bug#21567: 25.0.50; ediff-region-wordwise fails for latex buffers, emacs -Q

[Uwe Brauer]

> Yes.  Or simply describe in your own words what you did after starting
> Emacs.

Sorry for the delay. Attached you find two short latex files for which
the problem occurs. I prefer to describe the steps.

    -  emacs -Q

    -  set-variable debug-on-error t

    -  open old.tex via find-file

    -  open new.tex via find-file

    -  in new tex run ediff-regions-wordswise

    -  enter buffer new.tex and buffer old.tex  

    -  the error described occurs.

Uwe Brauer 

\documentclass[12pt]{article}
\newcommand*{\setR}{\mathbb{R}}
\usepackage{amsmath,amssymb}
% (setq font-latex-fontify-script 'invisible)
% (setq font-latex-fontify-script nil) 
% (setq font-latex-fontify-script t) 
% (setq font-latex-fontify-script 'multi-level)
% (font-lock-flush) this 
\begin{document}

New Integral: 
  \begin{equation*}
    \left\|\left( \Psi_m A^a\right)_{2^j}\right\|_{H^{s}}\lesssim
    \left\|\left( (\psi_m A^a)_{2^m}\right)_{2^{j-m}}\right\|_{H^{s}}\leq 
C(2^{j-m})
    \left\| (\psi_m A^a)_{2^m}\right\|_{H^{s}}.
  \end{equation*} 
\begin{equation}
\label{eq:new:2}
\int_{a+1} A^{a} dx = \sum\limits_a^b \lambda  \varrho 
\end{equation}
\begin{equation}
\label{eq:klaus-t15sep:6}
\int\limits_a^b \quad \qquad \qquad \qquad 
\end{equation}
\begin{equation}
\int_a
\end{equation}
\begin{equation}
  \label{eq:new:1}
  \int_1 y_{n+1} \int_{n} \quad 
\end{equation}
\end{document}


%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% End:

\documentclass[12pt]{article}
\newcommand*{\setR}{\mathbb{R}}
\usepackage{amsmath,amssymb}
% (setq font-latex-fontify-script 'invisible)
% (setq font-latex-fontify-script nil) 
% (setq font-latex-fontify-script t) 
% (setq font-latex-fontify-script 'multi-level)
% (font-lock-flush) this 
\begin{document}

old Integral:
\begin{equation}
  \label{eq:new:2}
  \int_{a+1} A^{a} dx = \sum\limits_a^b \lambda  \varrho 
\end{equation}
\begin{equation}
  \label{eq:klaus-t15sep:6}
  \int\limits_a^b \quad \qquad \qquad \qquad 
\end{equation}
\begin{equation}
  \int_a
\end{equation}
\begin{equation}
  \label{eq:new:1}
  \int_1 y_{n+1} \int_{n} \quad 
\end{equation}
\end{document}


%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% End: