diff -r 000000000000 -r 6474c204b198 toolkit/components/places/tests/unit/test_399264_query_to_string.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/places/tests/unit/test_399264_query_to_string.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,53 @@
+/* -*- 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/. */
+
+/**
+ * Obtains the id of the folder obtained from the query.
+ *
+ * @param aFolderID
+ *        The id of the folder we want to generate a query for.
+ * @returns the string representation of the query for the given folder.
+ */
+function query_string(aFolderID)
+{
+  var hs = Cc["@mozilla.org/browser/nav-history-service;1"].
+           getService(Ci.nsINavHistoryService);
+
+  var query = hs.getNewQuery();
+  query.setFolders([aFolderID], 1);
+  var options = hs.getNewQueryOptions();
+  return hs.queriesToQueryString([query], 1, options);
+}
+
+function run_test()
+{
+  var hs = Cc["@mozilla.org/browser/nav-history-service;1"].
+           getService(Ci.nsINavHistoryService);
+  var bs = Cc["@mozilla.org/browser/nav-bookmarks-service;1"].
+           getService(Ci.nsINavBookmarksService);
+
+  const QUERIES = [
+      "folder=PLACES_ROOT"
+    , "folder=BOOKMARKS_MENU"
+    , "folder=TAGS"
+    , "folder=UNFILED_BOOKMARKS"
+    , "folder=TOOLBAR"
+  ];
+  const FOLDER_IDS = [
+      bs.placesRoot
+    , bs.bookmarksMenuFolder
+    , bs.tagsFolder
+    , bs.unfiledBookmarksFolder
+    , bs.toolbarFolder
+  ];
+
+
+  for (var i = 0; i < QUERIES.length; i++) {
+    var result = query_string(FOLDER_IDS[i]);
+    dump("Looking for '" + QUERIES[i] + "' in '" + result + "'\n");
+    do_check_neq(-1, result.indexOf(QUERIES[i]));
+  }
+}