Project: mule
Issue MULE-8127: HTTP Listener Module is not adding the WWW-Authenticate header field in the response 
When you send bad basic credentials for authentication the response of the listener is not adding the WWW-Authenticate header field. But in the case you don't send the authentication header credential it includes the WWW-Authenticate header field. As I understand in the RFC (http://tools.ietf.org/html/rfc2616#section-10.4.2) the server has to add the WWW-Authenticate header field in both scenarios.
Story points: 5