Fix Time Zone when running with Globalization Invariant Mode

[tarekgh]

#59636

When enabling the globalization invariant mode on Linux, we'll always fallback to UTC time zone which is wrong and a regression from .NET 5.0. We have some docker containers (e.g. Alpine) which enable the globalization invariant mode by default on the whole image; the problem will be obvious there.

In .NET 6.0 we have introduced the Globalization Invariant Mode Breaking Change. This breaking change causes throwing exception when enabling the globalization invariant mode and creating any culture other than Invariant culture.
If the globalization invariant mode is enabled and trying to get the local time zone when running on Linux platform, the creation process will try to initialize the display names of the time zone. This initialization tries to reset the UI culture to en-US if it is set to Invariant culture. When we have the globalization invariant mode is on, the UI culture will always be Invariant and cause the time zone initialization to fallback to en-US which will throw exception because it is not allowed to create any other cultures in the Invariant mode. We catch the exception and then fallback to use UTC time zone instead of the actual time zone set on the running machine.

The fix is simple and not risky which is avoid creating any culture during time zone initialization when the globalization invariant mode is on.

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Issue Details

---

#59636

When enabling the globalization invariant mode on Linux, we'll always fallback to UTC time zone which is wrong and a regression from .NET 5.0. We have some docker containers which enable the globalization invariant mode by default on the whole image; the problem will be obvious there.

In .NET 6.0 we have introduced the Globalization Invariant Mode Breaking Change. This breaking change causes throwing exception when enabling the globalization invariant mode and creating any culture other than Invariant culture.
If the globalization invariant mode is enabled and trying to get the local time zone when running on Linux platform, the creation process will try to initialize the display names of the time zone. This initialization tries to reset the UI culture to en-US if it is set to Invariant culture. When we have the globalization invariant mode is on, the UI culture will always be Invariant and cause the time zone initialization to fallback to en-US which will throw exception because it is not allowed to create any other cultures in the Invariant mode. We catch the exception and then fallback to use UTC time zone instead of the actual time zone set on the running machine.

The fix is simple and not risky which is avoid creating any culture during time zone initialization when the globalization invariant mode is on.

Author:	tarekgh
Assignees:	-
Labels:	area-System.Globalization
Milestone:	-

[ghost]

Tagging subscribers to this area: @dotnet/area-system-runtime
See info in area-owners.md if you want to be subscribed.

Issue Details

---

#59636

When enabling the globalization invariant mode on Linux, we'll always fallback to UTC time zone which is wrong and a regression from .NET 5.0. We have some docker containers which enable the globalization invariant mode by default on the whole image; the problem will be obvious there.

In .NET 6.0 we have introduced the Globalization Invariant Mode Breaking Change. This breaking change causes throwing exception when enabling the globalization invariant mode and creating any culture other than Invariant culture.
If the globalization invariant mode is enabled and trying to get the local time zone when running on Linux platform, the creation process will try to initialize the display names of the time zone. This initialization tries to reset the UI culture to en-US if it is set to Invariant culture. When we have the globalization invariant mode is on, the UI culture will always be Invariant and cause the time zone initialization to fallback to en-US which will throw exception because it is not allowed to create any other cultures in the Invariant mode. We catch the exception and then fallback to use UTC time zone instead of the actual time zone set on the running machine.

The fix is simple and not risky which is avoid creating any culture during time zone initialization when the globalization invariant mode is on.

Author:	tarekgh
Assignees:	tarekgh
Labels:	area-System.Runtime
Milestone:	-

[tarekgh]

@eerhardt@safern could you please help reviewing this one? I am planning to have this for 6.0 release.

CC @ericstj@danmoseley

[safern]

LGTM

[tarekgh]

@am11

We have used PlatformDetection.IsInvariantGlobalization in other places.

Thanks for reminding using it.

[danmoseley]

I support taking this. Please send tactics mail when ready.

[tarekgh]

/backport to release/6.0

[github-actions]

Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/1284491644