Bug 206279 Removed computed cols listed in expression builder[07]
Description: Removed computed column listed in expression builder inside DataSet Editor dialog Build number:2.2.2.v20071011 Steps to reproduce: 1. New data source and dataset. 2. Add a computed column in dataset and click OK. 3. Open the dataset, remove the computed column. 4. Add a new computed column and check columns in available Data Sets. Expected result: The removed computed column isn't there. Actual result: The removed computed column is still there for selection. Error log:n/a
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
}
			columns = null;
		}
		
		
		if ( columns == null )
		{
			columns = new DataSetViewData[]{};
			updateModel( dataSet, columns );
			htColumns.put( dataSet, columns );
		}
		return columns;
	}
    
	/**
	 * populate all output columns in viewer display. The output columns is
	 * retrieved from oda dataset handles's RESULT_SET_PROP and
	 * COMPUTED_COLUMNS_PROP.
	 * 
	 * @throws BirtException
	 */
	public DataSetViewData[] populateAllOutputColumns(
			DataSetHandle dataSetHandle, DataRequestSession session ) throws BirtException
	{
		IResultMetaData metaData = session.getDataSetMetaData( dataSetHandle,
				false );
		DataSetViewData[] items = new DataSetViewData[metaData.getColumnCount( )];
		for ( int i = 0; i < metaData.getColumnCount( ); i++ )
		{
			items[i] = new DataSetViewData( );