diff -r 000000000000 -r 6474c204b198 netwerk/test/unit/test_proxy-failover_canceled.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netwerk/test/unit/test_proxy-failover_canceled.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,51 @@
+Cu.import("resource://testing-common/httpd.js");
+
+var httpServer = null;
+
+function make_channel(url, callback, ctx) {
+  var ios = Cc["@mozilla.org/network/io-service;1"].
+            getService(Ci.nsIIOService);
+  return ios.newChannel(url, "", null);
+}
+
+const responseBody = "response body";
+
+function contentHandler(metadata, response)
+{
+  response.setHeader("Content-Type", "text/plain");
+  response.bodyOutputStream.write(responseBody, responseBody.length);
+}
+
+function finish_test(request, buffer)
+{
+  do_check_eq(buffer, "");
+  httpServer.stop(do_test_finished);
+}
+
+function run_test()
+{
+  httpServer = new HttpServer();
+  httpServer.registerPathHandler("/content", contentHandler);
+  httpServer.start(-1);
+
+  // we want to cancel the failover proxy engage, so, do not allow
+  // redirects from now.
+
+  var nc = new ChannelEventSink();
+  nc._flags = ES_ABORT_REDIRECT;
+
+  var prefserv = Cc["@mozilla.org/preferences-service;1"].
+                 getService(Ci.nsIPrefService);
+  var prefs = prefserv.getBranch("network.proxy.");
+  prefs.setIntPref("type", 2);
+  prefs.setCharPref("autoconfig_url", "data:text/plain," +
+    "function FindProxyForURL(url, host) {return 'PROXY a_non_existent_domain_x7x6c572v:80; PROXY localhost:" +
+    httpServer.identity.primaryPort + "';}"
+  );
+
+  var chan = make_channel("http://localhost:" +
+                          httpServer.identity.primaryPort + "/content");
+  chan.notificationCallbacks = nc;
+  chan.asyncOpen(new ChannelListener(finish_test, null, CL_EXPECT_FAILURE), null);
+  do_test_pending();
+}