cut_line
if (cut_line(sp, lno, 0, CUT_LINE_TO_EOL, cbp))
if (cut_line(sp, fm->lno, fm->cno, fm->lno != tm->lno ?
if (cut_line(sp, lno, 0, CUT_LINE_TO_EOL, cbp))
cut_line(sp, lno, 0, tm->cno + 1, cbp))
if (cut_line(sp, cnt, 0, CUT_LINE_TO_EOL, &cb)) {
int cut_line(SCR *, recno_t, size_t, size_t, CB *);