delayedStartup, and will restore the session from the data received from
+ * the nsSessionStartup service.
+ */
+
+/* :::::::: Constants and Helpers ::::::::::::::: */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+
+const CID = Components.ID("{5280606b-2510-4fe0-97ef-9b5a22eafe6b}");
+const CONTRACT_ID = "@mozilla.org/browser/sessionstore;1";
+const CLASS_NAME = "Browser Session Store Service";
+
+const STATE_STOPPED = 0;
+const STATE_RUNNING = 1;
+const STATE_QUITTING = -1;
+
+const STATE_STOPPED_STR = "stopped";
+const STATE_RUNNING_STR = "running";
+
+const PRIVACY_NONE = 0;
+const PRIVACY_ENCRYPTED = 1;
+const PRIVACY_FULL = 2;
+
+/* :::::::: Pref Defaults :::::::::::::::::::: */
+
+// whether the service is enabled
+const DEFAULT_ENABLED = true;
+
+// minimal interval between two save operations (in milliseconds)
+const DEFAULT_INTERVAL = 10000;
+
+// maximum number of closed tabs remembered (per window)
+const DEFAULT_MAX_TABS_UNDO = 10;
+
+// maximal amount of POSTDATA to be stored (in bytes, -1 = all of it)
+const DEFAULT_POSTDATA = 0;
+
+// on which sites to save text data, POSTDATA and cookies
+// (0 = everywhere, 1 = unencrypted sites, 2 = nowhere)
+const DEFAULT_PRIVACY_LEVEL = PRIVACY_ENCRYPTED;
+
+// resume the current session at startup just this once
+const DEFAULT_RESUME_SESSION_ONCE = false;
+
+// resume the current session at startup if it had previously crashed
+const DEFAULT_RESUME_FROM_CRASH = true;
+
+// global notifications observed
+const OBSERVING = [
+  "domwindowopened", "domwindowclosed",
+  "quit-application-requested", "quit-application-granted",
+  "quit-application", "browser:purge-session-history"
+];
+
+/*
+XUL Window properties to (re)store
+Restored in restoreDimensions_proxy()
+*/
+const WINDOW_ATTRIBUTES = ["width", "height", "screenX", "screenY", "sizemode"];
+
+/* 
+Hideable window features to (re)store
+Restored in restoreWindowFeatures()
+*/
+const WINDOW_HIDEABLE_FEATURES = [
+  "menubar", "toolbar", "locationbar", 
+  "personalbar", "statusbar", "scrollbars"
+];
+
+/*
+docShell capabilities to (re)store
+Restored in restoreHistory()
+eg: browser.docShell["allow" + aCapability] = false;
+*/
+const CAPABILITIES = [
+  "Subframes", "Plugins", "Javascript", "MetaRedirects", "Images"
+];
+
+function debug(aMsg) {
+  aMsg = ("SessionStore: " + aMsg).replace(/\S{80}/g, "$&\n");
+  Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService)
+                                     .logStringMessage(aMsg);
+}
+
+/* :::::::: The Service ::::::::::::::: */
+
+function SessionStoreService() {
+}
+
+SessionStoreService.prototype = {
+
+  // xul:tab attributes to (re)store (extensions might want to hook in here)
+  xulAttributes: [],
+
+  // set default load state
+  _loadState: STATE_STOPPED,
+
+  // minimal interval between two save operations (in milliseconds)
+  _interval: DEFAULT_INTERVAL,
+
+  // when crash recovery is disabled, session data is not written to disk
+  _resume_from_crash: DEFAULT_RESUME_FROM_CRASH,
+
+  // time in milliseconds (Date.now()) when the session was last written to file
+  _lastSaveTime: 0, 
+
+  // states for all currently opened windows
+  _windows: {},
+
+  // in case the last closed window ain't a navigator:browser one
+  _lastWindowClosed: null,
+
+  // not-"dirty" windows usually don't need to have their data updated
+  _dirtyWindows: {},
+
+  // flag all windows as dirty
+  _dirty: false,
+
+/* ........ Global Event Handlers .............. */
+
+  /**
+   * Initialize the component
+   */
+  init: function sss_init(aWindow) {
+    if (!aWindow || this._loadState == STATE_RUNNING) {
+      // make sure that all browser windows which try to initialize
+      // SessionStore are really tracked by it
+      if (aWindow && (!aWindow.__SSi || !this._windows[aWindow.__SSi]))
+        this.onLoad(aWindow);
+      return;
+    }
+
+    this._prefBranch = Cc["@mozilla.org/preferences-service;1"].
+                       getService(Ci.nsIPrefService).getBranch("browser.");
+    this._prefBranch.QueryInterface(Ci.nsIPrefBranch2);
+
+    // if the service is disabled, do not init 
+    if (!this._getPref("sessionstore.enabled", DEFAULT_ENABLED))
+      return;
+
+    var observerService = Cc["@mozilla.org/observer-service;1"].
+                          getService(Ci.nsIObserverService);
+
+    OBSERVING.forEach(function(aTopic) {
+      observerService.addObserver(this, aTopic, true);
+    }, this);
+    
+    // get interval from prefs - used often, so caching/observing instead of fetching on-demand
+    this._interval = this._getPref("sessionstore.interval", DEFAULT_INTERVAL);
+    this._prefBranch.addObserver("sessionstore.interval", this, true);
+    
+    // get crash recovery state from prefs and allow for proper reaction to state changes
+    this._resume_from_crash = this._getPref("sessionstore.resume_from_crash", DEFAULT_RESUME_FROM_CRASH);
+    this._prefBranch.addObserver("sessionstore.resume_from_crash", this, true);
+    
+    // observe prefs changes so we can modify stored data to match
+    this._prefBranch.addObserver("sessionstore.max_tabs_undo", this, true);
+
+    // get file references
+    var dirService = Cc["@mozilla.org/file/directory_service;1"].
+                     getService(Ci.nsIProperties);
+    this._sessionFile = dirService.get("ProfD", Ci.nsILocalFile);
+    this._sessionFileBackup = this._sessionFile.clone();
+    this._sessionFile.append("sessionstore.js");
+    this._sessionFileBackup.append("sessionstore.bak");
+   
+    // get string containing session state
+    var iniString;
+    try {
+      var ss = Cc["@mozilla.org/browser/sessionstartup;1"].
+               getService(Ci.nsISessionStartup);
+      if (ss.doRestore())
+        iniString = ss.state;
+    }
+    catch(ex) { dump(ex + "\n"); } // no state to restore, which is ok
+
+    if (iniString) {
+      try {
+        // parse the session state into JS objects
+        this._initialState = this._safeEval(iniString);
+        // set bool detecting crash
+        this._lastSessionCrashed =
+          this._initialState.session && this._initialState.session.state &&
+          this._initialState.session.state == STATE_RUNNING_STR;
+        
+        // restore the features of the first window from localstore.rdf
+        WINDOW_ATTRIBUTES.forEach(function(aAttr) {
+          delete this._initialState.windows[0][aAttr];
+        }, this);
+        delete this._initialState.windows[0].hidden;
+      }
+      catch (ex) { debug("The session file is invalid: " + ex); }
+    }
+    
+    // if last session crashed, backup the session
+    if (this._lastSessionCrashed) {
+      try {
+        this._writeFile(this._sessionFileBackup, iniString);
+      }
+      catch (ex) { } // nothing else we can do here
+    }
+
+    // remove the session data files if crash recovery is disabled
+    if (!this._resume_from_crash)
+      this._clearDisk();
+    
+    // As this is called at delayedStartup, restoration must be initiated here
+    this.onLoad(aWindow);
+  },
+
+  /**
+   * Called on application shutdown, after notifications:
+   * quit-application-granted, quit-application
+   */
+  _uninit: function sss_uninit() {
+    if (this._doResumeSession()) { // save all data for session resuming 
+      this.saveState(true);
+    }
+    else { // discard all session related data 
+      this._clearDisk();
+    }
+    // Make sure to break our cycle with the save timer
+    if (this._saveTimer) {
+      this._saveTimer.cancel();
+      this._saveTimer = null;
+    }
+  },
+
+  /**
+   * Handle notifications
+   */
+  observe: function sss_observe(aSubject, aTopic, aData) {
+    // for event listeners
+    var _this = this;
+
+    switch (aTopic) {
+    case "domwindowopened": // catch new windows
+      aSubject.addEventListener("load", function(aEvent) {
+        aEvent.currentTarget.removeEventListener("load", arguments.callee, false);
+        _this.onLoad(aEvent.currentTarget);
+        }, false);
+      break;
+    case "domwindowclosed": // catch closed windows
+      this.onClose(aSubject);
+      break;
+    case "quit-application-requested":
+      // get a current snapshot of all windows
+      this._forEachBrowserWindow(function(aWindow) {
+        this._collectWindowData(aWindow);
+      });
+      this._dirtyWindows = [];
+      this._dirty = false;
+      break;
+    case "quit-application-granted":
+      // freeze the data at what we've got (ignoring closing windows)
+      this._loadState = STATE_QUITTING;
+      break;
+    case "quit-application":
+      if (aData == "restart")
+        this._prefBranch.setBoolPref("sessionstore.resume_session_once", true);
+      this._loadState = STATE_QUITTING; // just to be sure
+      this._uninit();
+      break;
+    case "browser:purge-session-history": // catch sanitization 
+      this._forEachBrowserWindow(function(aWindow) {
+        Array.forEach(aWindow.getBrowser().browsers, function(aBrowser) {
+          delete aBrowser.parentNode.__SS_data;
+        });
+      });
+      this._lastWindowClosed = null;
+      this._clearDisk();
+      // also clear all data about closed tabs
+      for (ix in this._windows) {
+        this._windows[ix]._closedTabs = [];
+      }
+      // give the tabbrowsers a chance to clear their histories first
+      var win = this._getMostRecentBrowserWindow();
+      if (win)
+        win.setTimeout(function() { _this.saveState(true); }, 0);
+      else
+        this.saveState(true);
+      break;
+    case "nsPref:changed": // catch pref changes
+      switch (aData) {
+      // if the user decreases the max number of closed tabs they want
+      // preserved update our internal states to match that max
+      case "sessionstore.max_tabs_undo":
+        var ix;
+        for (ix in this._windows) {
+          this._windows[ix]._closedTabs.splice(this._getPref("sessionstore.max_tabs_undo", DEFAULT_MAX_TABS_UNDO));
+        }
+        break;
+      case "sessionstore.interval":
+        this._interval = this._getPref("sessionstore.interval", this._interval);
+        // reset timer and save
+        if (this._saveTimer) {
+          this._saveTimer.cancel();
+          this._saveTimer = null;
+        }
+        this.saveStateDelayed(null, -1);
+        break;
+      case "sessionstore.resume_from_crash":
+        this._resume_from_crash = this._getPref("sessionstore.resume_from_crash", this._resume_from_crash);
+        // either create the file with crash recovery information or remove it
+        // (when _loadState is not STATE_RUNNING, that file is used for session resuming instead)
+        if (this._resume_from_crash)
+          this.saveState(true);
+        else if (this._loadState == STATE_RUNNING)
+          this._clearDisk();
+        break;
+      }
+      break;
+    case "timer-callback": // timer call back for delayed saving
+      this._saveTimer = null;
+      this.saveState();
+      break;
+    }
+  },
+
+/* ........ Window Event Handlers .............. */
+
+  /**
+   * Implement nsIDOMEventListener for handling various window and tab events
+   */
+  handleEvent: function sss_handleEvent(aEvent) {
+    switch (aEvent.type) {
+      case "load":
+        this.onTabLoad(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
+        break;
+      case "pageshow":
+        this.onTabLoad(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
+        break;
+      case "input":
+        this.onTabInput(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
+        break;
+      case "DOMAutoComplete":
+        this.onTabInput(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
+        break;
+      case "TabOpen":
+      case "TabClose":
+        var panelID = aEvent.originalTarget.linkedPanel;
+        var tabpanel = aEvent.originalTarget.ownerDocument.getElementById(panelID);
+        if (aEvent.type == "TabOpen") {
+          this.onTabAdd(aEvent.currentTarget.ownerDocument.defaultView, tabpanel);
+        }
+        else {
+          this.onTabClose(aEvent.currentTarget.ownerDocument.defaultView, aEvent.originalTarget);
+          this.onTabRemove(aEvent.currentTarget.ownerDocument.defaultView, tabpanel);
+        }
+        break;
+      case "TabSelect":
+        var tabpanels = aEvent.currentTarget.mPanelContainer;
+        this.onTabSelect(aEvent.currentTarget.ownerDocument.defaultView, tabpanels);
+        break;
+    }
+  },
+
+  /**
+   * If it's the first window load since app start...
+   * - determine if we're reloading after a crash or a forced-restart
+   * - restore window state
+   * - restart downloads
+   * Set up event listeners for this window's tabs
+   * @param aWindow
+   *        Window reference
+   */
+  onLoad: function sss_onLoad(aWindow) {
+    // return if window has already been initialized
+    if (aWindow && aWindow.__SSi && this._windows[aWindow.__SSi])
+      return;
+
+    var _this = this;
+
+    // ignore non-browser windows and windows opened while shutting down
+    if (aWindow.document.documentElement.getAttribute("windowtype") != "navigator:browser" ||
+      this._loadState == STATE_QUITTING)
+      return;
+
+    // assign it a unique identifier (timestamp)
+    aWindow.__SSi = "window" + Date.now();
+
+    // and create its data object
+    this._windows[aWindow.__SSi] = { tabs: [], selected: 0, _closedTabs: [] };
+    
+    // perform additional initialization when the first window is loading
+    if (this._loadState == STATE_STOPPED) {
+      this._loadState = STATE_RUNNING;
+      this._lastSaveTime = Date.now();
+      
+      // don't save during the first five seconds
+      // (until most of the pages have been restored)
+      this.saveStateDelayed(aWindow, 10000);
+
+      // restore a crashed session resp. resume the last session if requested
+      if (this._initialState) {
+        // make sure that the restored tabs are first in the window
+        this._initialState._firstTabs = true;
+        this.restoreWindow(aWindow, this._initialState, this._isCmdLineEmpty(aWindow));
+        delete this._initialState;
+      }
+      
+      if (this._lastSessionCrashed) {
+        // restart any interrupted downloads
+        aWindow.setTimeout(function(){ _this.retryDownloads(aWindow); }, 0);
+      }
+    }
+    
+    var tabbrowser = aWindow.getBrowser();
+    var tabpanels = tabbrowser.mPanelContainer;
+    
+    // add tab change listeners to all already existing tabs
+    for (var i = 0; i < tabpanels.childNodes.length; i++) {
+      this.onTabAdd(aWindow, tabpanels.childNodes[i], true);
+    }
+    // notification of tab add/remove/selection
+    tabbrowser.addEventListener("TabOpen", this, true);
+    tabbrowser.addEventListener("TabClose", this, true);
+    tabbrowser.addEventListener("TabSelect", this, true);
+  },
+
+  /**
+   * On window close...
+   * - remove event listeners from tabs
+   * - save all window data
+   * @param aWindow
+   *        Window reference
+   */
+  onClose: function sss_onClose(aWindow) {
+    // ignore windows not tracked by SessionStore
+    if (!aWindow.__SSi || !this._windows[aWindow.__SSi]) {
+      return;
+    }
+    
+    var tabbrowser = aWindow.getBrowser();
+    var tabpanels = tabbrowser.mPanelContainer;
+
+    tabbrowser.removeEventListener("TabOpen", this, true);
+    tabbrowser.removeEventListener("TabClose", this, true);
+    tabbrowser.removeEventListener("TabSelect", this, true);
+    
+    for (var i = 0; i < tabpanels.childNodes.length; i++) {
+      this.onTabRemove(aWindow, tabpanels.childNodes[i], true);
+    }
+    
+    if (this._loadState == STATE_RUNNING) { // window not closed during a regular shut-down 
+      // update all window data for a last time
+      this._collectWindowData(aWindow);
+      
+      // preserve this window's data (in case it was the last navigator:browser)
+      this._lastWindowClosed = this._windows[aWindow.__SSi];
+      this._lastWindowClosed.title = aWindow.content.document.title;
+      this._updateCookies([this._lastWindowClosed]);
+      
+      // clear this window from the list
+      delete this._windows[aWindow.__SSi];
+      
+      // save the state without this window to disk
+      this.saveStateDelayed();
+    }
+    
+    delete aWindow.__SSi;
+  },
+
+  /**
+   * set up listeners for a new tab
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aNoNotification
+   *        bool Do not save state if we're updating an existing tab
+   */
+  onTabAdd: function sss_onTabAdd(aWindow, aPanel, aNoNotification) {
+    aPanel.addEventListener("load", this, true);
+    aPanel.addEventListener("pageshow", this, true);
+    aPanel.addEventListener("input", this, true);
+    aPanel.addEventListener("DOMAutoComplete", this, true);
+    
+    if (!aNoNotification) {
+      this.saveStateDelayed(aWindow);
+    }
+  },
+
+  /**
+   * remove listeners for a tab
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aNoNotification
+   *        bool Do not save state if we're updating an existing tab
+   */
+  onTabRemove: function sss_onTabRemove(aWindow, aPanel, aNoNotification) {
+    aPanel.removeEventListener("load", this, true);
+    aPanel.removeEventListener("pageshow", this, true);
+    aPanel.removeEventListener("input", this, true);
+    aPanel.removeEventListener("DOMAutoComplete", this, true);
+    
+    delete aPanel.__SS_data;
+    delete aPanel.__SS_text;
+    
+    if (!aNoNotification) {
+      this.saveStateDelayed(aWindow);
+    }
+  },
+
+  /**
+   * When a tab closes, collect it's properties
+   * @param aWindow
+   *        Window reference
+   * @param aTab
+   *        TabPanel reference
+   */
+  onTabClose: function sss_onTabClose(aWindow, aTab) {
+    // don't update our internal state if we don't have to
+    if (this._getPref("sessionstore.max_tabs_undo", DEFAULT_MAX_TABS_UNDO) == 0) {
+      return;
+    }
+    
+    // make sure that the tab related data is up-to-date
+    this._saveWindowHistory(aWindow);
+    this._updateTextAndScrollData(aWindow);
+    
+    // store closed-tab data for undo
+    var tabState = this._windows[aWindow.__SSi].tabs[aTab._tPos];
+    if (tabState && (tabState.entries.length > 1 ||
+        tabState.entries[0].url != "about:blank")) {
+      this._windows[aWindow.__SSi]._closedTabs.unshift({
+        state: tabState,
+        title: aTab.getAttribute("label"),
+        pos: aTab._tPos
+      });
+      var maxTabsUndo = this._getPref("sessionstore.max_tabs_undo", DEFAULT_MAX_TABS_UNDO);
+      var length = this._windows[aWindow.__SSi]._closedTabs.length;
+      if (length > maxTabsUndo)
+        this._windows[aWindow.__SSi]._closedTabs.splice(maxTabsUndo, length - maxTabsUndo);
+    }
+  },
+
+  /**
+   * When a tab loads, save state.
