The Tor Browser / file revision

 function handleRequest(request, response)

 {

   var file = Components.classes["@mozilla.org/file/directory_service;1"]

              .getService(Components.interfaces.nsIProperties)

              .get("CurWorkD", Components.interfaces.nsIFile);

   file.append("tests");

   file.append("image");

   file.append("test");

   file.append("mochitest");

   file.append('lime100x100.svg');

   response.setStatusLine("1.1", 500, "Internal Server Error");

   response.setHeader("Content-Type", "image/svg+xml", false);

   var fileStream = Components.classes['@mozilla.org/network/file-input-stream;1']

                    .createInstance(Components.interfaces.nsIFileInputStream);

   fileStream.init(file, 1, 0, false);

   var binaryStream = Components.classes['@mozilla.org/binaryinputstream;1']

                      .createInstance(Components.interfaces.nsIBinaryInputStream);

   binaryStream.setInputStream(fileStream);

   response.bodyOutputStream.writeFrom(binaryStream, binaryStream.available());

   binaryStream.close();

   fileStream.close();

 }