Open Radar

 
Summary:
UICollectionView self-sizing cells not rendering properly after using UICollectionFlowLayout's invalidateLayout and estimatedItemSize methods.

Also, if you try to override preferredLayoutAttributesFittingAttributes to manually the right frame.x position is completely ignored. 

No combination of constraints that I could find would solve the problem.

Steps to Reproduce:
1. Run the app in iPad Portrait Mode.
2. Scroll the UICollectionView down to set the first cells not visible.
3. With a swipe from the right edge of the screen, invoke Split Screen to pick a secondary app (i.e. Calendar). App should be in split-screen multitasking.
4. App now show a single row of cells.
5. Scroll to top.

Animation: https://www.dropbox.com/s/4z0d0wcb8piuqtu/Animation.gif?dl=0

Expected Results:
First UICollectionViewCell is rendered in the same position as the other cells.

Actual Results:
First UICollectionViewCell is not rendered in the right position.

Version:
iOS 9.0

Notes:


Configuration:
iPad Air 2

Attachments:
'UICollectionViewResizingCells.zip' was successfully uploaded.