class Gem::Package::TarReader::Entry

def readpartial(maxlen, outbuf = "".b)
  if eof? && maxlen > 0
    raise EOFError, "end of file reached"
  end
  max_read = [maxlen, @header.size - @read].min
  @io.readpartial(max_read, outbuf)
  @read += outbuf.size
  outbuf
end