rem: CHECK(*handle);
context: iptc_get_references(unsigned int *ref, const ipt_chainlabel chain,		    iptc_handle_t *handle){	struct chain_cache *c;	CHECK(*handle);	if (!(c = find_label(chain, *handle))) {		errno = ENOENT;		return 0;	}	*ref = 0;	IPT_ENTRY_ITERATE((*handle)->entries.entries,			  (*handle)->entries.size,			  count_ref, entry2offset(*handle, c->start), ref);	return 1;}