Description:
------------
When i upload a file with unicode filename (in my case, it is in Persian) PHP convert each character to an underscore sign (_).

for example when i upload a file, named "علی.php", it will convert to "___.php"

the written program works fine with PHP 5.0.5.

Regards,
omid

Reproduce code:
---------------
the very very simple code that i tested is:

<form action="" method="post" enctype="multipart/form-data">
<input type="file" name="file"><br>
<input type="submit" name="submit" value="submit">
</form>

<?php
    echo '<pre>';
    print_r($_FILES['file']);
    echo '</pre>';
?>

Expected result:
----------------
Array
(
    [name] => سلام.php
    [type] => application/octet-stream
    [tmp_name] => D:\php\tmp\php4D.tmp
    [error] => 0
    [size] => 0
)

Actual result:
--------------
Array
(
    [name] => ____.php
    [type] => application/octet-stream
    [tmp_name] => D:\php\tmp\php4D.tmp
    [error] => 0
    [size] => 0
)