diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug686654.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug686654.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+
+  newWindowWithTabView(function(win) {
+    let cw = win.TabView.getContentWindow();
+    let groupItem = cw.GroupItems.groupItems[0];
+
+    // set the group to 180 x 100 so it shows two tab items without going into
+    // the stacked mode
+    groupItem.setBounds(new cw.Rect(100, 0, 180, 100));
+
+    hideTabView(function() {
+      groupItem.addSubscriber("childAdded", function onChildAdded(data) {
+        groupItem.removeSubscriber("childAdded", onChildAdded);
+
+        is(groupItem.getChildren().length, 3, "The number of children in group is 3");
+        ok(groupItem.isStacked(), "The group item is stacked after adding a new tab");
+
+        let tabItem = groupItem.getChild(2);
+        groupItem.addSubscriber("childRemoved", function onChildRemoved() {
+          tabItem.removeSubscriber("childRemoved", onChildRemoved);
+
+          is(groupItem.getChildren().length, 2, "The number of children in group is 2");
+          // give a delay for the active item to be set
+          executeSoon(function() {
+            showTabView(function() {
+              ok(!groupItem.isStacked(), "The group item is not stacked after removing a tab");
+              finish();
+            }, win);
+          });
+        });
+        win.BrowserCloseTabOrWindow();
+      });
+      win.gBrowser.loadOneTab("", {inBackground: true});
+    }, win);
+  }, function(win) {
+    registerCleanupFunction(function () {
+      win.close();
+    });
+
+    win.gBrowser.addTab();
+  });
+}