diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug598600.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug598600.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,73 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+let newWin;
+function test() {
+  let ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
+
+  requestLongerTimeout(2);
+  waitForExplicitFinish();
+
+  // open a new window and setup the window state.
+  newWin = openDialog(getBrowserURL(), "_blank", "chrome,all,dialog=no", "about:blank");
+  newWin.addEventListener("load", function onLoad(event) {
+    this.removeEventListener("load", onLoad, false);
+
+    let newState = {
+      windows: [{
+        tabs: [{
+          entries: [{ "url": "about:blank" }],
+          hidden: true,
+          attributes: {},
+          extData: {
+            "tabview-tab":
+              '{"bounds":{"left":20,"top":35,"width":280,"height":210},' +
+              '"userSize":null,"url":"about:blank","groupID":1,' + 
+              '"imageData":null,"title":null}'
+          }
+        },{
+          entries: [{ url: "about:blank" }],
+          index: 1,
+          hidden: false,
+          attributes: {},
+          extData: {
+            "tabview-tab": 
+              '{"bounds":{"left":375,"top":35,"width":280,"height":210},' + 
+              '"userSize":null,"url":"about:blank","groupID":2,' + 
+              '"imageData":null,"title":null}'
+          }
+        }],
+        selected:2,
+        _closedTabs: [],
+        extData: {
+          "tabview-groups": '{"nextID":3,"activeGroupId":2}',
+          "tabview-group": 
+            '{"1":{"bounds":{"left":15,"top":10,"width":320,"height":375},' + 
+            '"userSize":null,"title":"","id":1},' + 
+            '"2":{"bounds":{"left":380,"top":5,"width":320,"height":375},' + 
+            '"userSize":null,"title":"","id":2}}',
+          "tabview-ui": '{"pageBounds":{"left":0,"top":0,"width":875,"height":650}}'
+        }, sizemode:"normal"
+      }]
+    };
+    ss.setWindowState(newWin, JSON.stringify(newState), true);
+
+    // add a new tab.
+    newWin.gBrowser.addTab();
+    is(newWin.gBrowser.tabs.length, 3, "There are 3 browser tabs"); 
+
+    let onTabViewShow = function() {
+      newWin.removeEventListener("tabviewshown", onTabViewShow, false);
+
+      let contentWindow = newWin.TabView.getContentWindow();
+      is(contentWindow.GroupItems.groupItems.length, 2, "Has two group items");
+
+      // clean up and finish
+      newWin.close();
+
+      finish();
+    }
+    newWin.addEventListener("tabviewshown", onTabViewShow, false);
+    waitForFocus(function() { newWin.TabView.toggle(); });
+  }, false);
+}