bug#34032: 12.1.1; Syntax coloring broken by when $x''$ is used instead of $x^{\prime\prime}$.

[Luca Marconato]

When two single quotes are inserted in a math formula the syntax
coloring does not work properly anymore, by messing up the colors of
large areas of text. The problem is not present in AUCTeX 11.90.
The problem could be related to
https://www.gnu.org/software/auctex/manual/auctex/Known-problems.html
I suspect that the are also other text sequences which cause the syntax
coloring to behave wrongly, but I have only isolated the cause cited in
this bug report.


Emacs  : GNU Emacs 26.1 (build 1, x86_64-apple-darwin18.0.0, NS appkit-1671.00 
Version 10.14 (Build 18A391))
 of 2018-10-04
Package: 12.1.1

current state:
==============
(setq
 AUCTeX-date "2018-03-20"
 window-system 'ns
 LaTeX-version "2e"
 TeX-style-path '("/usr/local/var/auctex" 
"/Users/macbook/.emacs.d/elpa/auctex-12.1.1/style" 
"/Users/macbook/.emacs.d/auctex/auto"
                  "/Users/macbook/.emacs.d/auctex/style" "auto" "style")
 TeX-auto-save t
 TeX-parse-self t
 TeX-master t
 TeX-command-list '(("TeX" "%(PDF)%(tex) %(file-line-error) %(extraopts) 
%`%S%(PDFout)%(mode)%' %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) %t" TeX-run-compile nil 
(texinfo-mode) :help "Run Makeinfo with Info output")
                    ("Makeinfo HTML" "makeinfo %(extraopts) --html %t" 
TeX-run-compile nil (texinfo-mode) :help
                     "Run Makeinfo with HTML output")
                    ("AmSTeX" "amstex %(PDFout) %(extraopts) %`%S%(mode)%' %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 %s" TeX-run-BibTeX nil t :help "Run 
BibTeX")
                    ("Biber" "biber %s" TeX-run-Biber nil t :help "Run Biber")
                    ("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 t :help 
"Generate PostScript file")
                    ("Dvips" "%(o?)dvips %d -o %f " TeX-run-dvips nil t :help 
"Convert DVI file to PostScript")
                    ("Dvipdfmx" "dvipdfmx %d" TeX-run-dvipdfmx nil t :help 
"Convert DVI file to PDF with dvipdfmx")
                    ("Ps2pdf" "ps2pdf %f" TeX-run-ps2pdf nil t :help "Convert 
PostScript file to PDF")
                    ("Glossaries" "makeglossaries %s" TeX-run-command nil t 
:help "Run makeglossaries to create glossary file")
                    ("Index" "makeindex %s" TeX-run-index nil t :help "Run 
makeindex to create index file")
                    ("upMendex" "upmendex %s" TeX-run-index t t :help "Run 
upmendex to create index file")
                    ("Xindy" "texindy %s" TeX-run-command nil t :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"))
 )