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aEvent
+   *        Event obj
+   */
+  onTabLoad: function sss_onTabLoad(aWindow, aPanel, aEvent) { 
+    // react on "load" and solitary "pageshow" events (the first "pageshow"
+    // following "load" is too late for deleting the data caches)
+    if (aEvent.type != "load" && !aEvent.persisted) {
+      return;
+    }
+    
+    delete aPanel.__SS_data;
+    delete aPanel.__SS_text;
+    this.saveStateDelayed(aWindow);
+  },
+
+  /**
+   * Called when a tabpanel sends the "input" notification 
+   * stores textarea data
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aEvent
+   *        Event obj
+   */
+  onTabInput: function sss_onTabInput(aWindow, aPanel, aEvent) {
+    if (this._saveTextData(aPanel, aEvent.originalTarget)) {
+      this.saveStateDelayed(aWindow, 3000);
+    }
+  },
+
+  /**
+   * When a tab is selected, save session data
+   * @param aWindow
+   *        Window reference
+   * @param aPanels
+   *        TabPanel reference
+   */
+  onTabSelect: function sss_onTabSelect(aWindow, aPanels) {
+    if (this._loadState == STATE_RUNNING) {
+      this._windows[aWindow.__SSi].selected = aPanels.selectedIndex;
+      this.saveStateDelayed(aWindow);
+    }
+  },
+
+/* ........ nsISessionStore API .............. */
+
+  getBrowserState: function sss_getBrowserState() {
+    return this._toJSONString(this._getCurrentState());
+  },
+
+  setBrowserState: function sss_setBrowserState(aState) {
+    var window = this._getMostRecentBrowserWindow();
+    if (!window) {
+      this._openWindowWithState("(" + aState + ")");
+      return;
+    }
+
+    // close all other browser windows
+    this._forEachBrowserWindow(function(aWindow) {
+      if (aWindow != window) {
+        aWindow.close();
+      }
+    });
+
+    // restore to the given state
+    this.restoreWindow(window, "(" + aState + ")", true);
+  },
+
+  getWindowState: function sss_getWindowState(aWindow) {
+    return this._toJSONString(this._getWindowState(aWindow));
+  },
+
+  setWindowState: function sss_setWindowState(aWindow, aState, aOverwrite) {
+    this.restoreWindow(aWindow, "(" + aState + ")", aOverwrite);
+  },
+
+  getClosedTabCount: function sss_getClosedTabCount(aWindow) {
+    return this._windows[aWindow.__SSi]._closedTabs.length;
+  },
+
+  closedTabNameAt: function sss_closedTabNameAt(aWindow, aIx) {
+    var tabs = this._windows[aWindow.__SSi]._closedTabs;
+    
+    return aIx in tabs ? tabs[aIx].title : null;
+  },
+
+  getClosedTabData: function sss_getClosedTabDataAt(aWindow) {
+    return this._toJSONString(this._windows[aWindow.__SSi]._closedTabs);
+  },
+
+  undoCloseTab: function sss_undoCloseTab(aWindow, aIndex) {
+    var closedTabs = this._windows[aWindow.__SSi]._closedTabs;
+
+    // default to the most-recently closed tab
+    aIndex = aIndex || 0;
+    
+    if (aIndex in closedTabs) {
+      var browser = aWindow.getBrowser();
+
+      // fetch the data of closed tab, while removing it from the array
+      var closedTab = closedTabs.splice(aIndex, 1).shift();
+      var closedTabState = closedTab.state;
+
+      // create a new tab
+      closedTabState._tab = browser.addTab();
+      
+      // restore the tab's position
+      browser.moveTabTo(closedTabState._tab, closedTab.pos);
+
+      // restore tab content
+      this.restoreHistoryPrecursor(aWindow, [closedTabState], 1, 0, 0);
+    }
+    else {
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+    }
+  },
+
+  getWindowValue: function sss_getWindowValue(aWindow, aKey) {
+    if (aWindow.__SSi) {
+      var data = this._windows[aWindow.__SSi].extData || {};
+      return data[aKey] || "";
+    }
+    else {
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+    }
+  },
+
+  setWindowValue: function sss_setWindowValue(aWindow, aKey, aStringValue) {
+    if (aWindow.__SSi) {
+      if (!this._windows[aWindow.__SSi].extData) {
+        this._windows[aWindow.__SSi].extData = {};
+      }
+      this._windows[aWindow.__SSi].extData[aKey] = aStringValue;
+      this.saveStateDelayed(aWindow);
+    }
+    else {
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+    }
+  },
+
+  deleteWindowValue: function sss_deleteWindowValue(aWindow, aKey) {
+    if (this._windows[aWindow.__SSi].extData[aKey])
+      delete this._windows[aWindow.__SSi].extData[aKey];
+    else
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+  },
+
+  getTabValue: function sss_getTabValue(aTab, aKey) {
+    var data = aTab.__SS_extdata || {};
+    return data[aKey] || "";
+  },
+
+  setTabValue: function sss_setTabValue(aTab, aKey, aStringValue) {
+    if (!aTab.__SS_extdata) {
+      aTab.__SS_extdata = {};
+    }
+    aTab.__SS_extdata[aKey] = aStringValue;
+    this.saveStateDelayed(aTab.ownerDocument.defaultView);
+  },
+
+  deleteTabValue: function sss_deleteTabValue(aTab, aKey) {
+    if (aTab.__SS_extdata[aKey])
+      delete aTab.__SS_extdata[aKey];
+    else
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+  },
+
+
+  persistTabAttribute: function sss_persistTabAttribute(aName) {
+    this.xulAttributes.push(aName);
+    this.saveStateDelayed();
+  },
+
+/* ........ Saving Functionality .............. */
+
+  /**
+   * Store all session data for a window
+   * @param aWindow
+   *        Window reference
+   */
+  _saveWindowHistory: function sss_saveWindowHistory(aWindow) {
+    var tabbrowser = aWindow.getBrowser();
+    var browsers = tabbrowser.browsers;
+    var tabs = this._windows[aWindow.__SSi].tabs = [];
+    this._windows[aWindow.__SSi].selected = 0;
+    var prefs = Components.classes["@mozilla.org/preferences-service;1"]
+        .getService(Components.interfaces.nsIPrefBranch);
+    var bypass_tor = prefs.getBoolPref("extensions.torbutton.notor_sessionstore");
+    var bypass_nontor = prefs.getBoolPref("extensions.torbutton.nonontor_sessionstore");
+    
+    for (var i = 0; i < browsers.length; i++) {
+      var tabData = { entries: [], index: 0 };
+      
+      var browser = browsers[i];
+      if(bypass_tor && typeof(browser.__tb_tor_fetched) != "undefined" && 
+              browser.__tb_tor_fetched) {
+          //dump("bypassing tor tab\n");
+          //tabs.push(tabData);
+          continue;
+      }
+      if(bypass_nontor && typeof(browser.__tb_tor_fetched) != "undefined" &&
+              !browser.__tb_tor_fetched) {
+          continue;
+      }
+
+      if (!browser || !browser.currentURI) {
+        // can happen when calling this function right after .addTab()
+        tabs.push(tabData);
+        continue;
+      }
+      else if (browser.parentNode.__SS_data && browser.parentNode.__SS_data._tab) {
+        // use the data to be restored when the tab hasn't been completely loaded
+        tabs.push(browser.parentNode.__SS_data);
+        continue;
+      }
+      var history = null;
+      
+      try {
+        history = browser.sessionHistory;
+      }
+      catch (ex) { } // this could happen if we catch a tab during (de)initialization
+      
+      if (history && browser.parentNode.__SS_data && browser.parentNode.__SS_data.entries[history.index]) {
+        tabData = browser.parentNode.__SS_data;
+        if(!tabData) continue;
+        tabData.index = history.index + 1;
+      }
+      else if (history && history.count > 0) {
+        for (var j = 0; j < history.count; j++) {
+          tabData.entries.push(this._serializeHistoryEntry(history.getEntryAtIndex(j, false)));
+        }
+        tabData.index = history.index + 1;
+        
+        browser.parentNode.__SS_data = tabData;
+      }
+      else {
+        tabData.entries[0] = { url: browser.currentURI.spec };
+        tabData.index = 1;
+      }
+      tabData.zoom = browser.markupDocumentViewer.textZoom;
+      
+      var disallow = CAPABILITIES.filter(function(aCapability) {
+        return !browser.docShell["allow" + aCapability];
+      });
+      tabData.disallow = disallow.join(",");
+      
+      var _this = this;
+      var xulattr = Array.filter(tabbrowser.mTabs[i].attributes, function(aAttr) {
+        return (_this.xulAttributes.indexOf(aAttr.name) > -1);
+      }).map(function(aAttr) {
+        return aAttr.name + "=" + encodeURI(aAttr.value);
+      });
+      tabData.xultab = xulattr.join(" ");
+      
+      tabData.extData = tabbrowser.mTabs[i].__SS_extdata || null;
+      
+      tabs.push(tabData);
+      
+      if (browser == tabbrowser.selectedBrowser) {
+        this._windows[aWindow.__SSi].selected = i + 1;
+      }
+    }
+  },
+
+  /**
+   * Get an object that is a serialized representation of a History entry
+   * Used for data storage
+   * @param aEntry
+   *        nsISHEntry instance
+   * @returns object
+   */
+  _serializeHistoryEntry: function sss_serializeHistoryEntry(aEntry) {
+    var entry = { url: aEntry.URI.spec, children: [] };
+    
+    if (aEntry.title && aEntry.title != entry.url) {
+      entry.title = aEntry.title;
+    }
+    if (aEntry.isSubFrame) {
+      entry.subframe = true;
+    }
+    if (!(aEntry instanceof Ci.nsISHEntry)) {
+      return entry;
+    }
+    
+    var cacheKey = aEntry.cacheKey;
+    if (cacheKey && cacheKey instanceof Ci.nsISupportsPRUint32) {
+      entry.cacheKey = cacheKey.data;
+    }
+    entry.ID = aEntry.ID;
+    
+    var x = {}, y = {};
+    aEntry.getScrollPosition(x, y);
+    entry.scroll = x.value + "," + y.value;
+    
+    try {
+      var prefPostdata = this._getPref("sessionstore.postdata", DEFAULT_POSTDATA);
+      if (prefPostdata && aEntry.postData && this._checkPrivacyLevel(aEntry.URI.schemeIs("https"))) {
+        aEntry.postData.QueryInterface(Ci.nsISeekableStream).
+                        seek(Ci.nsISeekableStream.NS_SEEK_SET, 0);
+        var stream = Cc["@mozilla.org/scriptableinputstream;1"].
+                     createInstance(Ci.nsIScriptableInputStream);
+        stream.init(aEntry.postData);
+        var postdata = stream.read(stream.available());
+        if (prefPostdata == -1 || postdata.replace(/^(Content-.*\r\n)+(\r\n)*/, "").length <= prefPostdata) {
+          entry.postdata = postdata;
+        }
+      }
+    }
+    catch (ex) { debug(ex); } // POSTDATA is tricky - especially since some extensions don't get it right
+
+    var ownerURI =
+      (aEntry instanceof Ci.nsISHEntry_MOZILLA_1_8_BRANCH2) ?
+        aEntry.ownerURI : null;
+    if (ownerURI) {
+        entry.ownerURI = ownerURI.spec;
+    }
+    
+    if (!(aEntry instanceof Ci.nsISHContainer)) {
+      return entry;
+    }
+    
+    for (var i = 0; i < aEntry.childCount; i++) {
+      var child = aEntry.GetChildAt(i);
+      if (child) {
+        entry.children.push(this._serializeHistoryEntry(child));
+      }
+      else { // to maintain the correct frame order, insert a dummy entry 
+        entry.children.push({ url: "about:blank" });
+      }
+    }
+    
+    return entry;
+  },
+
+  /**
+   * Updates the current document's cache of user entered text data
+   * @param aPanel
+   *        TabPanel reference
+   * @param aTextarea
+   *        HTML content element (without an XPCNativeWrapper applied)
+   * @returns bool
+   */
+  _saveTextData: function sss_saveTextData(aPanel, aTextarea) {
+    var wrappedTextarea = XPCNativeWrapper(aTextarea);
+    var id = wrappedTextarea.id ? "#" + wrappedTextarea.id :
+                                  wrappedTextarea.name;
+    if (!id
+      || !(wrappedTextarea instanceof Ci.nsIDOMHTMLTextAreaElement 
+      || wrappedTextarea instanceof Ci.nsIDOMHTMLInputElement)) {
+      return false; // nothing to save
+    }
+    
+    if (!aPanel.__SS_text) {
+      aPanel.__SS_text = [];
+      aPanel.__SS_text._refs = [];
+    }
+    
+    // get the index of the reference to the text element
+    var ix = aPanel.__SS_text._refs.indexOf(aTextarea);
+    if (ix == -1) {
+      // we haven't registered this text element yet - do so now
+      aPanel.__SS_text._refs.push(aTextarea);
+      ix = aPanel.__SS_text.length;
+    }
+    else if (!aPanel.__SS_text[ix].cache) {
+      // we've already marked this text element for saving (the cache is
+      // added during save operations and would have to be updated here)
+      return false;
+    }
+    
+    // determine the frame we're in and encode it into the textarea's ID
+    var content = wrappedTextarea.ownerDocument.defaultView;
+    while (content != content.top) {
+      var frames = content.parent.frames;
+      for (var i = 0; i < frames.length && frames[i] != content; i++);
+      id = i + "|" + id;
+      content = content.parent;
+    }
+    
+    // mark this element for saving
+    aPanel.__SS_text[ix] = { id: id, element: wrappedTextarea };
+    
+    return true;
+  },
+
+  /**
+   * go through all frames and store the current scroll positions
+   * and innerHTML content of WYSIWYG editors
+   * @param aWindow
+   *        Window reference
+   */
+  _updateTextAndScrollData: function sss_updateTextAndScrollData(aWindow) {
+    var _this = this;
+    function updateRecursively(aContent, aData) {
+      for (var i = 0; i < aContent.frames.length; i++) {
+        if (aData.children && aData.children[i]) {
+          updateRecursively(aContent.frames[i], aData.children[i]);
+        }
+      }
+      // designMode is undefined e.g. for XUL documents (as about:config)
+      var isHTTPS = _this._getURIFromString((aContent.parent || aContent).
+                                        document.location.href).schemeIs("https");
+      if ((aContent.document.designMode || "") == "on" && _this._checkPrivacyLevel(isHTTPS)) {
+        if (aData.innerHTML == undefined) {
+          // we get no "input" events from iframes - listen for keypress here
+          aContent.addEventListener("keypress", function(aEvent) { _this.saveStateDelayed(aWindow, 3000); }, true);
+        }
+        aData.innerHTML = aContent.document.body.innerHTML;
+      }
+      aData.scroll = aContent.scrollX + "," + aContent.scrollY;
+    }
+    
+    Array.forEach(aWindow.getBrowser().browsers, function(aBrowser, aIx) {
+      try {
+        var tabData = this._windows[aWindow.__SSi].tabs[aIx];
+        if (!tabData || tabData.entries.length == 0 ||
+            aBrowser.parentNode.__SS_data && aBrowser.parentNode.__SS_data._tab)
+          return; // ignore incompletely initialized tabs
+        
+        var text = [];
+        if (aBrowser.parentNode.__SS_text && this._checkPrivacyLevel(aBrowser.currentURI.schemeIs("https"))) {
+          for (var ix = aBrowser.parentNode.__SS_text.length - 1; ix >= 0; ix--) {
+            var data = aBrowser.parentNode.__SS_text[ix];
+            if (!data.cache) {
+              // update the text element's value before adding it to the data structure
+              data.cache = encodeURI(data.element.value);
+            }
+            text.push(data.id + "=" + data.cache);
+          }
+        }
+        if (aBrowser.currentURI.spec == "about:config") {
+          text = ["#textbox=" + encodeURI(aBrowser.contentDocument.getElementById("textbox").wrappedJSObject.value)];
+        }
+        tabData.text = text.join(" ");
+        
+        updateRecursively(XPCNativeWrapper(aBrowser.contentWindow), tabData.entries[tabData.index - 1]);
+      }
+      catch (ex) { debug(ex); } // get as much data as possible, ignore failures (might succeed the next time)
+    }, this);
+  },
+
+  /**
+   * store all hosts for a URL
+   * @param aWindow
+   *        Window reference
+   */
+  _updateCookieHosts: function sss_updateCookieHosts(aWindow) {
+    var hosts = this._windows[aWindow.__SSi]._hosts = {};
+    
+    // get all possible subdomain levels for a given URL
+    var _this = this;
+    function extractHosts(aEntry) {
+      if (/^https?:\/\/(?:[^@\/\s]+@)?([\w.-]+)/.test(aEntry.url) &&
+        !hosts[RegExp.$1] && _this._checkPrivacyLevel(_this._getURIFromString(aEntry.url).schemeIs("https"))) {
+        var host = RegExp.$1;
+        var ix;
+        for (ix = host.indexOf(".") + 1; ix; ix = host.indexOf(".", ix) + 1) {
+          hosts[host.substr(ix)] = true;
+        }
+        hosts[host] = true;
+      }
+      if (aEntry.children) {
+        aEntry.children.forEach(extractHosts);
+      }
+    }
+    
+    this._windows[aWindow.__SSi].tabs.forEach(function(aTabData) {
+      if (aTabData.entries instanceof Array) // cf. bug 402349
+        aTabData.entries.forEach(extractHosts);
+    });
+  },
+
+  /**
+   * Serialize cookie data
+   * @param aWindows
+   *        array of Window references
+   */
+  _updateCookies: function sss_updateCookies(aWindows) {
+    var cookiesEnum = Cc["@mozilla.org/cookiemanager;1"].
