\pdffilesize and spaces

[Joseph Wright]

Hello all,

Tracking down the cause of 
https://tex.stackexchange.com/questions/512768, I spot a bug in 
\pdffilesize. This leads If you create a file "file_1.tex" and try

\edef\test{\pdffilesize{file_1.tex}}\show\test
\edef\test{\pdffilesize{file_1.tex }}\show\test
\edef\test{\pdffilesize{"file_1.tex "}}\show\test

all three results are the same. However, if you try the same with a 
Lua-based emulation in LuaTeX, it does what it 'should' and doesn't find 
the file with a space in the name.

This looks like a bug in \pdffilesize (and perhaps other pdfTeX file 
utilities): I'll try to track it down.

Joseph