diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug591706.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug591706.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,107 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+
+  window.addEventListener("tabviewshown", onTabViewWindowLoaded, false);
+  if (TabView.isVisible())
+    onTabViewWindowLoaded();
+  else
+    TabView.show();
+}
+
+function onTabViewWindowLoaded() {
+  window.removeEventListener("tabviewshown", onTabViewWindowLoaded, false);
+
+  ok(TabView.isVisible(), "Tab View is visible");
+
+  let contentWindow = document.getElementById("tab-view").contentWindow;
+  let [originalTab] = gBrowser.visibleTabs;
+
+  // Create a first tab and orphan it
+  let firstTab = gBrowser.loadOneTab("about:blank#1", {inBackground: true});
+  let firstTabItem = firstTab._tabViewTabItem;
+  let currentGroup = contentWindow.GroupItems.getActiveGroupItem();
+  ok(currentGroup.getChildren().some(function(child) child == firstTabItem),"The first tab was made in the current group");
+  contentWindow.GroupItems.getActiveGroupItem().remove(firstTabItem);
+  ok(!currentGroup.getChildren().some(function(child) child == firstTabItem),"The first tab was orphaned");
+
+  // Create a group and make it active
+  let box = new contentWindow.Rect(10, 10, 300, 300);
+  let group = new contentWindow.GroupItem([], { bounds: box });
+  ok(group.isEmpty(), "This group is empty");
+  contentWindow.UI.setActive(group);
+  
+  // Create a second tab in this new group
+  let secondTab = gBrowser.loadOneTab("about:blank#2", {inBackground: true});
+  let secondTabItem = secondTab._tabViewTabItem;
+  ok(group.getChildren().some(function(child) child == secondTabItem),"The second tab was made in our new group");
+  is(group.getChildren().length, 1, "Only one tab in the first group");
+  isnot(firstTab.linkedBrowser.currentURI.spec, secondTab.linkedBrowser.currentURI.spec, "The two tabs must have different locations");
+
+  // Add the first tab to the group *programmatically*, without specifying a dropPos
+  group.add(firstTabItem);
+  is(group.getChildren().length, 2, "Two tabs in the group");
+
+  is(group.getChildren()[0].tab.linkedBrowser.currentURI.spec, secondTab.linkedBrowser.currentURI.spec, "The second tab was there first");
+  is(group.getChildren()[1].tab.linkedBrowser.currentURI.spec, firstTab.linkedBrowser.currentURI.spec, "The first tab was just added and went to the end of the line");
+
+  group.addSubscriber("close", function onClose() {
+    group.removeSubscriber("close", onClose);
+
+    ok(group.isEmpty(), "The group is empty again");
+
+    is(contentWindow.GroupItems.getActiveGroupItem(), currentGroup, "There is an active group");
+    is(gBrowser.tabs.length, 1, "There is only one tab left");
+    is(gBrowser.visibleTabs.length, 1, "There is also only one visible tab");
+
+    let onTabViewHidden = function() {
+      window.removeEventListener("tabviewhidden", onTabViewHidden, false);
+      finish();
+    };
+    window.addEventListener("tabviewhidden", onTabViewHidden, false);
+    gBrowser.selectedTab = originalTab;
+
+    TabView.hide();
+  });
+
+  // Get rid of the group and its children
+  group.closeAll();
+  // close undo group
+  let closeButton = group.$undoContainer.find(".close");
+  EventUtils.sendMouseEvent(
+    { type: "click" }, closeButton[0], contentWindow);
+}
+
+function simulateDragDrop(srcElement, offsetX, offsetY, contentWindow) {
+  // enter drag mode
+  let dataTransfer;
+
+  EventUtils.synthesizeMouse(
+    srcElement, 1, 1, { type: "mousedown" }, contentWindow);
+  event = contentWindow.document.createEvent("DragEvents");
+  event.initDragEvent(
+    "dragenter", true, true, contentWindow, 0, 0, 0, 0, 0,
+    false, false, false, false, 1, null, dataTransfer);
+  srcElement.dispatchEvent(event);
+
+  // drag over
+  for (let i = 4; i >= 0; i--)
+    EventUtils.synthesizeMouse(
+      srcElement,  Math.round(offsetX/5),  Math.round(offsetY/4),
+      { type: "mousemove" }, contentWindow);
+  event = contentWindow.document.createEvent("DragEvents");
+  event.initDragEvent(
+    "dragover", true, true, contentWindow, 0, 0, 0, 0, 0,
+    false, false, false, false, 0, null, dataTransfer);
+  srcElement.dispatchEvent(event);
+
+  // drop
+  EventUtils.synthesizeMouse(srcElement, 0, 0, { type: "mouseup" }, contentWindow);
+  event = contentWindow.document.createEvent("DragEvents");
+  event.initDragEvent(
+    "drop", true, true, contentWindow, 0, 0, 0, 0, 0,
+    false, false, false, false, 0, null, dataTransfer);
+  srcElement.dispatchEvent(event);
+}