Prevent installation on SQLite3 dbs

Author: iMattPro

ext.php

@@ -22,16 +22,21 @@ class ext extends \phpbb\extension\base
 {
 	/**
 	 * Check whether or not the extension can be enabled.
-	 * The current phpBB version should meet or exceed
-	 * the minimum version required by this extension:
 	 *
-	 * Requires phpBB 3.2.1 due to use of $event->update_subarray()
+	 * Requires phpBB >= 3.2.1 due to use of $event->update_subarray()
+	 * Also incompatible with SQLite which does not support SQRT in SQL queries
 	 *
 	 * @return bool
 	 * @access public
 	 */
 	public function is_enableable()
 	{
-		return phpbb_version_compare(PHPBB_VERSION, '3.2.1', '>=');
+		if (phpbb_version_compare(PHPBB_VERSION, '3.2.1', '<'))
+		{
+			return false;
+		}
+
+		$db = $this->container->get('dbal.conn');
+		return ($db->get_sql_layer() !== 'sqlite3');
 	}
 }