bug#49723: 28.0.50; Test in coding.c for NUL bytes in filenames is not reliable

[Federico Tedin]

Michael Albinus <michael.albinus@gmx.de> writes:

> Federico Tedin <federicotedin@gmail.com> writes:
>
> Hi,
>
> Sorry for being late, I have seen this just now only.
>
>> +** 'expand-file-name' now checks for null bytes in filenames.
>> +The function will now check for null bytes in both NAME and
>> +DEFAULT-DIRECTORY arguments, as well as in the 'default-directory'
>> +buffer-local variable, assuming its value is used.  If null bytes are
>> +found, 'expand-file-name' will signal an error.
>
> Should this be implemented also in remote file names?
>
> Best regards, Michael.

Would this imply only doing it in `tramp-handle-expand-file-name`, or
other functions as well?

I had thought of doing it for at least `tramp-handle-expand-file-name`,
but then I noticed that the function eventually calls `expand-file-name`
with a combination of name + dir, or only with name. So in that case I
figured that the null bytes check would be performed by
`expand-file-name` anyways.