[RFC] Handle process token groups in server/file.c::sd_to_mode

[Paul Chitescu]

Hi!

How should server/file.c sd_to_mode() deal with filesystems that don't support 
full POSIX ownership and access permissions? It is quite popular to mount FAT 
filesystems - either from a removable media or a partition shared with a 
Windows installation.

Furthermore, there could be symlinks to such files so filesystem capability 
should be detected somehow from the file itself.

Since recently I am unable to patch WoW since it started to call 
SetFileSecurity on the program directory which is located on a FAT32 
partition. Everything appears owned by root but with rwxrwxrwx access. Wine 
tries to set ---rwx--- which is, to say the least, not commonly seen.

http://bugs.winehq.org/show_bug.cgi?id=20643

Paul