bug#35273: "Marker does not point anywhere" when reading next article

[Noam Postavsky]

Eli Zaretskii <eliz@gnu.org> writes:

>> Date: Sat, 20 Apr 2019 16:44:04 +0300
>> From: Eli Zaretskii <eliz@gnu.org>
>> Cc: contovob@tcd.ie, 35273@debbugs.gnu.org, leah@vuxu.org
>> 
>> > > I think it would be better to try to understand how we got such an
>> > > overlay.  Was it deleted, per chance?
>> > 
>> > I entirely agree with this, but how to check for that?
>> 
>> But a breakpoint in delete-overlay?

I managed to reproduce (wasn't too hard actually).  All the overlay
deletion seems to come from gnus.  I got hits from erase-buffer (called
by gnus), gnus-kill-all-overlays, and gnus-cite-delete-overlays.

> Btw, does anyone understand how does elscreen affect this issue?  Does
> that package manipulate overlays or help-echo properties?

Unclear.  It doesn't have any delete-overlay calls at all.  But it does
create and move its own overlay.  And it does have a few help-echo
properties.