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Xin Chen
cf9c7d51ef
Summary:
This is a two step (1/2) fix to a race that could caused a `DELETE`...`CREATE` mutations being sent over to the fabric mounting layer. Such combination was assumed not possible from the differ, yet it happened at least in the existence of layout animation and when certain commits happen while animation is active.
This race condition could cause a view to get deleted at the end of one UI frame, yet the mount instructions generated from animation in the next frame still need to access the deleted view and caused crashes like T112157805. Note that even though such crash is recorded as `RetryableMountingLayerException` and is a soft crash (which only gets logged but not crash in production), the out-of-order mount instructions could lead to illegal view state and make the surface unusable, like what's shown here:
{F820669000}
The diff fixes this issue by removing the `DELETE` [conflict animation](https://fburl.com/code/5ctckvz3) keyframe, as well as the `CREATE` [immediate mutations](https://fburl.com/code/txyomytd) from the layout animation. The Fabric mounting layer assumes no combination of `DELETE...CREATE` in the same frame from differ + [layout animation overrides](https://fburl.com/code/zn17uqch).
Reviewed By: sammy-SC
Differential Revision: D41895427
fbshipit-source-id: d6df02663ba707af6db4a63a325ac776ca54d18e