zendframework/zf2 — pull request #2962 by cyberwolf (2012-11-14 08:22:59+00:00)
Title: Allow Accept-Encoding header to be set explicitly by http request

Currently it does not seem possible to override the Accept-Encoding header, I think because of some code in Zend\Http\Client::prepareHeaders that uses an undefined $headers member variable while it should check if the header is already explicitly set in the request.