[Rd] Changes to Windows registry in R-2.2.0

[Len Thomas]

R-Devel,

I note from the CHANGES log accompanying the Windows version of R-2.2.0 that 
the behaviour with respect to the Windows registry has changed.  It says:

"If the user chooses to register R during installation, a registry entry
HKEY_LOCAL_MACHINE\Software\R-core\R\{version}\InstallPath will be added.
Users require administrative privileges to create this key.  For others,
the same key will be put under the HKEY_CURRENT_USER root."

The old behaviour was to add or modify the registry entry at
HKEY_LOCAL_MACHINE\Software\R-core\R\InstallPath
(ie the same entry, but without the extra {version} key).   Having installed 
R-2.2.0, I notice that the entry at this location, which used to say
C:\Program Files\R\R-2.1.1
now says
C:\Program Files\R\R-2.2.0
I also tried deleting the \R-core\R key, and re-installing R, and it added 
both the 
HKEY_LOCAL_MACHINE\Software\R-core\R\R-2.2.0\InstallPath
and
HKEY_LOCAL_MACHINE\Software\R-core\R\InstallPath
entries

In other words, the new behaviour seems to be to *both* modify/add an entry 
under
HKEY_LOCAL_MACHINE\Software\R-core\R\InstallPath
*and* 
HKEY_LOCAL_MACHINE\Software\R-core\R\{version}\InstallPath

I note also that it adds another entry 
HKEY_LOCAL_MACHINE\Software\R-core\R\Current Version

My questions are:

(1) Am I correct that this is the new behaviour?

(2) Can the appropriate developer confirm that this behaviour will be 
continued in future versions (at least for a while)?  I ask, because I 
distribute software that uses R, and it uses the 
HKEY_LOCAL_MACHINE\Software\R-core\R\InstallPath
to find R.  (It will also now look under HKEY_CURRENT_USER, as documented in 
CHANGES.)  If future versions will not update this entry, then I'll switch 
the behaviour of my software.

(3) Might it be worth documenting this behaviour somewhere?  I've searched 
all the files in the R-2.2.0 distribution and didn't find it, as well as 
looking in the recent r-devel and r-help archives.

There is one out-of-date entry: in R-2.2.0\doc\manual\R-exts.html it says:
[...]
Find and set the R home directory and the user's home directory.  The
former may be available from the Windows Registry: it will normally be
in <code>HKEY_LOCAL_MACHINE\Software\R-core\R\InstallPath</code> and can be
set there by running the program <span class="file">R_HOME\bin\RSetReg.exe
</span>

Perhaps I missed it elsewhere?

Thanks for any help,

 - Len Thomas


--
Len Thomas   len at mcs.st-and.ac.uk    http://www.creem.st-and.ac.uk/len/
Centre for Research into Ecological and Environmental Modelling
The Observatory, University of St Andrews, Scotland KY16 9LZ
Tel. (0)1334-461801  Fax. (0)1334-461800  Secretary (0)1334-461842