Bug 148503 [regression]Data in list footer cannot be previewed in Web viewer
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/RowSaveUtil.java
private DataOutputStream rowExprsDos;
	private DataOutputStream rowLenDos;
	private boolean inited;
	private Set exprNameSet;
	/**
	 * 
	 */
	public RowSaveUtil( int rowCount, OutputStream rowExprsOs,
			OutputStream rowLenOs, Set exprNameSet )
	{
		this.rowCount = rowCount;
		this.exprNameSet = exprNameSet;
		
		this.rowExprsDos = new DataOutputStream( rowExprsOs );
		this.rowLenDos = new DataOutputStream( rowLenOs );
	}
	/**
	 * @param currIndex
	 * @param valueMap
	 * @throws DataException
	 */
	public void saveExprValue( int currIndex, Map valueMap )
			throws DataException
	{
		try
		{
			saveNullRowsBetween( lastRowIndex, currIndex );