Yes, that's correct and certainly a bug. In extreme cases it might even turn a terminating computation into non-terminating. Annoying n-plus-a-half loop strikes again. Easy to fix, but turns the code into a mess anyway. :)

Great solution!

But I think, it has one sneaky problem.
Your takeS will actually compute one more element than needed. This might be a problem, i.e. if the stream is exausted.