RE: show-paren-mode prevents page-down from displaying next 1/2 page.

[Maguire, Andrew \(GE Infra, Energy\)]

Hmm, I thought I would play a bit more and there is still something
strange going on, I have not been able to write some repeatable code yet though.

My reason for looking further was that the fix includes a check for window-start
when dir is -1 but no check for when dir is 1. So I thought I would try and
provoke a mirror case with scroll-down ie. when dir is 1 and no window-start
test is used. So far I cannot find anything wrong, despite that suspicion!

However, the situation I have now uncovered seems to be related to
an overlay being left behind after scroll event and then the next scroll
event finds this overlay, removes it but this causes an extra window redisplay
and thus a recenter when one was not expected. Point is moved to the correct 
place. Therefore, my suspicion is that it is related to the new when test
preventing the deletion of a previous overlay when one is needed but it is
outside the new window's bounds. I suspect that the when clause needs to always 
set
the pos variable if dir is set but only set the mismatch variable using the 
test with
window-start.

I hope that makes sense and you see what I mean.

I will try and write some test code but it may have to be next week.

Thanks,
Andrew

"If it runs, script it!"


> -----Original Message-----
> From: Maguire, Andrew (GE Infra, Energy) 
> Sent: 19 April 2007 11:55
> To: 'Glenn Morris'; Chong Yidong
> Cc: address@hidden; address@hidden
> Subject: RE: show-paren-mode prevents page-down from 
> displaying next 1/2
> page.
> 
> 
> Yes, that patch fixes the behaviour. 
> 
> Thanks for the fast response!
> 
> Andrew
> 
> 
> > -----Original Message-----
> > From: Glenn Morris [mailto:address@hidden
> > Sent: 19 April 2007 07:50
> > To: Chong Yidong
> > Cc: Maguire, Andrew (GE Infra, Energy); address@hidden; 
> > address@hidden
> > Subject: Re: show-paren-mode prevents page-down from 
> > displaying next 1/2
> > page.
> > 
> > 
> > Chong Yidong wrote:
> > 
> > > This glitch occurs because show-paren-mode tries to 
> highlight before
> > > window-start, which forces the redisplay engine to 
> recenter. It's no
> > > big deal, but I believe this patch fixes it. Could someone help me
> > > double-check?
> > 
> > Looks ok to me.
> > 
> > 
>