Implement browser startup autorecovery module.

4 files changed, 64 insertions, 0 deletions

diff --git a/browser/base/content/autorecovery.js b/browser/base/content/autorecovery.js
new file mode 100644
index 000000000..f0a1da8f1
--- /dev/null
+++ b/browser/base/content/autorecovery.js
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Auto-recovery module.
+ * This module aims to catch fatal browser initialization errors and either
+ * automatically correct likely causes from them, or automatically restarting
+ * the browser in safe mode. This is hooked into the browser's "onload"
+ * event because it can be assumed that at that point, everything must
+ * have been properly initialized already.
+ */
+
+let Cc = Components.classes;
+let Ci = Components.interfaces;
+let Cu = Components.utils;
+
+// Services = object with smart getters for common XPCOM services
+Cu.import("resource://gre/modules/Services.jsm");
+
+var browser_autoRecovery =
+{
+  onLoad: function() {
+    if (typeof gBrowser === "undefined") {
+      // gBrowser should always be defined at this point, but if it is not, then most likely 
+      // it is due to an incompatible or outdated language pack being installed and selected.
+      // In this case, we reset "general.useragent.locale" to try to recover browser startup.
+      if (Services.prefs.prefHasUserValue("general.useragent.locale")) {
+        // Restart automatically in en-US.
+        Services.prefs.clearUserPref("general.useragent.locale");
+        a=Ci.nsIAppStartup,Cc["@mozilla.org/toolkit/app-startup;1"].getService(a).quit(a.eRestart | a.eAttemptQuit);
+      } else if (!Services.appinfo.inSafeMode) {
+        // gBrowser isn't defined, and we're not using a custom locale. Most likely
+        // a user-installed add-on causes issues here, so we restart in Safe Mode.
+        Services.prompt.alert(null, "Error",
+                              "The Browser didn't start properly!\n"+
+                              "This is usually caused by an add-on or misconfiguration.\n"+
+                              "Restarting in Safe Mode...");        
+        a=Ci.nsIAppStartup,Cc["@mozilla.org/toolkit/app-startup;1"].getService(a).restartInSafeMode(a.eRestart | a.eAttemptQuit);
+      }
+      // Something else caused this issue and we're already in Safe Mode, so we return
+      // without doing anything else, and let normal error handling take place.
+    }
+    // Remove our listener, since we don't want this to fire on every load.
+    window.removeEventListener("load", browser_autoRecovery.onLoad, false);
+  }
+};
+
+window.addEventListener("load", browser_autoRecovery.onLoad, false);
diff --git a/browser/base/content/autorecovery.xul b/browser/base/content/autorecovery.xul
new file mode 100644
index 000000000..866bdf288
--- /dev/null
+++ b/browser/base/content/autorecovery.xul
@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+
+<overlay
+  id="autorecovery"
+  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+
+<script type="application/x-javascript" src="chrome://browser/content/autorecovery.js"/>
+
+<!-- This is an empty overlay to allow separation of the script into its
+     own context (needed for locale issues preventing browser start) -->
+
+</overlay>
diff --git a/browser/base/content/browser.xul b/browser/base/content/browser.xul
index 1bdbee831..f83010023 100644
--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -25,6 +25,8 @@
 <?xul-overlay href="chrome://browser/content/padlock.xul"?>
 # Improve bookmark menu dragging
 <?xul-overlay href="chrome://browser/content/browser-menudragging.xul"?>
+# Automatic browser recovery
+<?xul-overlay href="chrome://browser/content/autorecovery.xul"?>
 
  
 # All DTD information is stored in a separate file so that it can be shared by
diff --git a/browser/base/jar.mn b/browser/base/jar.mn
index 26a63ed1c..49d83da4a 100644
--- a/browser/base/jar.mn
+++ b/browser/base/jar.mn
@@ -45,6 +45,8 @@ browser.jar:
         content/browser/abouthome/restore-large@2x.png (content/abouthome/restore-large@2x.png)
         content/browser/aboutRobots-icon.png          (content/aboutRobots-icon.png)
         content/browser/aboutRobots-widget-left.png   (content/aboutRobots-widget-left.png)
+        content/browser/autorecovery.js               (content/autorecovery.js)
+        content/browser/autorecovery.xul              (content/autorecovery.xul)
 *       content/browser/browser.css                   (content/browser.css)
         content/browser/browser-menudragging.xul      (content/browser-menudragging.xul)
         content/browser/browser-menudragging.js       (content/browser-menudragging.js)