static i64 read_header(rzip_control *control, void *ss, uchar *head)
{
	bool err = false;

	*head = read_u8(control, ss, 0, &err);
	if (err)
		return -1;
	return read_vchars(control, ss, 0, control->chunk_bytes);
}
static i64 read_header(rzip_control *control, void *ss, uchar *head)
{
	bool err = false;

	*head = read_u8(control, ss, 0, &err);
	if (err)
		return -1;
	return read_vchars(control, ss, 0, control->chunk_bytes);
}