The Tor Browser / file revision

 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();

 }