diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug662266.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug662266.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,39 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+
+  newWindowWithTabView(function (win) {
+    registerCleanupFunction(function () win.close());
+
+    for (let i = 0; i < 4; i++)
+      win.gBrowser.loadOneTab("about:blank", {inBackground: true});
+
+    let cw = win.TabView.getContentWindow();
+    let groupItem = cw.GroupItems.groupItems[0];
+    let children = groupItem.getChildren();
+
+    groupItem.setSize(200, 200, true);
+    ok(groupItem.isStacked(), "groupItem is now stacked");
+    is(win.gBrowser.tabs.length, 5, "we have five tabs");
+
+    groupItem.addSubscriber("expanded", function onExpanded() {
+      groupItem.removeSubscriber("expanded", onExpanded);
+
+      ok(groupItem.expanded, "groupItem is expanded");
+      let bounds = children[1].getBounds();
+
+      // remove two tabs and see if the remaining tabs are re-arranged to fill
+      // the resulting gaps
+      for (let i = 0; i < 2; i++) {
+        EventUtils.synthesizeMouseAtCenter(children[1].container, {button: 1}, cw);
+        ok(bounds.equals(children[1].getBounds()), "tabItems were re-arranged");
+      }
+
+      waitForFocus(finish);
+    });
+
+    groupItem.expand();
+  });
+}