[4.0] Add minimum db version check to the installation's database connection check

installation/src/Model/SetupModel.php

@@ -28,6 +28,33 @@
  */
 class SetupModel extends BaseInstallationModel
 {
+	/**
+	 * The minimum database server version for MariaDB databases as required by the CMS.
+	 * This is not necessarily equal to what the database driver requires.
+	 *
+	 * @var    string
+	 * @since  4.0.0
+	 */
+	protected static $dbMinimumMariaDb = '10.1';
+
+	/**
+	 * The minimum database server version for MySQL databases as required by the CMS.
+	 * This is not necessarily equal to what the database driver requires.
+	 *
+	 * @var    string
+	 * @since  4.0.0
+	 */
+	protected static $dbMinimumMySql = '5.6';
+
+	/**
+	 * The minimum database server version for PostgreSQL databases as required by the CMS.
+	 * This is not necessarily equal to what the database driver requires.
+	 *
+	 * @var    string
+	 * @since  4.0.0
+	 */
+	protected static $dbMinimumPostgreSql = '11.0';
+
 	/**
 	 * Get the current setup options from the session.
 	 *
@@ -527,6 +554,67 @@ public function validateDbConnection()
 			return false;
 		}
 
+		$dbVersion = $db->getVersion();
+
+		// Get minimum database version required by the database driver
+		$minDbVersionRequired = $db->getMinimum();
+
+		// Get minimum database version required by the CMS
+		if (in_array($options->db_type, ['mysql', 'mysqli']))
+		{
+			if ($db->isMariaDb())
+			{
+				$minDbVersionCms = self::$dbMinimumMariaDb;
+			}
+			else
+			{
+				$minDbVersionCms = self::$dbMinimumMySql;
+			}
+		}
+		else
+		{
+			$minDbVersionCms = self::$dbMinimumPostgreSql;
+		}
+
+		// Use most restrictive minimum database version requirement
+		if (version_compare($minDbVersionCms, $minDbVersionRequired) > 0)
+		{
+			$minDbVersionRequired = $minDbVersionCms;
+		}
+
+		// Check minimum database version as required by the CMS
+		if (in_array($options->db_type, ['mysql', 'mysqli']) && $db->isMariaDb())
+		{
+			// MariaDB: Check with sanitized version string
+			if (version_compare(preg_replace('/^5\.5\.5-/', '', $dbVersion), $minDbVersionRequired) < 0)
+			{
+				Factory::getApplication()->enqueueMessage(
+					Text::sprintf(
+						'INSTL_DATABASE_INVALID_MARIADB_VERSION',
+						$minDbVersionRequired,
+						$dbVersion
+					),
+					'error'
+				);
+
+				return false;
+			}
+		}
+		elseif (version_compare($dbVersion, $minDbVersionRequired) < 0)
+		{
+			Factory::getApplication()->enqueueMessage(
+				Text::sprintf(
+					'INSTL_DATABASE_INVALID_' . strtoupper($options->db_type) . '_VERSION',
+					$minDbVersionRequired,
+					$dbVersion
+				),
+				'error'
+			);
+
+			return false;
+		}
+
+		// Check database connection encryption
 		if ($options->db_encryption !== 0 && empty($db->getConnectionEncryption()))
 		{
 			if ($db->isConnectionEncryptionSupported())