diff -r 000000000000 -r 6474c204b198 toolkit/components/thumbnails/test/browser_thumbnails_bug726727.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/thumbnails/test/browser_thumbnails_bug726727.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,19 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * These tests ensure that capturing a sites's thumbnail, saving it and
+ * retrieving it from the cache works.
+ */
+function runTests() {
+  // Create a tab that shows an error page.
+  let tab = gBrowser.addTab("http://127.0.0.1:1/");
+  let browser = tab.linkedBrowser;
+
+  yield browser.addEventListener("DOMContentLoaded", function onLoad() {
+    browser.removeEventListener("DOMContentLoaded", onLoad, false);
+    executeSoon(next);
+  }, false);
+
+  ok(!gBrowserThumbnails._shouldCapture(browser), "we're not going to capture an error page");
+}