Jruby-rack with rails send_file bug

rackup.ru

%w(action_controller/railtie).map &method(:require)

run JrubyRackTest ||= Class.new(Rails::Application) {
  config.secret_token = routes.append { root to: 'send_file#deliver' }.inspect
  initialize!
}

class SendFileController < ActionController::Base
  def deliver
    send_file Rails.root.join("testdata.jpeg")
  end
end