解决方法：
sourcemoduleforumforum_viewthread.php
找到
- $_G['gp_extra'] = '';
- foreach($extra as $_k => $_v) {
- if(preg_match('/^w+$/', $_k)) {
- $_G['gp_extra'] .= '&'.$_k.'='.$_v;
- }
- }
-
- $_G['gp_extra'] = array();
- foreach($extra as $_k => $_v) {
- if(preg_match('/^w+$/', $_k)) {
- $_G['gp_extra'][] = $_k.'='.$_v;
- }
- }
- $_G['gp_extra'] = implode('&', $_G['gp_extra']);
- $upnavlink = 'forum.php?mod=forumdisplay&fid='.$_G['fid'].($_G['gp_extra'] && !IS_ROBOT ? $_G['gp_extra'] : '');
- $upnavlink = 'forum.php?mod=forumdisplay&fid='.$_G['fid'].($_G['gp_extra'] && !IS_ROBOT ? '&'.$_G['gp_extra'] : '');
