Bug 121682 Exception throws when export data from table containing highlight/map.
Description: Exception throws when export data from attached report. Steps to reproduce: 1. I add a table which has a group, a highlight rule and a map rule in group row. 2. Preview the report attached. 3. Export the data in table. Expected result: Data are exported. Actual result: Exception in: ReportEngineService.getMetaData( )
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/DataExtractionTask.java
}
			catch ( BirtException e )
			{
				e.printStackTrace();
			}
		}
		else
		{
			DataSetID parentId = dataSetId.getParentID( );
			assert parentId != null;
			try
			{
				queryResultName = parentId.getDataSetName( );
				DataSetID parId = parentId;
				while( queryResultName == null && parId != null )
				{
					parId = parId.getParentID();
					if( parId != null )
						queryResultName = parId.getDataSetName();
				}
				assert queryResultName != null;
				
				IQueryResults parentQueryResult = dataEngine
						.getQueryResults( queryResultName );
				assert parentQueryResult != null;
				
				IResultIterator iter = parentQueryResult.getResultIterator( );
				long rowid = dataSetId.getRowID( );
				
				int i = 0;