[Dev-luatex] Quotation marks in \write18

[Martin Heller]

The document below compiles fine with pdflatex (MiKTeX-pdfTeX 2.9.4535 
(1.40.13) (MiKTeX 2.9)) but the last \write18 call fails with lualatex 
(Version beta-0.70.2 (MiKTeX 2.9)) with the error:

Overfull \hbox (22.4968pt too wide) in paragraph at lines 9--9
[][]\OT1/cmtt/m/n/10 \immediate\write18{"grep" "string with spaces" 
\jobname.te
x > tmp.txt}[]
'grep" "string' is not recognized as an internal or external command,
operable program or batch file.

% testdoc
\documentclass{article}
\usepackage{verbatim}
\begin{document}

\immediate\write18{grep "string with spaces" \jobname.tex > tmp.txt}
\verbatiminput{tmp.txt}

\immediate\write18{grep "string with spaces" "\jobname.tex" > tmp.txt}
\verbatiminput{tmp.txt}

% Does not work with luaLaTeX
\immediate\write18{"grep" "string with spaces" \jobname.tex > tmp.txt}
\verbatiminput{tmp.txt}

\end{document}

is this intentional?