shazow/urllib3 — pull request #99 by clippit (2012-09-11 08:05:11+00:00)
Title: request_encode_body will empty the potential headers defined when HTTPConnectionPool init

When creating a `HTTPConnectionPool` object, you can pass `headers` which should be included in all requests. However the `request_encode_body` method from parent class will empty these default headers and add a `Content-Type` value, unless you pass `headers` explicitly when calling this method.

I think it's a bug and there is a rough fix.