Bug 123219 Export data in attached file which has a table covers multiple page will throw exception.
Description: Export data in attached file which has a table covers multiple page will throw exception. Steps to reproduce: 1. Preview attached design file in viewer. 2. Select the table and click Export Data Expected result: No errors. Actual result: Exception Exception in: ReportEngineService.getMetaData( )
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/DataExtractionTask.java
this.reportDocReader = reader;
		executionContext.setReportDocument( reportDocReader );
		executionContext.setFactoryMode( false );
		executionContext.setPresentationMode( true );
		report = new ReportParser( ).parse( ( (ReportRunnable) runnable )
				.getReport( ) );
		
		executionContext.setReport( report );
		setParameterValues( reportDocReader.getParameterValues( ) );
		
		IDataEngine dataEngine = executionContext.getDataEngine();
		dataEngine.prepare( report, appContext );
	}
	
	/*
	 * prepare the meta data of DataExtractionTask.
	 */
	private void prepareMetaData( )
	{
		if( isMetaDataPrepared == true ) 
			return;
			
		mapQueryToReportItem = report.getReportItemToQueryMap( );
		mapQueryToValueExprs = report.getQueryToValueExprMap( );
		
		
		try
		{
			loadResultSetMetaData( );