Re: Should overlays evaporate by default?

[Richard Stallman]

    > It occur to me that we could make it easier to find those places.
    > Suppose that by default the `evaporate' property is set to 
`display-warning'.
    > Suppose that in this case, when the overlay becomes empty, it evaporates
    > and displays a warning using `display-warning'.

    We can do that immediately AFTER the release.

Why would it be better then than now?
No matter when we do it, it will cause some programs
to issue these warnings.  People will have to report them
so we can fix them.  The natural time to do that will be
in pretesting.  We will soon (I hope) do pretesting.
Why postpone this till the pretest of the subsequent version?

If this were a new feature, I would say let's put it off.
But it is not a feature but a way of finding bugs, such as
the bug that Bob and others tracked down with so much effort
and time.

This change would involve some work.  We would have to
check all 136 or so calls to make-overlay or its synonyms
in the Emacs sources, and change each of them to DTRT
with the overlay property.  That's a substantial job
and maybe nobody wants to do it.