R devel - Apr 2018 - system() and system2() do not use long filenames on Windows

Hi,

On Windows, it appears that system() and system2() both use the 8.3 filename to
run the supplied command, even if the full name is used. Most of the time this
doesn't matter, but for .NET programs, it stops the program from finding its
app.config file (which has the same name as the app, with '.config'
appended).

Here is a simple test program, compiled with: g++ -o longfilename.exe test.cpp


#include <iostream>

int main(int argc, char **argv)
{
    std::cout << argv[0] << '\n';
    return 0;
}


When I run this from a command prompt, it prints the full name:

C:\>\users\hongooi\longfilename.exe
\users\hongooi\longfilename.exe


But when I run it from R (3.4.3) via system() or system2(), it prints the 8.3
filename:
> system2("c:\\users\\hongooi\\longfilename.exe")
c:\users\hongooi\LONGFI~1.EXE


And here is a question on StackOverflow where this cropped up:
https://stackoverflow.com/questions/50090450/config-file-is-ignored-when-net-executable-is-called-from-r

Would it be possible to modify system() and system2() to respect long filenames?