st_untilbuf.length = 0;
st_untilbuf.term[0] = '\0';
r = isamb_pp_forward(sf->isam_pp, &st, &st_untilbuf);
if (r && st.sysno == si->sysno)
{
wrbuf_write(w, st.term, st.length);
st_untilbuf.length = 0;
st_untilbuf.term[0] = '\0';
r = isamb_pp_forward(sf->isam_pp, &st, &st_untilbuf);
if (r && st.sysno == si->sysno)
{
wrbuf_write(w, st.term, st.length);