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/util/ExprDataReader2.java
if ( lastRowIndex == currRowIndex )
					return this.exprValueMap;
				lastRowIndex = currRowIndex;
				this.skipTo( nextDestIndex );
				this.exprValueMap = this.getValueMap( );
			}
		}
		catch ( IOException e )
		{
			throw new DataException( ResourceConstants.RD_LOAD_ERROR,
					e,
					"Result Data" );
		}
		return exprValueMap;
	}
	
	/**
	 * @param absoluteIndex
	 * @throws IOException
	 * @throws DataException
	 */
	private void skipTo( int absoluteIndex ) throws IOException, DataException
	{
		if ( this.dataSetResultSet!= null )
		{
			this.dataSetResultSet.skipTo( absoluteIndex );
		}
		
		if ( currRowLenReadIndex == absoluteIndex )
			return;