Re: The unwarranted scrolling assumption

[Eli Zaretskii]

> From: Lennart Borgman <address@hidden>
> Date: Thu, 17 Jun 2010 21:35:51 +0200
> Cc: address@hidden
> 
> > What parts of the above condition prevented
> > reconsider_clip_changes from resetting b->clip_changed to zero?
> 
> Sorry, I thought I did tell that, but maybe I deleted that from some message.
> 
> It is !NILP (w->window_end_valid).

??? How can this be?  The code says:

  if (b->clip_changed
           && !NILP (w->window_end_valid)
           && w->current_matrix->buffer == b
           && w->current_matrix->zv == BUF_ZV (b)
           && w->current_matrix->begv == BUF_BEGV (b))
    b->clip_changed = 0;

So if w->window_end_valid is non-nil, this code should reset
b->clip_changed to zero.  And you say it does _not_ reset it to zero.
So what prevents b->clip_changed from being reset to zero?

> But it is not this that normally gives the "jumping scrolling". I am
> not sure it is a problem at all.

Then what _is_ the problem?