Why must the user be the owner of the WINEPREFIX dir?

[Gabriel Sailer]

Hello,
after an update of wine on my Debian etch i got the error:

libwine: Refuse to use a WINEPREFIX dir owned by a different user.

I found that there is a patch in Wine release 0.9.49 but i did not found
why this patch is needed. Are the linux access rights not secure enough?
I have the full access of the directory and all subdirectories and files.

I used the same WinXX Application with wine for a few people (not
parallel but serialized) in the same group and gave the WINEPREFIX dir
(and all subdirectories and files) to this group.

Is it really nesseccary to use this protection? Did i get a security hole
without the check?

Many thanks for your help

Gabriel Sailer