if (h->hist[next]) h->cur = next;
h->cur = h->hist[next] ? next : 0;
char *mutt_history_next (history_class_t hclass){  int next;  struct history *h = &History[hclass];    if (!HistSize)    return (""); /* disabled */  next = h->cur + 1;  if (next > h->last - 1)    next = 0;  if (h->hist[next])    h->cur = next;  return (h->hist[h->cur] ? h->hist[h->cur] : "");}