Create a wine prefix per user

[Maykin-99]

Fixes #4820 by setting the base directory of CompatData from steamapps/compatdata/<steamid>/ to steamapps/compatdata/<steamid>/<userid>/ (I'm honestly surprised that it worked without a hitch).

The only issue is that the old files still exist.
Ideally we would move them to the new path.
I assume that would belong in upgrade_pfx? Or is it even necessary?

[VannTen]

How could we make this progress forward ?
I just got it by the exact same problem when trying to make family sharing work.

[Nomz420]

Could someone look into this? This fix would prove really useful for us.

[CorruptComputer]

Does this break Steam Cloud save backups? Might need some coordination with the Steam folks to make sure this doesn't break existing save backups.

[jessecambon]

+1 also related to ValveSoftware/steam-for-linux#3942

[etyarews]

+1 This would fix so many issues

[eilimrib]

Please. This is giving me nightmare having to recompile Proton just to share my games with my wife.

[Damglador]

@eilimrib you don't have to compile it. Since it's a change in a simple python file, you can just do the same change in already installed Proton version

[Damglador]

Perhaps it's better to store prefixes in the local compatdata? Because in case user1 with 1000 and user2 with 1001 on the first system won't get swapped prefixes on a system where user1 is 1001 and user2 is 1000

[shaft8472]

So, I found that this is the reason why I cannot let my two sons make use of the same gamedata as my account. Seems like a simple fix.

[Damglador]

I would do this as a personal patch:

self.base_dir = os.path.join(os.environ["STEAM_COMPAT_CLIENT_INSTALL_PATH"], "steamapps", "compatdata", os.environ["SteamAppId"]) + "/"

Or, from my understanding, Steam just could supply a local compatdata directory in STEAM_COMPAT_DATA_PATH variable, instead of the one in portable library.

[etyarews]

I've been thinking about it, and Steam really needs to redo the library side of things. I understand this is probably not the best place for it, but...

Yeah, moving /compatdata/ inside a /userid/ is a necessary step (although I'd rather make it steamapps/compatdata/<userid>/<steamid>/ instead of /<steamid>/<userid>/), but the rest of the library also makes no goddamnit sense.

IMO:

1. /compatdata/ shouldn't be on the library folder. The library should only include game data. By putting /compatdata/ inside the library, you make it really hard to use an external device as a "mobile" library between computers with different users in the same household
2. Steam should use a special group for file permissions on the library itself. It is a pain to set up multiple users sharing the same library because the first user who created the library has file permissions on the library, so other users cannot use it or update it.
3. moving /compatdata/ (and possibly /shadercache/) outside the library folder means that the entire library could have a "shared" group/user permission, while /compatdata/ could have the "Linux user" creator permission, which simplifies things because Wine does not like the virtual c:/ to have permissions other than the user who is executing it

[Damglador]

@etyarews there's ValveSoftware/steam-for-linux#12030 for the first point. It also eliminates the need of doing /.

From what I understand from the code, Steam passes the compatdata location to Proton, so it's an issue with Steam and has to be resolved there.