Subject: bug#45898: 27.1; wedged in redisplay again

From: Lars Ingebrigtsen <[email-masked]>
Date: Wed, 08 Jun 2022 13:47:28 +0200

Eli Zaretskii <[email-masked]> writes:

> We could perhaps push an event onto the input queue that would do
> something Lispy when processed, like turn on some mode.  But I think
> the main problem here is that we don't necessarily read the keyboard
> or do QUIT processing inside redisplay, at least the parts of it which
> triggered this discussion.
>
> We also don't currently have any mechanism to quickly exit redisplay,
> so we will need to develop that somehow.

Right.

> Basically, each time this issue comes up, I get the impression that it
> is not quite clear what (not how, but what) people would like to
> happen.  They want to unwedge Emacs, that much is clear, but what to
> do after that to avoid immediately wedging it again?  Because even
> so-long-mode is not a guarantee of getting a responsive Emacs.

It's better than nothing, though, and will unwedge Emacs in many
situations.

But if we had this facility (i.e., a way to make Emacs call some
function after `C-g'-ing a lot during redisplay), then we can start
experimenting -- and users can, too.  So I think having a
`break-during-redisplay-function' variable that specifies something to
be called in these situations would allow some possible progress in this
area.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no