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
}
		return getColumns( dataSet, refresh );
	}
	/**
	 * get column data by data set handle
	 * @param dataSet
	 * @param refresh
	 * @return
	 */
	public DataSetViewData[] getColumns( DataSetHandle dataSet, boolean refresh )
	{
		return getColumns( dataSet, refresh, true, false );
	}
	/**
	 * 
	 * @param dataSet
	 * @param refresh
	 * @param useColumnHints
	 *            Only applicable if the list is refreshed.
	 * @return
	 */
	public DataSetViewData[] getColumns( DataSetHandle dataSet,
			boolean refresh, boolean useColumnHints,
			boolean suppressErrorMessage )
	{
		if ( dataSet == null )
		{
			return new DataSetViewData[0];
		}