diff -r 000000000000 -r 6474c204b198 browser/base/content/test/general/browser_bug817947.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/general/browser_bug817947.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+
+const URL = "http://mochi.test:8888/browser/";
+const PREF = "browser.sessionstore.restore_on_demand";
+
+function test() {
+  waitForExplicitFinish();
+
+  Services.prefs.setBoolPref(PREF, true);
+  registerCleanupFunction(function () {
+    Services.prefs.clearUserPref(PREF);
+  });
+
+  preparePendingTab(function (aTab) {
+    let win = gBrowser.replaceTabWithWindow(aTab);
+
+    whenDelayedStartupFinished(win, function () {
+      let [tab] = win.gBrowser.tabs;
+
+      whenLoaded(tab.linkedBrowser, function () {
+        is(tab.linkedBrowser.currentURI.spec, URL, "correct url should be loaded");
+        ok(!tab.hasAttribute("pending"), "tab should not be pending");
+
+        win.close();
+        finish();
+      });
+    });
+  });
+}
+
+function preparePendingTab(aCallback) {
+  let tab = gBrowser.addTab(URL);
+
+  whenLoaded(tab.linkedBrowser, function () {
+    gBrowser.removeTab(tab);
+    let [{state}] = JSON.parse(SessionStore.getClosedTabData(window));
+
+    tab = gBrowser.addTab("about:blank");
+    whenLoaded(tab.linkedBrowser, function () {
+      SessionStore.setTabState(tab, JSON.stringify(state));
+      ok(tab.hasAttribute("pending"), "tab should be pending");
+      aCallback(tab);
+    });
+  });
+}
+
+function whenLoaded(aElement, aCallback) {
+  aElement.addEventListener("load", function onLoad() {
+    aElement.removeEventListener("load", onLoad, true);
+    executeSoon(aCallback);
+  }, true);
+}