+                      getService(Ci.nsICookieManager).enumerator;
+    // collect the cookies per window
+    for (var i = 0; i < aWindows.length; i++) {
+      aWindows[i].cookies = { count: 0 };
+    }
+    
+    var _this = this;
+    while (cookiesEnum.hasMoreElements()) {
+      var cookie = cookiesEnum.getNext().QueryInterface(Ci.nsICookie2);
+      if (cookie.isSession && cookie.host) {
+        var url = "", value = "";
+        aWindows.forEach(function(aWindow) {
+          if (aWindow._hosts && aWindow._hosts[cookie.rawHost]) {
+            // make sure to construct URL and value only once per cookie
+            if (!url) {
+              var url = "http" + (cookie.isSecure ? "s" : "") + "://" + cookie.host + (cookie.path || "").replace(/^(?!\/)/, "/");
+              if (_this._checkPrivacyLevel(cookie.isSecure)) {
+                value = (cookie.name || "name") + "=" + (cookie.value || "") + ";";
+                value += cookie.isDomain ? "domain=" + cookie.rawHost + ";" : "";
+                value += cookie.path ? "path=" + cookie.path + ";" : "";
+                value += cookie.isSecure ? "secure;" : "";
+                value += cookie.isHttpOnly ? "httponly;" : "";
+              }
+            }
+            if (value) {
+              // in order to not unnecessarily bloat the session file,
+              // all window cookies are saved into one JS object
+              var cookies = aWindow.cookies;
+              cookies["domain" + ++cookies.count] = url;
+              cookies["value" + cookies.count] = value;
+            }
+          }
+        });
+      }
+    }
+    
+    // don't include empty cookie sections
+    for (i = 0; i < aWindows.length; i++) {
+      if (aWindows[i].cookies.count == 0) {
+        delete aWindows[i].cookies;
+      }
+    }
+  },
+
+  /**
+   * Store window dimensions, visibility, sidebar
+   * @param aWindow
+   *        Window reference
+   */
+  _updateWindowFeatures: function sss_updateWindowFeatures(aWindow) {
+    var winData = this._windows[aWindow.__SSi];
+    
+    WINDOW_ATTRIBUTES.forEach(function(aAttr) {
+      winData[aAttr] = this._getWindowDimension(aWindow, aAttr);
+    }, this);
+    
+    winData.hidden = WINDOW_HIDEABLE_FEATURES.filter(function(aItem) {
+      return aWindow[aItem] && !aWindow[aItem].visible;
+    }).join(",");
+    
+    winData.sidebar = aWindow.document.getElementById("sidebar-box").getAttribute("sidebarcommand");
+  },
+
+  /**
+   * serialize session data as Ini-formatted string
+   * @returns string
+   */
+  _getCurrentState: function sss_getCurrentState() {
+    var activeWindow = this._getMostRecentBrowserWindow();
+    
+    if (this._loadState == STATE_RUNNING) {
+      // update the data for all windows with activities since the last save operation
+      this._forEachBrowserWindow(function(aWindow) {
+        if (this._dirty || this._dirtyWindows[aWindow.__SSi] || aWindow == activeWindow) {
+          this._collectWindowData(aWindow);
+        }
+        else { // always update the window features (whose change alone never triggers a save operation)
+          this._updateWindowFeatures(aWindow);
+        }
+      }, this);
+      this._dirtyWindows = [];
+      this._dirty = false;
+    }
+    
+    // collect the data for all windows
+    var total = [], windows = [];
+    var ix;
+    for (ix in this._windows) {
+      total.push(this._windows[ix]);
+      windows.push(ix);
+    }
+    this._updateCookies(total);
+    
+    // make sure that the current window is restored first
+    var ix = activeWindow ? windows.indexOf(activeWindow.__SSi || "") : -1;
+    if (ix > 0) {
+      total.unshift(total.splice(ix, 1)[0]);
+    }
+
+    // if no browser window remains open, return the state of the last closed window
+    if (total.length == 0 && this._lastWindowClosed) {
+      total.push(this._lastWindowClosed);
+    }
+    
+    return { windows: total };
+  },
+
+  /**
+   * serialize session data for a window 
+   * @param aWindow
+   *        Window reference
+   * @returns string
+   */
+  _getWindowState: function sss_getWindowState(aWindow) {
+    if (this._loadState == STATE_RUNNING) {
+      this._collectWindowData(aWindow);
+    }
+    
+    var total = [this._windows[aWindow.__SSi]];
+    this._updateCookies(total);
+    
+    return { windows: total };
+  },
+
+  _collectWindowData: function sss_collectWindowData(aWindow) {
+    // update the internal state data for this window
+    this._saveWindowHistory(aWindow);
+    this._updateTextAndScrollData(aWindow);
+    this._updateCookieHosts(aWindow);
+    this._updateWindowFeatures(aWindow);
+    
+    this._dirtyWindows[aWindow.__SSi] = false;
+  },
+
+/* ........ Restoring Functionality .............. */
+
+  /**
+   * restore features to a single window
+   * @param aWindow
+   *        Window reference
+   * @param aState
+   *        JS object or its eval'able source
+   * @param aOverwriteTabs
+   *        bool overwrite existing tabs w/ new ones
+   */
+  restoreWindow: function sss_restoreWindow(aWindow, aState, aOverwriteTabs) {
+    // initialize window if necessary
+    if (aWindow && (!aWindow.__SSi || !this._windows[aWindow.__SSi]))
+      this.onLoad(aWindow);
+
+    try {
+      var root = typeof aState == "string" ? this._safeEval(aState) : aState;
+      if (!root.windows[0]) {
+        return; // nothing to restore
+      }
+    }
+    catch (ex) { // invalid state object - don't restore anything 
+      debug(ex);
+      return;
+    }
+    
+    var winData;
+    // open new windows for all further window entries of a multi-window session
+    // (unless they don't contain any tab data)
+    for (var w = 1; w < root.windows.length; w++) {
+      winData = root.windows[w];
+      if (winData && winData.tabs && winData.tabs[0]) {
+        this._openWindowWithState({ windows: [winData], opener: aWindow });
+      }
+    }
+    
+    winData = root.windows[0];
+    if (!winData.tabs) {
+      winData.tabs = [];
+    }
+    
+    var tabbrowser = aWindow.getBrowser();
+    var openTabCount = aOverwriteTabs ? tabbrowser.browsers.length : -1;
+    var newTabCount = winData.tabs.length;
+    
+    for (var t = 0; t < newTabCount; t++) {
+      winData.tabs[t]._tab = t < openTabCount ? tabbrowser.mTabs[t] : tabbrowser.addTab();
+      // when resuming at startup: add additionally requested pages to the end
+      if (!aOverwriteTabs && root._firstTabs) {
+        tabbrowser.moveTabTo(winData.tabs[t]._tab, t);
+      }
+    }
+
+    // when overwriting tabs, remove all superflous ones
+    for (t = openTabCount - 1; t >= newTabCount; t--) {
+      tabbrowser.removeTab(tabbrowser.mTabs[t]);
+    }
+    
+    if (aOverwriteTabs) {
+      this.restoreWindowFeatures(aWindow, winData, root.opener || null);
+    }
+    if (winData.cookies) {
+      this.restoreCookies(winData.cookies);
+    }
+    if (winData.extData) {
+      if (!this._windows[aWindow.__SSi].extData) {
+        this._windows[aWindow.__SSi].extData = {}
+      }
+      for (var key in winData.extData) {
+        this._windows[aWindow.__SSi].extData[key] = winData.extData[key];
+      }
+    }
+    if (winData._closedTabs && (root._firstTabs || aOverwriteTabs)) {
+      //XXXzeniko remove the slice call as soon as _closedTabs instanceof Array
+      this._windows[aWindow.__SSi]._closedTabs = winData._closedTabs.slice();
+    }
+    
+    this.restoreHistoryPrecursor(aWindow, winData.tabs, (aOverwriteTabs ?
+      (parseInt(winData.selected) || 1) : 0), 0, 0);
+  },
+
+  /**
+   * Manage history restoration for a window
+   * @param aTabs
+   *        Array of tab data
+   * @param aCurrentTabs
+   *        Array of tab references
+   * @param aSelectTab
+   *        Index of selected tab
+   * @param aCount
+   *        Counter for number of times delaying b/c browser or history aren't ready
+   */
+  restoreHistoryPrecursor: function sss_restoreHistoryPrecursor(aWindow, aTabs, aSelectTab, aIx, aCount) {
+    var tabbrowser = aWindow.getBrowser();
+    
+    // make sure that all browsers and their histories are available
+    // - if one's not, resume this check in 100ms (repeat at most 10 times)
+    for (var t = aIx; t < aTabs.length; t++) {
+      try {
+        if (!tabbrowser.getBrowserForTab(aTabs[t]._tab).webNavigation.sessionHistory) {
+          throw new Error();
+        }
+      }
+      catch (ex) { // in case browser or history aren't ready yet 
+        if (aCount < 10) {
+          var restoreHistoryFunc = function(self) {
+            self.restoreHistoryPrecursor(aWindow, aTabs, aSelectTab, aIx, aCount + 1);
+          }
+          aWindow.setTimeout(restoreHistoryFunc, 100, this);
+          return;
+        }
+      }
+    }
+    
+    // mark the tabs as loading
+    for (t = 0; t < aTabs.length; t++) {
+      if (!aTabs[t].entries || !aTabs[t].entries[0])
+        continue; // there won't be anything to load
+      
+      var tab = aTabs[t]._tab;
+      var browser = tabbrowser.getBrowserForTab(tab);
+      browser.stop(); // in case about:blank isn't done yet
+      
+      tab.setAttribute("busy", "true");
+      tabbrowser.updateIcon(tab);
+      tabbrowser.setTabTitleLoading(tab);
+      
+      // keep the data around to prevent dataloss in case
+      // a tab gets closed before it's been properly restored
+      browser.parentNode.__SS_data = aTabs[t];
+    }
+    
+    // make sure to restore the selected tab first (if any)
+    if (aSelectTab-- && aTabs[aSelectTab]) {
+        aTabs.unshift(aTabs.splice(aSelectTab, 1)[0]);
+        tabbrowser.selectedTab = aTabs[0]._tab;
+    }
+    
+    this.restoreHistory(aWindow, aTabs);
+  },
+
+  /**
+   * Restory history for a window
+   * @param aWindow
+   *        Window reference
+   * @param aTabs
+   *        Array of tab data
+   * @param aCurrentTabs
+   *        Array of tab references
+   * @param aSelectTab
+   *        Index of selected tab
+   */
+  restoreHistory: function sss_restoreHistory(aWindow, aTabs, aIdMap) {
+    var _this = this;
+    while (aTabs.length > 0 && (!aTabs[0]._tab || !aTabs[0]._tab.parentNode)) {
+      aTabs.shift(); // this tab got removed before being completely restored
+    }
+    if (aTabs.length == 0) {
+      return; // no more tabs to restore
+    }
+    
+    var tabData = aTabs.shift();
+
+    // helper hash for ensuring unique frame IDs
+    var idMap = { used: {} };
+    
+    var tab = tabData._tab;
+    var browser = aWindow.getBrowser().getBrowserForTab(tab);
+    var history = browser.webNavigation.sessionHistory;
+    
+    if (history.count > 0) {
+      history.PurgeHistory(history.count);
+    }
+    history.QueryInterface(Ci.nsISHistoryInternal);
+    
+    if (!tabData.entries) {
+      tabData.entries = [];
+    }
+    if (tabData.extData) {
+      tab.__SS_extdata = tabData.extData;
+    }
+    
+    browser.markupDocumentViewer.textZoom = parseFloat(tabData.zoom || 1);
+    
+    for (var i = 0; i < tabData.entries.length; i++) {
+      history.addEntry(this._deserializeHistoryEntry(tabData.entries[i], idMap), true);
+    }
+    
+    // make sure to reset the capabilities and attributes, in case this tab gets reused
+    var disallow = (tabData.disallow)?tabData.disallow.split(","):[];
+    CAPABILITIES.forEach(function(aCapability) {
+      browser.docShell["allow" + aCapability] = disallow.indexOf(aCapability) == -1;
+    });
+    Array.filter(tab.attributes, function(aAttr) {
+      return (_this.xulAttributes.indexOf(aAttr.name) > -1);
+    }).forEach(tab.removeAttribute, tab);
+    if (tabData.xultab) {
+      tabData.xultab.split(" ").forEach(function(aAttr) {
+        if (/^([^\s=]+)=(.*)/.test(aAttr)) {
+          tab.setAttribute(RegExp.$1, decodeURI(RegExp.$2));
+        }
+      });
+    }
+    
+    // notify the tabbrowser that the tab chrome has been restored
+    var event = aWindow.document.createEvent("Events");
+    event.initEvent("SSTabRestoring", true, false);
+    tab.dispatchEvent(event);
+    
+    var activeIndex = (tabData.index || tabData.entries.length) - 1;
+    try {
+      browser.webNavigation.gotoIndex(activeIndex);
+    }
+    catch (ex) { } // ignore an invalid tabData.index
+    
+    // restore those aspects of the currently active documents
+    // which are not preserved in the plain history entries
+    // (mainly scroll state and text data)
+    browser.__SS_restore_data = tabData.entries[activeIndex] || {};
+    browser.__SS_restore_text = tabData.text || "";
+    browser.__SS_restore_tab = tab;
+    browser.__SS_restore = this.restoreDocument_proxy;
+    browser.addEventListener("load", browser.__SS_restore, true);
+    
+    aWindow.setTimeout(function(){ _this.restoreHistory(aWindow, aTabs, aIdMap); }, 0);
+  },
+
+  /**
+   * expands serialized history data into a session-history-entry instance
+   * @param aEntry
+   *        Object containing serialized history data for a URL
+   * @param aIdMap
+   *        Hash for ensuring unique frame IDs
+   * @returns nsISHEntry
+   */
+  _deserializeHistoryEntry: function sss_deserializeHistoryEntry(aEntry, aIdMap) {
+    var shEntry = Cc["@mozilla.org/browser/session-history-entry;1"].
+                  createInstance(Ci.nsISHEntry_MOZILLA_1_8_BRANCH2);
+    
+    var ioService = Cc["@mozilla.org/network/io-service;1"].
+                    getService(Ci.nsIIOService);
+    shEntry.setURI(ioService.newURI(aEntry.url, null, null));
+    shEntry.setTitle(aEntry.title || aEntry.url);
+    shEntry.setIsSubFrame(aEntry.subframe || false);
+    shEntry.loadType = Ci.nsIDocShellLoadInfo.loadHistory;
+    
+    if (aEntry.cacheKey) {
+      var cacheKey = Cc["@mozilla.org/supports-PRUint32;1"].
+                     createInstance(Ci.nsISupportsPRUint32);
+      cacheKey.data = aEntry.cacheKey;
+      shEntry.cacheKey = cacheKey;
+    }
+    if (aEntry.ID) {
+      // get a new unique ID for this frame (since the one from the last
+      // start might already be in use)
+      var id = aIdMap[aEntry.ID] || 0;
+      if (!id) {
+        for (id = Date.now(); aIdMap.used[id]; id++);
+        aIdMap[aEntry.ID] = id;
+        aIdMap.used[id] = true;
+      }
+      shEntry.ID = id;
+    }
+    
+    var scrollPos = (aEntry.scroll || "0,0").split(",");
+    scrollPos = [parseInt(scrollPos[0]) || 0, parseInt(scrollPos[1]) || 0];
+    shEntry.setScrollPosition(scrollPos[0], scrollPos[1]);
+    
+    if (aEntry.postdata) {
+      var stream = Cc["@mozilla.org/io/string-input-stream;1"].
+                   createInstance(Ci.nsIStringInputStream);
+      stream.setData(aEntry.postdata, -1);
+      shEntry.postData = stream;
+    }
+
+    if (aEntry.ownerURI) {
+        shEntry.ownerURI = ioService.newURI(aEntry.ownerURI, null, null);
+    }
+    
+    if (aEntry.children && shEntry instanceof Ci.nsISHContainer) {
+      for (var i = 0; i < aEntry.children.length; i++) {
+        shEntry.AddChild(this._deserializeHistoryEntry(aEntry.children[i], aIdMap), i);
+      }
+    }
+    
+    return shEntry;
+  },
+
+  /**
+   * Restore properties to a loaded document
+   */
+  restoreDocument_proxy: function sss_restoreDocument_proxy(aEvent) {
+    // wait for the top frame to be loaded completely
+    if (!aEvent || !aEvent.originalTarget || !aEvent.originalTarget.defaultView || aEvent.originalTarget.defaultView != aEvent.originalTarget.defaultView.top) {
+      return;
+    }
+    
+    var textArray = this.__SS_restore_text ? this.__SS_restore_text.split(" ") : [];
+    function restoreTextData(aContent, aPrefix) {
+      textArray.forEach(function(aEntry) {
+        if (/^((?:\d+\|)*)(#?)([^\s=]+)=(.*)$/.test(aEntry) && (!RegExp.$1 || RegExp.$1 == aPrefix)) {
+          var document = aContent.document;
+          var node = RegExp.$2 ? document.getElementById(RegExp.$3) : document.getElementsByName(RegExp.$3)[0] || null;
+          if (node && "value" in node) {
+            node.value = decodeURI(RegExp.$4);
+            
+            var event = document.createEvent("UIEvents");
+            event.initUIEvent("input", true, true, aContent, 0);
+            node.dispatchEvent(event);
+          }
+        }
+      });
+    }
+    
+    function restoreTextDataAndScrolling(aContent, aData, aPrefix) {
+      restoreTextData(aContent, aPrefix);
+      if (aData.innerHTML) {
+        aContent.setTimeout(function(aHTML) { if (this.document.designMode == "on") { this.document.body.innerHTML = aHTML; } }, 0, aData.innerHTML);
+      }
+      if (aData.scroll && /(\d+),(\d+)/.test(aData.scroll)) {
+        aContent.scrollTo(RegExp.$1, RegExp.$2);
+      }
+      for (var i = 0; i < aContent.frames.length; i++) {
+        if (aData.children && aData.children[i]) {
+          restoreTextDataAndScrolling(aContent.frames[i], aData.children[i], i + "|" + aPrefix);
+        }
+      }
+    }
+    
+    var content = XPCNativeWrapper(aEvent.originalTarget).defaultView;
+    if (this.currentURI.spec == "about:config") {
+      // unwrap the document for about:config because otherwise the properties
+      // of the XBL bindings - as the textbox - aren't accessible (see bug 350718)
+      content = content.wrappedJSObject;
+    }
+    restoreTextDataAndScrolling(content, this.__SS_restore_data, "");
+    
+    // notify the tabbrowser that this document has been completely restored
+    var event = this.ownerDocument.createEvent("Events");
+    event.initEvent("SSTabRestored", true, false);
+    this.__SS_restore_tab.dispatchEvent(event);
+    
+    this.removeEventListener("load", this.__SS_restore, true);
+    delete this.__SS_restore_data;
+    delete this.__SS_restore_text;
+    delete this.__SS_restore_tab;
+    delete this.__SS_restore;
+  },
+
+  /**
+   * Restore visibility and dimension features to a window
+   * @param aWindow
+   *        Window reference
+   * @param aWinData
+   *        Object containing session data for the window
+   * @param aOpener
+   *        Opening window, for refocusing
+   */
+  restoreWindowFeatures: function sss_restoreWindowFeatures(aWindow, aWinData, aOpener) {
+    var hidden = (aWinData.hidden)?aWinData.hidden.split(","):[];
+    WINDOW_HIDEABLE_FEATURES.forEach(function(aItem) {
+      aWindow[aItem].visible = hidden.indexOf(aItem) == -1;
+    });
+    
+    var _this = this;
+    aWindow.setTimeout(function() {
+      _this.restoreDimensions_proxy.apply(_this, [aWindow, aOpener, aWinData.width || 0, 
+        aWinData.height || 0, "screenX" in aWinData ? aWinData.screenX : NaN,
+        "screenY" in aWinData ? aWinData.screenY : NaN,
+        aWinData.sizemode || "", aWinData.sidebar || ""]);
+    }, 0);
+  },
+
+  /**
+   * Restore a window's dimensions
+   * @param aOpener
+   *        Opening window, for refocusing
+   * @param aWidth
+   *        Window width
+   * @param aHeight
+   *        Window height
+   * @param aLeft
+   *        Window left
+   * @param aTop
+   *        Window top
+   * @param aSizeMode
+   *        Window size mode (eg: maximized)
+   * @param aSidebar
+   *        Sidebar command
+   */
+  restoreDimensions_proxy: function sss_restoreDimensions_proxy(aWindow, aOpener, aWidth, aHeight, aLeft, aTop, aSizeMode, aSidebar) {
+    var win = aWindow;
+    var _this = this;
+    function win_(aName) { return _this._getWindowDimension(win, aName); }
+    
+    // only modify those aspects which aren't correct yet
+    if (aWidth && aHeight && (aWidth != win_("width") || aHeight != win_("height"))) {
+      aWindow.resizeTo(aWidth, aHeight);
+    }
+    if (!isNaN(aLeft) && !isNaN(aTop) && (aLeft != win_("screenX") || aTop != win_("screenY"))) {
+      aWindow.moveTo(aLeft, aTop);
+    }
+    if (aSizeMode == "maximized" && win_("sizemode") != "maximized") {
+      aWindow.maximize();
+    }
+    else if (aSizeMode && aSizeMode != "maximized" && win_("sizemode") != "normal") {
+      aWindow.restore();
+    }
+    var sidebar = aWindow.document.getElementById("sidebar-box");
+    if (sidebar.getAttribute("sidebarcommand") != aSidebar) {
+      aWindow.toggleSidebar(aSidebar);
+    }
+    // since resizing/moving a window brings it to the foreground,
+    // we might want to re-focus the window which created this one
+    if (aOpener) {
+      aOpener.focus();
+    }
+  },
+
+  /**
+   * Restores cookies to cookie service
+   * @param aCookies
+   *        Array of cookie data
+   */
+  restoreCookies: function sss_restoreCookies(aCookies) {
+    var cookieService = Cc["@mozilla.org/cookieService;1"].
+                        getService(Ci.nsICookieService);
+    var ioService = Cc["@mozilla.org/network/io-service;1"].
+                    getService(Ci.nsIIOService);
+    
+    for (var i = 1; i <= aCookies.count; i++) {
+      try {
+        cookieService.setCookieStringFromHttp(ioService.newURI(aCookies["domain" + i], null, null), null, null, aCookies["value" + i] + "expires=0", null, null);
+      }
+      catch (ex) { debug(ex); } // don't let a single cookie stop recovering (might happen if a user tried to edit the session file)
+    }
+  },
+
+  /**
+   * Restart incomplete downloads
+   * @param aWindow
+   *        Window reference
+   */
+  retryDownloads: function sss_retryDownloads(aWindow) {
+    var downloadManager = Cc["@mozilla.org/download-manager;1"].
+                          getService(Ci.nsIDownloadManager);
+    var rdfService = Cc["@mozilla.org/rdf/rdf-service;1"].
+                     getService(Ci.nsIRDFService);
+    var ioService = Cc["@mozilla.org/network/io-service;1"].
