bug#81606: Mojibake with UTF-8 file names

> Cc: [email protected]
> From: Arash Esbati <[email protected]>
> Date: Thu, 13 Aug 2026 12:52:45 +0200
> 
> > Agreed.  So please reassign :-)
> 
> Done.  FWIW, this issue can be reproduced with tex-mode.el provided by
> Emacs as well.  Save the files attached in a directory, start Emacs as
> 'emacs -Q' and open 'ä-include.tex'.  Emacs now tries to open ä.tex
> (`tex-main-file') which doesn't work.  I see this after hitting
> 'C-x C-b':
> 
> 
> I suspect the entry
> 
>   ("\\.\\(tex\\|ltx\\|dtx\\|drv\\)\\'" . latexenc-find-file-coding-system)
> 
> in `file-coding-system-alist' is relevant, but I don't know the
> internals of file loading enough, so this assumption might be wrong.

If you instrument latexenc-find-file-coding-system with Edebug, does
it get called in the above scenario?  If so, can you step through the
code and tell what happens, and also show the Lisp backtrace, so we
know how this function is called and by what code?

Thanks.

P.S. The test file doesn't have the line which
latexenc-find-file-coding-system is supposed to use for determining
the encoding, so I'm not sure it is relevant.