The pipe() method previously showed some inconsistent behavior depending on which side of the pipe closed at which time (prior to piping or during piping).
The pipe() method now shows consistent behavior of calling pause() on the source side if the target is saturated or closed and now cleanly removes the event forwarding if either side is closed.
This should not affect normal usage, but some of the more hidden scenarios may in fact rely on the previous behavior. As such, I'm marking this as a BC break just to be safe.
If you want to review, also consider looking at the individual commits, this should make the changes more obvious.