diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug616729.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug616729.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,109 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  let cw;
+
+  let createGroupItem = function () {
+    return createGroupItemWithBlankTabs(window, 400, 200, 0, 5);
+  }
+
+  let assertCorrectItemOrder = function (items) {
+    for (let i=1; i<items.length; i++) {
+      if (items[i-1].tab._tPos > items[i].tab._tPos) {
+        ok(false, 'tabs were correctly reordered');
+        return;
+      }
+    }
+    ok(true, 'tabs were correctly reordered');
+  }
+
+  let testVariousTabOrders = function () {
+    let groupItem = createGroupItem();
+    let [tab1, tab2, tab3, tab4, tab5] = groupItem.getChildren();
+
+    // prepare tests
+    let tests = [];
+    tests.push([tab1, tab2, tab3, tab4, tab5]);
+    tests.push([tab5, tab4, tab3, tab2, tab1]);
+    tests.push([tab1, tab2, tab3, tab4]);
+    tests.push([tab4, tab3, tab2, tab1]);
+    tests.push([tab1, tab2, tab3]);
+    tests.push([tab1, tab2, tab3]);
+    tests.push([tab1, tab3, tab2]);
+    tests.push([tab2, tab1, tab3]);
+    tests.push([tab2, tab3, tab1]);
+    tests.push([tab3, tab1, tab2]);
+    tests.push([tab3, tab2, tab1]);
+    tests.push([tab1, tab2]);
+    tests.push([tab2, tab1]);
+    tests.push([tab1]);
+
+    // test reordering of empty groups - removes the last tab and causes
+    // the groupItem to close
+    tests.push([]);
+
+    while (tests.length) {
+      let test = tests.shift();
+
+      // prepare
+      let items = groupItem.getChildren();
+      while (test.length < items.length)
+        items[items.length-1].close();
+
+      let orig = cw.Utils.copy(items);
+      items.sort(function (a, b) test.indexOf(a) - test.indexOf(b));
+
+      // order and check
+      groupItem.reorderTabsBasedOnTabItemOrder();
+      assertCorrectItemOrder(items);
+
+      // revert to original item order
+      items.sort(function (a, b) orig.indexOf(a) - orig.indexOf(b));
+      groupItem.reorderTabsBasedOnTabItemOrder();
+    }
+
+    testMoveBetweenGroups();
+  }
+
+  let testMoveBetweenGroups = function () {
+    let groupItem = createGroupItem();
+    let groupItem2 = createGroupItem();
+    
+    afterAllTabsLoaded(function () {
+      // move item from group1 to group2
+      let child = groupItem.getChild(2);
+      groupItem.remove(child);
+
+      groupItem2.add(child, {index: 3});
+      groupItem2.reorderTabsBasedOnTabItemOrder();
+
+      assertCorrectItemOrder(groupItem.getChildren());
+      assertCorrectItemOrder(groupItem2.getChildren());
+
+      // move item from group2 to group1
+      child = groupItem2.getChild(1);
+      groupItem2.remove(child);
+
+      groupItem.add(child, {index: 1});
+      groupItem.reorderTabsBasedOnTabItemOrder();
+
+      assertCorrectItemOrder(groupItem.getChildren());
+      assertCorrectItemOrder(groupItem2.getChildren());
+
+      // cleanup
+      closeGroupItem(groupItem, function () {
+        closeGroupItem(groupItem2, function () {
+          hideTabView(finish);
+        });
+      });
+    });
+  }
+
+  waitForExplicitFinish();
+
+  showTabView(function () {
+    cw = TabView.getContentWindow();
+    afterAllTabsLoaded(testVariousTabOrders);
+  });
+}