Re: [PATCH v3] filename.7: new manual page

Florian Weimer
2021-10-20T08:12:15Z

* Thaddeus H. Black:

>> What does this mean? I think only byte 0x2f is reserved. The UTF-8
>> comment is misleading. A historic/overlong encoding of / in multiple
>> UTF-8 bytes is *not* reserved.
>
> I had not known that UTF-8 had an alternate encoding for any ASCII
> character. Does it indeed have an alternate encoding? If so, where
> can I learn more?

See the Security Considerations section in the RFC:

<https://datatracker.ietf.org/doc/html/rfc3629#section-10>

Most file systems do not treat file names as UTF-8, so they do not
perform any validation.

Thanks,
Florian