Bug 200500 Error happens while share result set from item behind it.[0005]
Description: Error happens while share result set from item behind it. Build number:2.2.1.v20070820 Steps to reproduce: 1. New sample data source and dataset. 2. Drag the dataset to Layout and name it t1. 3. Insert a table before t1 and share result set from t1. 4. Preview. Expected result: If this situation isn't supported by Engine, at least we should provide friendly error message. Actual result: Error happened while running the report. Error log:n/a
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryResults.java
* hint to the query that it can safely release all associated resources.
	 * The query results might have iterators open on them. Iterators associated
	 * with the query result sets are invalidated and can no longer be used.
	 * 
	 * @see org.eclipse.birt.data.engine.api.IQueryResults#close()
	 */
	public void close( ) throws BirtException
	{
		if ( this.queryService == null )
		{
			
			return;
		}
		if ( iterator != null )
		{
			iterator.close( );
			iterator = null;
		}
	    
		queryService.close( );
		queryService = null;
		logger.logp( Level.FINE,
				QueryResults.class.getName( ),
				"close",
				"QueryResults is closed" );
	}
	
	/**
	 * @param rootQueryResultID
	 * @param selfQueryResultID