UITextView becomes blank when view controller is dismissed

Number:rdar://FB7403506 Date Originated:23 october 2019
Status:Open Resolved:
Product:UIKit Product Version:
Classification:Incorrect/Unexpected Behavior Reproducible:Yes
iOS version - 13.1

In certain conditions UITextView becomes blank when dismissing view controller.

1. Create view controller with UITextView. Set attributed text with specified 'NSAttributedString.Key.font' attribute to the text view. It should be fairly long, for example: "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. ".
2. Modally present created view controller, i.e. by 'func present(: animated: completion:)' method of UIViewController.
3. Dismiss view controller by calling 'dismiss(animated: true)' on presented view controller.

UITextView appears blank, i.e. without text, during dismiss animation view controller. This is not apparent with default animation speed, but effect very visible after turning on Slow Animations in Simulator.

Text is visible. As on iOS 12.


Repository with sample project


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!