PHPのpathinfoの仕様、変わりすぎぃ！！

pathinfo.php

<?php
function pathinfo($f)
{
    $ret = pathinfo($f);
    
    if (!isset($ret['filename'])){
        $filename = substr($f, strrpos($f, '/') + 1);
        $filename = substr($filename, 0, strrpos($filename, '.'.$ret['extension']));
        $ret['filename'] = $filename;
    }
    
    return $ret;
}