+                    getService(Ci.nsIIOService);
+    
+    var rdfContainer = Cc["@mozilla.org/rdf/container;1"].
+                       createInstance(Ci.nsIRDFContainer);
+    var datasource = downloadManager.datasource;
+    
+    try {
+      rdfContainer.Init(datasource, rdfService.GetResource("NC:DownloadsRoot"));
+    }
+    catch (ex) { // missing downloads datasource
+      return;
+    }
+    
+    // iterate through all downloads currently available in the RDF store
+    // and restart the ones which were in progress before the crash
+    var downloads = rdfContainer.GetElements();
+    while (downloads.hasMoreElements()) {
+      var download = downloads.getNext().QueryInterface(Ci.nsIRDFResource);
+
+      // restart only if the download's in progress
+      var node = datasource.GetTarget(download, rdfService.GetResource("http://home.netscape.com/NC-rdf#DownloadState";), true);
+      if (node) {
+        node.QueryInterface(Ci.nsIRDFInt);
+      }
+      if (!node || node.Value != Ci.nsIDownloadManager.DOWNLOAD_DOWNLOADING) {
+        continue;
+      }
+
+      // URL being downloaded
+      node = datasource.GetTarget(download, rdfService.GetResource("http://home.netscape.com/NC-rdf#URL";), true);
+      var url = node.QueryInterface(Ci.nsIRDFResource).Value;
+      
+      // location where download's being saved
+      node = datasource.GetTarget(download, rdfService.GetResource("http://home.netscape.com/NC-rdf#File";), true);
+
+      // nsIRDFResource.Value is a string that's a URI; the downloads.rdf from
+      // which this was created will have a string in one of the following two
+      // forms, depending on platform:
+      //
+      //    /home/lumpy/dogtreat.txt
+      //    C:\lumpy\dogtreat.txt
+      //
+      // During RDF loading, the string *appears* to be converted to a URL if
+      // necessary.  Strings in the first form are not URLs and are converted to
+      // file: URLs; strings in the latter form seem to be treated as if they
+      // already are URLs and thus are not modified.  Consequently, on platforms
+      // where paths aren't URLs, we need to extract the path from the file:
+      // URL.
+      //
+      // See also bug 335725, bug 239948, and bug 349971.
+      var savedTo = node.QueryInterface(Ci.nsIRDFResource).Value;
+      try {
+        var savedToURI = Cc["@mozilla.org/network/io-service;1"].
+                         getService(Ci.nsIIOService).
+                         newURI(savedTo, null, null);
+        if (savedToURI.schemeIs("file"))
+          savedTo = savedToURI.path;
+      }
+      catch (e) { /* not a URI, assume it was a string of form #1 */ }
+
+      var linkChecker = Cc["@mozilla.org/network/urichecker;1"].
+                        createInstance(Ci.nsIURIChecker);
+      linkChecker.init(ioService.newURI(url, null, null));
+      linkChecker.loadFlags = Ci.nsIRequest.LOAD_BACKGROUND;
+      linkChecker.asyncCheck(new AutoDownloader(url, savedTo, aWindow), null);
+    }
+  },
+
+/* ........ Disk Access .............. */
+
+  /**
+   * save state delayed by N ms
+   * marks window as dirty (i.e. data update can't be skipped)
+   * @param aWindow
+   *        Window reference
+   * @param aDelay
+   *        Milliseconds to delay
+   */
+  saveStateDelayed: function sss_saveStateDelayed(aWindow, aDelay) {
+    if (aWindow) {
+      this._dirtyWindows[aWindow.__SSi] = true;
+    }
+
+    if (!this._saveTimer && this._resume_from_crash) {
+      // interval until the next disk operation is allowed
+      var minimalDelay = this._lastSaveTime + this._interval - Date.now();
+      
+      // if we have to wait, set a timer, otherwise saveState directly
+      aDelay = Math.max(minimalDelay, aDelay || 2000);
+      if (aDelay > 0) {
+        this._saveTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+        this._saveTimer.init(this, aDelay, Ci.nsITimer.TYPE_ONE_SHOT);
+      }
+      else {
+        this.saveState();
+      }
+    }
+  },
+
+  /**
+   * save state to disk
+   * @param aUpdateAll
+   *        Bool update all windows 
+   */
+  saveState: function sss_saveState(aUpdateAll) {
+    // if crash recovery is disabled, only save session resuming information
+    if (!this._resume_from_crash && this._loadState == STATE_RUNNING)
+      return;
+    
+    this._dirty = aUpdateAll;
+    var oState = this._getCurrentState();
+    oState.session = { state: ((this._loadState == STATE_RUNNING) ? STATE_RUNNING_STR : STATE_STOPPED_STR) };
+    this._writeFile(this._sessionFile, oState.toSource());
+    this._lastSaveTime = Date.now();
+  },
+
+  /**
+   * delete session datafile and backup
+   */
+  _clearDisk: function sss_clearDisk() {
+    if (this._sessionFile.exists()) {
+      try {
+        this._sessionFile.remove(false);
+      }
+      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
+    }
+    if (this._sessionFileBackup.exists()) {
+      try {
+        this._sessionFileBackup.remove(false);
+      }
+      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
+    }
+  },
+
+/* ........ Auxiliary Functions .............. */
+
+  /**
+   * call a callback for all currently opened browser windows
+   * (might miss the most recent one)
+   * @param aFunc
+   *        Callback each window is passed to
+   */
+  _forEachBrowserWindow: function sss_forEachBrowserWindow(aFunc) {
+    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
+                         getService(Ci.nsIWindowMediator);
+    var windowsEnum = windowMediator.getEnumerator("navigator:browser");
+    
+    while (windowsEnum.hasMoreElements()) {
+      var window = windowsEnum.getNext();
+      if (window.__SSi) {
+        aFunc.call(this, window);
+      }
+    }
+  },
+
+  /**
+   * Returns most recent window
+   * @returns Window reference
+   */
+  _getMostRecentBrowserWindow: function sss_getMostRecentBrowserWindow() {
+    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
+                         getService(Ci.nsIWindowMediator);
+    return windowMediator.getMostRecentWindow("navigator:browser");
+  },
+
+  /**
+   * open a new browser window for a given session state
+   * called when restoring a multi-window session
+   * @param aState
+   *        Object containing session data
+   */
+  _openWindowWithState: function sss_openWindowWithState(aState) {
+    
+    var argString = Cc["@mozilla.org/supports-string;1"].
+                    createInstance(Ci.nsISupportsString);
+    argString.data = "";
+
+    //XXXzeniko shouldn't it be possible to set the window's dimensions here (as feature)?
+    var window = Cc["@mozilla.org/embedcomp/window-watcher;1"].
+                 getService(Ci.nsIWindowWatcher).
+                 openWindow(null, this._getPref("chromeURL", null), "_blank", "chrome,dialog=no,all", argString);
+    
+    window.__SS_state = aState;
+    var _this = this;
+    window.addEventListener("load", function(aEvent) {
+      aEvent.currentTarget.removeEventListener("load", arguments.callee, true);
+      _this.restoreWindow(aEvent.currentTarget, aEvent.currentTarget.__SS_state, true, true);
+      delete aEvent.currentTarget.__SS_state;
+    }, true);
+  },
+
+  /**
+   * Whether or not to resume session, if not recovering from a crash.
+   * @returns bool
+   */
+  _doResumeSession: function sss_doResumeSession() {
+    return this._getPref("startup.page", 1) == 3 ||
+      this._getPref("sessionstore.resume_session_once", DEFAULT_RESUME_SESSION_ONCE);
+  },
+
+  /**
+   * whether the user wants to load any other page at startup
+   * (except the homepage) - needed for determining whether to overwrite the current tabs
+   * @returns bool
+   */
+  _isCmdLineEmpty: function sss_isCmdLineEmpty(aWindow) {
+    var defaultArgs = Cc["@mozilla.org/browser/clh;1"].
+                      getService(Ci.nsIBrowserHandler).defaultArgs;
+    if (aWindow.arguments && aWindow.arguments[0] &&
+        aWindow.arguments[0] == defaultArgs)
+      aWindow.arguments[0] = null;
+
+    return !aWindow.arguments || !aWindow.arguments[0];
+  },
+
+  /**
+   * don't save sensitive data if the user doesn't want to
+   * (distinguishes between encrypted and non-encrypted sites)
+   * @param aIsHTTPS
+   *        Bool is encrypted
+   * @returns bool
+   */
+  _checkPrivacyLevel: function sss_checkPrivacyLevel(aIsHTTPS) {
+    return this._getPref("sessionstore.privacy_level", DEFAULT_PRIVACY_LEVEL) < (aIsHTTPS ? PRIVACY_ENCRYPTED : PRIVACY_FULL);
+  },
+
+  /**
+   * on popup windows, the XULWindow's attributes seem not to be set correctly
+   * we use thus JSDOMWindow attributes for sizemode and normal window attributes
+   * (and hope for reasonable values when maximized/minimized - since then
+   * outerWidth/outerHeight aren't the dimensions of the restored window)
+   * @param aWindow
+   *        Window reference
+   * @param aAttribute
+   *        String sizemode | width | height | other window attribute
+   * @returns string
+   */
+  _getWindowDimension: function sss_getWindowDimension(aWindow, aAttribute) {
+    if (aAttribute == "sizemode") {
+      switch (aWindow.windowState) {
+      case aWindow.STATE_MAXIMIZED:
+        return "maximized";
+      case aWindow.STATE_MINIMIZED:
+        return "minimized";
+      default:
+        return "normal";
+      }
+    }
+    
+    var dimension;
+    switch (aAttribute) {
+    case "width":
+      dimension = aWindow.outerWidth;
+      break;
+    case "height":
+      dimension = aWindow.outerHeight;
+      break;
+    default:
+      dimension = aAttribute in aWindow ? aWindow[aAttribute] : "";
+      break;
+    }
+    
+    if (aWindow.windowState == aWindow.STATE_NORMAL) {
+      return dimension;
+    }
+    return aWindow.document.documentElement.getAttribute(aAttribute) || dimension;
+  },
+
+  /**
+   * Convenience method to get localized string bundles
+   * @param aURI
+   * @returns nsIStringBundle
+   */
+  _getStringBundle: function sss_getStringBundle(aURI) {
+     var bundleService = Cc["@mozilla.org/intl/stringbundle;1"].
+                         getService(Ci.nsIStringBundleService);
+     var appLocale = Cc["@mozilla.org/intl/nslocaleservice;1"].
+                     getService(Ci.nsILocaleService).getApplicationLocale();
+     return bundleService.createBundle(aURI, appLocale);
+  },
+
+  /**
+   * Get nsIURI from string
+   * @param string
+   * @returns nsIURI
+   */
+   _getURIFromString: function sss_getURIFromString(aString) {
+     var ioService = Cc["@mozilla.org/network/io-service;1"].
+                     getService(Ci.nsIIOService);
+     return ioService.newURI(aString, null, null);
+   },
+
+  /**
+   * safe eval'ing
+   */
+  _safeEval: function sss_safeEval(aStr) {
+    var s = new Components.utils.Sandbox("about:blank");
+    return Components.utils.evalInSandbox(aStr, s);
+  },
+
+  /**
+   * Converts a JavaScript object into a JSON string
+   * (see http://www.json.org/ for the full grammar).
+   *
+   * The inverse operation consists of eval("(" + JSON_string + ")");
+   * and should be provably safe.
+   *
+   * @param aJSObject is the object to be converted
+   * @return the object's JSON representation
+   */
+  _toJSONString: function sss_toJSONString(aJSObject) {
+    // these characters have a special escape notation
+    const charMap = { "\b": "\\b", "\t": "\\t", "\n": "\\n", "\f": "\\f",
+                      "\r": "\\r", '"': '\\"', "\\": "\\\\" };
+    // we use a single string builder for efficiency reasons
+    var parts = [];
+    
+    // this recursive function walks through all objects and appends their
+    // JSON representation to the string builder
+    function jsonIfy(aObj) {
+      if (typeof aObj == "boolean") {
+        parts.push(aObj ? "true" : "false");
+      }
+      else if (typeof aObj == "number" && isFinite(aObj)) {
+        // there is no representation for infinite numbers or for NaN!
+        parts.push(aObj.toString());
+      }
+      else if (typeof aObj == "string") {
+        aObj = aObj.replace(/[\\"\x00-\x1F\u0080-\uFFFF]/g, function($0) {
+          // use the special escape notation if one exists, otherwise
+          // produce a general unicode escape sequence
+          return charMap[$0] ||
+            "\\u" + ("0000" + $0.charCodeAt(0).toString(16)).slice(-4);
+        });
+        parts.push('"' + aObj + '"')
+      }
+      else if (aObj == null) {
+        parts.push("null");
+      }
+      // if it looks like an array, treat it as such -
+      // this is required for all arrays from a sandbox
+      else if (aObj instanceof Array ||
+               typeof aObj == "object" && "length" in aObj &&
+               (aObj.length === 0 || aObj[aObj.length - 1] !== undefined)) {
+        parts.push("[");
+        for (var i = 0; i < aObj.length; i++) {
+          jsonIfy(aObj[i]);
+          parts.push(",");
+        }
+        if (parts[parts.length - 1] == ",")
+          parts.pop(); // drop the trailing colon
+        parts.push("]");
+      }
+      else if (typeof aObj == "object") {
+        parts.push("{");
+        for (var key in aObj) {
+          if (key == "_tab")
+            continue; // XXXzeniko we might even want to drop all private members
+          
+          jsonIfy(key.toString());
+          parts.push(":");
+          jsonIfy(aObj[key]);
+          parts.push(",");
+        }
+        if (parts[parts.length - 1] == ",")
+          parts.pop(); // drop the trailing colon
+        parts.push("}");
+      }
+      else {
+        throw new Error("No JSON representation for this object!");
+      }
+    }
+    jsonIfy(aJSObject);
+    
+    var newJSONString = parts.join(" ");
+    // sanity check - so that API consumers can just eval this string
+    if (/[^,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t]/.test(
+      newJSONString.replace(/"(\\.|[^"\\])*"/g, "")
+    ))
+      throw new Error("JSON conversion failed unexpectedly!");
+    
+    return newJSONString;
+  },
+
+/* ........ Storage API .............. */
+
+  /**
+   * basic pref reader
+   * @param aName
+   * @param aDefault
+   * @param aUseRootBranch
+   */
+  _getPref: function sss_getPref(aName, aDefault) {
+    var pb = this._prefBranch;
+    try {
+      switch (pb.getPrefType(aName)) {
+      case pb.PREF_STRING:
+        return pb.getCharPref(aName);
+      case pb.PREF_BOOL:
+        return pb.getBoolPref(aName);
+      case pb.PREF_INT:
+        return pb.getIntPref(aName);
+      default:
+        return aDefault;
+      }
+    }
+    catch(ex) {
+      return aDefault;
+    }
+  },
+
+  /**
+   * write file to disk
+   * @param aFile
+   *        nsIFile
+   * @param aData
+   *        String data
+   */
+  _writeFile: function sss_writeFile(aFile, aData) {
+    // init stream
+    var stream = Cc["@mozilla.org/network/safe-file-output-stream;1"].
+                 createInstance(Ci.nsIFileOutputStream);
+    stream.init(aFile, 0x02 | 0x08 | 0x20, 0600, 0);
+
+    // convert to UTF-8
+    var converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"].
+                    createInstance(Ci.nsIScriptableUnicodeConverter);
+    converter.charset = "UTF-8";
+    var convertedData = converter.ConvertFromUnicode(aData);
+    convertedData += converter.Finish();
+
+    // write and close stream
+    stream.write(convertedData, convertedData.length);
+    if (stream instanceof Ci.nsISafeOutputStream) {
+      stream.finish();
+    } else {
+      stream.close();
+    }
+  },
+
+/* ........ QueryInterface .............. */
+
+  QueryInterface: function(aIID) {
+    if (!aIID.equals(Ci.nsISupports) && 
+      !aIID.equals(Ci.nsIObserver) && 
+      !aIID.equals(Ci.nsISupportsWeakReference) && 
+      !aIID.equals(Ci.nsIDOMEventListener) &&
+      !aIID.equals(Ci.nsISessionStore)) {
+      Components.returnCode = Cr.NS_ERROR_NO_INTERFACE;
+      return null;
+    }
+    
+    return this;
+  }
+};
+
+/* :::::::::: Asynchronous File Downloader :::::::::::::: */
+
+function AutoDownloader(aURL, aFilename, aWindow) {
+   this._URL = aURL;
+   this._filename = aFilename;
+   this._window = aWindow;
+}
+
+AutoDownloader.prototype = {
+  onStartRequest: function(aRequest, aContext) { },
+  onStopRequest: function(aRequest, aContext, aStatus) {
+    if (Components.isSuccessCode(aStatus)) {
+      var file =
+        Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsILocalFile);
+      file.initWithPath(this._filename);
+      if (file.exists()) {
+        file.remove(false);
+      }
+      
+      this._window.saveURL(this._URL, this._filename, null, true, true, null);
+    }
+  }
+};
+
+/* :::::::: Service Registration & Initialization ::::::::::::::: */
+
+/* ........ nsIModule .............. */
+
+const SessionStoreModule = {
+
+  getClassObject: function(aCompMgr, aCID, aIID) {
+    if (aCID.equals(CID)) {
+      return SessionStoreFactory;
+    }
+    
+    Components.returnCode = Cr.NS_ERROR_NOT_REGISTERED;
+    return null;
+  },
+
+  registerSelf: function(aCompMgr, aFileSpec, aLocation, aType) {
+    aCompMgr.QueryInterface(Ci.nsIComponentRegistrar);
+    aCompMgr.registerFactoryLocation(CID, CLASS_NAME, CONTRACT_ID, aFileSpec, aLocation, aType);
+
+    var catMan = Cc["@mozilla.org/categorymanager;1"].
+                 getService(Ci.nsICategoryManager);
+    catMan.addCategoryEntry("app-startup", CLASS_NAME, "service," + CONTRACT_ID, true, true);
+  },
+
+  unregisterSelf: function(aCompMgr, aLocation, aType) {
+    aCompMgr.QueryInterface(Ci.nsIComponentRegistrar);
+    aCompMgr.unregisterFactoryLocation(CID, aLocation);
+
+    var catMan = Cc["@mozilla.org/categorymanager;1"].
+                 getService(Ci.nsICategoryManager);
+    catMan.deleteCategoryEntry( "app-startup", "service," + CONTRACT_ID, true);
+  },
+
+  canUnload: function(aCompMgr) {
+    return true;
+  }
+}
+
+/* ........ nsIFactory .............. */
+
+const SessionStoreFactory = {
+
+  createInstance: function(aOuter, aIID) {
+    if (aOuter != null) {
+      Components.returnCode = Cr.NS_ERROR_NO_AGGREGATION;
+      return null;
+    }
+    
+    return (new SessionStoreService()).QueryInterface(aIID);
+  },
+
+  lockFactory: function(aLock) { },
+
+  QueryInterface: function(aIID) {
+    if (!aIID.equals(Ci.nsISupports) && !aIID.equals(Ci.nsIModule) &&
+        !aIID.equals(Ci.nsIFactory) && !aIID.equals(Ci.nsISessionStore)) {
+      Components.returnCode = Cr.NS_ERROR_NO_INTERFACE;
+      return null;
+    }
+    
+    return this;
+  }
+};
+
+const NoModule = {
+  getClassObject: function(aCompMgr, aCID, aIID) {
+    Components.returnCode = Cr.NS_ERROR_NOT_REGISTERED;
+    return null;
+  },
+  registerSelf: function(aCompMgr, aFileSpec, aLocation, aType) { return; },
+  unregisterSelf: function(aCompMgr, aLocation, aType) { return; },
+  canUnload: function(aCompMgr) { return true; }
+};
+
+
+function NSGetModule(aComMgr, aFileSpec) {
+  var prefs = Components.classes["@mozilla.org/preferences-service;1"]
+        .getService(Components.interfaces.nsIPrefBranch);
+  if(prefs.getBoolPref("extensions.torbutton.notor_sessionstore")) {
+    return SessionStoreModule;
+  } else {
+    return NoModule;
+  }
+}

Added: torbutton/trunk/src/components/nsSessionStore3.js
===================================================================
--- torbutton/trunk/src/components/nsSessionStore3.js	                        (rev 0)
+++ torbutton/trunk/src/components/nsSessionStore3.js	2008-06-22 09:39:28 UTC (rev 15413)
@@ -0,0 +1,2160 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the nsSessionStore component.
