Since ClientResponse does only return the first Cookie in Set-Cookie, here is a workaround:

httpfix.coffee

old = HTTP.IncomingMessage.prototype._addHeaderLine
HTTP.IncomingMessage.prototype._addHeaderLine = (field, value) ->
  if field is 'set-cookie' and @headers['set-cookie']
    @headers['set-cookie'] += "; #{value}"
  else
    old.apply this, arguments

httpfix.js

old = HTTP.IncomingMessage.prototype._addHeaderLine;
HTTP.IncomingMessage.prototype._addHeaderLine = function(field, value) {
  return field === 'set-cookie' && this.headers['set-cookie'] ? this.headers['set-cookie'] += ("; " + (value)) : old.apply(this, arguments);
};