diff -r 000000000000 -r 6474c204b198 toolkit/components/places/tests/unit/test_history_notifications.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/places/tests/unit/test_history_notifications.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,75 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+const NS_PLACES_INIT_COMPLETE_TOPIC = "places-init-complete";
+const NS_PLACES_DATABASE_LOCKED_TOPIC = "places-database-locked";
+
+function run_test() {
+  do_test_pending();
+
+  // Create an observer for the Places notifications
+  var os = Cc["@mozilla.org/observer-service;1"].
+         getService(Ci.nsIObserverService);
+  var observer = {
+    _lockedNotificationReceived: false,
+    observe: function thn_observe(aSubject, aTopic, aData)
+    {
+      switch (aTopic) {
+        case NS_PLACES_INIT_COMPLETE_TOPIC:
+          do_check_true(this._lockedNotificationReceived);
+          os.removeObserver(this, NS_PLACES_INIT_COMPLETE_TOPIC);
+          os.removeObserver(this, NS_PLACES_DATABASE_LOCKED_TOPIC);
+          do_test_finished();
+          break;
+        case NS_PLACES_DATABASE_LOCKED_TOPIC:
+          if (this._lockedNotificationReceived)
+            do_throw("Locked notification should be observed only one time");
+          this._lockedNotificationReceived = true;
+          break;
+      }
+    }
+  };
+  os.addObserver(observer, NS_PLACES_INIT_COMPLETE_TOPIC, false);
+  os.addObserver(observer, NS_PLACES_DATABASE_LOCKED_TOPIC, false);
+
+  // Create a dummy places.sqlite and open an unshared connection on it
+  var dirSvc = Cc["@mozilla.org/file/directory_service;1"].
+               getService(Ci.nsIProperties);
+  var db = dirSvc.get('ProfD', Ci.nsIFile);
+  db.append("places.sqlite");
+  var storage = Cc["@mozilla.org/storage/service;1"].
+                getService(Ci.mozIStorageService);
+  var dbConn = storage.openUnsharedDatabase(db);
+  do_check_true(db.exists());
+
+  // We need an exclusive lock on the db
+  dbConn.executeSimpleSQL("PRAGMA locking_mode = EXCLUSIVE");
+  // Exclusive locking is lazy applied, we need to make a write to activate it
+  dbConn.executeSimpleSQL("PRAGMA USER_VERSION = 1");
+
+  // Try to create history service while the db is locked
+  try {
+    var hs1 = Cc["@mozilla.org/browser/nav-history-service;1"].
+              getService(Ci.nsINavHistoryService);
+    do_throw("Creating an instance of history service on a locked db should throw");
+  } catch (ex) {}
+
+  // Close our connection and try to cleanup the file (could fail on Windows)
+  dbConn.close();
+  if (db.exists()) {
+    try {
+      db.remove(false);
+    } catch(e) { dump("Unable to remove dummy places.sqlite"); }
+  }
+
+  // Create history service correctly
+  try {
+    var hs2 = Cc["@mozilla.org/browser/nav-history-service;1"].
+              getService(Ci.nsINavHistoryService);
+  } catch (ex) {
+    do_throw("Creating an instance of history service on a not locked db should not throw");
+  }
+}