+ *
+ * The Initial Developer of the Original Code is
+ * Simon Bünzli <zeniko@xxxxxxxxx>
+ * Portions created by the Initial Developer are Copyright (C) 2006
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Dietrich Ayala <dietrich@xxxxxxxxxxx>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/**
+ * Session Storage and Restoration
+ * 
+ * Overview
+ * This service keeps track of a user's session, storing the various bits
+ * required to return the browser to it's current state. The relevant data is 
+ * stored in memory, and is periodically saved to disk in a file in the 
+ * profile directory. The service is started at first window load, in
+ * delayedStartup, and will restore the session from the data received from
+ * the nsSessionStartup service.
+ */
+
+/* :::::::: Constants and Helpers ::::::::::::::: */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+const Cu = Components.utils;
+
+const STATE_STOPPED = 0;
+const STATE_RUNNING = 1;
+const STATE_QUITTING = -1;
+const STATE_DISABLED = -2;
+
+const STATE_STOPPED_STR = "stopped";
+const STATE_RUNNING_STR = "running";
+
+const PRIVACY_NONE = 0;
+const PRIVACY_ENCRYPTED = 1;
+const PRIVACY_FULL = 2;
+
+const NOTIFY_WINDOWS_RESTORED = "sessionstore-windows-restored";
+
+// global notifications observed
+const OBSERVING = [
+  "domwindowopened", "domwindowclosed",
+  "quit-application-requested", "quit-application-granted",
+  "quit-application", "browser:purge-session-history"
+];
+
+/*
+XUL Window properties to (re)store
+Restored in restoreDimensions()
+*/
+const WINDOW_ATTRIBUTES = ["width", "height", "screenX", "screenY", "sizemode"];
+
+/* 
+Hideable window features to (re)store
+Restored in restoreWindowFeatures()
+*/
+const WINDOW_HIDEABLE_FEATURES = [
+  "menubar", "toolbar", "locationbar", 
+  "personalbar", "statusbar", "scrollbars"
+];
+
+/*
+docShell capabilities to (re)store
+Restored in restoreHistory()
+eg: browser.docShell["allow" + aCapability] = false;
+*/
+const CAPABILITIES = [
+  "Subframes", "Plugins", "Javascript", "MetaRedirects", "Images"
+];
+
+// module for JSON conversion (needed for the nsISessionStore API)
+Cu.import("resource://gre/modules/JSON.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+function debug(aMsg) {
+  aMsg = ("SessionStore: " + aMsg).replace(/\S{80}/g, "$&\n");
+  Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService)
+                                     .logStringMessage(aMsg);
+}
+
+/* :::::::: The Service ::::::::::::::: */
+
+function SessionStoreService() {
+}
+
+SessionStoreService.prototype = {
+  classDescription: "Browser Session Store Service",
+  contractID: "@mozilla.org/browser/sessionstore;1",
+  classID: Components.ID("{5280606b-2510-4fe0-97ef-9b5a22eafe6b}"),
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsISessionStore,
+                                         Ci.nsIDOMEventListener,
+                                         Ci.nsIObserver,
+                                         Ci.nsISupportsWeakReference]),
+
+  // xul:tab attributes to (re)store (extensions might want to hook in here)
+  xulAttributes: [],
+
+  // set default load state
+  _loadState: STATE_STOPPED,
+
+  // minimal interval between two save operations (in milliseconds)
+  _interval: 10000,
+
+  // when crash recovery is disabled, session data is not written to disk
+  _resume_from_crash: true,
+
+  // During the initial restore tracks the number of windows yet to be restored
+  _restoreCount: 0,
+
+  // time in milliseconds (Date.now()) when the session was last written to file
+  _lastSaveTime: 0, 
+
+  // states for all currently opened windows
+  _windows: {},
+
+  // in case the last closed window ain't a navigator:browser one
+  _lastWindowClosed: null,
+
+  // not-"dirty" windows usually don't need to have their data updated
+  _dirtyWindows: {},
+
+  // flag all windows as dirty
+  _dirty: false,
+
+/* ........ Global Event Handlers .............. */
+
+  /**
+   * Initialize the component
+   */
+  init: function sss_init(aWindow) {
+    if (this._loadState == STATE_DISABLED)
+      return;
+
+    if (!aWindow || this._loadState == STATE_RUNNING) {
+      // make sure that all browser windows which try to initialize
+      // SessionStore are really tracked by it
+      if (aWindow && (!aWindow.__SSi || !this._windows[aWindow.__SSi]))
+        this.onLoad(aWindow);
+      return;
+    }
+
+    this._prefBranch = Cc["@mozilla.org/preferences-service;1"].
+                       getService(Ci.nsIPrefService).getBranch("browser.");
+    this._prefBranch.QueryInterface(Ci.nsIPrefBranch2);
+
+    var observerService = Cc["@mozilla.org/observer-service;1"].
+                          getService(Ci.nsIObserverService);
+
+    // if the service is disabled, do not init 
+    if (!this._prefBranch.getBoolPref("sessionstore.enabled")) {
+      // Notify observers that the sessionstore has done everything it is going to.
+      observerService.notifyObservers(null, NOTIFY_WINDOWS_RESTORED, "");
+      // Mark as disabled so we don't even try to initialise again.
+      this._loadState = STATE_DISABLED;
+      return;
+    }
+
+    OBSERVING.forEach(function(aTopic) {
+      observerService.addObserver(this, aTopic, true);
+    }, this);
+    
+    // get interval from prefs - used often, so caching/observing instead of fetching on-demand
+    this._interval = this._prefBranch.getIntPref("sessionstore.interval");
+    this._prefBranch.addObserver("sessionstore.interval", this, true);
+    
+    // get crash recovery state from prefs and allow for proper reaction to state changes
+    this._resume_from_crash = this._prefBranch.getBoolPref("sessionstore.resume_from_crash");
+    this._prefBranch.addObserver("sessionstore.resume_from_crash", this, true);
+    
+    // observe prefs changes so we can modify stored data to match
+    this._prefBranch.addObserver("sessionstore.max_tabs_undo", this, true);
+
+    // get file references
+    var dirService = Cc["@mozilla.org/file/directory_service;1"].
+                     getService(Ci.nsIProperties);
+    this._sessionFile = dirService.get("ProfD", Ci.nsILocalFile);
+    this._sessionFileBackup = this._sessionFile.clone();
+    this._sessionFile.append("sessionstore.js");
+    this._sessionFileBackup.append("sessionstore.bak");
+   
+    // get string containing session state
+    var iniString;
+    try {
+      var ss = Cc["@mozilla.org/browser/sessionstartup;1"].
+               getService(Ci.nsISessionStartup);
+      if (ss.doRestore())
+        iniString = ss.state;
+    }
+    catch(ex) { dump(ex + "\n"); } // no state to restore, which is ok
+
+    if (iniString) {
+      try {
+        // parse the session state into JS objects
+        this._initialState = this._safeEval(iniString);
+        // set bool detecting crash
+        this._lastSessionCrashed =
+          this._initialState.session && this._initialState.session.state &&
+          this._initialState.session.state == STATE_RUNNING_STR;
+        
+        // restore the features of the first window from localstore.rdf
+        WINDOW_ATTRIBUTES.forEach(function(aAttr) {
+          delete this._initialState.windows[0][aAttr];
+        }, this);
+        delete this._initialState.windows[0].hidden;
+      }
+      catch (ex) { debug("The session file is invalid: " + ex); }
+    }
+    
+    // if last session crashed, backup the session
+    if (this._lastSessionCrashed) {
+      try {
+        this._writeFile(this._sessionFileBackup, iniString);
+      }
+      catch (ex) { } // nothing else we can do here
+    }
+
+    // remove the session data files if crash recovery is disabled
+    if (!this._resume_from_crash)
+      this._clearDisk();
+    
+    // As this is called at delayedStartup, restoration must be initiated here
+    this.onLoad(aWindow);
+  },
+
+  /**
+   * Called on application shutdown, after notifications:
+   * quit-application-granted, quit-application
+   */
+  _uninit: function sss_uninit() {
+    if (this._doResumeSession()) { // save all data for session resuming 
+      this.saveState(true);
+    }
+    else { // discard all session related data 
+      this._clearDisk();
+    }
+    // Make sure to break our cycle with the save timer
+    if (this._saveTimer) {
+      this._saveTimer.cancel();
+      this._saveTimer = null;
+    }
+  },
+
+  /**
+   * Handle notifications
+   */
+  observe: function sss_observe(aSubject, aTopic, aData) {
+    // for event listeners
+    var _this = this;
+
+    switch (aTopic) {
+    case "domwindowopened": // catch new windows
+      aSubject.addEventListener("load", function(aEvent) {
+        aEvent.currentTarget.removeEventListener("load", arguments.callee, false);
+        _this.onLoad(aEvent.currentTarget);
+        }, false);
+      break;
+    case "domwindowclosed": // catch closed windows
+      this.onClose(aSubject);
+      break;
+    case "quit-application-requested":
+      // get a current snapshot of all windows
+      this._forEachBrowserWindow(function(aWindow) {
+        this._collectWindowData(aWindow);
+      });
+      this._dirtyWindows = [];
+      this._dirty = false;
+      break;
+    case "quit-application-granted":
+      // freeze the data at what we've got (ignoring closing windows)
+      this._loadState = STATE_QUITTING;
+      break;
+    case "quit-application":
+      if (aData == "restart")
+        this._prefBranch.setBoolPref("sessionstore.resume_session_once", true);
+      this._loadState = STATE_QUITTING; // just to be sure
+      this._uninit();
+      break;
+    case "browser:purge-session-history": // catch sanitization 
+      this._forEachBrowserWindow(function(aWindow) {
+        Array.forEach(aWindow.getBrowser().browsers, function(aBrowser) {
+          delete aBrowser.parentNode.__SS_data;
+        });
+      });
+      this._lastWindowClosed = null;
+      this._clearDisk();
+      // also clear all data about closed tabs
+      for (ix in this._windows) {
+        this._windows[ix]._closedTabs = [];
+      }
+      // give the tabbrowsers a chance to clear their histories first
+      var win = this._getMostRecentBrowserWindow();
+      if (win)
+        win.setTimeout(function() { _this.saveState(true); }, 0);
+      else
+        this.saveState(true);
+      break;
+    case "nsPref:changed": // catch pref changes
+      switch (aData) {
+      // if the user decreases the max number of closed tabs they want
+      // preserved update our internal states to match that max
+      case "sessionstore.max_tabs_undo":
+        var ix;
+        for (ix in this._windows) {
+          this._windows[ix]._closedTabs.splice(this._prefBranch.getIntPref("sessionstore.max_tabs_undo"));
+        }
+        break;
+      case "sessionstore.interval":
+        this._interval = this._prefBranch.getIntPref("sessionstore.interval");
+        // reset timer and save
+        if (this._saveTimer) {
+          this._saveTimer.cancel();
+          this._saveTimer = null;
+        }
+        this.saveStateDelayed(null, -1);
+        break;
+      case "sessionstore.resume_from_crash":
+        this._resume_from_crash = this._prefBranch.getBoolPref("sessionstore.resume_from_crash");
+        // either create the file with crash recovery information or remove it
+        // (when _loadState is not STATE_RUNNING, that file is used for session resuming instead)
+        if (this._resume_from_crash)
+          this.saveState(true);
+        else if (this._loadState == STATE_RUNNING)
+          this._clearDisk();
+        break;
+      }
+      break;
+    case "timer-callback": // timer call back for delayed saving
+      this._saveTimer = null;
+      this.saveState();
+      break;
+    }
+  },
+
+/* ........ Window Event Handlers .............. */
+
+  /**
+   * Implement nsIDOMEventListener for handling various window and tab events
+   */
+  handleEvent: function sss_handleEvent(aEvent) {
+    switch (aEvent.type) {
+      case "load":
+      case "pageshow":
+        this.onTabLoad(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
+        break;
+      case "input":
+      case "DOMAutoComplete":
+        this.onTabInput(aEvent.currentTarget.ownerDocument.defaultView, aEvent.currentTarget, aEvent);
+        break;
+      case "TabOpen":
+      case "TabClose":
+        var panelID = aEvent.originalTarget.linkedPanel;
+        var tabpanel = aEvent.originalTarget.ownerDocument.getElementById(panelID);
+        if (aEvent.type == "TabOpen") {
+          this.onTabAdd(aEvent.currentTarget.ownerDocument.defaultView, tabpanel);
+        }
+        else {
+          this.onTabClose(aEvent.currentTarget.ownerDocument.defaultView, aEvent.originalTarget);
+          this.onTabRemove(aEvent.currentTarget.ownerDocument.defaultView, tabpanel);
+        }
+        break;
+      case "TabSelect":
+        var tabpanels = aEvent.currentTarget.mPanelContainer;
+        this.onTabSelect(aEvent.currentTarget.ownerDocument.defaultView, tabpanels);
+        break;
+    }
+  },
+
+  /**
+   * If it's the first window load since app start...
+   * - determine if we're reloading after a crash or a forced-restart
+   * - restore window state
+   * - restart downloads
+   * Set up event listeners for this window's tabs
+   * @param aWindow
+   *        Window reference
+   */
+  onLoad: function sss_onLoad(aWindow) {
+    // return if window has already been initialized
+    if (aWindow && aWindow.__SSi && this._windows[aWindow.__SSi])
+      return;
+
+    // ignore non-browser windows and windows opened while shutting down
+    if (aWindow.document.documentElement.getAttribute("windowtype") != "navigator:browser" ||
+      this._loadState == STATE_QUITTING)
+      return;
+
+    // assign it a unique identifier (timestamp)
+    aWindow.__SSi = "window" + Date.now();
+
+    // and create its data object
+    this._windows[aWindow.__SSi] = { tabs: [], selected: 0, _closedTabs: [] };
+    
+    // perform additional initialization when the first window is loading
+    if (this._loadState == STATE_STOPPED) {
+      this._loadState = STATE_RUNNING;
+      this._lastSaveTime = Date.now();
+      
+      // don't save during the first ten seconds
+      // (until most of the pages have been restored)
+      this.saveStateDelayed(aWindow, 10000);
+
+      // restore a crashed session resp. resume the last session if requested
+      if (this._initialState) {
+        // make sure that the restored tabs are first in the window
+        this._initialState._firstTabs = true;
+        this._restoreCount = this._initialState.windows ? this._initialState.windows.length : 0;
+        this.restoreWindow(aWindow, this._initialState, this._isCmdLineEmpty(aWindow));
+        delete this._initialState;
+      }
+      else {
+        // Nothing to restore, notify observers things are complete.
+        var observerService = Cc["@mozilla.org/observer-service;1"].
+                              getService(Ci.nsIObserverService);
+        observerService.notifyObservers(null, NOTIFY_WINDOWS_RESTORED, "");
+      }
+    }
+    
+    var tabbrowser = aWindow.getBrowser();
+    var tabpanels = tabbrowser.mPanelContainer;
+    
+    // add tab change listeners to all already existing tabs
+    for (var i = 0; i < tabpanels.childNodes.length; i++) {
+      this.onTabAdd(aWindow, tabpanels.childNodes[i], true);
+    }
+    // notification of tab add/remove/selection
+    tabbrowser.addEventListener("TabOpen", this, true);
+    tabbrowser.addEventListener("TabClose", this, true);
+    tabbrowser.addEventListener("TabSelect", this, true);
+  },
+
+  /**
+   * On window close...
+   * - remove event listeners from tabs
+   * - save all window data
+   * @param aWindow
+   *        Window reference
+   */
+  onClose: function sss_onClose(aWindow) {
+    // ignore windows not tracked by SessionStore
+    if (!aWindow.__SSi || !this._windows[aWindow.__SSi]) {
+      return;
+    }
+    
+    if (this.windowToFocus && this.windowToFocus == aWindow) {
+      delete this.windowToFocus;
+    }
+    
+    var tabbrowser = aWindow.getBrowser();
+    var tabpanels = tabbrowser.mPanelContainer;
+
+    tabbrowser.removeEventListener("TabOpen", this, true);
+    tabbrowser.removeEventListener("TabClose", this, true);
+    tabbrowser.removeEventListener("TabSelect", this, true);
+    
+    if (this._loadState == STATE_RUNNING) { // window not closed during a regular shut-down 
+      // update all window data for a last time
+      this._collectWindowData(aWindow);
+      
+      // preserve this window's data (in case it was the last navigator:browser)
+      this._lastWindowClosed = this._windows[aWindow.__SSi];
+      this._lastWindowClosed.title = aWindow.content.document.title;
+      this._updateCookies([this._lastWindowClosed]);
+      
+      // clear this window from the list
+      delete this._windows[aWindow.__SSi];
+      
+      // save the state without this window to disk
+      this.saveStateDelayed();
+    }
+    
+    for (var i = 0; i < tabpanels.childNodes.length; i++) {
+      this.onTabRemove(aWindow, tabpanels.childNodes[i], true);
+    }
+    
+    // cache the window state until the window is completely gone
+    aWindow.__SS_dyingCache = this._windows[aWindow.__SSi] || this._lastWindowClosed;
+    
+    // reset the _tab property to avoid keeping the tab's XUL element alive
+    // longer than we need it
+    var tabCount = aWindow.__SS_dyingCache.tabs.length;
+    for (var t = 0; t < tabCount; t++) {
+      delete aWindow.__SS_dyingCache.tabs[t]._tab;
+    }
+    
+    delete aWindow.__SSi;
+  },
+
+  /**
+   * set up listeners for a new tab
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aNoNotification
+   *        bool Do not save state if we're updating an existing tab
+   */
+  onTabAdd: function sss_onTabAdd(aWindow, aPanel, aNoNotification) {
+    aPanel.addEventListener("load", this, true);
+    aPanel.addEventListener("pageshow", this, true);
+    aPanel.addEventListener("input", this, true);
+    aPanel.addEventListener("DOMAutoComplete", this, true);
+    
+    if (!aNoNotification) {
+      this.saveStateDelayed(aWindow);
+    }
+  },
+
+  /**
+   * remove listeners for a tab
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aNoNotification
+   *        bool Do not save state if we're updating an existing tab
+   */
+  onTabRemove: function sss_onTabRemove(aWindow, aPanel, aNoNotification) {
+    aPanel.removeEventListener("load", this, true);
+    aPanel.removeEventListener("pageshow", this, true);
+    aPanel.removeEventListener("input", this, true);
+    aPanel.removeEventListener("DOMAutoComplete", this, true);
+    
+    delete aPanel.__SS_data;
+    delete aPanel.__SS_text;
+    
+    if (!aNoNotification) {
+      this.saveStateDelayed(aWindow);
+    }
+  },
+
+  /**
+   * When a tab closes, collect it's properties
+   * @param aWindow
+   *        Window reference
+   * @param aTab
+   *        TabPanel reference
+   */
+  onTabClose: function sss_onTabClose(aWindow, aTab) {
+    // notify the tabbrowser that the tab state will be retrieved for the last time
+    // (so that extension authors can easily set data on soon-to-be-closed tabs)
+    var event = aWindow.document.createEvent("Events");
+    event.initEvent("SSTabClosing", true, false);
+    aTab.dispatchEvent(event);
+    
+    var maxTabsUndo = this._prefBranch.getIntPref("sessionstore.max_tabs_undo");
+    // don't update our internal state if we don't have to
+    if (maxTabsUndo == 0) {
+      return;
+    }
+    
+    // make sure that the tab related data is up-to-date
+    var tabState = this._collectTabData(aTab);
+    this._updateTextAndScrollDataForTab(aWindow, aTab.linkedBrowser, tabState);
+
+    // reset the _tab property to avoid keeping the tab's XUL element alive
+    // longer than we need it
+    delete tabState._tab;
+    
+    // store closed-tab data for undo
+    if (tabState.entries.length > 1 || tabState.entries[0].url != "about:blank") {
+      this._windows[aWindow.__SSi]._closedTabs.unshift({
+        state: tabState,
+        title: aTab.getAttribute("label"),
+        image: aTab.getAttribute("image"),
+        pos: aTab._tPos
+      });
+      var length = this._windows[aWindow.__SSi]._closedTabs.length;
+      if (length > maxTabsUndo)
+        this._windows[aWindow.__SSi]._closedTabs.splice(maxTabsUndo, length - maxTabsUndo);
+    }
+  },
+
+  /**
+   * When a tab loads, save state.
