radioline_common(cp, nacross, ap);
nbuttons = 0; while (1) { char *btext = va_arg(ap, char *); int bid; if (!btext) break; bid = va_arg(ap, int); }
void bareradioline(struct ctlpos *cp, int nacross, ...){    va_list ap;    va_start(ap, nacross);    radioline_common(cp, nacross, ap);    va_end(ap);}