Summary:
When performing a particular set of batch updates on a UICollectionView with a certain number of sections, it appears there is a heap corruption and crash in objc_release in -[UICollectionViewUpdate _computeItemUpdates].
Steps to Reproduce:
Setup a UICollectionView with 8 sections, each with 3 items
Perform batch updates with:
a. Insert item at section 1, item 0
b. Insert section 0
c. Move section 3 to section 1
Make sure data source is properly updated to reflect changes
Expected Results:
UICollectionView performs the queued updates on the view hierarchy.
Actual Results:
UICollectionView crashes with the following trace:
#0 0x0000000101a3bd7b in objc_release ()
#1 0x000000010325241c in -[UICollectionViewUpdate _computeItemUpdates] ()
#2 0x0000000103251315 in -[UICollectionViewUpdate initWithCollectionView:updateItems:oldModel:newModel:oldVisibleBounds:newVisibleBounds:] ()
#3 0x00000001032c078b in -[UICollectionView _endItemAnimationsWithInvalidationContext:tentativelyForReordering:] ()
#4 0x00000001032c8497 in -[UICollectionView _performBatchUpdates:completion:invalidationContext:tentativelyForReordering:] ()
#5 0x00000001032c82d5 in -[UICollectionView _performBatchUpdates:completion:invalidationContext:] ()
#6 0x00000001032c8278 in -[UICollectionView performBatchUpdates:completion:] ()
Version:
Crash reports from production show issue occurring on iOS 7.1.2, 8.3, 8.4, 9.1, 9.2, 9.2.1, 9.3, and 9.3.1. Locally reproduce on iOS 9.3.1 and Xcode 7.3 simulators.
Notes:
Changing from 8 to 9 sections in the sample project seems to mitigate the issue. The same happens when using only 7 sections.
rnystrom
commented
7 years ago
Summary: When performing a particular set of batch updates on a UICollectionView with a certain number of sections, it appears there is a heap corruption and crash in objc_release in -
[UICollectionViewUpdate _computeItemUpdates].Steps to Reproduce:
Expected Results: UICollectionView performs the queued updates on the view hierarchy.
Actual Results: UICollectionView crashes with the following trace:
Version: Crash reports from production show issue occurring on iOS 7.1.2, 8.3, 8.4, 9.1, 9.2, 9.2.1, 9.3, and 9.3.1. Locally reproduce on iOS 9.3.1 and Xcode 7.3 simulators.
Notes: Changing from 8 to 9 sections in the sample project seems to mitigate the issue. The same happens when using only 7 sections.
Configuration: All iPhones and iOS Simulators
UICollectionViewHeapCorruption.zip