Cannot find an outgoing row head for incoming head ... (internal error)

Originator:av
Number:rdar://13280693 Date Originated:Sat, 23 Feb 2013 9:42:58 GMT
Status:Open Resolved:
Product:iPad SDK Product Version:6.1.2
Classification:Bug Reproducible:Sometimes
 
Summary:
When using UITableView (or UICollectionView) with NSFetchedResultsController, I sometimes get a very strange crash during table view updates. This is symptomatic part:
---
internal error.  Cannot find an outgoing row head for incoming head <unknown var (bug!) with engine as delegate:0x1db13500>, which should never happen.'
---

Steps to Reproduce:
This particular instance happened in table view + search bar which acts as filter bar. UISearchDisplayController is not used, but whatever is typed into UISearchBar is used to change predicate for the NSFRC, then re-fetch is done. It's hard to reproduce this, as it's seemingly random. TableView has no sections, if it helps.

Expected Results:
Table view should update to show result.

Actual Results:
App crashes.

Regression:

Notes:
Attached huge crash log and also an output from LLDB's bt all.

Comments

Crash log: http://cl.ly/0g3I1G2n1P2C

By av at Feb. 24, 2013, 10:40 a.m. (reply...)

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!