# File lib/rubygems/package/tar_reader/entry.rb, line 113
  def read(len = nil)
    check_closed

    return nil if @read >= @header.size

    len ||= @header.size - @read
    max_read = [len, @header.size - @read].min

    ret = @io.read max_read
    @read += ret.size

    ret
  end