Re: The unwarranted scrolling assumption

[David De La Harpe Golden]

On 21/06/10 03:59, Eli Zaretskii wrote:
> > Date: Sun, 20 Jun 2010 22:40:44 +0100
> > From: David De La Harpe Golden<address@hidden>
> > CC: address@hidden
> >
> > window.c: Still recentering sometimes.
>
> Does the problem go away if you disable font-lock-mode?

I could not reproduce today without font-lock-mode on two complete 
scrollthroughs (one with redisplay-dont-pause and one without).


font-lock-mode on:

redisplay-dont-pause nil (that's nil):

I counted about 114 visible recenters on one complete scrollthrough 
(N.B. definitely recenters i.e. cursor restarting from the middle, not 
just update lags),

redisplay-dont-pause t (that's t):

No visible recenters on one complete scrollthough.


> > I guess you've fixed _something_, just not the issue Lennart is talking
> > about: HELLO is definitely recentering less often than it was (making
> > the window narrower so that lines wrap makes it happen more repeatably).
>
> Again, does it happen if you disable font-lock-mode and
> bidi-display-reordering?

Yes (font-lock-mode doesn't appear to do anything visible at a glance on 
HELLO, but I turned it off anyway).

redisplay-dont-pause nil (that's nil):

Only visibly once in 20 whole buffer scrollthroughs (HELLO being a lot 
shorter than window.c...), though with at least one of those update lags 
every time.

redisplay-dont-pause t (that's t):

11 times in 20 whole buffer scrollthroughs.

Note there were still some wrapped lines during that test, which I have 
some difficulty eliminating with emacs -Q at present with typical
window sizes owing to #6471.