Re: The unwarranted scrolling assumption

[Lennart Borgman]

On Thu, Jun 17, 2010 at 2:54 AM, Stefan Monnier
<address@hidden> wrote:
>>> However I dislike the way the problem is solved. I would rather wish
>>> that the display engine instead calculated a new window start point
>>> from the input command queue. I have no idea if that is actually
>>> possible.
>> I think it's impossible.  How can you guess the effect of list of
>> arbitrary input events on the display, without actually redisplaying?
>
> Indeed what he suggests is probably impossible.  But the end result he's
> after is definitely possible: move the window-start as little as possible
> (tho still, line by line) to keep point displayed.


Though it is not easy to understand what is happening.

I believed I safely could assume that save_restriction_save and
save_restriction_restore always was called in pair. Is not that the
case?

I do not understand the output I see. I added a counter, initialized
to 0, that is incremented when entering save_restriction_save and
decremented when exiting ..._restore. It looks like it becomes -1
right at the end before "jumping scrolling". Maybe this is just my bad
C fu. Can I do

  DebPrint (("%d", current_buffer));

where current_buffer is a Lisp_Object? Or does that result in some overflow?