Bug 141950 Selection of select value in data set filter is error
Details: Selection of select value in data set filter is error Step: 1.New a report design. 2.Create a sample datasource and dataset. 3.Switch to filter. 4.Select a value in expression. 5.Drop the list of the value1 and select <select value...> Actual result: No value is appear and pop up an error. It said that "An expression has not been set"
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
return instance;
	}
	/**
	 * get columns data by data set name
	 * @param dataSetName
	 * @param refresh
	 * @return
	 */
	public DataSetViewData[] getColumns( String dataSetName, boolean refresh )
	{
		ModuleHandle handle = Utility.getReportModuleHandle( );
		DataSetHandle dataSet = handle.findDataSet( dataSetName );
		if ( dataSet == null )
		{
			return new DataSetViewData[]{};
		}
		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 );
	}
	/**
	 *