Bug 147263 Data can't be retrieved for extended item
Steps to reproduce: 1.Add a table in library 2.New a report, extend lib.table 3.Add a filter on table, choose "select value" Expected result: Available value will be listed Actual result: Error: The expression's value can not be retrieved. The DataSetHandle shouldn't be null.
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/impl/DataRequestSessionImpl.java
resultIt.close( );
		queryResults.close( );
		
		return values;
	}
	/*
	 * @see org.eclipse.birt.report.data.adaptor.api.DataRequestSession#refreshMetaData(org.eclipse.birt.report.model.api.DataSetHandle)
	 */
	public IResultMetaData refreshMetaData( DataSetHandle dataSetHandle )
			throws BirtException
	{
		return new DataSetMetaDataHelper( this.dataEngine,
				this.modelAdaptor,
				this.sessionContext.getModuleHandle( ) ).refreshMetaData( dataSetHandle );
	}
	/*
	 * @see org.eclipse.birt.report.data.adaptor.api.DataRequestSession#executeQuery(org.eclipse.birt.data.engine.api.IQueryDefinition,
	 *      java.util.Iterator, java.util.Iterator, java.util.Iterator)
	 */
	public IQueryResults executeQuery( QueryDefinition queryDefn,
			Iterator paramBindingIt, Iterator filterIt, Iterator bindingIt )
			throws BirtException
	{
		return new QueryExecutionHelper( this.dataEngine,
				this.modelAdaptor,
				this.sessionContext.getModuleHandle( ) ).executeQuery( queryDefn,
				paramBindingIt,
				filterIt,
				bindingIt );
	}