The Tor Browser / file revision

 function run_test() {

   var ioServ = Components.classes["@mozilla.org/network/io-service;1"]

                          .getService(Components.interfaces.nsIIOService);

   var base = ioServ.newURI("http://www.example.com", null, null);

   var about1 = ioServ.newURI("about:blank", null, null);

   var about2 = ioServ.newURI("about:blank", null, base);

   var chan1 = ioServ.newChannelFromURI(about1)

                     .QueryInterface(Components.interfaces.nsIPropertyBag2);

   var chan2 = ioServ.newChannelFromURI(about2)

                     .QueryInterface(Components.interfaces.nsIPropertyBag2);

   var haveProp = false;

   var propVal = null;

   try {

     propVal = chan1.getPropertyAsInterface("baseURI",

                                            Components.interfaces.nsIURI);

     haveProp = true;

   } catch (e if e.result == Components.results.NS_ERROR_NOT_AVAILABLE) {

     // Property shouldn't be there.

   }

   do_check_eq(propVal, null);

   do_check_eq(haveProp, false);

   do_check_eq(chan2.getPropertyAsInterface("baseURI",

                                            Components.interfaces.nsIURI),

               base);

 }