diff -r 000000000000 -r 6474c204b198 browser/components/customizableui/test/browser_888817_currentset_updating.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/customizableui/test/browser_888817_currentset_updating.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,57 @@
+/* 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/. */
+
+"use strict";
+
+// Adding, moving and removing items should update the relevant currentset attributes
+add_task(function() {
+  ok(CustomizableUI.inDefaultState, "Should be in the default state when we start");
+  let personalbar = document.getElementById(CustomizableUI.AREA_BOOKMARKS);
+  setToolbarVisibility(personalbar, true);
+  ok(!CustomizableUI.inDefaultState, "Making the bookmarks toolbar visible takes it out of the default state");
+
+  let navbar = document.getElementById(CustomizableUI.AREA_NAVBAR);
+  let personalbar = document.getElementById(CustomizableUI.AREA_BOOKMARKS);
+  let navbarCurrentset = navbar.getAttribute("currentset") || navbar.currentSet;
+  let personalbarCurrentset = personalbar.getAttribute("currentset") || personalbar.currentSet;
+
+  let otherWin = yield openAndLoadWindow();
+  let otherNavbar = otherWin.document.getElementById(CustomizableUI.AREA_NAVBAR);
+  let otherPersonalbar = otherWin.document.getElementById(CustomizableUI.AREA_BOOKMARKS);
+
+  CustomizableUI.moveWidgetWithinArea("home-button", 0);
+  navbarCurrentset = "home-button," + navbarCurrentset.replace(",home-button", "");
+  is(navbar.getAttribute("currentset"), navbarCurrentset,
+     "Should have updated currentSet after move.");
+  is(otherNavbar.getAttribute("currentset"), navbarCurrentset,
+     "Should have updated other window's currentSet after move.");
+
+  CustomizableUI.addWidgetToArea("home-button", CustomizableUI.AREA_BOOKMARKS);
+  navbarCurrentset = navbarCurrentset.replace("home-button,", "");
+  personalbarCurrentset = personalbarCurrentset + ",home-button";
+  is(navbar.getAttribute("currentset"), navbarCurrentset,
+     "Should have updated navbar currentSet after implied remove.");
+  is(otherNavbar.getAttribute("currentset"), navbarCurrentset,
+     "Should have updated other window's navbar currentSet after implied remove.");
+  is(personalbar.getAttribute("currentset"), personalbarCurrentset,
+     "Should have updated personalbar currentSet after add.");
+  is(otherPersonalbar.getAttribute("currentset"), personalbarCurrentset,
+     "Should have updated other window's personalbar currentSet after add.");
+
+  CustomizableUI.removeWidgetFromArea("home-button");
+  personalbarCurrentset = personalbarCurrentset.replace(",home-button", "");
+  is(personalbar.getAttribute("currentset"), personalbarCurrentset,
+     "Should have updated currentSet after remove.");
+  is(otherPersonalbar.getAttribute("currentset"), personalbarCurrentset,
+     "Should have updated other window's currentSet after remove.");
+
+  yield promiseWindowClosed(otherWin);
+  // Reset in asyncCleanup will put our button back for us.
+});
+
+add_task(function asyncCleanup() {
+  let personalbar = document.getElementById(CustomizableUI.AREA_BOOKMARKS);
+  setToolbarVisibility(personalbar, false);
+  yield resetCustomization();
+});