Bug 191637 Empty cube causes error
Comment removed as requested by the submitter - 2007-06-08 droy
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/olap/data/util/DiskIndex.java
* @param selections
	 * @return
	 * @throws IOException
	 * @throws DataException 
	 */
	public IDiskArray find( ISelection[] selections ) throws IOException, DataException
	{
		documentObject.seek( rootNodeOffset );
		NonLeafNode currentNode = readNonLeafNode( );
		
		if ( !checkValid( currentNode ) )
		{
			throw new DataException( ResourceConstants.OLAPFILE_DATA_ERROR,
					name );
		}
		
		boolean find = false;
		NodeSelection nodeSelection = new NodeSelection( currentNode,
				selections.length );
		for ( int i = 0; i < selections.length; i++ )
		{
			if ( match( currentNode, selections[i] ) )
			{
				nodeSelection.addSelection( i );
				find = true;
			}
		}
		if ( !find )
		{
			return null;