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aEvent
+   *        Event obj
+   */
+  onTabLoad: function sss_onTabLoad(aWindow, aPanel, aEvent) { 
+    // react on "load" and solitary "pageshow" events (the first "pageshow"
+    // following "load" is too late for deleting the data caches)
+    if (aEvent.type != "load" && !aEvent.persisted) {
+      return;
+    }
+    
+    delete aPanel.__SS_data;
+    delete aPanel.__SS_text;
+    this.saveStateDelayed(aWindow);
+    
+    // attempt to update the current URL we send in a crash report
+    this._updateCrashReportURL(aWindow);
+  },
+
+  /**
+   * Called when a tabpanel sends the "input" notification 
+   * stores textarea data
+   * @param aWindow
+   *        Window reference
+   * @param aPanel
+   *        TabPanel reference
+   * @param aEvent
+   *        Event obj
+   */
+  onTabInput: function sss_onTabInput(aWindow, aPanel, aEvent) {
+    if (this._saveTextData(aPanel, aEvent.originalTarget)) {
+      this.saveStateDelayed(aWindow, 3000);
+    }
+  },
+
+  /**
+   * When a tab is selected, save session data
+   * @param aWindow
+   *        Window reference
+   * @param aPanels
+   *        TabPanel reference
+   */
+  onTabSelect: function sss_onTabSelect(aWindow, aPanels) {
+    if (this._loadState == STATE_RUNNING) {
+      this._windows[aWindow.__SSi].selected = aPanels.selectedIndex;
+      this.saveStateDelayed(aWindow);
+
+      // attempt to update the current URL we send in a crash report
+      this._updateCrashReportURL(aWindow);
+    }
+  },
+
+/* ........ nsISessionStore API .............. */
+
+  getBrowserState: function sss_getBrowserState() {
+    return this._toJSONString(this._getCurrentState());
+  },
+
+  setBrowserState: function sss_setBrowserState(aState) {
+    var window = this._getMostRecentBrowserWindow();
+    if (!window) {
+      this._openWindowWithState("(" + aState + ")");
+      return;
+    }
+
+    // close all other browser windows
+    this._forEachBrowserWindow(function(aWindow) {
+      if (aWindow != window) {
+        aWindow.close();
+      }
+    });
+
+    // restore to the given state
+    this.restoreWindow(window, "(" + aState + ")", true);
+  },
+
+  getWindowState: function sss_getWindowState(aWindow) {
+    if (!aWindow.__SSi && aWindow.__SS_dyingCache)
+      return this._toJSONString({ windows: [aWindow.__SS_dyingCache] });
+    
+    return this._toJSONString(this._getWindowState(aWindow));
+  },
+
+  setWindowState: function sss_setWindowState(aWindow, aState, aOverwrite) {
+    this.restoreWindow(aWindow, "(" + aState + ")", aOverwrite);
+  },
+
+  getTabState: function sss_getTabState(aTab) {
+    var tabState = this._collectTabData(aTab);
+    
+    var window = aTab.ownerDocument.defaultView;
+    this._updateTextAndScrollDataForTab(window, aTab.linkedBrowser, tabState);
+    
+    return this._toJSONString(tabState);
+  },
+
+  setTabState: function sss_setTabState(aTab, aState) {
+    var tabState = this._safeEval("(" + aState + ")");
+    if (!tabState.entries || !tabState.entries.length) {
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+      return;
+    }
+    tabState._tab = aTab;
+    
+    var window = aTab.ownerDocument.defaultView;
+    this.restoreHistoryPrecursor(window, [tabState], 0, 0, 0);
+  },
+
+  duplicateTab: function sss_duplicateTab(aWindow, aTab) {
+    var tabState = this._collectTabData(aTab, true);
+    var sourceWindow = aTab.ownerDocument.defaultView;
+    this._updateTextAndScrollDataForTab(sourceWindow, aTab.linkedBrowser, tabState, true);
+    
+    var newTab = aWindow.getBrowser().addTab();
+    tabState._tab = newTab;
+    this.restoreHistoryPrecursor(aWindow, [tabState], 0, 0, 0);
+    
+    return newTab;
+  },
+
+  getClosedTabCount: function sss_getClosedTabCount(aWindow) {
+    if (!aWindow.__SSi && aWindow.__SS_dyingCache)
+      return aWindow.__SS_dyingCache._closedTabs.length;
+    if (!aWindow.__SSi)
+      return 0; // not a browser window, or not otherwise tracked by SS.
+    
+    return this._windows[aWindow.__SSi]._closedTabs.length;
+  },
+
+  closedTabNameAt: function sss_closedTabNameAt(aWindow, aIx) {
+    var tabs;
+    
+    if (aWindow.__SSi && aWindow.__SSi in this._windows)
+      tabs = this._windows[aWindow.__SSi]._closedTabs;
+    else if (aWindow.__SS_dyingCache)
+      tabs = aWindow.__SS_dyingCache._closedTabs;
+    else
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+    
+    return tabs && aIx in tabs ? tabs[aIx].title : null;
+  },
+
+  getClosedTabData: function sss_getClosedTabDataAt(aWindow) {
+    if (!aWindow.__SSi && aWindow.__SS_dyingCache)
+      return this._toJSONString(aWindow.__SS_dyingCache._closedTabs);
+    
+    return this._toJSONString(this._windows[aWindow.__SSi]._closedTabs);
+  },
+
+  undoCloseTab: function sss_undoCloseTab(aWindow, aIndex) {
+    var closedTabs = this._windows[aWindow.__SSi]._closedTabs;
+
+    // default to the most-recently closed tab
+    aIndex = aIndex || 0;
+
+    if (aIndex in closedTabs) {
+      var browser = aWindow.getBrowser();
+
+      // fetch the data of closed tab, while removing it from the array
+      var closedTab = closedTabs.splice(aIndex, 1).shift();
+      var closedTabState = closedTab.state;
+
+      // create a new tab
+      closedTabState._tab = browser.addTab();
+        
+      // restore the tab's position
+      browser.moveTabTo(closedTabState._tab, closedTab.pos);
+  
+      // restore tab content
+      this.restoreHistoryPrecursor(aWindow, [closedTabState], 1, 0, 0);
+
+      // focus the tab's content area
+      var content = browser.getBrowserForTab(closedTabState._tab).contentWindow;
+      aWindow.setTimeout(function() { content.focus(); }, 0);
+    }
+    else {
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+    }
+  },
+
+  getWindowValue: function sss_getWindowValue(aWindow, aKey) {
+    if (aWindow.__SSi) {
+      var data = this._windows[aWindow.__SSi].extData || {};
+      return data[aKey] || "";
+    }
+    else if (aWindow.__SS_dyingCache) {
+      data = aWindow.__SS_dyingCache.extData || {};
+      return data[aKey] || "";
+    }
+    else {
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+    }
+  },
+
+  setWindowValue: function sss_setWindowValue(aWindow, aKey, aStringValue) {
+    if (aWindow.__SSi) {
+      if (!this._windows[aWindow.__SSi].extData) {
+        this._windows[aWindow.__SSi].extData = {};
+      }
+      this._windows[aWindow.__SSi].extData[aKey] = aStringValue;
+      this.saveStateDelayed(aWindow);
+    }
+    else {
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+    }
+  },
+
+  deleteWindowValue: function sss_deleteWindowValue(aWindow, aKey) {
+    if (this._windows[aWindow.__SSi].extData[aKey])
+      delete this._windows[aWindow.__SSi].extData[aKey];
+    else
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+  },
+
+  getTabValue: function sss_getTabValue(aTab, aKey) {
+    var data = aTab.__SS_extdata || {};
+    return data[aKey] || "";
+  },
+
+  setTabValue: function sss_setTabValue(aTab, aKey, aStringValue) {
+    if (!aTab.__SS_extdata) {
+      aTab.__SS_extdata = {};
+    }
+    aTab.__SS_extdata[aKey] = aStringValue;
+    this.saveStateDelayed(aTab.ownerDocument.defaultView);
+  },
+
+  deleteTabValue: function sss_deleteTabValue(aTab, aKey) {
+    if (aTab.__SS_extdata[aKey])
+      delete aTab.__SS_extdata[aKey];
+    else
+      Components.returnCode = Cr.NS_ERROR_INVALID_ARG;
+  },
+
+
+  persistTabAttribute: function sss_persistTabAttribute(aName) {
+    this.xulAttributes.push(aName);
+    this.saveStateDelayed();
+  },
+
+/* ........ Saving Functionality .............. */
+
+  /**
+   * Store all session data for a window
+   * @param aWindow
+   *        Window reference
+   */
+  _saveWindowHistory: function sss_saveWindowHistory(aWindow) {
+    var tabbrowser = aWindow.getBrowser();
+    var tabs = tabbrowser.mTabs;
+    var tabsData = this._windows[aWindow.__SSi].tabs = [];
+    
+    for (var i = 0; i < tabs.length; i++)
+      tabsData.push(this._collectTabData(tabs[i]));
+    
+    this._windows[aWindow.__SSi].selected = tabbrowser.mTabBox.selectedIndex + 1;
+  },
+
+  /**
+   * Collect data related to a single tab
+   * @param aTab
+   *        tabbrowser tab
+   * @param aFullData
+   *        always return privacy sensitive data (use with care)
+   * @returns object
+   */
+  _collectTabData: function sss_collectTabData(aTab, aFullData) {
+    var tabData = { entries: [], index: 0 };
+    var browser = aTab.linkedBrowser;
+    
+    if (!browser || !browser.currentURI)
+      // can happen when calling this function right after .addTab()
+      return tabData;
+    else if (browser.parentNode.__SS_data && browser.parentNode.__SS_data._tab)
+      // use the data to be restored when the tab hasn't been completely loaded
+      return browser.parentNode.__SS_data;
+    
+    var history = null;
+    try {
+      history = browser.sessionHistory;
+    }
+    catch (ex) { } // this could happen if we catch a tab during (de)initialization
+    
+    if (history && browser.parentNode.__SS_data &&
+        browser.parentNode.__SS_data.entries[history.index] && !aFullData) {
+      tabData = browser.parentNode.__SS_data;
+      tabData.index = history.index + 1;
+    }
+    else if (history && history.count > 0) {
+      for (var j = 0; j < history.count; j++)
+        tabData.entries.push(this._serializeHistoryEntry(history.getEntryAtIndex(j, false),
+                                                         aFullData));
+      tabData.index = history.index + 1;
+
+      // make sure not to cache privacy sensitive data which shouldn't get out
+      if (!aFullData)
+        browser.parentNode.__SS_data = tabData;
+    }
+    else {
+      tabData.entries[0] = { url: browser.currentURI.spec };
+      tabData.index = 1;
+    }
+    
+    var disallow = [];
+    for (var i = 0; i < CAPABILITIES.length; i++)
+      if (!browser.docShell["allow" + CAPABILITIES[i]])
+        disallow.push(CAPABILITIES[i]);
+    if (disallow.length > 0)
+      tabData.disallow = disallow.join(",");
+    else if (tabData.disallow)
+      delete tabData.disallow;
+    
+    if (this.xulAttributes.length > 0) {
+      var xulattr = Array.filter(aTab.attributes, function(aAttr) {
+        return this.xulAttributes.indexOf(aAttr.name) > -1;
+      }, this).map(function(aAttr) {
+        return aAttr.name + "=" + encodeURI(aAttr.value);
+      });
+      tabData.xultab = xulattr.join(" ");
+    }
+    
+    if (aTab.__SS_extdata)
+      tabData.extData = aTab.__SS_extdata;
+    else if (tabData.extData)
+      delete tabData.extData;
+    
+    return tabData;
+  },
+
+  /**
+   * Get an object that is a serialized representation of a History entry
+   * Used for data storage
+   * @param aEntry
+   *        nsISHEntry instance
+   * @param aFullData
+   *        always return privacy sensitive data (use with care)
+   * @returns object
+   */
+  _serializeHistoryEntry: function sss_serializeHistoryEntry(aEntry, aFullData) {
+    var entry = { url: aEntry.URI.spec };
+    
+    if (aEntry.title && aEntry.title != entry.url) {
+      entry.title = aEntry.title;
+    }
+    if (aEntry.isSubFrame) {
+      entry.subframe = true;
+    }
+    if (!(aEntry instanceof Ci.nsISHEntry)) {
+      return entry;
+    }
+    
+    var cacheKey = aEntry.cacheKey;
+    if (cacheKey && cacheKey instanceof Ci.nsISupportsPRUint32 &&
+        cacheKey.data != 0) {
+      // XXXbz would be better to have cache keys implement
+      // nsISerializable or something.
+      entry.cacheKey = cacheKey.data;
+    }
+    entry.ID = aEntry.ID;
+    
+    if (aEntry.contentType)
+      entry.contentType = aEntry.contentType;
+    
+    var x = {}, y = {};
+    aEntry.getScrollPosition(x, y);
+    if (x.value != 0 || y.value != 0)
+      entry.scroll = x.value + "," + y.value;
+    
+    try {
+      var prefPostdata = this._prefBranch.getIntPref("sessionstore.postdata");
+      if (aEntry.postData && (aFullData ||
+            prefPostdata && this._checkPrivacyLevel(aEntry.URI.schemeIs("https")))) {
+        aEntry.postData.QueryInterface(Ci.nsISeekableStream).
+                        seek(Ci.nsISeekableStream.NS_SEEK_SET, 0);
+        var stream = Cc["@mozilla.org/binaryinputstream;1"].
+                     createInstance(Ci.nsIBinaryInputStream);
+        stream.setInputStream(aEntry.postData);
+        var postBytes = stream.readByteArray(stream.available());
+        var postdata = String.fromCharCode.apply(null, postBytes);
+        if (aFullData || prefPostdata == -1 ||
+            postdata.replace(/^(Content-.*\r\n)+(\r\n)*/, "").length <=
+              prefPostdata) {
+          // We can stop doing base64 encoding once our serialization into JSON
+          // is guaranteed to handle all chars in strings, including embedded
+          // nulls.
+          entry.postdata_b64 = btoa(postdata);
+        }
+      }
+    }
+    catch (ex) { debug(ex); } // POSTDATA is tricky - especially since some extensions don't get it right
+
+    if (aEntry.owner) {
+      // Not catching anything specific here, just possible errors
+      // from writeCompoundObject and the like.
+      try {
+        var binaryStream = Cc["@mozilla.org/binaryoutputstream;1"].
+                           createInstance(Ci.nsIObjectOutputStream);
+        var pipe = Cc["@mozilla.org/pipe;1"].createInstance(Ci.nsIPipe);
+        pipe.init(false, false, 0, 0xffffffff, null);
+        binaryStream.setOutputStream(pipe.outputStream);
+        binaryStream.writeCompoundObject(aEntry.owner, Ci.nsISupports, true);
+        binaryStream.close();
+
+        // Now we want to read the data from the pipe's input end and encode it.
+        var scriptableStream = Cc["@mozilla.org/binaryinputstream;1"].
+                               createInstance(Ci.nsIBinaryInputStream);
+        scriptableStream.setInputStream(pipe.inputStream);
+        var ownerBytes =
+          scriptableStream.readByteArray(scriptableStream.available());
+        // We can stop doing base64 encoding once our serialization into JSON
+        // is guaranteed to handle all chars in strings, including embedded
+        // nulls.
+        entry.owner_b64 = btoa(String.fromCharCode.apply(null, ownerBytes));
+      }
+      catch (ex) { debug(ex); }
+    }
+    
+    if (!(aEntry instanceof Ci.nsISHContainer)) {
+      return entry;
+    }
+    
+    if (aEntry.childCount > 0) {
+      entry.children = [];
+      for (var i = 0; i < aEntry.childCount; i++) {
+        var child = aEntry.GetChildAt(i);
+        if (child) {
+          entry.children.push(this._serializeHistoryEntry(child, aFullData));
+        }
+        else { // to maintain the correct frame order, insert a dummy entry 
+          entry.children.push({ url: "about:blank" });
+        }
+      }
+    }
+    
+    return entry;
+  },
+
+  /**
+   * Updates the current document's cache of user entered text data
+   * @param aPanel
+   *        TabPanel reference
+   * @param aTextarea
+   *        HTML content element
+   * @returns bool
+   */
+  _saveTextData: function sss_saveTextData(aPanel, aTextarea) {
+    var id = aTextarea.id ? "#" + aTextarea.id :
+                            aTextarea.name;
+    if (!id
+      || !(aTextarea instanceof Ci.nsIDOMHTMLTextAreaElement 
+      || aTextarea instanceof Ci.nsIDOMHTMLInputElement)) {
+      return false; // nothing to save
+    }
+    
+    if (!aPanel.__SS_text) {
+      aPanel.__SS_text = [];
+      aPanel.__SS_text._refs = [];
+    }
+    
+    // get the index of the reference to the text element
+    var ix = aPanel.__SS_text._refs.indexOf(aTextarea);
+    if (ix == -1) {
+      // we haven't registered this text element yet - do so now
+      aPanel.__SS_text._refs.push(aTextarea);
+      ix = aPanel.__SS_text.length;
+    }
+    else if (!aPanel.__SS_text[ix].cache) {
+      // we've already marked this text element for saving (the cache is
+      // added during save operations and would have to be updated here)
+      return false;
+    }
+    
+    // determine the frame we're in and encode it into the textarea's ID
+    var content = aTextarea.ownerDocument.defaultView;
+    while (content != content.top) {
+      var frames = content.parent.frames;
+      for (var i = 0; i < frames.length && frames[i] != content; i++);
+      id = i + "|" + id;
+      content = content.parent;
+    }
+    
+    // mark this element for saving
+    aPanel.__SS_text[ix] = { id: id, element: aTextarea };
+    
+    return true;
+  },
+
+  /**
+   * go through all tabs and store the current scroll positions
+   * and innerHTML content of WYSIWYG editors
+   * @param aWindow
+   *        Window reference
+   */
+  _updateTextAndScrollData: function sss_updateTextAndScrollData(aWindow) {
+    var browsers = aWindow.getBrowser().browsers;
+    for (var i = 0; i < browsers.length; i++) {
+      try {
+        var tabData = this._windows[aWindow.__SSi].tabs[i];
+        if (tabData.entries.length == 0 ||
+            browsers[i].parentNode.__SS_data && browsers[i].parentNode.__SS_data._tab)
+          continue; // ignore incompletely initialized tabs
+        this._updateTextAndScrollDataForTab(aWindow, browsers[i], tabData);
+      }
+      catch (ex) { debug(ex); } // get as much data as possible, ignore failures (might succeed the next time)
+    }
+  },
+
+  /**
+   * go through all frames and store the current scroll positions
+   * and innerHTML content of WYSIWYG editors
+   * @param aWindow
+   *        Window reference
+   * @param aBrowser
+   *        single browser reference
+   * @param aTabData
+   *        tabData object to add the information to
+   * @param aFullData
+   *        always return privacy sensitive data (use with care)
+   */
+  _updateTextAndScrollDataForTab:
+    function sss_updateTextAndScrollDataForTab(aWindow, aBrowser, aTabData, aFullData) {
+    var text = [];
+    if (aBrowser.parentNode.__SS_text &&
+        (aFullData || this._checkPrivacyLevel(aBrowser.currentURI.schemeIs("https")))) {
+      for (var ix = aBrowser.parentNode.__SS_text.length - 1; ix >= 0; ix--) {
+        var data = aBrowser.parentNode.__SS_text[ix];
+        if (!data.cache)
+          // update the text element's value before adding it to the data structure
+          data.cache = encodeURI(data.element.value);
+        text.push(data.id + "=" + data.cache);
+      }
+    }
+    if (aBrowser.currentURI.spec == "about:config")
+      text = ["#textbox=" + encodeURI(aBrowser.contentDocument.getElementById("textbox").
