Shield Steam from timezone mess

[nanonyme]

TLDR: Steam timezone handling relies on assumptions about zoneinfo files instead of just UTC deltas being used.

Copy from @tomgar

The workaround would be better if it interprets a TZ env which references a file. In my case I have set >TZ as :/etc/localtime for good reasons:
https://blog.packagecloud.io/eng/2017/02/21/set-environment-variable-save-thousands-of-system-calls/
, being this way of setting up the TZ env part of the spec:
https://www.gnu.org/software/libc/manual/html_node/TZ-Variable.html (search for third format)

In your steam-wrapper, you are almost there... you need to check if the TZ env starts with a colon and >then check if it's a symbolic link and follow it. Either after that or if it's not a symbolic link, just extract >the filename as you are already doing in that for loop.

Steam doesn't work with this kind of TZ representation so that's why I'm commenting here:
ValveSoftware/steam-for-linux#5609

Hopefully Steam will fix this issue in their side some day...

See #120
Essentially we should in all cases normalize input into something that Steam likes whether or not TZ is given in environment.

[nanonyme]

So there's a couple cases for TZ

1. Difference from UTC. By far easiest for us to use, I think /etc/localtime has all the relevant information for this
2. Format with daylight saving time. Seems really complex, I would really hope this isn't needed
3. :characters name of the file that contains zoneinfo. This is a bit iffy. That file might not exist in the sandbox; should also be tested if this in fact has the same bug as 4
4. :characters that does not begin with slash and refers to zoneinfo file; also a bit iffy. Should be just fallback to /etc/localtime?

Seems glibc violates its own documentation though and fourth case is allowed to be present without leading ":". This might well be a bug from early ages of glibc that is now an undocumented feature.

[nanonyme]

So currently it works so that your host TZ is simply ignored. If you really know what you're doing

flatpak --user override --env=TZ=zoneinfo com.valvesoftware.Steam

works to set different zoneinfo than what the algorithm gives

[nanonyme]

@tomgar do you think that's sufficient or do we need real TZ handling?

[tomgar]

Sorry, I didn't see the "override" in your command.

I think it's ok... Maybe you should output a message if you had to forcely mask the TZ env. Linux users are used to see the command line output first before going to look for answers in case there are consequences of such masking.

[tomgar]

By the way, I appreciate the efforts you're taking with this.

[nanonyme]

I guess the console output could also have a link to https://github.com/flathub/com.valvesoftware.Steam/wiki/Frequently-asked-questions

I've been trying to document reasons for that kind of hammer solutions there

[nanonyme]

Note current behaviour has the downside that timezone handling isn't dynamic like it's normally supposed to be. You need to restart Steam to change timezone

[nanonyme]

Added link, updated FAQ https://github.com/flathub/com.valvesoftware.Steam/wiki/Frequently-asked-questions#im-having-incorrect-timezone-in-steam, closing