Prevent System.ArgumentException

[Optano-Dev]

Prevent System.ArgumentException: 'The tasks argument included a null value. (Parameter 'tasks')'.

Where Iterator uses the original source array to iterate. So it is crucial to not call .ToList() or create a new array.

This solves #128

[ReubenBond]

This should probably be a slice instead: ArrayPool.Rent returns an array which is at least the requested length, so the non-null items will always be at the beginning and the null items will always be at the end.

However, given that we need to trim the array and Task.WhenAll will convert whatever you pass it into an array (or is it a list?), it would be cheaper just to declare subscriptionTasks as a new List with no pooling.

[galvesribeiro]

Thanks for the PR. It was fixed later. It ended up like this:

var subscriptions = await _serverDisconnectedStream.GetAllSubscriptionHandles();
            var subscriptionTasks = new Task[subscriptions.Count];
            for (int i = 0; i < subscriptions.Count; i++)
            {
                var subscription = subscriptions[i];
                subscriptionTasks[i] = subscription.ResumeAsync((serverId, _) => OnDisconnect("server-disconnected"));
            }

            await Task.WhenAll(subscriptionTasks);

I'm closing this PR. Thanks!