Re: Revamping sit-for [Was: Lingering input pending with motif menu bar]

[Richard Stallman]

    Can you give a _precise_ description of what behaviour of the old sit-for
    is "lost" in the new sit-for.

I don't have one, because that behavior was never designed.  It was a
bug.  It arose in the 90s as an unintended consequence of the
existence of events (I think even X events) that the user would never
see.

I think the behavior is that internal events can appear in the queue
and cause sit-for to return, but then no input is really available.

Chances are that this behavior causes nothing but bugs, and that all
callers will benefit from the correction of it.  However, I think we
ought to check the callers, so as to make sure we don't introduce any
new bugs by this change.