diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug600812.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug600812.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,45 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  let cw;
+
+  let createGroupItem = function () {
+    let bounds = new cw.Rect(20, 20, 150, 150);
+    let groupItem = new cw.GroupItem([], {bounds: bounds, immediately: true});
+
+    cw.UI.setActive(groupItem);
+    gBrowser.loadOneTab('about:blank', {inBackground: true});
+
+    return groupItem;
+  }
+
+  let testVeryQuickDragAndDrop = function () {
+    let sourceGroup = createGroupItem();
+    let targetGroup = cw.GroupItems.groupItems[0];
+
+    sourceGroup.pushAway(true);
+    targetGroup.pushAway(true);
+
+    let sourceTab = sourceGroup.getChild(0).container;
+    EventUtils.synthesizeMouseAtCenter(sourceTab, {type: 'mousedown'}, cw);
+
+    let targetTab = targetGroup.getChild(0).container;
+    EventUtils.synthesizeMouseAtCenter(targetTab, {type: 'mousemove'}, cw);
+    EventUtils.synthesizeMouseAtCenter(targetTab, {type: 'mouseup'}, cw);
+
+    is(targetGroup.getChildren().length, 2, 'target group has two tabs');
+    is(cw.GroupItems.groupItems.length, 1, 'sourceGroup was closed');
+    isnot(cw.GroupItems.groupItems[0], sourceGroup, 'sourceGroup was closed');
+
+    targetGroup.getChild(0).close();
+    hideTabView(finish);
+  }
+
+  waitForExplicitFinish();
+
+  showTabView(function () {
+    cw = TabView.getContentWindow();
+    afterAllTabsLoaded(testVeryQuickDragAndDrop);
+  });
+}