BUG #4108: PgInstaller Update modify install paths in Registry

The following bug has been logged online:

Bug reference: 4108
Logged by: Gildas PRIME
Email address: g(dot)prime(at)aeschemunex(dot)com
PostgreSQL version: 8.3.1
Operating system: XP Professionnal
Description: PgInstaller Update modify install paths in Registry
Details:

On the update of an existing PostGreSQL install 8.3.1 to 8.3.1 version
causes some bad modifications in the Windows registry.

To reproduce this bug :
1 - install PostGreSQL 8.3.1 into a directory different from the default
directory (by example : C:\Program Files\My Install\My PostGreSQL Install).I
insatll it with command line to have a slient install.
2 - Check in
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\{B823632F-3B72-4514-886
1-B961CE263224}\
the keys "Base Directory" and "Data Directory" and in
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Services\pgsql-8.3
the key Data Directory the Directories must be the path where you install
the PostGreSQL
3 - Launch the update.bat file present in the PostGreSQL installer archive
4 - Check again the different Keys, the values have changed to the "by
default" directory of PostGreSQL installation (C:\Program
Files\PostgreSQL\8.3\)...

PC : XP Professional French SP2 - Pentium 4 3.2Ghz - 1,5 Go RAM