一对多withField无效

public function files()
{
    return $this->belongsToMany(Fileinfo::class, RoomFile::class, 'fileid', 'serial');
}

$query->field('serial,roomname,starttime,endtime')
->with([
    'files' => function (\think\model\Relation $query) {
        $query->withField(['fileid','filename']);
    }
])

依然还是查询了所有字段

SELECT fileinfo.*,pivot.serial AS pivot__serial,pivot.fileid AS pivot__fileid,pivot.showname AS pivot__showname,pivot.type AS pivot__type,pivot.addtime AS pivot__addtime,pivot.suffix AS pivot__suffix,pivot.sort AS pivot__sort,pivot.warmvideo AS pivot__warmvideo FROM fileinfo INNER JOIN roomfile pivot ON pivot.fileid=fileinfo.fileid WHERE ( fileinfo.companyid = 1001219 AND pivot.serial = '21431077062245' ) AND fileinfo.deletetime = 0

Start with the belongsToMany relation and the withField call shown in the issue, then reproduce the generated SQL for the files relation. Trace how the requested fileid and filename fields are applied and verify that the query no longer selects every fileinfo and pivot column.