Kohana DB builder, MariaDB and PHP7

[k03n00b]

UNION is behaving differently with newer MariaDB and PHP7.

Kohana's DB builder is using brackets
(SELECT ...) UNION ALL (SELECT ...) ORDER BY id DESC
With brackets result won't be ordered / sorted correctly. Brackets will break ORDER BY.

Here's fix:
SELECT ... UNION ALL SELECT ... ORDER BY id DESC

/modules/database/classes/Kohana/Database/Query/Builder/Select.php

	if ( ! empty($this->_union))
	{
		$query = ''.$query.'';
		foreach ($this->_union as $u) {
			$query .= ' UNION ';
			if ($u['all'] === TRUE)
			{
				$query .= 'ALL ';
			}
			$query .= ''.$u['select']->compile($db).'';
		}
	}

[svenbw]

Looks like a bug in MariaDB and should be fixed in MariaDB version 10.2.1
(see MDEV-10037 UNION with LIMIT ROWS EXAMINED does not require parentheses)