/* {{{ php_openssl_discard_errors */
void php_openssl_discard_errors(void)
{
	int error_code;
	while ((error_code = ERR_get_error()));
}
/* }}} */

static EVP_PKEY *php_openssl_pkey_from_zval(
		zval *val, int public_key, char *passphrase, size_t passphrase_len, uint32_t arg_num)
{
  // ...
  php_openssl_store_errors();
  cert = php_openssl_x509_from_str(Z_STR_P(val), arg_num, false, NULL, true);
  if (cert) {
    free_cert = 1;
  } else {
    php_openssl_discard_errors();
    // ...
  }
}

static X509 *php_openssl_x509_from_str(
		zend_string *cert_str, uint32_t arg_num, bool is_from_array, const char *option_name, const int store_errors) {
  // ... (4 times)
  if (store_errors) {
    php_openssl_store_errors();
  }
  // ...
}

/* {{{ php_openssl_errors_set_mark */
void php_openssl_errors_set_mark(void) {
	if (!OPENSSL_G(errors)) {
		return;
	}

	OPENSSL_G(errors_mark) = pecalloc(1, sizeof(struct php_openssl_errors), 1);
	memcpy(OPENSSL_G(errors), OPENSSL_G(errors_mark), sizeof(struct php_openssl_errors));
}
/* }}} */

/* {{{ php_openssl_errors_restore_mark */
void php_openssl_errors_restore_mark(void) {
	struct php_openssl_errors *errors;

	if (!OPENSSL_G(errors)) {
		return;
	}

	if (!OPENSSL_G(errors_mark)) {
		errors = OPENSSL_G(errors);
		errors->top = 0;
		errors->bottom = 0;
	} else {
		memcpy(OPENSSL_G(errors_mark), OPENSSL_G(errors), sizeof(struct php_openssl_errors));
	}
}
/* }}} */

static EVP_PKEY *php_openssl_pkey_from_zval(
		zval *val, int public_key, char *passphrase, size_t passphrase_len, uint32_t arg_num)
{
  // ...
  php_openssl_errors_set_mark();
  cert = php_openssl_x509_from_str(Z_STR_P(val), arg_num, false, NULL);

  if (cert) {
    free_cert = 1;
  } else {
    php_openssl_errors_restore_mark();
    // ...
  }
}