bug#81606: Mojibake with UTF-8 file names

Eli Zaretskii <[email protected]> writes:

> If you instrument latexenc-find-file-coding-system with Edebug, does
> it get called in the above scenario?

Yes, it gets called inside the files I sent.

> 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?

I can't tell how where the caller is, it doesn't throw an error so I
don't see a backtrace.  What I can tell is that while the funcion is
called, the problematic part is:

  (let ((file (if (re-search-forward
                   "^%+ *\\(TeX-master\\|tex-main-file\\): *\"\\(.+\\)\""
                   nil t)
                  (match-string 2)

The search is successful and (match-string 2) returns

  Result: "\303\244.tex"

I would have expected a plain "ä.tex".  With the search result above,
things start going wrong since `latexenc-main-file' carries the wrong
value further down in the function.

> 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.

See above.  The function isn't called if the file has this local
variable:

%%% coding: utf-8

I can't tell why, though.

Best, Arash