[luatex] quote around filename leads to error

[Ulrike Fischer]

The following document works fine with pdflatex but gives an error
with lualatex (the icc-file is part of the pdfx package).

The source of the problems are the quotes around the file name.
Without them the document works fine. 

\documentclass{minimal}
\immediate\pdfobj stream attr{/N 3^^J/Alternate/DeviceRGB}
file{"sRGB_IEC61966-2-1_black_scaled.icc"} %error

%\immediate\pdfobj stream attr{/N 3^^J/Alternate/DeviceRGB} 
% file{sRGB_IEC61966-2-1_black_scaled.icc} %works

\begin{document}
  Hello World!
\end{document}

! LuaTeX error (ext5): cannot open file for embedding.
l.10 ...}
file{"sRGB_IEC61966-2-1_black_scaled.icc"}

%error


This is LuaTeX, Version beta-0.80.0 (TeX Live 2015/W32TeX) (rev
5238)

Is this a bug or aren't quotes allowed around file names? Are the
quotes actually needed here or are spaces in file names protected by
the braces? 

-- 
Ulrike Fischer 
http://www.troubleshooting-tex.de/