Re: The unwarranted scrolling assumption

[Lennart Borgman]

On Fri, Jun 18, 2010 at 5:35 PM, Eli Zaretskii <address@hidden> wrote:
>> From: Lennart Borgman <address@hidden>
>> Date: Fri, 18 Jun 2010 17:08:18 +0200
>> Cc: address@hidden
>>
>> You are looking for the reason why reconsider_clip_changes does not do
>> its job. I have said (though maybe not explicitly enough, I don't
>> know) that it can't because it does not have the information it needs.
>>
>> It does not have that information because narrow_to_region has erased
>> it by setting clip_changed to 1.
>
> The information is not erased, it is still present in
> w->current_matrix->zv and w->current_matrix->begv.  You will see that
> reconsider_clip_changes uses those to decide whether to reset the
> clip_changed flag.


Oh, fine, I missed that. Then we do not need the new variables I introduced.

But that does not change the logic.

What I did was setting clip_changed to 1 if the clipping had changed
since last redisplay instead of doing it in narrow_to_region etc.

Can you see anything wrong in that?

You seem to say that window_valid_end should be considered too. I
can't see why since setting it here is instead of setting it in
narrow_... etc. Do you really see a reason why window_valid_end shoudl
be considered in this step? (It will be considered later in
reconsider_clip_changes but that is a different thing.)


So sofar I am not aware of any valid objections to the logic of my
patch. Please tell me if I am missing some.