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Pull request overview
This PR fixes a concurrent modification crash in the iOS gesture handler implementation. The crash occurred when reattachHandlersIfNeeded iterated over the handlers registry while the collection was being modified, causing a "NSDictionary was mutated while being enumerated" error. This method was introduced in PR #3964 to handle view recycling on the new architecture when parent views have display: none.
Changes:
- Create a defensive copy of the handlers collection before iterating in
reattachHandlersIfNeeded - Add a comment explaining the defensive copy to prevent concurrent modification
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Description
In
reattachHandlersIfNeededmethod we are iterating over handlers contained in registry. The following crash was reported:In this PR I've changed the loop to iterate over copy - this should fix this issue.
Note
For now we have no consistent reproduction. I'm also not sure where this concurrent modification takes place. It seems to be indirect, as previous keyframe in provided stack trace was
flushOperations.Test plan
Tested on the example code from #3964