+                                               wrappedJSObject.value)];
+    if (text.length > 0)
+      aTabData.text = text.join(" ");
+    else if (aTabData.text)
+      delete aTabData.text;
+    
+    var tabIndex = (aTabData.index || aTabData.entries.length) - 1;
+    // entry data needn't exist for tabs just initialized with an incomplete session state
+    if (aTabData.entries[tabIndex])
+      this._updateTextAndScrollDataForFrame(aWindow, aBrowser.contentWindow,
+                                            aTabData.entries[tabIndex], aFullData);
+  },
+
+  /**
+   * go through all subframes and store the current scroll positions
+   * and innerHTML content of WYSIWYG editors
+   * @param aWindow
+   *        Window reference
+   * @param aContent
+   *        frame reference
+   * @param aData
+   *        part of a tabData object to add the information to
+   * @param aFullData
+   *        always return privacy sensitive data (use with care)
+   */
+  _updateTextAndScrollDataForFrame:
+    function sss_updateTextAndScrollDataForFrame(aWindow, aContent, aData, aFullData) {
+    for (var i = 0; i < aContent.frames.length; i++) {
+      if (aData.children && aData.children[i])
+        this._updateTextAndScrollDataForFrame(aWindow, aContent.frames[i], aData.children[i], aFullData);
+    }
+    // designMode is undefined e.g. for XUL documents (as about:config)
+    var isHTTPS = this._getURIFromString((aContent.parent || aContent).
+                                         document.location.href).schemeIs("https");
+    if ((aContent.document.designMode || "") == "on" &&
+        (aFullData || this._checkPrivacyLevel(isHTTPS))) {
+      if (aData.innerHTML === undefined && !aFullData) {
+        // we get no "input" events from iframes - listen for keypress here
+        var _this = this;
+        aContent.addEventListener("keypress", function(aEvent) {
+          _this.saveStateDelayed(aWindow, 3000); }, true);
+      }
+      aData.innerHTML = aContent.document.body.innerHTML;
+    }
+    aData.scroll = aContent.scrollX + "," + aContent.scrollY;
+   },
+
+  /**
+   * store all hosts for a URL
+   * @param aWindow
+   *        Window reference
+   */
+  _updateCookieHosts: function sss_updateCookieHosts(aWindow) {
+    var hosts = this._windows[aWindow.__SSi]._hosts = {};
+    
+    // get all possible subdomain levels for a given URL
+    var _this = this;
+    function extractHosts(aEntry) {
+      if (/^https?:\/\/(?:[^@\/\s]+@)?([\w.-]+)/.test(aEntry.url) &&
+        !hosts[RegExp.$1] && _this._checkPrivacyLevel(_this._getURIFromString(aEntry.url).schemeIs("https"))) {
+        var host = RegExp.$1;
+        var ix;
+        for (ix = host.indexOf(".") + 1; ix; ix = host.indexOf(".", ix) + 1) {
+          hosts[host.substr(ix)] = true;
+        }
+        hosts[host] = true;
+      }
+      else if (/^file:\/\/([^\/]*)/.test(aEntry.url)) {
+        hosts[RegExp.$1] = true;
+      }
+      if (aEntry.children) {
+        aEntry.children.forEach(extractHosts);
+      }
+    }
+    
+    this._windows[aWindow.__SSi].tabs.forEach(function(aTabData) { aTabData.entries.forEach(extractHosts); });
+  },
+
+  /**
+   * Serialize cookie data
+   * @param aWindows
+   *        array of Window references
+   */
+  _updateCookies: function sss_updateCookies(aWindows) {
+    var cookiesEnum = Cc["@mozilla.org/cookiemanager;1"].
+                      getService(Ci.nsICookieManager).enumerator;
+    // collect the cookies per window
+    for (var i = 0; i < aWindows.length; i++)
+      aWindows[i].cookies = [];
+    
+    // MAX_EXPIRY should be 2^63-1, but JavaScript can't handle that precision
+    var MAX_EXPIRY = Math.pow(2, 62);
+    while (cookiesEnum.hasMoreElements()) {
+      var cookie = cookiesEnum.getNext().QueryInterface(Ci.nsICookie2);
+      if (cookie.isSession && this._checkPrivacyLevel(cookie.isSecure)) {
+        var jscookie = null;
+        aWindows.forEach(function(aWindow) {
+          if (aWindow._hosts && aWindow._hosts[cookie.rawHost]) {
+            // serialize the cookie when it's first needed
+            if (!jscookie) {
+              jscookie = { host: cookie.host, value: cookie.value };
+              // only add attributes with non-default values (saving a few bits)
+              if (cookie.path) jscookie.path = cookie.path;
+              if (cookie.name) jscookie.name = cookie.name;
+              if (cookie.isSecure) jscookie.secure = true;
+              if (cookie.isHttpOnly) jscookie.httponly = true;
+              if (cookie.expiry < MAX_EXPIRY) jscookie.expiry = cookie.expiry;
+            }
+            aWindow.cookies.push(jscookie);
+          }
+        });
+      }
+    }
+    
+    // don't include empty cookie sections
+    for (i = 0; i < aWindows.length; i++)
+      if (aWindows[i].cookies.length == 0)
+        delete aWindows[i].cookies;
+  },
+
+  /**
+   * Store window dimensions, visibility, sidebar
+   * @param aWindow
+   *        Window reference
+   */
+  _updateWindowFeatures: function sss_updateWindowFeatures(aWindow) {
+    var winData = this._windows[aWindow.__SSi];
+    
+    WINDOW_ATTRIBUTES.forEach(function(aAttr) {
+      winData[aAttr] = this._getWindowDimension(aWindow, aAttr);
+    }, this);
+    
+    var hidden = WINDOW_HIDEABLE_FEATURES.filter(function(aItem) {
+      return aWindow[aItem] && !aWindow[aItem].visible;
+    });
+    if (hidden.length != 0)
+      winData.hidden = hidden.join(",");
+    else if (winData.hidden)
+      delete winData.hidden;
+
+    var sidebar = aWindow.document.getElementById("sidebar-box").getAttribute("sidebarcommand");
+    if (sidebar)
+      winData.sidebar = sidebar;
+    else if (winData.sidebar)
+      delete winData.sidebar;
+  },
+
+  /**
+   * serialize session data as Ini-formatted string
+   * @returns string
+   */
+  _getCurrentState: function sss_getCurrentState() {
+    var activeWindow = this._getMostRecentBrowserWindow();
+    
+    if (this._loadState == STATE_RUNNING) {
+      // update the data for all windows with activities since the last save operation
+      this._forEachBrowserWindow(function(aWindow) {
+        if (this._dirty || this._dirtyWindows[aWindow.__SSi] || aWindow == activeWindow) {
+          this._collectWindowData(aWindow);
+        }
+        else { // always update the window features (whose change alone never triggers a save operation)
+          this._updateWindowFeatures(aWindow);
+        }
+      }, this);
+      this._dirtyWindows = [];
+      this._dirty = false;
+    }
+    
+    // collect the data for all windows
+    var total = [], windows = [];
+    var ix;
+    for (ix in this._windows) {
+      total.push(this._windows[ix]);
+      windows.push(ix);
+    }
+    this._updateCookies(total);
+    
+    // if no browser window remains open, return the state of the last closed window
+    if (total.length == 0 && this._lastWindowClosed) {
+      total.push(this._lastWindowClosed);
+    }
+    if (activeWindow) {
+      this.activeWindowSSiCache = activeWindow.__SSi || "";
+    }
+    ix = this.activeWindowSSiCache ? windows.indexOf(this.activeWindowSSiCache) : -1;
+
+    return { windows: total, selectedWindow: ix + 1 };
+  },
+
+  /**
+   * serialize session data for a window 
+   * @param aWindow
+   *        Window reference
+   * @returns string
+   */
+  _getWindowState: function sss_getWindowState(aWindow) {
+    if (this._loadState == STATE_RUNNING) {
+      this._collectWindowData(aWindow);
+    }
+    
+    var total = [this._windows[aWindow.__SSi]];
+    this._updateCookies(total);
+    
+    return { windows: total };
+  },
+
+  _collectWindowData: function sss_collectWindowData(aWindow) {
+    // update the internal state data for this window
+    this._saveWindowHistory(aWindow);
+    this._updateTextAndScrollData(aWindow);
+    this._updateCookieHosts(aWindow);
+    this._updateWindowFeatures(aWindow);
+    
+    this._dirtyWindows[aWindow.__SSi] = false;
+  },
+
+/* ........ Restoring Functionality .............. */
+
+  /**
+   * restore features to a single window
+   * @param aWindow
+   *        Window reference
+   * @param aState
+   *        JS object or its eval'able source
+   * @param aOverwriteTabs
+   *        bool overwrite existing tabs w/ new ones
+   * @param aFollowUp
+   *        bool this isn't the restoration of the first window
+   */
+  restoreWindow: function sss_restoreWindow(aWindow, aState, aOverwriteTabs, aFollowUp) {
+    if (this._restoreCount) {
+      this._restoreCount--;
+      if (this._restoreCount == 0) {
+        // This was the last window restored at startup, notify observers.
+        var observerService = Cc["@mozilla.org/observer-service;1"].
+                              getService(Ci.nsIObserverService);
+        observerService.notifyObservers(null, NOTIFY_WINDOWS_RESTORED, "");
+      }
+    }
+
+    if (!aFollowUp) {
+      this.windowToFocus = aWindow;
+    }
+    // initialize window if necessary
+    if (aWindow && (!aWindow.__SSi || !this._windows[aWindow.__SSi]))
+      this.onLoad(aWindow);
+
+    try {
+      var root = typeof aState == "string" ? this._safeEval(aState) : aState;
+      if (!root.windows[0]) {
+        return; // nothing to restore
+      }
+    }
+    catch (ex) { // invalid state object - don't restore anything 
+      debug(ex);
+      return;
+    }
+    
+    var winData;
+    if (!aState.selectedWindow) {
+      aState.selectedWindow = 0;
+    }
+    // open new windows for all further window entries of a multi-window session
+    // (unless they don't contain any tab data)
+    for (var w = 1; w < root.windows.length; w++) {
+      winData = root.windows[w];
+      if (winData && winData.tabs && winData.tabs[0]) {
+        var window = this._openWindowWithState({ windows: [winData] });
+        if (w == aState.selectedWindow - 1) {
+          this.windowToFocus = window;
+        }
+      }
+    }
+    winData = root.windows[0];
+    if (!winData.tabs) {
+      winData.tabs = [];
+    }
+    
+    var tabbrowser = aWindow.getBrowser();
+    var openTabCount = aOverwriteTabs ? tabbrowser.browsers.length : -1;
+    var newTabCount = winData.tabs.length;
+    
+    for (var t = 0; t < newTabCount; t++) {
+      winData.tabs[t]._tab = t < openTabCount ? tabbrowser.mTabs[t] : tabbrowser.addTab();
+      // when resuming at startup: add additionally requested pages to the end
+      if (!aOverwriteTabs && root._firstTabs) {
+        tabbrowser.moveTabTo(winData.tabs[t]._tab, t);
+      }
+    }
+
+    // when overwriting tabs, remove all superflous ones
+    for (t = openTabCount - 1; t >= newTabCount; t--) {
+      tabbrowser.removeTab(tabbrowser.mTabs[t]);
+    }
+    
+    if (aOverwriteTabs) {
+      this.restoreWindowFeatures(aWindow, winData);
+    }
+    if (winData.cookies) {
+      this.restoreCookies(winData.cookies);
+    }
+    if (winData.extData) {
+      if (!this._windows[aWindow.__SSi].extData) {
+        this._windows[aWindow.__SSi].extData = {}
+      }
+      for (var key in winData.extData) {
+        this._windows[aWindow.__SSi].extData[key] = winData.extData[key];
+      }
+    }
+    if (winData._closedTabs && (root._firstTabs || aOverwriteTabs)) {
+      this._windows[aWindow.__SSi]._closedTabs = winData._closedTabs;
+    }
+    
+    this.restoreHistoryPrecursor(aWindow, winData.tabs, (aOverwriteTabs ?
+      (parseInt(winData.selected) || 1) : 0), 0, 0);
+  },
+
+  /**
+   * Manage history restoration for a window
+   * @param aTabs
+   *        Array of tab data
+   * @param aCurrentTabs
+   *        Array of tab references
+   * @param aSelectTab
+   *        Index of selected tab
+   * @param aIx
+   *        Index of the next tab to check readyness for
+   * @param aCount
+   *        Counter for number of times delaying b/c browser or history aren't ready
+   */
+  restoreHistoryPrecursor: function sss_restoreHistoryPrecursor(aWindow, aTabs, aSelectTab, aIx, aCount) {
+    var tabbrowser = aWindow.getBrowser();
+    
+    // make sure that all browsers and their histories are available
+    // - if one's not, resume this check in 100ms (repeat at most 10 times)
+    for (var t = aIx; t < aTabs.length; t++) {
+      try {
+        if (!tabbrowser.getBrowserForTab(aTabs[t]._tab).webNavigation.sessionHistory) {
+          throw new Error();
+        }
+      }
+      catch (ex) { // in case browser or history aren't ready yet 
+        if (aCount < 10) {
+          var restoreHistoryFunc = function(self) {
+            self.restoreHistoryPrecursor(aWindow, aTabs, aSelectTab, aIx, aCount + 1);
+          }
+          aWindow.setTimeout(restoreHistoryFunc, 100, this);
+          return;
+        }
+      }
+    }
+    
+    // mark the tabs as loading
+    for (t = 0; t < aTabs.length; t++) {
+      if (!aTabs[t].entries || !aTabs[t].entries[0])
+        continue; // there won't be anything to load
+      
+      var tab = aTabs[t]._tab;
+      var browser = tabbrowser.getBrowserForTab(tab);
+      browser.stop(); // in case about:blank isn't done yet
+      
+      tab.setAttribute("busy", "true");
+      tabbrowser.updateIcon(tab);
+      tabbrowser.setTabTitleLoading(tab);
+      
+      // keep the data around to prevent dataloss in case
+      // a tab gets closed before it's been properly restored
+      browser.parentNode.__SS_data = aTabs[t];
+    }
+    
+    // make sure to restore the selected tab first (if any)
+    if (aSelectTab-- && aTabs[aSelectTab]) {
+        aTabs.unshift(aTabs.splice(aSelectTab, 1)[0]);
+        tabbrowser.selectedTab = aTabs[0]._tab;
+    }
+
+    // helper hash for ensuring unique frame IDs
+    var idMap = { used: {} };
+    this.restoreHistory(aWindow, aTabs, idMap);
+  },
+
+  /**
+   * Restory history for a window
+   * @param aWindow
+   *        Window reference
+   * @param aTabs
+   *        Array of tab data
+   * @param aIdMap
+   *        Hash for ensuring unique frame IDs
+   */
+  restoreHistory: function sss_restoreHistory(aWindow, aTabs, aIdMap) {
+    var _this = this;
+    while (aTabs.length > 0 && (!aTabs[0]._tab || !aTabs[0]._tab.parentNode)) {
+      aTabs.shift(); // this tab got removed before being completely restored
+    }
+    if (aTabs.length == 0) {
+      return; // no more tabs to restore
+    }
+    
+    var tabData = aTabs.shift();
+
+    var tab = tabData._tab;
+    var browser = aWindow.getBrowser().getBrowserForTab(tab);
+    var history = browser.webNavigation.sessionHistory;
+    
+    if (history.count > 0) {
+      history.PurgeHistory(history.count);
+    }
+    history.QueryInterface(Ci.nsISHistoryInternal);
+    
+    if (!tabData.entries) {
+      tabData.entries = [];
+    }
+    if (tabData.extData) {
+      tab.__SS_extdata = tabData.extData;
+    }
+    
+    for (var i = 0; i < tabData.entries.length; i++) {
+      history.addEntry(this._deserializeHistoryEntry(tabData.entries[i], aIdMap), true);
+    }
+    
+    // make sure to reset the capabilities and attributes, in case this tab gets reused
+    var disallow = (tabData.disallow)?tabData.disallow.split(","):[];
+    CAPABILITIES.forEach(function(aCapability) {
+      browser.docShell["allow" + aCapability] = disallow.indexOf(aCapability) == -1;
+    });
+    Array.filter(tab.attributes, function(aAttr) {
+      return (_this.xulAttributes.indexOf(aAttr.name) > -1);
+    }).forEach(tab.removeAttribute, tab);
+    if (tabData.xultab) {
+      tabData.xultab.split(" ").forEach(function(aAttr) {
+        if (/^([^\s=]+)=(.*)/.test(aAttr)) {
+          tab.setAttribute(RegExp.$1, decodeURI(RegExp.$2));
+        }
+      });
+    }
+    
+    // notify the tabbrowser that the tab chrome has been restored
+    var event = aWindow.document.createEvent("Events");
+    event.initEvent("SSTabRestoring", true, false);
+    tab.dispatchEvent(event);
+    
+    var activeIndex = (tabData.index || tabData.entries.length) - 1;
+    try {
+      browser.webNavigation.gotoIndex(activeIndex);
+    }
+    catch (ex) { } // ignore an invalid tabData.index
+    
+    // restore those aspects of the currently active documents
+    // which are not preserved in the plain history entries
+    // (mainly scroll state and text data)
+    browser.__SS_restore_data = tabData.entries[activeIndex] || {};
+    browser.__SS_restore_text = tabData.text || "";
+    browser.__SS_restore_tab = tab;
+    browser.__SS_restore = this.restoreDocument_proxy;
+    browser.addEventListener("load", browser.__SS_restore, true);
+    
+    aWindow.setTimeout(function(){ _this.restoreHistory(aWindow, aTabs, aIdMap); }, 0);
+  },
+
+  /**
+   * expands serialized history data into a session-history-entry instance
+   * @param aEntry
+   *        Object containing serialized history data for a URL
+   * @param aIdMap
+   *        Hash for ensuring unique frame IDs
+   * @returns nsISHEntry
+   */
+  _deserializeHistoryEntry: function sss_deserializeHistoryEntry(aEntry, aIdMap) {
+    var shEntry = Cc["@mozilla.org/browser/session-history-entry;1"].
+                  createInstance(Ci.nsISHEntry);
+    
+    var ioService = Cc["@mozilla.org/network/io-service;1"].
+                    getService(Ci.nsIIOService);
+    shEntry.setURI(ioService.newURI(aEntry.url, null, null));
+    shEntry.setTitle(aEntry.title || aEntry.url);
+    if (aEntry.subframe)
+      shEntry.setIsSubFrame(aEntry.subframe || false);
+    shEntry.loadType = Ci.nsIDocShellLoadInfo.loadHistory;
+    if (aEntry.contentType)
+      shEntry.contentType = aEntry.contentType;
+    
+    if (aEntry.cacheKey) {
+      var cacheKey = Cc["@mozilla.org/supports-PRUint32;1"].
