title: Magical Record, saving, and NSFetchedResultsController
body: <p>Not sure if this is an issue with the way Magical Record does saves, or I'm just making an noob mistake somewhere.</p>
  
  <p>I'm using an NSFetchedResultController (FRC) and UITableView to display a list of entities, when the user taps "Add" a new View Controller with an editor is pushed, a new entity is created with <code>[MyEntity MR_createEntity]</code>. The user can add additional entities here that are added to the main entity via a relationship. When the user taps "Save" in this View Controller the context is saved using <code>[[NSManagedObjectContext MR_contextForCurrentThread] MR_save]</code></p>
  
  <p>The NSFetchedResultsController appears to update, but when I tap to edit the entity none of the child entities are there.  Debugging seems to show that even though the entity has been saved the FRC still has the entity with it's temporary ID.  </p>
  
  <p>I'm doing a naive <code>[self.tableView reloadData]</code> in the FRC <code>controllerDidChangeContent</code> delegate method.</p>
  
  <p>Restarting the application loads the correct entities and the child entities are show properly in the editor view controller.</p>
  
  <p>It looks like the FRC responds to the "main thread" save event, but the save is actually happening on a background thread so the FRC doesn't see it.  I've checked and all "my" operations (setting up the FRC, creating and fetching entities) are all happening on the main thread context.</p>
  
  <p>I tried listening for change notifications on MR_rootSavingContext and merging them with the main thread context, which sort of worked but I ended up with duplicates rows in the FRC (one was the correct "permanent" entity and one was the temporary one).</p>