Re: Problem with revert-buffer and overlays

[martin rudalics <rudalics@gmx.at>]

 >     Why not do this in kill-all-local-variables then?
 >
 > The reason to get rid of the overlays after revert is because they
 > cannot reliably point to the right place any more.
 >
 > Changing the major mode should not delete the overlays--that would be
 > incorrect.  (Some might be used by minor modes or other features.)
 > Instead, the major mode should explicitly delete the overlays that it
 > uses.

Might be I don't understand this correctly but to get rid of an overlay
you have to find it in the first place.  The original problem was that
kill-all-local-variables killed the reference to the overlay and CUA's
post-command hook wasn't able to find it any more.  Hence, any attempt
to correct this problem (semi-)automatically would have to do that in
kill-all-local-variables.  Suppose I have a CUA rectangle in cperl-mode
and do M-x perl-mode.  The overlay would become inaccessible and any fix
of revert-buffer wouldn't help here.

I believe that Kim's approach to make such variables permanent-local is
the right one to handle this - when and if the problem shows up again.
The only thing I would do is leave a note about this, somewhere.

 >     Deactivating the mark would have to be done by insert-file-contents if
 >     it finds out that the mark has been invalidated during reversion.  I'd
 >     leave this alone until someone complains.
 >
 > I just tried it and revert-buffer did deactivate the mark.
 > Can someone describe a test case where it fails to do so?

With text-mode it doesn't.  And I never had any problems with that.