void MDBReleasesModel::sort( int column, Qt::SortOrder order )
{
	QHash<int, int> mapping;
	MDBModelSorter sorter( mReleases, mapping, column, Qt::DisplayRole );
	sorter.sort( order );

	const QModelIndexList oldList = persistentIndexList();
	QModelIndexList newList;

	emit layoutAboutToBeChanged();

	foreach ( const QModelIndex& index, oldList ) {
		const int nativeRow = mSortMapping.value( index.row(), index.row() );
		newList << createIndex( mapping.key( nativeRow ), index.column() );
	}

	mSortMapping = mapping;
	changePersistentIndexList( oldList, newList );

	emit layoutChanged();
}