remove constants

Closes #3437786

core/modules/mysql/src/Driver/Database/mysql/Install/Tasks.php

@@ -8,8 +8,6 @@
 use Drupal\mysql\Driver\Database\mysql\Connection;
 use Drupal\Core\Database\DatabaseNotFoundException;
 
-// cspell:ignore libmysqlclient
-
 /**
  * Specifies installation tasks for MySQL and equivalent databases.
  */
@@ -31,16 +29,6 @@ class Tasks extends InstallTasks {
    */
   const MARIADB_MINIMUM_VERSION = '10.3.7';
 
-  /**
-   * Minimum required MySQLnd version.
-   */
-  const MYSQLND_MINIMUM_VERSION = '5.0.9';
-
-  /**
-   * Minimum required libmysqlclient version.
-   */
-  const LIBMYSQLCLIENT_MINIMUM_VERSION = '5.5.3';
-
   /**
    * The PDO driver name for MySQL and equivalent databases.
    *
@@ -94,34 +82,7 @@ protected function connect() {
       // This doesn't actually test the connection.
       Database::setActiveConnection();
       // Now actually do a check.
-      try {
-        Database::getConnection();
-      }
-      catch (\Exception $e) {
-        // Detect utf8mb4 incompatibility.
-        if ($e->getCode() == Connection::UNSUPPORTED_CHARSET || ($e->getCode() == Connection::SQLSTATE_SYNTAX_ERROR && $e->errorInfo[1] == Connection::UNKNOWN_CHARSET)) {
-          $this->fail(t('Your MySQL server and PHP MySQL driver must support utf8mb4 character encoding. Make sure to use a database system that supports this (such as MySQL/MariaDB/Percona 5.5.3 and up), and that the utf8mb4 character set is compiled in. See the <a href=":documentation" target="_blank">MySQL documentation</a> for more information.', [':documentation' => 'https://dev.mysql.com/doc/refman/5.0/en/cannot-initialize-character-set.html']));
-          $info = Database::getConnectionInfo();
-          $info_copy = $info;
-          // Set a flag to fall back to utf8. Note: this flag should only be
-          // used here and is for internal use only.
-          $info_copy['default']['_dsn_utf8_fallback'] = TRUE;
-          // In order to change the Database::$databaseInfo array, we need to
-          // remove the active connection, then re-add it with the new info.
-          Database::removeConnection('default');
-          Database::addConnectionInfo('default', 'default', $info_copy['default']);
-          // Connect with the new database info, using the utf8 character set so
-          // that we can run the checkEngineVersion test.
-          Database::getConnection();
-          // Revert to the old settings.
-          Database::removeConnection('default');
-          Database::addConnectionInfo('default', 'default', $info['default']);
-        }
-        else {
-          // Rethrow the exception.
-          throw $e;
-        }
-      }
+      Database::getConnection();
       $this->pass('Drupal can CONNECT to the database ok.');
     }
     catch (\Exception $e) {
@@ -203,27 +164,4 @@ public function ensureInnoDbAvailable() {
     }
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  protected function checkEngineVersion() {
-    parent::checkEngineVersion();
-
-    // Ensure that the MySQL driver supports utf8mb4 encoding.
-    $version = Database::getConnection()->clientVersion();
-    if (str_contains($version, 'mysqlnd')) {
-      // The mysqlnd driver supports utf8mb4 starting at version 5.0.9.
-      $version = preg_replace('/^\D+([\d.]+).*/', '$1', $version);
-      if (version_compare($version, self::MYSQLND_MINIMUM_VERSION, '<')) {
-        $this->fail(t("The MySQLnd driver version %version is less than the minimum required version. Upgrade to MySQLnd version %mysqlnd_minimum_version or up, or alternatively switch mysql drivers to libmysqlclient version %libmysqlclient_minimum_version or up.", ['%version' => $version, '%mysqlnd_minimum_version' => self::MYSQLND_MINIMUM_VERSION, '%libmysqlclient_minimum_version' => self::LIBMYSQLCLIENT_MINIMUM_VERSION]));
-      }
-    }
-    else {
-      // The libmysqlclient driver supports utf8mb4 starting at version 5.5.3.
-      if (version_compare($version, self::LIBMYSQLCLIENT_MINIMUM_VERSION, '<')) {
-        $this->fail(t("The libmysqlclient driver version %version is less than the minimum required version. Upgrade to libmysqlclient version %libmysqlclient_minimum_version or up, or alternatively switch mysql drivers to MySQLnd version %mysqlnd_minimum_version or up.", ['%version' => $version, '%libmysqlclient_minimum_version' => self::LIBMYSQLCLIENT_MINIMUM_VERSION, '%mysqlnd_minimum_version' => self::MYSQLND_MINIMUM_VERSION]));
-      }
-    }
-  }
-
 }