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
items[i].setPosition( i + 1 );
			items[i].setDataType( metaData.getColumnType( i + 1 ) );
		}
		return items;
	}
	
	
	/**
	 * This function should be called very carefully. Presently it is only
	 * called in DataSetEditorDialog#performCancel.
	 * 
	 * @param dataSet
	 * @param itemModel
	 */
	public void setModelOfDataSetHandle( DataSetHandle dataSet,
			DataSetViewData[] dsItemModel )
	{
		if ( dataSet == null || dsItemModel == null )
			return;
		updateModel( dataSet, dsItemModel );
		cleanUnusedResultSetColumn( dataSet, dsItemModel );
		cleanUnusedComputedColumn( dataSet, dsItemModel );
		htColumns.put( dataSet, dsItemModel );
	}
	
	/**
	 * To rollback original datasetHandle, clean unused resultset columm
	 * 
	 * @param dataSetHandle
	 * @param dsItemModel