code: func (d *Decoder) padEntry(idx *Index, e *Entry, read int) error {
  	if idx.Version == 4 {
  		return nil
  	}
  
  	entrySize := read + len(e.Name)
  	padLen := 8 - entrySize%8
  	_, err := io.CopyN(ioutil.Discard, d.r, int64(padLen))
  	return err
  }
docs: // Index entries are padded out to the next 8 byte alignment
  // for historical reasons related to how C Git read the files.