ObservableList's AddRange enumerates multiple times

[abeham]

It enumerates it a total of three times which may produce three different collections.

    public void AddRange(IEnumerable<T> collection) {
      int capacity = list.Capacity;
      int index = list.Count;
      list.AddRange(collection); // HERE
      List<IndexedItem<T>> items = new List<IndexedItem<T>>();
      foreach (T item in collection) { // HERE
        items.Add(new IndexedItem<T>(index, item));
        index++;
      }
      if (items.Count > 0) {
        OnItemsAdded(items);
        OnItemsAdded(collection); // HERE
        if (list.Capacity != capacity)
          OnPropertyChanged("Capacity");
        OnPropertyChanged("Item[]");
        OnPropertyChanged("Count");
      }
    }

[abeham]

r13597: fixed multiple enumeration of collection in ObservableCollection and ObservableList

[mkommend]

Reviewed r13597.

[mkommend]

r13886: Merged r13597 into stable.