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
* Returns the current result's iterator. Repeated call of this method
	 * without having advanced to the next result would return the same iterator
	 * at its current state.
	 * 
	 * @see org.eclipse.birt.data.engine.api.IQueryResults#getResultIterator()
	 */
	public IResultIterator getResultIterator( ) throws DataException
	{ 
		
		if ( queryService == null )
			throw new DataException( ResourceConstants.RESULT_CLOSED );
		try
		{
			if ( iterator == null )
			{
				
				this.queryService.initAutoBinding( );
				this.queryService.validateQuery( );
				org.eclipse.birt.data.engine.odi.IResultIterator odiIterator = queryService.executeQuery( );
				if ( isDummyQuery( odiIterator ) )
				{
					iterator = new DummyResultIterator( new ResultService( context,
							this ),
							odiIterator,
							this.queryScope );
				}
				else
				{
					if ( queryService.getQueryDefn( ).usesDetails( ) == true )
					{