bug#30823: 25.3; modification-hooks of overlays are not run in some cases

[Noam Postavsky]

Eli Zaretskii <eliz@gnu.org> writes:

> Btw, I'm somewhat worried by the solution being proposed: it removes a
> general safety device and replaces it by a solution that targets only
> bug#21824, a much narrower class of problems.  Is that wise?

IMO, a safety device which causes new bugs is disqualified from its job.
So yes, replacing this device with a more targeted fix seems like the
Right Thing to me.  Furthermore, we're currently calling the after
change hooks without the before change hooks which is just asking for
trouble (as exemplified by Bug#21824 and this one).