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
ExceptionHandler.handle( e );
		}
	}
	
	/**
	 * @param dataSetType
	 * @param dataSourceType
	 * @return
	 */
	public static IConfigurationElement findDataSetElement( String dataSetType,
			String dataSourceType )
	{
		
		IConfigurationElement dataSourceElem = findDataSourceElement( dataSourceType );
		if ( dataSourceElem != null )
		{
			
			IExtension ext = dataSourceElem.getDeclaringExtension( );
			IConfigurationElement[] elements = ext.getConfigurationElements( );
			for ( int n = 0; n < elements.length; n++ )
			{
				if ( elements[n].getAttribute( "id" ).equals( dataSetType ) ) 
				{
					return elements[n];
				}
			}
		}
		return null;
	}