Let me address this one thing at a time, the point on smb really confused me and I got into thinking that how smb (being more common), the issue was not raised. Looks smb url will always start with smb:// (// are the requirements for identified netloc, empty or otherwise) and cases for smb are fine - http://tools.ietf.org/html/draft-crhertel-smb-url-00

That said, the dependency on uses_netloc has come many times and I am still looking for way to remove the dependency without affecting the previous parsing behaviors and ofcourse tests.