Drag and drop crashing with Right to left languages in iOS 11

Originator:huncsacsika
Number:rdar://34456456 Date Originated:2017.09.15.
Status:New Resolved:
Product:UIKit Product Version:iOS 11
Classification:crash Reproducible:yes
 
Area:
UIKit

Summary:
During the implementation of the drag and drop in our application, we noticed that the app is crashing when we want to use the feature for right to left languages. We made a sample application to produce the bug, and it is clear that something is not fine when we want to move a cell in the collection view.

Steps to Reproduce:
Set the application language to right to left Pseudolanguage. 
Start the sample application. 
Drag the green cell to the cyan arrea. It will make a copy into the collection view.
Get the green cell again and drag it to the right side of the collection view (above the copied cell).
The `_UICollectionViewDragAndDropController _beginDragAndDropInsertingItemAtIndexPath:` will crash with Assertion failure (see the log in the attached `crashlog.txt`)

Expected Results:
No crash when copying or moving cells.

Actual Results:
Crash

Version/Build:
iOS 11, Xcode: Version 9.0 (9A235)

Configuration:
Application language is set to Right-to-Left Pseudolanguage

Github link for the example files: https://github.com/csacsi/RightToLeftExample

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!