Bug 204430 [Automation][Regression]An exception is thrown in console when preview reportdesign
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/util/ExprDataReader1.java
if( this.currRowIndex < this.rowCount - 1)
		{
			this.currRowIndex++;
			if( this.dataSetData!= null )
				this.dataSetData.next( );
			return true;
		}
		else
			return false;
	}
	
	/*
	 * @see org.eclipse.birt.data.engine.impl.document.IExprResultReader#getRowValue()
	 */
	public Map getRowValue( ) throws DataException
	{
		try
		{
			if ( this.rowCount == 0 )
			{
				if ( this.exprValueMap == null )
					this.exprValueMap = this.getValueMap( );
			}
			else if ( currReadIndex < currRowIndex + 1 )
			{
				this.skipTo( currRowIndex );
				this.exprValueMap = this.getValueMap( );
			}
			currReadIndex = currRowIndex + 1;
		}