+                     createInstance(Ci.nsISupportsPRUint32);
+      cacheKey.data = aEntry.cacheKey;
+      shEntry.cacheKey = cacheKey;
+    }
+
+    if (aEntry.ID) {
+      // get a new unique ID for this frame (since the one from the last
+      // start might already be in use)
+      var id = aIdMap[aEntry.ID] || 0;
+      if (!id) {
+        for (id = Date.now(); aIdMap.used[id]; id++);
+        aIdMap[aEntry.ID] = id;
+        aIdMap.used[id] = true;
+      }
+      shEntry.ID = id;
+    }
+    
+    if (aEntry.scroll) {
+      var scrollPos = (aEntry.scroll || "0,0").split(",");
+      scrollPos = [parseInt(scrollPos[0]) || 0, parseInt(scrollPos[1]) || 0];
+      shEntry.setScrollPosition(scrollPos[0], scrollPos[1]);
+    }
+
+    var postdata;
+    if (aEntry.postdata_b64) {  // Firefox 3
+      postdata = atob(aEntry.postdata_b64);
+    } else if (aEntry.postdata) { // Firefox 2
+      postdata = aEntry.postdata;
+    }
+
+    if (postdata) {
+      var stream = Cc["@mozilla.org/io/string-input-stream;1"].
+                   createInstance(Ci.nsIStringInputStream);
+      stream.setData(postdata, postdata.length);
+      shEntry.postData = stream;
+    }
+
+    if (aEntry.owner_b64) {  // Firefox 3
+      var ownerInput = Cc["@mozilla.org/io/string-input-stream;1"].
+                       createInstance(Ci.nsIStringInputStream);
+      var binaryData = atob(aEntry.owner_b64);
+      ownerInput.setData(binaryData, binaryData.length);
+      var binaryStream = Cc["@mozilla.org/binaryinputstream;1"].
+                         createInstance(Ci.nsIObjectInputStream);
+      binaryStream.setInputStream(ownerInput);
+      try { // Catch possible deserialization exceptions
+        shEntry.owner = binaryStream.readObject(true);
+      } catch (ex) { debug(ex); }
+    } else if (aEntry.ownerURI) { // Firefox 2
+      var uriObj = ioService.newURI(aEntry.ownerURI, null, null);
+      shEntry.owner = Cc["@mozilla.org/scriptsecuritymanager;1"].
+                      getService(Ci.nsIScriptSecurityManager).
+                      getCodebasePrincipal(uriObj);
+    }
+    
+    if (aEntry.children && shEntry instanceof Ci.nsISHContainer) {
+      for (var i = 0; i < aEntry.children.length; i++) {
+        shEntry.AddChild(this._deserializeHistoryEntry(aEntry.children[i], aIdMap), i);
+      }
+    }
+    
+    return shEntry;
+  },
+
+  /**
+   * Restore properties to a loaded document
+   */
+  restoreDocument_proxy: function sss_restoreDocument_proxy(aEvent) {
+    // wait for the top frame to be loaded completely
+    if (!aEvent || !aEvent.originalTarget || !aEvent.originalTarget.defaultView || aEvent.originalTarget.defaultView != aEvent.originalTarget.defaultView.top) {
+      return;
+    }
+    
+    var textArray = this.__SS_restore_text ? this.__SS_restore_text.split(" ") : [];
+    function restoreTextData(aContent, aPrefix) {
+      textArray.forEach(function(aEntry) {
+        if (/^((?:\d+\|)*)(#?)([^\s=]+)=(.*)$/.test(aEntry) && (!RegExp.$1 || RegExp.$1 == aPrefix)) {
+          var document = aContent.document;
+          var node = RegExp.$2 ? document.getElementById(RegExp.$3) : document.getElementsByName(RegExp.$3)[0] || null;
+          if (node && "value" in node) {
+            node.value = decodeURI(RegExp.$4);
+            
+            var event = document.createEvent("UIEvents");
+            event.initUIEvent("input", true, true, aContent, 0);
+            node.dispatchEvent(event);
+          }
+        }
+      });
+    }
+    
+    function restoreTextDataAndScrolling(aContent, aData, aPrefix) {
+      restoreTextData(aContent, aPrefix);
+      if (aData.innerHTML) {
+        aContent.setTimeout(function(aHTML) { if (this.document.designMode == "on") { this.document.body.innerHTML = aHTML; } }, 0, aData.innerHTML);
+      }
+      if (aData.scroll && /(\d+),(\d+)/.test(aData.scroll)) {
+        aContent.scrollTo(RegExp.$1, RegExp.$2);
+      }
+      for (var i = 0; i < aContent.frames.length; i++) {
+        if (aData.children && aData.children[i]) {
+          restoreTextDataAndScrolling(aContent.frames[i], aData.children[i], i + "|" + aPrefix);
+        }
+      }
+    }
+    
+    var content = aEvent.originalTarget.defaultView;
+    if (this.currentURI.spec == "about:config") {
+      // unwrap the document for about:config because otherwise the properties
+      // of the XBL bindings - as the textbox - aren't accessible (see bug 350718)
+      content = content.wrappedJSObject;
+    }
+    restoreTextDataAndScrolling(content, this.__SS_restore_data, "");
+    
+    // notify the tabbrowser that this document has been completely restored
+    var event = this.ownerDocument.createEvent("Events");
+    event.initEvent("SSTabRestored", true, false);
+    this.__SS_restore_tab.dispatchEvent(event);
+    
+    this.removeEventListener("load", this.__SS_restore, true);
+    delete this.__SS_restore_data;
+    delete this.__SS_restore_text;
+    delete this.__SS_restore_tab;
+    delete this.__SS_restore;
+  },
+
+  /**
+   * Restore visibility and dimension features to a window
+   * @param aWindow
+   *        Window reference
+   * @param aWinData
+   *        Object containing session data for the window
+   */
+  restoreWindowFeatures: function sss_restoreWindowFeatures(aWindow, aWinData) {
+    var hidden = (aWinData.hidden)?aWinData.hidden.split(","):[];
+    WINDOW_HIDEABLE_FEATURES.forEach(function(aItem) {
+      aWindow[aItem].visible = hidden.indexOf(aItem) == -1;
+    });
+    
+    var _this = this;
+    aWindow.setTimeout(function() {
+      _this.restoreDimensions.apply(_this, [aWindow, aWinData.width || 0, 
+        aWinData.height || 0, "screenX" in aWinData ? aWinData.screenX : NaN,
+        "screenY" in aWinData ? aWinData.screenY : NaN,
+        aWinData.sizemode || "", aWinData.sidebar || ""]);
+    }, 0);
+  },
+
+  /**
+   * Restore a window's dimensions
+   * @param aWidth
+   *        Window width
+   * @param aHeight
+   *        Window height
+   * @param aLeft
+   *        Window left
+   * @param aTop
+   *        Window top
+   * @param aSizeMode
+   *        Window size mode (eg: maximized)
+   * @param aSidebar
+   *        Sidebar command
+   */
+  restoreDimensions: function sss_restoreDimensions(aWindow, aWidth, aHeight, aLeft, aTop, aSizeMode, aSidebar) {
+    var win = aWindow;
+    var _this = this;
+    function win_(aName) { return _this._getWindowDimension(win, aName); }
+    
+    // only modify those aspects which aren't correct yet
+    if (aWidth && aHeight && (aWidth != win_("width") || aHeight != win_("height"))) {
+      aWindow.resizeTo(aWidth, aHeight);
+    }
+    if (!isNaN(aLeft) && !isNaN(aTop) && (aLeft != win_("screenX") || aTop != win_("screenY"))) {
+      aWindow.moveTo(aLeft, aTop);
+    }
+    if (aSizeMode == "maximized" && win_("sizemode") != "maximized") {
+      aWindow.maximize();
+    }
+    else if (aSizeMode && aSizeMode != "maximized" && win_("sizemode") != "normal") {
+      aWindow.restore();
+    }
+    var sidebar = aWindow.document.getElementById("sidebar-box");
+    if (sidebar.getAttribute("sidebarcommand") != aSidebar) {
+      aWindow.toggleSidebar(aSidebar);
+    }
+    // since resizing/moving a window brings it to the foreground,
+    // we might want to re-focus the last focused window
+    if (this.windowToFocus) {
+      this.windowToFocus.focus();
+    }
+  },
+
+  /**
+   * Restores cookies (accepting both Firefox 2.0 and current format)
+   * @param aCookies
+   *        Array of cookie objects
+   */
+  restoreCookies: function sss_restoreCookies(aCookies) {
+    if (aCookies.count && aCookies.domain1) {
+      // convert to the new cookie serialization format
+      var converted = [];
+      for (var i = 1; i <= aCookies.count; i++) {
+        // for simplicity we only accept the format we produced ourselves
+        var parsed = aCookies["value" + i].match(/^([^=;]+)=([^;]*);(?:domain=[^;]+;)?(?:path=([^;]*);)?(secure;)?(httponly;)?/);
+        if (parsed && /^https?:\/\/([^\/]+)/.test(aCookies["domain" + i]))
+          converted.push({
+            host: RegExp.$1, path: parsed[3], name: parsed[1], value: parsed[2],
+            secure: parsed[4], httponly: parsed[5]
+          });
+      }
+      aCookies = converted;
+    }
+    
+    var cookieManager = Cc["@mozilla.org/cookiemanager;1"].
+                        getService(Ci.nsICookieManager2);
+    // MAX_EXPIRY should be 2^63-1, but JavaScript can't handle that precision
+    var MAX_EXPIRY = Math.pow(2, 62);
+    for (i = 0; i < aCookies.length; i++) {
+      var cookie = aCookies[i];
+      try {
+        cookieManager.add(cookie.host, cookie.path || "", cookie.name || "", cookie.value, !!cookie.secure, !!cookie.httponly, true, "expiry" in cookie ? cookie.expiry : MAX_EXPIRY);
+      }
+      catch (ex) { Cu.reportError(ex); } // don't let a single cookie stop recovering
+    }
+  },
+
+/* ........ Disk Access .............. */
+
+  /**
+   * save state delayed by N ms
+   * marks window as dirty (i.e. data update can't be skipped)
+   * @param aWindow
+   *        Window reference
+   * @param aDelay
+   *        Milliseconds to delay
+   */
+  saveStateDelayed: function sss_saveStateDelayed(aWindow, aDelay) {
+    if (aWindow) {
+      this._dirtyWindows[aWindow.__SSi] = true;
+    }
+
+    if (!this._saveTimer && this._resume_from_crash) {
+      // interval until the next disk operation is allowed
+      var minimalDelay = this._lastSaveTime + this._interval - Date.now();
+      
+      // if we have to wait, set a timer, otherwise saveState directly
+      aDelay = Math.max(minimalDelay, aDelay || 2000);
+      if (aDelay > 0) {
+        this._saveTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+        this._saveTimer.init(this, aDelay, Ci.nsITimer.TYPE_ONE_SHOT);
+      }
+      else {
+        this.saveState();
+      }
+    }
+  },
+
+  /**
+   * save state to disk
+   * @param aUpdateAll
+   *        Bool update all windows 
+   */
+  saveState: function sss_saveState(aUpdateAll) {
+    // if crash recovery is disabled, only save session resuming information
+    if (!this._resume_from_crash && this._loadState == STATE_RUNNING)
+      return;
+    
+    this._dirty = aUpdateAll;
+    var oState = this._getCurrentState();
+    oState.session = { state: ((this._loadState == STATE_RUNNING) ? STATE_RUNNING_STR : STATE_STOPPED_STR) };
+    this._writeFile(this._sessionFile, oState.toSource());
+    this._lastSaveTime = Date.now();
+  },
+
+  /**
+   * delete session datafile and backup
+   */
+  _clearDisk: function sss_clearDisk() {
+    if (this._sessionFile.exists()) {
+      try {
+        this._sessionFile.remove(false);
+      }
+      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
+    }
+    if (this._sessionFileBackup.exists()) {
+      try {
+        this._sessionFileBackup.remove(false);
+      }
+      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
+    }
+  },
+
+/* ........ Auxiliary Functions .............. */
+
+  /**
+   * call a callback for all currently opened browser windows
+   * (might miss the most recent one)
+   * @param aFunc
+   *        Callback each window is passed to
+   */
+  _forEachBrowserWindow: function sss_forEachBrowserWindow(aFunc) {
+    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
+                         getService(Ci.nsIWindowMediator);
+    var windowsEnum = windowMediator.getEnumerator("navigator:browser");
+    
+    while (windowsEnum.hasMoreElements()) {
+      var window = windowsEnum.getNext();
+      if (window.__SSi) {
+        aFunc.call(this, window);
+      }
+    }
+  },
+
+  /**
+   * Returns most recent window
+   * @returns Window reference
+   */
+  _getMostRecentBrowserWindow: function sss_getMostRecentBrowserWindow() {
+    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
+                         getService(Ci.nsIWindowMediator);
+    return windowMediator.getMostRecentWindow("navigator:browser");
+  },
+
+  /**
+   * open a new browser window for a given session state
+   * called when restoring a multi-window session
+   * @param aState
+   *        Object containing session data
+   */
+  _openWindowWithState: function sss_openWindowWithState(aState) {
+    var argString = Cc["@mozilla.org/supports-string;1"].
+                    createInstance(Ci.nsISupportsString);
+    argString.data = "";
+
+    //XXXzeniko shouldn't it be possible to set the window's dimensions here (as feature)?
+    var window = Cc["@mozilla.org/embedcomp/window-watcher;1"].
+                 getService(Ci.nsIWindowWatcher).
+                 openWindow(null, this._prefBranch.getCharPref("chromeURL"), "_blank",
+                            "chrome,dialog=no,all", argString);
+    
+    window.__SS_state = aState;
+    var _this = this;
+    window.addEventListener("load", function(aEvent) {
+      aEvent.currentTarget.removeEventListener("load", arguments.callee, true);
+      _this.restoreWindow(aEvent.currentTarget, aEvent.currentTarget.__SS_state, true, true);
+      delete aEvent.currentTarget.__SS_state;
+    }, true);
+    
+    return window;
+  },
+
+  /**
+   * Whether or not to resume session, if not recovering from a crash.
+   * @returns bool
+   */
+  _doResumeSession: function sss_doResumeSession() {
+    return this._prefBranch.getIntPref("startup.page") == 3 ||
+      this._prefBranch.getBoolPref("sessionstore.resume_session_once");
+  },
+
+  /**
+   * whether the user wants to load any other page at startup
+   * (except the homepage) - needed for determining whether to overwrite the current tabs
+   * C.f.: nsBrowserContentHandler's defaultArgs implementation.
+   * @returns bool
+   */
+  _isCmdLineEmpty: function sss_isCmdLineEmpty(aWindow) {
+    var defaultArgs = Cc["@mozilla.org/browser/clh;1"].
+                      getService(Ci.nsIBrowserHandler).defaultArgs;
+    if (aWindow.arguments && aWindow.arguments[0] &&
+        aWindow.arguments[0] == defaultArgs)
+      aWindow.arguments[0] = null;
+
+    return !aWindow.arguments || !aWindow.arguments[0];
+  },
+
+  /**
+   * don't save sensitive data if the user doesn't want to
+   * (distinguishes between encrypted and non-encrypted sites)
+   * @param aIsHTTPS
+   *        Bool is encrypted
+   * @returns bool
+   */
+  _checkPrivacyLevel: function sss_checkPrivacyLevel(aIsHTTPS) {
+    return this._prefBranch.getIntPref("sessionstore.privacy_level") < (aIsHTTPS ? PRIVACY_ENCRYPTED : PRIVACY_FULL);
+  },
+
+  /**
+   * on popup windows, the XULWindow's attributes seem not to be set correctly
+   * we use thus JSDOMWindow attributes for sizemode and normal window attributes
+   * (and hope for reasonable values when maximized/minimized - since then
+   * outerWidth/outerHeight aren't the dimensions of the restored window)
+   * @param aWindow
+   *        Window reference
+   * @param aAttribute
+   *        String sizemode | width | height | other window attribute
+   * @returns string
+   */
+  _getWindowDimension: function sss_getWindowDimension(aWindow, aAttribute) {
+    if (aAttribute == "sizemode") {
+      switch (aWindow.windowState) {
+      case aWindow.STATE_MAXIMIZED:
+        return "maximized";
+      case aWindow.STATE_MINIMIZED:
+        return "minimized";
+      default:
+        return "normal";
+      }
+    }
+    
+    var dimension;
+    switch (aAttribute) {
+    case "width":
+      dimension = aWindow.outerWidth;
+      break;
+    case "height":
+      dimension = aWindow.outerHeight;
+      break;
+    default:
+      dimension = aAttribute in aWindow ? aWindow[aAttribute] : "";
+      break;
+    }
+    
+    if (aWindow.windowState == aWindow.STATE_NORMAL) {
+      return dimension;
+    }
+    return aWindow.document.documentElement.getAttribute(aAttribute) || dimension;
+  },
+
+  /**
+   * Convenience method to get localized string bundles
+   * @param aURI
+   * @returns nsIStringBundle
+   */
+  _getStringBundle: function sss_getStringBundle(aURI) {
+     var bundleService = Cc["@mozilla.org/intl/stringbundle;1"].
+                         getService(Ci.nsIStringBundleService);
+     var appLocale = Cc["@mozilla.org/intl/nslocaleservice;1"].
+                     getService(Ci.nsILocaleService).getApplicationLocale();
+     return bundleService.createBundle(aURI, appLocale);
+  },
+
+  /**
+   * Get nsIURI from string
+   * @param string
+   * @returns nsIURI
+   */
+  _getURIFromString: function sss_getURIFromString(aString) {
+    var ioService = Cc["@mozilla.org/network/io-service;1"].
+                    getService(Ci.nsIIOService);
+    return ioService.newURI(aString, null, null);
+  },
+
+  /**
+   * Annotate a breakpad crash report with the currently selected tab's URL.
+   */
+  _updateCrashReportURL: function sss_updateCrashReportURL(aWindow) {
+    if (!Ci.nsICrashReporter) {
+      // if breakpad isn't built, don't bother next time at all
+      this._updateCrashReportURL = function(aWindow) {};
+      return;
+    }
+    try {
+      var currentUrl = aWindow.getBrowser().currentURI.spec;
+      var cr = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsICrashReporter);
+      cr.annotateCrashReport("URL", currentUrl);
+    }
+    catch (ex) {
+      // don't make noise when crashreporter is built but not enabled
+      if (ex.result != Components.results.NS_ERROR_NOT_INITIALIZED)
+        debug(ex);
+    }
+  },
+
+  /**
+   * safe eval'ing
+   */
+  _safeEval: function sss_safeEval(aStr) {
+    return Cu.evalInSandbox(aStr, new Cu.Sandbox("about:blank"));
+  },
+
+  /**
+   * Converts a JavaScript object into a JSON string
+   * (see http://www.json.org/ for more information).
+   *
+   * The inverse operation consists of eval("(" + JSON_string + ")");
+   * and should be provably safe.
+   *
+   * @param aJSObject is the object to be converted
+   * @return the object's JSON representation
+   */
+  _toJSONString: function sss_toJSONString(aJSObject) {
+    var str = JSON.toString(aJSObject, ["_tab", "_hosts"] /* keys to drop */);
+    
+    // sanity check - so that API consumers can just eval this string
+    if (!JSON.isMostlyHarmless(str))
+      throw new Error("JSON conversion failed unexpectedly!");
+    
+    return str;
+  },
+
+/* ........ Storage API .............. */
+
+  /**
+   * write file to disk
+   * @param aFile
+   *        nsIFile
+   * @param aData
+   *        String data
+   */
+  _writeFile: function sss_writeFile(aFile, aData) {
+    // init stream
+    var stream = Cc["@mozilla.org/network/safe-file-output-stream;1"].
+                 createInstance(Ci.nsIFileOutputStream);
+    stream.init(aFile, 0x02 | 0x08 | 0x20, 0600, 0);
+
+    // convert to UTF-8
+    var converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"].
+                    createInstance(Ci.nsIScriptableUnicodeConverter);
+    converter.charset = "UTF-8";
+    var convertedData = converter.ConvertFromUnicode(aData);
+    convertedData += converter.Finish();
+
+    // write and close stream
+    stream.write(convertedData, convertedData.length);
+    if (stream instanceof Ci.nsISafeOutputStream) {
+      stream.finish();
+    } else {
+      stream.close();
+    }
+  }
+};
+
+function NSGetModule(aComMgr, aFileSpec)
+  XPCOMUtils.generateModule([SessionStoreService]);