koajs/koa — pull request #296 by yorkie (2014-06-07 15:00:04+00:00)
Title: application: returns 400 when content-range is set in PUT

see the new HTTP draft: http://tools.ietf.org/html/rfc7231
> An origin server that allows PUT on a given target resource MUST send a 400 (Bad Request) response to a PUT request that contains a Content-Range header field

Range request would be the next huge job for every common http framework IMO, then start from here.
:P