}
	}
	if offset != b.currOffset {
		// Can never happen unless there are programmer bugs
		return 0, errUnexpected
	}
	b.h.Reset()
	_, err = io.ReadFull(b.rc, b.hashBytes)
	if err != nil {
		return 0, err
	}
	_, err = io.ReadFull(b.rc, buf)
	if err != nil {
		return 0, err
	}
	b.h.Write(buf)
	if !bytes.Equal(b.h.Sum(nil), b.hashBytes) {
		return 0, errFileCorrupt
	}