[Rd] tools::startDynamicHelp(): Randomly prevents R from exiting (on MS Windows)

[Henrik Bengtsson]

ISSUE:

On MS Windows, running cmd.exe, calling

Rscript --vanilla -e "port <- tools::startDynamicHelp(); port; port <-
tools::startDynamicHelp(FALSE); port"

will sometimes stall R at the end, preventing it from existing.  This
also happens when running R in interactive mode.  It seems to stem
from calling tools::startDynamicHelp(FALSE).

Before filing a formal bug report, can someone please confirm this
behavior? You might have to call it multiple times to hit the bug.

DETAILS:

Microsoft Windows [Version 10.0.19045.3803]
(c) Microsoft Corporation. All rights reserved.

C:\Users\hb>R --version
R version 4.3.2 (2023-10-31 ucrt) -- "Eye Holes"
Copyright (C) 2023 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64 (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
https://www.gnu.org/licenses/.

C:\Users\hb> Rscript --vanilla -e "port <- tools::startDynamicHelp();
port; port <- tools::startDynamicHelp(FALSE); port"
starting httpd help server ... done
[1] 18897
[1] 0

[WORKED]

C:\Users\hb> Rscript --vanilla -e "port <- tools::startDynamicHelp();
port; port <- tools::startDynamicHelp(FALSE); port"
starting httpd help server ... done
[1] 17840
[1] 0

[STALLED]

Bugwhisperer Bengtsson