bug#33442: 26.1.90; Cairo side-by-side windows scrolling fix should be cherry-picked

[Robert Pluim <rpluim@gmail.com>]

Dmitry Gutov <dgutov@yandex.ru> writes:

> On 08.12.2018 16:24, Eli Zaretskii wrote:
>
>> And never worked before since the code
>> was written.
>
> If that is true, I have no strong arguments for why it "has to" be on
> emacs-26.
>
>> I was asking why it has to be on emacs-26, and hoped for
>> responses that take the pros and cons into consideration and show how
>> the pros win over cons.
>
> But I'm not seeing any cons either. It's not like there are any
> plausible Cairo build users that are fine with the current state of
> emacs-26 but would get annoyed by any possible regression that the
> patch in question might introduce.
>
> Anyway, it seems I've already made all the applicable arguments at the
> beginning of this discussion. So I'll stop here.

I thought we were in a state on emacs-26 where we can get away with
cherry-picking minor fixes like the side-by-side stuff, precisely
because cairo is disabled by default.  Also if any brave soul does
turn it on on emacs-26, we should probably strive to have fixed things
for them that are easy to fix.

On a separate note, should we turn cairo on by default in master? It
will still only get compiled for people who have the appropriate
development packages installed.

Robert