Mariusz Klochowicz 528db7d9c5 fix(apple): Prevent Swift6 crash on iPadOS (#10916) ...

UserDefaults change notifications should always be handled on the main
thread.

This wasn't the case when PencilKit posted UserDefaults notifications
from a background thread during its initialization on iPadOS, causing a
Swift 6 MainActor violation crash.

Ultimately, the root cause of this issue was not abiding to strict
Swift6 concurrency checks by using unsafe code: even when the
UserDefaults themselves were `nonisolated(unsafe)` and bypassed the
checks, it was not the case for Apple PencilKit framework ultimately
initialised in wrong context.

Note: There are a few ways to fix, we're settling on Combine pattern as
it's used elsewhere in the codebase (e.g. in Store).

For other solutions, see:

https://stackoverflow.com/questions/74729010/swift-concurrency-notification-callbacks-on-mainactor-objects

2025-11-20 19:21:04 +00:00

..

apple

fix(apple): Prevent Swift6 crash on iPadOS (#10916)

2025-11-20 19:21:04 +00:00