PhusionPassenger::Utils::TeeInput should support seek method

[bachue]

When an http request comes with GZip compressed, some request handler use Zlib::GzipReader to read from TeeInput (because it's in env['rack.input'], e.g. https://github.com/schacon/grack/blob/master/lib%2Fgrack.rb#L243), then if someone call request.body.rewind, the error happens:

undefined method `seek' for #PhusionPassenger::Utils::TeeInput:0x0000000d4c7ab8

The reason is GzipReader calls seek to do rewind

rewind()
Resets the position of the file pointer to the point created the GzipReader object. The associated IO object needs to respond to the seek method.

So can TeeInput implement seek? Thanks.

[OnixGH]

Technically env['rack.input'] only needs to implement rewind (per the Rack specification) so Zlib::GzipReader is apparently depending on an optional feature.

But we'll see what we can do :)