UICollectionViewCompositionalLayout Doesn't Fully Self-Size When Updating additionalSafeAreaInsets

Originator:bryn.bodayle
Number:rdar://FB9079500 Date Originated:04/14/21
Status:Open Resolved:
Product:UIKit Product Version:iOS 14.4
Classification:Incorrect/Unexpected Behavior Reproducible:Always
 
Environment:
Xcode Version 12.4 (12D4e)
iOS 14.4 Simulator or Device

Steps to reproduce:
1. Download attached sample project and run on iPhone Simulator.
2. Notice after 5s when the additionalSafeAreaInsets are programmatically updated the UICollectionViewOrthogonalScrollerEmebeddedScrollView doesn't size to the preferred heights of the containing cells. It remains at it's estimated height.

Notes:
1. This only occurs if the collection view is constrained to the top anchor of the containing view's layoutMarginsGuide.
2. And if the additionalSafeAreaInsets are set after the collection view initially loads.

https://www.dropbox.com/s/mdp3d49jhx64ucl/Compositional%20Layout%20Bug.zip?dl=0

Comments


Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!