Subject: bug#25601: Possible need for an update to the \TeX "preview" package.

From: Arash Esbati <[email-masked]>
Date: Mon, 24 Apr 2017 13:31:31 +0200

Arash Esbati <[email-masked]> writes:

> Emmanuel Charpentier <[email-masked]> writes:
>
>> I recently stumbled on a  problem that is not specifically bound to
>> preview, but shows that a (slight) revision may be in order. See the
>> transcript of a thread in comp.text.tex at
>> https://groups.google.com/forum/#!topic/comp.text.tex/umzerAdDkX0 .
>>
>> Working on this problem, I saw that preview had an option specific to
>> the XeLaTeX compiler. This made me think that an analogous solution
>> was needed for the LuaTeX compiler, which uses the same mechanisms for
>> font loading and font metrics. However, I do not know welle enough the
>> internals of these engines to determine if the solution used for
>> XeLaTeX can be applied to LuaTeX, of if specific actions are needed.
>>
>> Do you think that a slight revision of your package could be done (if
>> only to document how to use it with LuaLaTeX) ?
>
> Thanks for your report.  For the records, LuaTeX and pdfTeX used to
> share some primitives like \pdfoutput, \pdfvorigin, \pdfhorigin,
> \pdfpageheight and \pdfpagewidth.  With the advent of LuaTeX 0.85,
> LuaTeX uses other names for these primitives and hence the code in
> preview.sty does not work with this engine.
>
> One can solve the issue by doing:
>
>     \RequirePackage{luatex85}
>     \documentclass{article}
>     ...
>
> I will try to update this in preview.pdf.  But the real solution will
> have to wait.

Following up myself, I had a discussion with maintainer of pst-pdf and
it seems that it is not easy to make preview support recent luatex
natively.  Hence, I added the following line to preview.dtx:

    \IfFileExists{luatex85.sty}{\RequirePackage{luatex85}}{}

Emmanuel, do you have a chance to install the latest preview from AUCTeX
git and give it roll?

TIA, Arash