if(ret) sk_free(ret);
STACK *sk_dup(STACK *sk)	{	STACK *ret;	char **s;	if ((ret=sk_new(sk->comp)) == NULL) goto err;	s=(char **)OPENSSL_realloc((char *)ret->data,		(unsigned int)sizeof(char *)*sk->num_alloc);	if (s == NULL) goto err;	ret->data=s;	ret->num=sk->num;	memcpy(ret->data,sk->data,sizeof(char *)*sk->num);	ret->sorted=sk->sorted;	ret->num_alloc=sk->num_alloc;	ret->comp=sk->comp;	return(ret);err:	return(NULL);	}