lib/forum/delarticle.class.php
找到
$this->db->update(pwQuery::buildClause("UPDATE :pw_table SET replies=replies-:replies WHERE tid=:tid", array('pw_threads', $value, $tid)));
改成
$this->db->update(pwQuery::buildClause("UPDATE :pw_table SET lastposter='',replies=replies-:replies WHERE tid=:tid", array('pw_threads', $value, $tid)));