if *c > 0 {
		*c--
		return 1, data[:1], nil
	}
	return 0, nil, nil
}

// Check that the looping-at-EOF check doesn't trigger for merely empty tokens.
func TestEmptyLinesOK(t *testing.T) {
	c := countdown(10000)
	s := NewScanner(strings.NewReader(strings.Repeat("\n", 10000)))
	s.Split(c.split)
	for s.Scan() {
	}
	if s.Err() != nil {