module ActionDispatch::Flash::RequestMethods

def commit_flash # :nodoc:
  session    = self.session || {}
  flash_hash = self.flash_hash
  if flash_hash && (flash_hash.present? || session.key?('flash'))
    session["flash"] = flash_hash.to_session_value
    self.flash = flash_hash.dup
  end
  if (!session.respond_to?(:loaded?) || session.loaded?) && # (reset_session uses {}, which doesn't implement #loaded?)
      session.key?('flash') && session['flash'].nil?
    session.delete('flash')
  end
end