NSFetchedResultsController Assertion failure in -[UITableView _endCellAnimationsWithContext:]

近期发现xcode7 连接iphone6（ios8.4）和iphone6plus（ios8.4）时会报错

Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit/UIKit-3347.44/UITableView.m:1222

xcode6却不会出现此问题，经过追查，发现uitableview在movecell的时候delete和reload的是同一行。

NSFetchedResultsController during a call to -controllerDidChangeContent:. attempt to delete and reload the same index path ( {length = 2, path = 0 - 0}) with userInfo (null)

该问题目前判断为xcode7或者ios9的bug，解决方案为在move时先判断index path和newindexpath是否是同一个即可。

 case .Move: if let indexPath = indexPath { if let newIndexPath = newIndexPath { tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade) tableView.insertRowsAtIndexPaths([newIndexPath], withRowAnimation: .Fade) } }

stackoverflow上有很多体温和解决方案，最符合我的就是如下两个讨论

http://stackoverflow.com/questions/31383760/ios-9-attempt-to-delete-and-reload-the-same-index-path

http://stackoverflow.com/questions/31968574/core-data-setting-the-relationship-on-an-entity-causes-error-in-fetch-results-c