isfg
v->v_num = isfg(w);
(!isfg(w) && (w->ww_order < s->ww_order || isfg(s)))))
if (w->ww_back != (isfg(w) ? framewin : fgwin) && !wwvisible(w)) {
addwin(w, isfg(w));
wwadd(w, selwin != 0 && selwin != w && !isfg(selwin)