if n > len(cmp) || bytes.Compare(cmp[:n], buf[:n]) != 0 {
return collisionOrCorrupt(hash, expect[:len(expect)-len(cmp)], buf[:n], rdr)
}
if n > len(cmp) || bytes.Compare(cmp[:n], buf[:n]) != 0 {
return collisionOrCorrupt(hash, expect[:len(expect)-len(cmp)], buf[:n], rdr)
}