diff -r 000000000000 -r 6474c204b198 browser/components/tabview/test/browser_tabview_bug634077.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/test/browser_tabview_bug634077.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,25 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  let ss = Cc["@mozilla.org/browser/sessionstore;1"]
+                     .getService(Ci.nsISessionStore);
+
+  let assertVisibilityDataEquals = function (val, msg) {
+    is(ss.getWindowValue(window, TabView.VISIBILITY_IDENTIFIER), val, msg);
+  }
+
+  waitForExplicitFinish();
+
+  ss.setWindowValue(window, window.TabView.VISIBILITY_IDENTIFIER, "null");
+  assertVisibilityDataEquals("null", "we start with <null>");
+
+  showTabView(function () {
+    assertVisibilityDataEquals("true", "after showing visibility data is <true>");
+
+    hideTabView(function () {
+      assertVisibilityDataEquals("false", "after hiding visibility data is <false>");
+      finish();
+    });
+  });
+}