Bug 142939 Invalid interval will cause incorrect group action.
Description: Invalid interval will cause incorrect group action. Steps to reproduce: 1. Insert a list 2. Add a group, key is string type column, set interval to year, range to 3 3. Preview Expected result: Error msg about invald interval and ignore the invalid interval. Actual result: No error msg and only return one group with all datarows.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutor.java
odiDataSource = null;
		aggregates = null;
		odiResult = null;
		queryScope = null;
		isPrepared = false;
		isExecuted = false;
		
		
		try
		{
			dataSet.afterClose( );
		}
		catch ( DataException e )
		{
			logger.logp( Level.FINE,
					QueryExecutor.class.getName( ),
					"close",
					e.getMessage( ),
					e );
		}
		dataSet = null;
		dataSource = null;
		logger.logp( Level.FINER,
				QueryExecutor.class.getName( ),
				"close",
				"executor closed " );
	}
	/*
	 * @see org.eclipse.birt.data.engine.impl.IQueryExecutor#getDataSet()
	 */