RSI returns null instead of 100 when there is no Average Loss

[tht12837a]

RSI should be 100 when the Average Loss equals zero. Using the RelativeStrengthIndexByTuple we should get 100 when there is no Average Loss, but instead RSI is null.

How to reproduce:

            List<decimal?> allTradyCandlesList = new List<decimal?>();

            for (int i = 1; i < 21; i++)
            {
                allTradyCandlesList.Add(i);
            }
            var rsi = new RelativeStrengthIndexByTuple(allTradyCandlesList, 10)[allTradyCandlesList.Count - 1];