title: NSFetchedResultsController: problems when having two table rows for one object
body: <p>I've got a tableView where each data set has two rows, therefore my datasource-methods look like the following:</p>
  
  <pre><code>- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
      return self.fetchedResultsController.sections.count;
  }
  
  - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)sectionIndex {
      id &lt;NSFetchedResultsSectionInfo&gt; section = self.fetchedResultsController.sections[sectionIndex];
      return section.numberOfObjects * 2;
  }
  </code></pre>
  
  <p>The NSFetchedResultsControllerDelegate method:</p>
  
  <pre><code>- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {
      if (NSFetchedResultsChangeDelete == type) {
          NSIndexPath *cellIndexPath = indexPath;
          NSIndexPath *separatorIndexPath = [NSIndexPath indexPathForRow:indexPath.row + 1 inSection:indexPath.section];
          [self.transactionTableView deleteRowsAtIndexPaths:@[cellIndexPath, separatorIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
      } else if (NSFetchedResultsChangeInsert == type) {
          NSIndexPath *cellIndexPath = newIndexPath;
          NSIndexPath *separatorIndexPath = [NSIndexPath indexPathForRow:newIndexPath.row + 1 inSection:newIndexPath.section];
          [self.transactionTableView insertRowsAtIndexPaths:@[cellIndexPath, separatorIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
      } else {
          [self.transactionTableView reloadData];
      }
  }
  </code></pre>
  
  <p>If I only use one row for each dataset, everything works as expected. But as soon as I make it this way, I get NSAssertionErrors here:</p>
  
  <pre><code>- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
      // The fetch controller has sent all current change notifications, so tell the table view to process all updates.
      [self.tableView endUpdates];
  }
  </code></pre>
  
  <p>Isn't it possible to use two rows for one data set? What am I doing wrong? I would have expected to work it this way as I always insert two indexPaths whenever the underlying core data changes.</p>