luatex problem with file with umlauts on windows 10

[Ulrike Fischer]

Dear Akira,

>> Currently the file search in expl3 is broken because of this, so
>> I'm considering our options
> 
> f = chgstrcp.utf8tosyscp(file)
>     (file: utf-8, f: local code page)
> 
> f = chgstrcp.syscptoutf8(file)
>     (file: local code page, f: utf-8)
> 
> work only in lua[hb]tex for TeX Live Windows.
> Please use them in expl3, if they are usable.

I tried with some chinese (at least I think it is chinese). And
there is breaks again: the file is input but lfs reports nil:

FILE:   ./gre.tex
SIZE:   5
isfile  true
 (./大豊饒諸衆善法.tex)
FILE:   ./???????.tex
SIZE:   nil
isfile  false


-- 
Ulrike Fischer 
https://www.troubleshooting-tex.de/