BUG #12806: Upper and Lower functions is not working as expected at some Turkish character sets on Windows OS

The following bug has been logged on the website:

Bug reference:      12806
Logged by:          Ugur YILMAZ
Email address:      ugurlu2001@hotmail.com
PostgreSQL version: 9.4.0
Operating system:   Windows 7 Ultimate 64bit
Description:

I found this bug today and done a small research on web. I think that is a
bug and not only for me. You can see well explained details at the fallowing
link :


http://stackoverflow.com/questions/13029824/postgres-upper-function-on-turkish-character-does-not-return-expected-result

Warm regards,
Ugur