bug#31686: 12.1.1 ; Generation of Previews for platex with cached preamble fails with filename having spaces

[jfbu]

Hi,

consider this file

\documentclass{jsarticle}
\def\abc{abc}
\begin{document}
$\abc$
\end{document}

Name it `abc def ghi.tex`.

Compilation (to DVI) works fine.

But generation of previews using cached preamble fails,
the format can not be used:

generation ok

Running `Preview-LaTeX' on `abc def ghi' with ``platex -ini 
-interaction=nonstopmode "&platex" prv_abc_def_ghi.ini    
"\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\ def\ ghi.tex\"''
This is e-pTeX, Version 3.14159265-p3.8.0-180226-2.6 (utf8.euc) (TeX Live 2018) 
(INITEX)

.... etc....


but usage fails

Running `Preview-LaTeX' on `abc def ghi' with ``platex  -kanji=utf8  
-interaction=nonstopmode "&prv_abc_def_ghi" \"abc\ def\ ghi.tex\"''
This is e-pTeX, Version 3.14159265-p3.8.0-180226-2.6 (utf8.euc) (TeX Live 2018) 
(preloaded format=platex)
 restricted \write18 enabled.
entering extended mode
! I can't find file `abcdefghi.tex'.
<*> &prv_abc_def_ghi "abc def ghi.tex"
                                      
(Press Enter to retry, or Control-D to exit)
Please type another input file name
! Emergency stop.
<*> &prv_abc_def_ghi "abc def ghi.tex"
                                      
No pages of output.
Transcript written on texput.log.

TeX Output exited as expected with code 1 at Sat Jun  2 14:19:27
LaTeX: LaTeX found no preview images


Explanation is simple, the hack of \dump in preview.el is effective only
if \pdfoutput primitive exists. This hack was done to counteract
mylatex.ltx making spaces ignored.

Notice though that even if that was fixed, bug #31684 would cause a problem

Best,

Jean-François