Bug 460346 - Privacy pref for Always on Private Browsing Mode; r=mconnor

browser/app/profile/firefox.js

@@ -791,3 +791,6 @@ pref("app.support.baseURL", "http://support.mozilla.com/1/%APP%/%VERSION%/%OS%/%
 
 // Name of alternate about: page for certificate errors (when undefined, defaults to about:neterror)
 pref("security.alternate_certificate_error_page", "certerror");
+
+// Whether to start the private browsing mode at application startup
+pref("browser.privatebrowsing.autostart", false);

browser/components/privatebrowsing/src/nsPrivateBrowsingService.js

@@ -43,7 +43,8 @@ const Cr = Components.results;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 function PrivateBrowsingService() {
-  this._obs.addObserver(this, "quit-application-granted", false);
+  this._obs.addObserver(this, "profile-after-change", true);
+  this._obs.addObserver(this, "quit-application-granted", true);
 }
 
 PrivateBrowsingService.prototype = {
@@ -71,6 +72,9 @@ PrivateBrowsingService.prototype = {
   // Make sure we don't allow re-enterant changing of the private mode
   _alreadyChangingMode: false,
 
+  // Whether we're entering the private browsing mode at application startup
+  _autoStart: false,
+
   // XPCOM registration
   classDescription: "PrivateBrowsing Service",
   contractID: "@mozilla.org/privatebrowsing;1",
@@ -80,59 +84,63 @@ PrivateBrowsingService.prototype = {
   ],
 
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIPrivateBrowsingService, 
-                                         Ci.nsIObserver]),
+                                         Ci.nsIObserver,
+                                         Ci.nsISupportsWeakReference]),
 
   _unload: function PBS__destroy() {
     // Force an exit from the private browsing mode on shutdown
     this._quitting = true;
     if (this._inPrivateBrowsing)
       this.privateBrowsingEnabled = false;
-
-    this._obs.removeObserver(this, "quit-application-granted");
   },
 
   _onPrivateBrowsingModeChanged: function PBS__onPrivateBrowsingModeChanged() {
-    // clear all auth tokens
-    let sdr = Cc["@mozilla.org/security/sdr;1"].
-              getService(Ci.nsISecretDecoderRing);
-    sdr.logoutAndTeardown();
+    // nothing needs to be done here if we're auto-starting
+    if (!this._autoStart) {
+      // clear all auth tokens
+      let sdr = Cc["@mozilla.org/security/sdr;1"].
+                getService(Ci.nsISecretDecoderRing);
+      sdr.logoutAndTeardown();
 
-    // clear plain HTTP auth sessions
-    let authMgr = Cc['@mozilla.org/network/http-auth-manager;1'].
-                  getService(Ci.nsIHttpAuthManager);
-    authMgr.clearAll();
+      // clear plain HTTP auth sessions
+      let authMgr = Cc['@mozilla.org/network/http-auth-manager;1'].
+                    getService(Ci.nsIHttpAuthManager);
+      authMgr.clearAll();
 
-    let ss = Cc["@mozilla.org/browser/sessionstore;1"].
-             getService(Ci.nsISessionStore);
-    if (this.privateBrowsingEnabled) {
-      // whether we should save and close the current session
-      this._saveSession = true;
-      var prefBranch = Cc["@mozilla.org/preferences-service;1"].
-                       getService(Ci.nsIPrefBranch);
-      try {
-        if (prefBranch.getBoolPref("browser.privatebrowsing.keep_current_session"))
-          this._saveSession = false;
-      } catch (ex) {}
+      let ss = Cc["@mozilla.org/browser/sessionstore;1"].
+               getService(Ci.nsISessionStore);
+      if (this.privateBrowsingEnabled) {
+        // whether we should save and close the current session
+        this._saveSession = true;
+        var prefBranch = Cc["@mozilla.org/preferences-service;1"].
+                         getService(Ci.nsIPrefBranch);
+        try {
+          if (prefBranch.getBoolPref("browser.privatebrowsing.keep_current_session"))
+            this._saveSession = false;
+        } catch (ex) {}
 
-      // save the whole browser state in order to restore all windows/tabs later
-      if (this._saveSession && !this._savedBrowserState) {
-        this._savedBrowserState = ss.getBrowserState();
+        // save the whole browser state in order to restore all windows/tabs later
+        if (this._saveSession && !this._savedBrowserState) {
+          this._savedBrowserState = ss.getBrowserState();
 
-        // Close all windows
-        this._closeAllWindows();
+          // Close all windows
+          this._closeAllWindows();
 
-        // Open a single window
-        this._openSingleWindow();
-      }
-    }
-    else {
-      // restore the windows/tabs which were open before entering the private mode
-      if (this._saveSession && this._savedBrowserState) {
-        if (!this._quitting) // don't restore when shutting down!
-          ss.setBrowserState(this._savedBrowserState);
-        this._savedBrowserState = null;
+          // Open a single window
+          this._openSingleWindow();
+        }
+      }
+      else {
+        // restore the windows/tabs which were open before entering the private mode
+        if (this._saveSession && this._savedBrowserState) {
+          if (!this._quitting) // don't restore when shutting down!
+            ss.setBrowserState(this._savedBrowserState);
+          this._savedBrowserState = null;
+        }
       }
     }
+    else
+      this._saveSession = false;
   },
 
 #ifndef XP_WIN
@@ -181,6 +189,20 @@ PrivateBrowsingService.prototype = {
 
   observe: function PBS_observe(aSubject, aTopic, aData) {
     switch (aTopic) {
+      case "profile-after-change":
+        // If the autostart prefs has been set, simulate entering the
+        // private browsing mode upon startup.
+        // This won't interfere with the session store component, because
+        // that component will be initialized on final-ui-startup.
+        let prefsService = Cc["@mozilla.org/preferences-service;1"].
+                           getService(Ci.nsIPrefBranch);
+        this._autoStart = prefsService.getBoolPref("browser.privatebrowsing.autostart");
+        if (this._autoStart) {
+          this.privateBrowsingEnabled = true;
+          this._autoStart = false;
+        }
+        this._obs.removeObserver(this, "profile-after-change");
+        break;
       case "quit-application-granted":
         this._unload();
         break;

browser/components/privatebrowsing/test/unit/test_privatebrowsing_autostart.js

@@ -0,0 +1,56 @@
+/* ***** 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 Private Browsing Tests.
+ *
+ * The Initial Developer of the Original Code is
+ * Ehsan Akhgari.
+ * Portions created by the Initial Developer are Copyright (C) 2008
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Ehsan Akhgari <ehsan.akhgari@gmail.com> (Original Author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of 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 ***** */
+
+// This test checks the browser.privatebrowsing.autostart preference.
+
+function run_test() {
+  // initialization
+  var prefsService = Cc["@mozilla.org/preferences-service;1"].
+                     getService(Ci.nsIPrefBranch);
+  prefsService.setBoolPref("browser.privatebrowsing.autostart", true);
+  do_check_true(prefsService.getBoolPref("browser.privatebrowsing.autostart"));
+
+  var pb = Cc["@mozilla.org/privatebrowsing;1"].
+           getService(Ci.nsIPrivateBrowsingService).
+           QueryInterface(Ci.nsIObserver);
+
+  // simulate startup to make the PB service read the prefs
+  pb.observe(null, "profile-after-change", "");
+
+  // the private mode should be entered automatically
+  do_check_true(pb.privateBrowsingEnabled);
+}