Ohh sorry, I thought you were talking about the merge, not the sort. Yes O(n log n) is allowed for the merge, but what I'm saying is that the Dr. Dobbs article'

Ohh sorry, I thought you were talking about the merge, not the sort. Yes O(n log n) is allowed for the merge, but what I'm saying is that the Dr. Dobbs article's in-place merge sort is actually not quite an in-place variant of merge sort: its complexity (as far as I can tell) is O(n log^2 n) rather than O(n log n).