Discuz DB层跨库映射关系表名前缀BUG修复后产生的新bug

function table_name($tablename) {
        if(!empty($this->map) && !empty($this->map[$tablename])) {
            $id = $this->map[$tablename];
            if(!empty($this->config[$id]['tablepre'])){
                $this->tablepre = $this->config[$id]['tablepre'];
            }
            if(!$this->link[$id]) {
                $this->connect($id);
            }
            $this->curlink = $this->link[$id];
        } else {
            $this->tablepre = $this->config['1']['tablepre'];
            $this->curlink = $this->link[1];
        }
        return $this->tablepre.$tablename;
    }

$_config['db']['1']['dbhost'] = 'localhost'; // 服务器地址
$_config['db']['1']['dbuser'] = 'root'; // 用户
$_config['db']['1']['dbpw'] = 'root';// 密码
$_config['db']['1']['dbcharset'] = 'gbk';// 字符集
$_config['db']['1']['pconnect'] = '0';// 是否持续连接
$_config['db']['1']['dbname'] = 'x1';// 数据库
$_config['db']['1']['tablepre'] = 'pre_';// 表名前缀

$_config['db']['2']['dbhost'] = 'localhost';
.....

//再配置一些数据源
$_config['db']['xxx_sys']['dbhost'] = 'localhost';

//映射
$_config['db']['map']['yyy_table'] = 'xxx_sys';