Conflict with unrecognised user agent strings

 
                //$best = 12; // maximum number of changes in UA string^M
                $best = min(12, intval($ua_size/2));
 

 
        private static function findByLevenshtein($ua, $devices)
        {
                $ua_size = strlen($ua);
 
                $data = null;
 
                //$best = 12; // maximum number of changes in UA string
                $best = min(12, intval($ua_size/2));
                foreach($devices as $device)
                {
                        if(abs(strlen($device->ua) - $ua_size) > $best)
                                continue;
 
                        $current = levenshtein($ua, $device->ua);
                        if($current <= $best)
                        {
                                $best = $current;
                                $data = $device->data;
                        }
                }
 
                return $data;
        }