Bug 145478 Unable "Select Value" in the Join data set's filter
Step to reproduce: 1.new a join data set(please use the attached file) 2.right click the dataset and click the Edit 3.go to the Filter pane and set a filer 4.click the list of Value1 Actual result: A warning pop up and cant select Value.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
if ( !( dataSet instanceof JointDataSetHandle ) )
			{
				IBaseDataSourceDesign dataSourceDesign = session.getModelAdaptor( )
						.adaptDataSource( dataSet.getDataSource( ) );
				session.defineDataSource( dataSourceDesign );
			}
			if ( dataSet instanceof JointDataSetHandle )
			{
				defineSourceDataSets( dataSet, dataSetDesign );
			}
			session.defineDataSet( dataSetDesign );
			return dataSetDesign;
		}
		return null;
	}
	
	/**
	 * @param dataSet
	 * @param dataSetDesign
	 * @throws BirtException
	 */
	private void defineSourceDataSets( DataSetHandle dataSet,
			IBaseDataSetDesign dataSetDesign ) throws BirtException
	{
		List dataSets = dataSet.getModuleHandle( ).getAllDataSets( );
		for ( int i = 0; i < dataSets.size( ); i++ )
		{
			DataSetHandle dsHandle = (DataSetHandle) dataSets.get( i );
			if ( dsHandle.getName( ) != null )
			{