Right. But then 19576 should be closed "for other reasons", right?
Correct, I fixed and closed 19576 a couple of days ago. I did the change in follow-mode as Eli suggested.
However, while we are discussing window-size-change-functions -- I noticed that on OS X and Windows, it is not called when the user manually resized a frame, whereas on X11 it is. It seems logical that is should be called -- should I file this as a bug (or one for each interface)?