Bug 168026 Still use the existing data binding even though the aggregate is different
I had a table in which a data binding which aggregates on a group. When I insert a new data item in the report, although the expressions are same, it aggregates on All, then it refered to the existing data binding. The expected behavior would be a new data binding is created with different aggregates.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ReportItemHandle.java
public ReportItemHandle( Module module, DesignElement element )
	{
		super( module, element );
	}
	/**
	 * Returns the data set of the report item.
	 * 
	 * @return the handle to the data set
	 */
	public DataSetHandle getDataSet( )
	{
		DesignElement dataSet = ( (ReportItem) getElement( ) )
				.getDataSetElement( module );
		if ( dataSet == null )
			return null;
		assert dataSet instanceof DataSet;
		return (DataSetHandle) dataSet.getHandle( dataSet.getRoot( ) );
	}
	/**
	 * Sets the data set of the report item.
	 * 
	 * @param handle
	 *            the handle of the data set
	 * 
	 * @throws SemanticException
	 *             if the property is locked.
	 */
	public void setDataSet( DataSetHandle handle ) throws SemanticException
	{
		if ( handle == null )