Keystone API is forcing Content-Transfer: chunked on responses

Hi,

I'am implementing CORS support for Keystone. Everything is working except that on response I'am setting Content-Length header to 0 but response is sent to user using Tramsfer-Encoding: chunked.

Code added to PublicRouter class:

       # Cors Operations
        cors_controller = CorsController()
        mapper.connect('/tokens',
                       controller=cors_controller,
                       action='get_options',
                       conditions=dict(method=['OPTIONS']))

CorsCotroller class is as follows:

class CorsController(wsgi.Application):
    def __init__(self):
        super(CorsController, self).__init__()
    def get_options(self, context):
        headers = [('Access-Control-Allow-Headers', 'origin,content-type,accept,x-auth-token')]
        headers.append(('Access-Control-Allow-Methods', 'POST'))
        headers.append(('Access-Control-Allow-Origin', 'https://178.239.138.10:8433'))
        headers.append(('Access-Control-Max-Age', '60'))
        headers.append(('Content-Length', '0'))
        return wsgi.render_response(status=(200, 'OK'),
                                    headers=headers)

Everything seems to be working:
echo -e 'OPTIONS /v2.0/tokens HTTP/1.1\r\n' | nc 10.76.0.206 5000
HTTP/1.1 200 OK
Access-Control-Allow-Headers: origin,content-type,accept,x-auth-token
Access-Control-Allow-Methods: POST
Access-Control-Allow-Origin: https://178.239.138.10:8433
Access-Control-Max-Age: 1728000
Content-Type: text/html; charset=UTF-8
Date: Thu, 21 Jun 2012 17:52:29 GMT
Transfer-Encoding: chunked

0

B