Is Rack partial hijack supported?

[Samuel Williams <samuel@oriontransfer.net>]

Hi Eric,

I’ve been testing Rack server conformance and behaviour and noticed that while unicorn advertises `env[‘rack.hijack?’]` as true, it fails to correctly stream the following response:

if env['rack.hijack?']
  callback = proc do |stream|
    stream.write "Hello World"
    stream.close
  end
  
  return [200, {'rack.hijack' => callback}, nil]
else
  [404, {}, []]
end

Am I misunderstanding something about how this should work or does Unicorn not support partial hijack?

Kind regards,
Samuel