diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug644097.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug644097.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,40 @@
+/* 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());
+
+    let cw = win.TabView.getContentWindow();
+    let groupItem = cw.GroupItems.groupItems[0];
+
+    // create some tabs with favIcons
+    for (let i = 0; i < 3; i++)
+      win.gBrowser.loadOneTab("http://mochi.test:8888/browser/browser/components/tabview/test/test_bug644097.html", {inBackground: true});
+
+    win.gBrowser.removeTab(win.gBrowser.tabs[0]);
+
+    // shrink the group until it stacks
+    let size = 400;
+    while (!groupItem.isStacked() && --size)
+      groupItem.setSize(size, size, true);
+
+    // determine the tabItem at the top of the stack
+    let tabItem;
+    groupItem.getChildren().forEach(function (item) {
+      if (groupItem.isTopOfStack(item))
+        tabItem = item;
+    });
+
+    ok(tabItem, "we found the tabItem at the top of the stack");
+
+    let fav = tabItem.$fav;
+    is(fav.css("display"), "block", "the favIcon is visible");
+    is(fav.css("left"), "0px", "the favIcon is at the left-most position");
+    is(fav.css("top"), "0px", "the favIcon is at the top-most position");
+
+    finish();
+  });
+}