diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug637840.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug637840.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,93 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+let cw;
+
+function test() {
+  requestLongerTimeout(2);
+  waitForExplicitFinish();
+
+  newWindowWithTabView(function(win) {
+    cw = win.TabView.getContentWindow();
+
+    let groupItemOne = cw.GroupItems.groupItems[0];
+    is(groupItemOne.getChildren().length, 1, "Group one has 1 tab item");
+
+    let groupItemTwo = createGroupItemWithBlankTabs(win, 300, 300, 40, 2);
+    is(groupItemTwo.getChildren().length, 2, "Group two has 2 tab items");
+
+    let groupItemThree = createGroupItemWithBlankTabs(win, 300, 300, 40, 2);
+    is(groupItemThree.getChildren().length, 2, "Group three has 2 tab items");
+
+    waitForFocus(() => {
+      testMoreRecentlyUsedGroup(groupItemOne, groupItemTwo, function() {
+        testMoreRecentlyUsedGroup(groupItemOne, groupItemThree, function() {
+          testRemoveGroupAndCheckMoreRecentlyUsedGroup(groupItemOne, groupItemTwo);
+        });
+      });
+    }, cw);
+  });
+}
+
+function testMoreRecentlyUsedGroup(groupItemOne, otherGroupItem, callback) {
+  let tabItem = otherGroupItem.getChild(1);
+  cw.UI.setActive(tabItem);
+  is(otherGroupItem.getActiveTab(), tabItem, "The second item in the other group is active");
+  is(cw.GroupItems.getActiveGroupItem(), otherGroupItem, "The other group is active");
+
+  let tabItemInGroupItemOne = groupItemOne.getChild(0);
+  cw.UI.setActive(tabItemInGroupItemOne);
+  is(groupItemOne.getActiveTab(), tabItemInGroupItemOne, "The first item in group one is active");
+  is(cw.GroupItems.getActiveGroupItem(), groupItemOne, "The group one is active");
+
+  groupItemOne.addSubscriber("groupHidden", function onHide() {
+    groupItemOne.removeSubscriber("groupHidden", onHide);
+
+    // group item three should have the focus
+    is(otherGroupItem.getActiveTab(), tabItem, "The second item in the other group is active after group one is hidden");
+    is(cw.GroupItems.getActiveGroupItem(), otherGroupItem, "The other group is active active after group one is hidden");
+
+    groupItemOne.addSubscriber("groupShown", function onShown() {
+      groupItemOne.removeSubscriber("groupShown", onShown);
+
+      is(groupItemOne.getActiveTab(), tabItemInGroupItemOne, "The first item in group one is active after it is shown");
+      is(cw.GroupItems.getActiveGroupItem(), groupItemOne, "The group one is active after it is shown");
+
+      callback();
+    });
+    // click on the undo button
+    EventUtils.sendMouseEvent(
+      { type: "click" }, groupItemOne.$undoContainer[0], cw);
+  });
+  // click on the close button of group item one
+  let closeButton = groupItemOne.container.getElementsByClassName("close");
+  ok(closeButton[0], "Group item one close button exists");
+  EventUtils.sendMouseEvent({ type: "click" }, closeButton[0], cw);
+}
+
+function testRemoveGroupAndCheckMoreRecentlyUsedGroup(groupItemOne, groupItemTwo) {
+  let tabItem = groupItemTwo.getChild(0);
+  cw.UI.setActive(tabItem);
+
+  is(groupItemTwo.getActiveTab(), tabItem, "The first item in the group two is active");
+  is(cw.GroupItems.getActiveGroupItem(), groupItemTwo, "The group two is active");
+
+  let tabItemInGroupItemOne = groupItemOne.getChild(0);
+
+  tabItemInGroupItemOne.addSubscriber("close", function onClose() {
+    tabItemInGroupItemOne.removeSubscriber("close", onClose);
+
+    is(groupItemTwo.getActiveTab(), tabItem, "The first item in the group two is still active after group one is closed");
+    is(cw.GroupItems.getActiveGroupItem(), groupItemTwo, "The group two is still active after group one is closed");
+
+    promiseWindowClosed(cw.top).then(() => {
+      cw = null;
+      finish();
+    });
+  });
+  // close the tab item and the group item
+  let closeButton = tabItemInGroupItemOne.container.getElementsByClassName("close");
+  ok(closeButton[0], "Tab item close button exists");
+  EventUtils.sendMouseEvent({ type: "mousedown" }, closeButton[0], cw);
+  EventUtils.sendMouseEvent({ type: "mouseup" }, closeButton[0], cw);
+}