Small issue with PriorityQueue.Replace

[xenoblitz]

Hey!

First of all thanks for sharing your pathfinding implementation.

I meet a small issue and was wondering whether it is something I am doing wrong or whether it is in fact a small bug. Sometimes when using the ShortestPathGraphSearch I am getting an error with this class's use of PriorityQueue.Replace(). I did the following small update without getting any adverse effects but am not 100% sure it's legit. Am sharing it here just in case:

public void Replace(V value, P oldPriority, P newPriority){
        if (list.ContainsKey(oldPriority))
        {
            LinkedList<V> v = list[oldPriority]; // <--- this was breaking
            v.Remove(value);

            if (v.Count == 0)
            { // nothing left of the top priority.
                list.Remove(oldPriority);
            }
        }

        Enqueue(value, newPriority);
}

Thanks again,
A