bug#34022: 26.1; Region highlight has lower priority than flymake overlays

[João Távora]

[BTW Johann: to CC the bug tracker, use 34022@debbugs.gnu.org, not
bug-gnu-emacs@gnu.org, since this will create a new bug, and has the
potential to annoy maintainers :-).  I'm guilty of that too, since I
replied to all in the email you did that (and so created another bug).]

Eli Zaretskii <eliz@gnu.org> writes:

> I'm not sure what I'm supposed to chime in about.  Are you asking
> whether it's okay for Flymake to use the same technique as the
> region's overlay?

I guess he is, yes.  It's a problem I didn't encounter during
development because the face properties of the Flymake overlays and the
region don't clash when using the default settings.

> Or are you asking something else?  If the former,
> I'm not sure I understand the problem well enough to answer the
> question.

In Flymake multiple overlays (error, warning, note) can overlap and
priorities are used so that an error is never hidden by a note.  I based
thosed priorities in the 100's range (so note = 101, warning=102,
error=103, sth like that). 100 was a number chosen quite arbitrarily
which worked fine until Johann noticed the bug (I do think it's a bug).

>In particular, how is Flymake different from any other package which
>uses overlays to mark portions of text?

Perhaps it isn't.  Can you point me to other packages that leave
persistent region-resisting overlays in the buffer? (or that "play nice"
with the region, for some meaning of "nice").

João