bug#56889: 13.1.3; Adjustment of foreground color not working for fraction lines and tikz in preview

[Frank Selensky]

I am using a theme with a dark background, so I rely on auctex to
convert the foreground color to the one set in my theme while previewing
latex fragments. This works fine for most latex fragments. But it does
not work for the lines of a fraction. Here the numerator and denominator
are converted to the right color, but the fraction line itself stays
black. Apart from that, in tikzpictures the color of the lines and text
is not converted and still black.

This happens for me for example when I try to preview the latex
fragments in the following:

```
\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage{tikz}

\begin{document}
\[\frac{123}{abv}\]

\begin{tikzpicture}
\draw(0,0) -- (1,2);
\node[draw] at (-1,-2) {A};
\end{tikzpicture}
\end{document}
```

What I would expect is, that everything (where no other color was
specified explicitly) is turned into the foreground color of my theme
when previewing.


Emacs  : GNU Emacs 28.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 
3.24.33, cairo version 1.17.6)
 of 2022-04-28
Package: 13.1.3

current state:
==============
(setq
 AUCTeX-date "2022-04-16"
 window-system 'x
 LaTeX-version "2e"
 TeX-style-path '("~/.emacs.d/auctex" 
"/home/user/.emacs.d/elpa/auctex-13.1.3/style"
                  "/home/user/.emacs.d/auctex/auto" 
"/home/user/.emacs.d/auctex/style" "auto" "style")
 TeX-auto-save t
 TeX-parse-self t
 TeX-master t
 TeX-command-list '(("XeLaTeX" "%`xelatex%(mode)%' %t" TeX-run-TeX nil t)
                    ("TeX"
                     "%(PDF)%(tex) %(file-line-error) %`%(extraopts) 
%S%(PDFout)%(mode)%' %(output-dir) %t"
                     TeX-run-TeX nil (plain-tex-mode ams-tex-mode 
texinfo-mode) :help "Run plain TeX")
                    ("LaTeX" "%`%l%(mode)%' %T" TeX-run-TeX nil 
(latex-mode doctex-mode) :help
                     "Run LaTeX")
                    ("Makeinfo" "makeinfo %(extraopts) %(o-dir) %t" 
TeX-run-compile nil (texinfo-mode)
                     :help "Run Makeinfo with Info output")
                    ("Makeinfo HTML" "makeinfo %(extraopts) %(o-dir) 
--html %t" TeX-run-compile nil
                     (texinfo-mode) :help "Run Makeinfo with HTML output")
                    ("AmSTeX" "amstex %(PDFout) %`%(extraopts) 
%S%(mode)%' %(output-dir) %t"
                     TeX-run-TeX nil (ams-tex-mode) :help "Run AMSTeX")
                    ("ConTeXt" "%(cntxcom) --once --texutil 
%(extraopts) %(execopts)%t" TeX-run-TeX nil
                     (context-mode) :help "Run ConTeXt once")
                    ("ConTeXt Full" "%(cntxcom) %(extraopts) 
%(execopts)%t" TeX-run-TeX nil
                     (context-mode) :help "Run ConTeXt until completion")
                    ("BibTeX" "bibtex %(O?aux)" TeX-run-BibTeX nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode context-mode)
                     :help "Run BibTeX")
                    ("Biber" "biber %(output-dir) %s" TeX-run-Biber nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Run Biber")
                    ("Texindex" "texindex %s.??" TeX-run-command nil 
(texinfo-mode) :help
                     "Run Texindex")
                    ("Texi2dvi" "%(PDF)texi2dvi %t" TeX-run-command nil 
(texinfo-mode) :help
                     "Run Texi2dvi or Texi2pdf")
                    ("View" "%V" TeX-run-discard-or-function t t :help 
"Run Viewer")
                    ("Print" "%p" TeX-run-command t t :help "Print the 
file")
                    ("Queue" "%q" TeX-run-background nil t :help "View 
the printer queue" :visible
                     TeX-queue-command)
                    ("File" "%(o?)dvips %d -o %f " TeX-run-dvips t
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Generate PostScript file")
                    ("Dvips" "%(o?)dvips %d -o %f " TeX-run-dvips nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Convert DVI file to PostScript")
                    ("Dvipdfmx" "dvipdfmx -o %(O?pdf) %d" 
TeX-run-dvipdfmx nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Convert DVI file to PDF with dvipdfmx")
                    ("Ps2pdf" "ps2pdf %f %(O?pdf)" TeX-run-ps2pdf nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Convert PostScript file to PDF")
                    ("Glossaries" "makeglossaries %(d-dir) %s" 
TeX-run-command nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Run makeglossaries to create glossary file")
                    ("Index" "makeindex %(O?idx)" TeX-run-index nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Run makeindex to create index file")
                    ("upMendex" "upmendex %(O?idx)" TeX-run-index t
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Run upmendex to create index file")
                    ("Xindy" "texindy %s" TeX-run-command nil
                     (plain-tex-mode latex-mode doctex-mode 
ams-tex-mode texinfo-mode) :help
                     "Run xindy to create index file")
                    ("Check" "lacheck %s" TeX-run-compile nil 
(latex-mode) :help
                     "Check LaTeX file for correctness")
                    ("ChkTeX" "chktex -v6 %s" TeX-run-compile nil 
(latex-mode) :help
                     "Check LaTeX file for common mistakes")
                    ("Spell" "(TeX-ispell-document \"\")" 
TeX-run-function nil t :help
                     "Spell-check the document")
                    ("Clean" "TeX-clean" TeX-run-function nil t :help
                     "Delete generated intermediate files")
                    ("Clean All" "(TeX-clean t)" TeX-run-function nil t 
:help
                     "Delete generated intermediate and output files")
                    ("Other" "" TeX-run-command t t :help "Run an 
arbitrary command"))
 )