CREATE TRIGGER bu_issues_tomerge_1
BEFORE UPDATE OF
    resolve
ON
    issues_tomerge
FOR EACH ROW WHEN
    NEW.resolve = 1 AND
    OLD.title != 0
BEGIN

    SELECT debug(
        'TRIGGER bu_issues_tomerge_1',
        OLD.issue_id
    );

    UPDATE
        issues
    SET
        title = (
            SELECT
                issue_updates.title
            FROM
                issue_updates
            INNER JOIN
                updates
            ON
                updates.id = issue_updates.update_id
            WHERE
                issue_updates.issue_id = OLD.issue_id AND
                issue_updates.title IS NOT NULL
            ORDER BY
                updates.mtime DESC,
                updates.uuid
            LIMIT
                1
        )
    WHERE
        id = OLD.issue_id
    ;

END;