Bug 198270 Copying an aggregate does not make a copy, only a reference
In a table with groups or multiple columns, create an aggregate in a footer or a header. Copy the aggregate to another cell in a footer or a header. Make changes to the new aggregate appropriate to its new location. Expected result: The changes appear in only the new copy of the aggregate. Actual result: The changes appear in both aggregates because the new aggregate is not a copy, but a reference to the same aggregate as the original.
xtab/org.eclipse.birt.report.item.crosstab.ui/src/org/eclipse/birt/report/item/crosstab/internal/ui/dialogs/CrosstabBindingDialogHelper.java
createAggregateSection( composite );
		}
		else
		{
			createCommonSection( composite );
		}
		createMessageSection( composite );
	}
	public void initDialog( )
	{
		if ( getBinding( ) == null )
		{
			setTypeSelect( dataTypes[0] );
			this.newBinding = StructureFactory.newComputedColumn( getBindingHolder( ),
					isAggregate( ) ? DEFAULT_AGGREGATION_NAME
							: DEFAULT_ITEM_NAME );
			setName( this.newBinding.getName( ) );
		}
		else
		{
			setName( getBinding( ).getName( ) );
			setDisplayName( getBinding( ).getDisplayName( ) );
			setTypeSelect( DATA_TYPE_CHOICE_SET.findChoice( getBinding( ).getDataType( ) )
					.getDisplayName( ) );
			setDataFieldExpression( getBinding( ).getExpression( ) );
		}
		if ( this.getBinding( ) != null )
		{
			this.txtName.setEnabled( false );
		}