square/retrofit — pull request #553 by JakeWharton (2014-07-02 19:06:29+00:00)
Title: Always add special-cased 'Content-Type' header to request.

Because 'Content-Type' needs special-cased to hand inside the request body's 'TypedOutput' we were erroneously omitting the header if no body was present. In the case of no body, we can just add it like any other header.

Closes #533.

@edenman