diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug628061.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug628061.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,53 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
+
+let state = {
+  windows: [{
+    tabs: [{
+      entries: [{ url: "about:robots" }],
+      hidden: true,
+      extData: {"tabview-tab": '{"url":"about:robots","groupID":1,"bounds":{"left":20,"top":20,"width":20,"height":20}}'}
+    },{
+      entries: [{ url: "about:robots" }],
+      hidden: false,
+      extData: {"tabview-tab": '{"url":"about:robots","groupID":2,"bounds":{"left":20,"top":20,"width":20,"height":20}}'},
+    }],
+    selected: 2,
+    extData: {
+      "tabview-groups": '{"nextID":3,"activeGroupId":2, "totalNumber":2}',
+      "tabview-group":
+        '{"1":{"bounds":{"left":15,"top":5,"width":280,"height":232},"id":1},' +
+        '"2":{"bounds":{"left":309,"top":5,"width":267,"height":226},"id":2}}'
+    }
+  }]
+};
+
+function test() {
+  waitForExplicitFinish();
+  testOne();
+}
+
+function testOne() {
+  newWindowWithTabView(
+    function(win) {
+      testTwo();
+      win.close();
+    },
+    function(win) {
+      registerCleanupFunction(function() win.close());
+      is(win.document.getElementById("tabviewGroupsNumber").getAttribute("groups"),
+         "1", "There is one group");
+    });
+}
+
+function testTwo() {
+  newWindowWithState(state, function(win) {
+    registerCleanupFunction(function() win.close());
+
+    is(win.document.getElementById("tabviewGroupsNumber").getAttribute("groups"),
+       "2", "There are two groups");
+    waitForFocus(finish);
+  });
+}