Lines ending in underscore in verbatim block cause confusion

[anka-213]

Diffing this file with itself will the first \begin{verbatim} to be replaced with a \begin{DIFverbatim} and the last \end{verbatim} to be replaced with a \end{DIFverbatim}, but the first \end{verbatim} and the second \begin{verbatim} are left as is, so the middle non-verbatim text gets included in the spurious DIFverbatim block.

\documentclass{article}
\usepackage[utf8]{inputenc}
\begin{document}

\begin{verbatim}
first _
block _
\end{verbatim}
non verbatim text
\begin{verbatim}
second block
\end{verbatim}

\end{document}

Running latexdiff strange.tex strange.tex | tail -n15 outputs:

\begin{document}

\DIFmodbegin
\begin{DIFverbatim}[alsolanguage=DIFcode]
first _
%block _
\end{verbatim}
non verbatim text
\begin{verbatim}
second block
\end{DIFverbatim}
\DIFmodend

\end{document}

As you can see, despite not actually having a diff, they get wrapped in a DIFverbatim block and each line after a line ending with underscore gets preceded with a % sign, which maybe is related to why the first \end{verbatim} is ignored? I don't really know what is going on.

If I only have one line ending with underscore in the verbatim block, the first \end{verbatim} will get the \end{DIFverbatim} instead of the second.

[ftilmann]

Thank you for reporting. As you can see the lastest commit has fixed this bug.