Re: The unwarranted scrolling assumption

[David Engster <deng@randomsample.de>]

Lennart Borgman writes:
> On Mon, Jun 21, 2010 at 2:11 PM, David Engster <deng@randomsample.de> wrote:
>>
>> I have recentering there, too, since my main problems pretty clearly
>> come from Emacs' redisplay not keeping up with keyboard input while
>> leaning on the <down> key. This is supported by the fact that when I
>> rebind <down> to '(progn (next-line) (redisplay t))', the recentering
>> practically disappears.
>
> I think that might be a misunderstanding. What is probably happening
> is rather that redisplay somehow resets the state of clip_changed.
> And that is needed. My patch does that without calling (redisplay t)
> which would be time consuming.

Well yes, which is why my rebinding to enforce redisplay isn't a real
solution but merely a circumvention of the problem.

I'm not sure if this is a misunderstanding; I think Juanma pretty much
summarized the problem with "Emacs should stop reading input until it
catches his breath", and Stefan's as well as Eli's response to that was
pretty clear that this cannot be done without redesigning
redisplay. This is why I thought you're actually working on another,
more subtle bug, which might very well be there but accounts only for a
small fraction of recenterings I'm witnessing. Please also note that I
really only see those recenterings while leaning on <down>, not when
scrolling one single line.

I actually did test the patch you first send, but I couldn't notice any
difference while scrolling; recentering did still happen when leaning on
<down>. However, you also said that the patches were not complete, so
I'd be happy to test anything you send me (feel free to send them via
private mail, no need to clean anything up).

-David