[R] tempdir() does not respect TMPDIR

[Jinsong Zhao]

Hi there,

When I started R by double clicking on Rgui icon (I am on Windows), the 
tempdir() returned the tmpdir in the directory I set in .Renviron. If I 
started R by double clicking on a *.RData file, the tempdir() return the 
tmpdir in the directory setting by Windows system. I don't know whether 
it's designed.

 > sessionInfo()
R version 4.0.2 (2020-06-22)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)
...

Best,
Jinsong