bug#81606: Mojibake with UTF-8 file names

>> If a master file `foo` is specified in the local variables block,
>> AUCTeX checks whether it is exists, otherwise it gets created.
>> This string `foo` must be given in the encoding specified by the
>> `coding` cookie.
> 
> But this is trivially correct: any non-ASCII text in a file which has
> a 'coding:' cookie _must_ be encoded in the encoding specified by
> 'coding:".  Right?

There might be situations where the file encoding and the file name
encoding differ, for example on Windows.  I don't know enough about
the encoding handling in Emacs whether it automatically maps UTF-8
encoded file name strings (as implied by the `coding` cookie) to
UTF-16...

> The cookie guarantees that the entire file, including the Local
> Variables section, uses that single encoding.

Yes, thus my suggestion of being more strict in the documentation and
stating exactly this.

> If you want to require the 'coding:' cookie in all cases, that's
> fine, but then latexenc.el is not needed at all, see above.

Well, the AUCTeX documentation doesn't require it yet — otherwise I
wouldn't have noticed the problem.  I think it's a good thing if Emacs
has a heuristic fallback mechanism to handle the case without a
`coding` cookie.


    Werner