Subject: bug#9246: Scrolling bug with word-wrap in emacs -nw

From: Richard Stallman <[email-masked]>
Date: Sat, 31 Dec 2011 21:59:24 -0500

> There's redisplay-end-trigger-functions, but it's deprecated.  Stefan
    > expressed the desire to have a hook you want many times in the past,
    > but no one stepped forward to do the job yet.

    Actually, I'd like a pre-redisplay-hook, not a post-redisplay-hook.

Hooks in redisplay make me worry, for two reasons:

1. If used in a nontrivial way, they will make it very hard to debug.
It is hard to see what's going on if the principal objects change when
you try to look at them.

2, Why would you want them?  If you put the correct contents in the buffer,
it will display the way you want, right?

We do use redisplay hooks for fontification.  The reason is that
fontifying everything would be too slow.  Fontification doesn't
cause problem #1 because it is stable as long as the buffer's
contents don't change in other ways.

However, I think we should resist adding more redisplay hooks
unless they are very very necessary.  And when we do, we should
try to make them limited.

-- 
Dr Richard Stallman
President, Free Software Foundation
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