Re: [AUCTeX-devel] TeXLive 2019 update broke preview-latex (was Re: Typeset LaTeX files with non-ascii file name in TeXLive 2018)

[Ikumi Keita]

Hi all,

1. Examination and observation

>>>>> Ikumi Keita <address@hidden> writes:
> It seems that the latest TeXLive 2019 update broke preview-latex.  I
> quote a failure log of the latest pdflatex and a successful log of the
> pdflatex with the latest update reverted, at the last of this message.

I removed "\detokenize" from preview.el locally and confirmed that
preview-latex doesn't fail under the latest TeXLive 2019:

,----
| Running `Preview-LaTeX' on `abc' with ``pdflatex  -file-line-error   
"\nonstopmode\nofiles\PassOptionsToPackage{active,tightpage,auctex}{preview}\AtBeginDocument{\ifx\ifPreview\undefined\RequirePackage[displaymath,floats,graphics,textmath,sections,footnotes]{preview}[2004/11/05]\fi}"
 "\input" abc.tex''
| This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019) (preloaded 
format=pdflatex)
|  restricted \write18 enabled.
| entering extended mode
| LaTeX2e <2019-10-01>
| 
| [...]
| 
| Output written on abc.pdf (1 page, 15960 bytes).
| Transcript written on abc.log.
| 
| TeX Output exited as expected with code 1 at Mon Oct  7 15:41:40
| Running `Preview-PDF2DSC' with ``pdf2dsc abc.pdf 
abc.prv/tmpE34oe0/preview.dsc''
| 
| [...]
| 
| Preview-Ghostscript finished at Mon Oct  7 15:41:43
`----

I confirmed that preamble caching is also fine without \detokenize in
.ini code of /AUCTEXINPUT.

> Is this common for others?  If so, I suspect that the change in the
> internal of latex invalidated "\detokenize" that preview-latex uses to
> input files with non-ascii names successfully.

However, this suspicion was not totally correct.  It seems that
"\detokenize" is harmless under normal typeset (not with preview-latex),
even with a non-ascii file name:

,----
| Running `LaTeX' on `prim?rias' with ``pdflatex  -file-line-error   
-interaction=nonstopmode "\pdfoutput=0 " "\input" \\detokenize\{\ 
prim\?rias.tex\ \}''
| This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019) (preloaded 
format=pdflatex)
|  restricted \write18 enabled.
| entering extended mode
| LaTeX2e <2019-10-01>
| 
| [...]
| 
| Output written on prim?rias.dvi (1 page, 340 bytes).
| Transcript written on prim?rias.log.
`----

I can view the generated dvi file by xdvi without any trouble.

Thus I infer that it is something in the preamble code "\nonstopmode
... {preview}[2004/11/05]\fi}" in preview-latex that conflicts with
\detokenize.  I have no idea whether this is a bug of the latest LaTeX
or not.

----------------------------------------------------------------------
2. What to do

I think that we have basically two ways to choose from.
(1) Just remove \detokenize from preview.el
    This makes preview-latex fail with non-ascii file name under TL2018
    and early TL2019 (and probably under MikTeX and W32TeX within some
    interval between 2018 and 2019).  We can live with it by answering
    to reporters of the errors caused by this change with "Update your
    TeX distribution to the latest version."
(2) Introduce a new customize option so that the user can choose whether
    to use \detokenize in preview-latex or not

What do you think about this?

Regards,
Ikumi Keita