Bug 156166 Error occour when previewing attached report in web viewer.
Decription:Error occour when previewing attached report in web viewer. Steps to reproduce: 1.run attached reports in web viewer. Expeceted results: preview properly Actual results: Error occour when previewing the reports in web viewer while it works properly in html and PDF
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/RowSaveUtil.java
return rowBytes;
		}
		catch ( IOException e )
		{
			throw new DataException( ResourceConstants.RD_SAVE_ERROR,
					e,
					"Result Data" );
		}
	}
	/**
	 * @return
	 */
	Set getExprNameSet( )
	{
		return this.exprNameSet;
	}
	
	/**
	 * @param currIndex
	 * @throws DataException
	 */
	void saveFinish( int currIndex ) throws DataException
	{
		initSave( true );
		try
		{
			saveNullRowsBetween( lastRowIndex, currIndex );
			rowExprsDos.close( );
			rowLenDos.close( );
		}