C5.HashDictionary<K, int>.Values are returned on first call only

[ddur]

C5 2.4.5891.40110 (NuGet)
Net 4.5.2

[ddur]

To be precise:
I use C5.HashDictionary<K, int>.Values
On second call to Values, all int values are 0 (zero)

[ondfisk]

Could you supply a piece of code to reproduce the bug?
Is the bug present in previous versions?

[ddur]

Test
Implementation under test
Bug was not present in 2.4.5828.26833

[ddur]

@ondfisk
Just add two or three Key-Value-Pair (T, int) with different int values.
Get the .Values, everything is OK.
Get the .Values again and all int values are 0.

[Dana-Ferguson]

I have found the change that caused the issue:

inside: internal class KeysCollection : CollectionValueBase<K>, ICollectionValue<K>
@ Dictionaries.cs

            public override SCG.IEnumerator<V> GetEnumerator()
            {
                //Updatecheck is performed by the pairs enumerator
                foreach (KeyValuePair<K, V> p in pairs)
                    yield return p.Value;
            }

became

            public override SCG.IEnumerator<V> GetEnumerator()
            {
                //Updatecheck is performed by the pairs enumerator
                _internalEnumerator.UpdateReference(_pairs);
                return _internalEnumerator;
            }

The new enumerator:

                internal void UpdateReference(ICollection<KeyValuePair<K, V>> list)
                {
                    _internalList = list;
                    Current = default(V);
                }

                public override bool MoveNext()
                {
                    ICollection<KeyValuePair<K, V>> list = _internalList;

                    if (_internalEnumerator == null)
                        _internalEnumerator = list.GetEnumerator();

                    if (_internalEnumerator.MoveNext())
                    {
                        Current = _internalEnumerator.Current.Value;
                        return true;
                    }

                    Current = default(V);
                    return false;
                }

And within that: (in MoveNext)

                    if (_internalEnumerator == null)
                        _internalEnumerator = list.GetEnumerator();

Is only ever called once and never updated.

if you add _internalEnumerator = list.GetEnumerator(); to UpdateReference, it works again.
I assume that its supposed to be linqy and update automagically, but its not (why this is a comment, and not a PR, I don't understand the intended behavior).

I noticed that the Keys collection resolves differently at runtime. Values uses the ValuesCollection and ValueEnumerator resolving to C5.TreeSet<C5.KeyValuePair<,>.Enumerator (which has the old stamp value of '0'), but Keys resolves to C5.SortedDictionaryBase<, >.SortedKeysCollection.KeyEnumerator. So I assume this bug would also affect Keys if Keys used the KeysCollection in the same way as the Values uses ValuesCollection.

I hope this helps in solving the problem.

[ondfisk]

It certainly does. Thanks.
I will look into it ASAP.
I have hidden the buggy NuGet packages.

[ddur]

Thanks

[ondfisk]

I've pushed a new version to NuGet. Please verify that the issue has been resolved