1258     SeqPortPtr curspp;  in SeqPortSeek()  local
1441         curspp = spp->segs;  in SeqPortSeek()
1442         if (curspp == NULL) return 1;  in SeqPortSeek()
1443         while ((curpos + curspp->totlen) <= sp)  in SeqPortSeek()
1445             curpos += curspp->totlen;  in SeqPortSeek()
1446             curspp = curspp->next;  in SeqPortSeek()
1447             if (curspp == NULL)  in SeqPortSeek()
1453             curpos = (curspp->totlen - 1) - (sp - curpos);  in SeqPortSeek()
1454         curspp->backing = spp->backing;  in SeqPortSeek()
1455         if (! SeqPortSeek(curspp, curpos, SEEK_SET))  in SeqPortSeek()
1457             curspp->backing = FALSE;  in SeqPortSeek()
1458             spp->curr = curspp;  in SeqPortSeek()
1464             curspp->backing = FALSE;  in SeqPortSeek()