diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug629195.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug629195.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/ */
+
+let win;
+let contentWindow;
+let originalTab;
+
+function test() {
+  waitForExplicitFinish();
+
+  newWindowWithTabView(
+    function() {
+      ok(win.TabView.isVisible(), "Tab View is visible");
+
+      contentWindow = win.document.getElementById("tab-view").contentWindow;
+      is(contentWindow.GroupItems.groupItems.length, 1, "There is one group");
+      is(contentWindow.GroupItems.groupItems[0].getChildren().length, 1,
+         "The group has only one tab item");
+
+      // show the undo close group button
+      let group = contentWindow.GroupItems.groupItems[0];
+      hideGroupItem(group, function () restore(group.id));
+    },
+    function(newWin) {
+      win = newWin;
+      originalTab = win.gBrowser.visibleTabs[0];
+      win.gBrowser.addTab();
+      win.gBrowser.pinTab(originalTab);
+    }
+  );
+}
+
+function restore(groupId) {
+  // window state ready
+  let handleSSWindowStateReady = function() {
+    win.removeEventListener("SSWindowStateReady", handleSSWindowStateReady, false);
+
+    executeSoon(function() { 
+      is(contentWindow.GroupItems.groupItems.length, 1, "There is one group");
+
+      let group = contentWindow.GroupItems.groupItems[0];
+      ok(!group.hidden, "The group is visible");
+      is(group.getChildren().length, 2, "This group has two tab items");
+
+      // check the position of the group item and the tab items.
+      let tabItemOne = group.getChildren()[0];
+      let tabItemTwo = group.getChildren()[1];
+
+      let groupBounds = group.getBounds();
+      let tabItemOneBounds = tabItemOne.getBounds();
+      let tabItemTwoBounds = tabItemTwo.getBounds();
+
+      ok(groupBounds.left < tabItemOneBounds.left && 
+         (groupBounds.right) > (tabItemOneBounds.right) &&
+         groupBounds.top < tabItemOneBounds.top && 
+         (groupBounds.bottom) > (tabItemOneBounds.bottom), 
+         "Tab item one is within the group");
+
+      ok(groupBounds.left < tabItemOneBounds.left && 
+         (groupBounds.right) > (tabItemTwoBounds.right) &&
+         groupBounds.top < tabItemOneBounds.top && 
+         (groupBounds.bottom) > (tabItemTwoBounds.bottom), 
+         "Tab item two is within the group");
+
+      win.close();
+      finish();
+    });
+  }
+  win.addEventListener("SSWindowStateReady", handleSSWindowStateReady, false);
+
+  // simulate restoring previous session (one group and two tab items)
+  const DUMMY_PAGE_URL = "http://example.com/";
+  let newState = {
+    windows: [{
+      tabs: [{
+        entries: [{ url: DUMMY_PAGE_URL }],
+        index: 2,
+        hidden: false,
+        attributes: {},
+        extData: {
+          "tabview-tab":
+            '{"bounds":{"left":208,"top":54,"width":205,"height":169},' +
+            '"userSize":null,"url":"' + DUMMY_PAGE_URL + '","groupID":' + 
+            groupId + ',"imageData":null,"title":null}'
+        }}, {
+        entries: [{ url: DUMMY_PAGE_URL }],
+        index: 1,
+        hidden: false,
+        attributes: {},
+        extData: {
+          "tabview-tab":
+            '{"bounds":{"left":429,"top":54,"width":205,"height":169},' +
+            '"userSize":null,"url":"' + DUMMY_PAGE_URL + '","groupID":' + 
+            groupId + ',"imageData":null,"title":null}'
+        }
+      }],
+      extData: {
+        "tabview-groups": '{"nextID":' + (groupId + 1) + ',"activeGroupId":' + groupId + '}',
+        "tabview-group": 
+          '{"' + groupId + '":{"bounds":{"left":202,"top":30,"width":455,"height":249},' + 
+          '"userSize":null,"locked":{},"title":"","id":' + groupId +'}}',
+        "tabview-ui": '{"pageBounds":{"left":0,"top":0,"width":788,"height":548}}'
+      }, sizemode:"normal"
+    }]
+  };
+  let ss = Cc["@mozilla.org/browser/sessionstore;1"].getService(Ci.nsISessionStore);
+  ss.setWindowState(win, JSON.stringify(newState), true);
+}
+