diff -r 000000000000 -r 6474c204b198 browser/base/content/test/newtab/browser_newtab_bug723121.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/newtab/browser_newtab_bug723121.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function runTests() {
+  yield setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks("");
+
+  yield addNewTabPageTab();
+  checkGridLocked(false, "grid is unlocked");
+
+  let cell = getCell(0).node;
+  let site = getCell(0).site.node;
+  let link = site.querySelector(".newtab-link");
+
+  sendDragEvent("dragstart", link);
+  checkGridLocked(true, "grid is now locked");
+
+  sendDragEvent("dragend", link);
+  checkGridLocked(false, "grid isn't locked anymore");
+
+  sendDragEvent("dragstart", cell);
+  checkGridLocked(false, "grid isn't locked - dragstart was ignored");
+
+  sendDragEvent("dragstart", site);
+  checkGridLocked(false, "grid isn't locked - dragstart was ignored");
+}
+
+function checkGridLocked(aLocked, aMessage) {
+  is(getGrid().node.hasAttribute("locked"), aLocked, aMessage);
+}