OpenSSL::PKey::EC#initialize_copy

static VALUE
ossl_ec_key_initialize_copy(VALUE self, VALUE other)
{
    EVP_PKEY *pkey;
    EC_KEY *ec, *ec_new;

    GetPKey(self, pkey);
    if (EVP_PKEY_base_id(pkey) != EVP_PKEY_NONE)
        ossl_raise(eECError, "EC already initialized");
    GetEC(other, ec);

    ec_new = EC_KEY_dup(ec);
    if (!ec_new)
        ossl_raise(eECError, "EC_KEY_dup");
    if (!EVP_PKEY_assign_EC_KEY(pkey, ec_new)) {
        EC_KEY_free(ec_new);
        ossl_raise(eECError, "EVP_PKEY_assign_EC_KEY");
    }

    return self;
}