diff -r 000000000000 -r 6474c204b198 browser/components/sessionstore/test/unit/test_startup_nosession_async.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/sessionstore/test/unit/test_startup_nosession_async.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+
+// Test nsISessionStartup.sessionType in the following scenario:
+// - no sessionstore.js;
+// - the session store has been loaded, so no need to go
+//    through the synchronous fallback
+
+function run_test() {
+  do_get_profile();
+  // Initialize the profile (the session startup uses it)
+
+  do_test_pending();
+  let startup = Cc["@mozilla.org/browser/sessionstartup;1"].
+    getService(Ci.nsISessionStartup);
+
+  afterSessionStartupInitialization(function cb() {
+    do_check_eq(startup.sessionType, Ci.nsISessionStartup.NO_SESSION);
+    do_test_finished();
+  });
+}
\ No newline at end of file