bug#9642: move-overlay creates an empty overlay with the evaporate property

[Paul Eggert]

On 09/30/11 21:01, Stefan Monnier wrote:

> if the user goes through the trouble to do the above, he probably
> doesn't want this overlay to disappear right away

I don't see why not.  Evaporating overlays are supposed
disappear when they become empty -- that's their whole point.
Why would one want an evaporating overflow that's empty?

Let's look at it a different way.  Suppose we were to try
to document the current behavior.  We'd add something to
the manual like "overlays with the evaporate property are deleted when
they become empty, except when X".  What would X be,
and why would it be a good idea to have X as an exception?

> I don't think we should change
> this behavior for 24.1.

OK, I'll leave it alone then.