idx[idxlen]->content->aptr = idx[idxlen];
static void update_idx (MUTTMENU *menu, ATTACHPTR **idx, short idxlen){  idx[idxlen]->level = (idxlen > 0) ? idx[idxlen-1]->level : 0;  if (idxlen)    idx[idxlen - 1]->content->next = idx[idxlen]->content;  menu->current = idxlen++;  mutt_update_tree (idx, idxlen);  menu->max = idxlen;  return;}