title: NSFetchedResultsController plus NSBatchUpdateRequest equals NSMergeConflict. What do I do wrong?
body: <p>I got a <code>NSFetchedResultsController</code> that I set up using a <code>NSManagedObjectContext</code>. I perform a fetch using this context.</p>
  
  <p>I have as well a <code>NSBatchUpdateRequest</code> that I set up using the same <code>NSManagedObjectContext</code>. I execute the request using the same <code>NSManagedObjectContext</code>.</p>
  
  <p>When I perform the request with the <code>NSBatchUpdateRequest</code>, I can see that all my data have been updated.
  If I restart the app, any fetch using <code>NSFetchedResultsController</code> is working as well.</p>
  
  <p>THe problem is when I'm not restarting the app and that I do both operations one after one, I got a <code>NSMergeConflict (0x17427a900) for NSManagedObject (0x1740d8d40) with objectID '0xd000000001b40000...</code> error when I call the method <code>save</code> from my context.</p>
  
  <p>I know that the problem comes from concurrent change on the same data but I don't know what is the solution? One might be to go through the <code>NSMergePolicy</code> class, but I doubt that's a clean way to solve my problem.</p>
  
  <p>What should I do? Have two different contexts ? (how?)</p>