Bug 204229 [Automation][Regression]Exception is thrown when preview reportdesign in webviewer
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/RDSave.java
public void saveExprValue( int currIndex, Map valueMap )
			throws DataException
	{
		if ( rowSaveUtil == null )
			this.initSaveRowUtil( );
		rowSaveUtil.saveExprValue( currIndex, valueMap );
	}
	
	/**
	 * @throws DataException
	 */
	private void initSaveRowUtil( ) throws DataException
	{
		rowExprsOs = streamManager.getOutStream( DataEngineContext.EXPR_VALUE_STREAM,
				StreamManager.ROOT_STREAM,
				StreamManager.SELF_SCOPE );
		rowLenOs = streamManager.getOutStream( DataEngineContext.EXPR_ROWLEN_STREAM,
				StreamManager.ROOT_STREAM,
				StreamManager.SELF_SCOPE );
		
		Map bindingNameColumnName = new HashMap();
		Set bindingNamesToSave = new HashSet();
		Iterator it = this.queryDefn.getBindings( ).keySet( ).iterator( );
		while( it.hasNext( ) )
		{
			String key = it.next( ).toString( );
			IBinding binding = (IBinding)this.queryDefn.getBindings( ).get( key );
			if ( this.streamManager.getVersion( ) >= VersionManager.VERSION_2_2_1_3
					&& this.queryDefn instanceof QueryDefinition
					&& ( (QueryDefinition) this.queryDefn ).getQueryResultsID( ) == null