bug#29279: Sharing the margins

[Eli Zaretskii]

> Cc: 29279@debbugs.gnu.org, joostkremers@fastmail.fm
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Wed, 15 Nov 2017 23:09:21 +0200
> 
> On 11/15/17 10:03 PM, Eli Zaretskii wrote:
> 
> >> I intend to drop most calls of 'window-configuration-change-hook' and
> >> replace them by 'window-size-change-functions' if all they do is to
> >> change the sizes of windows only.
> > 
> > Regardless of the reasons for this change, it doesn't affect the issue
> > at hand: calling window-size-change-functions from inside redisplay
> > has the same issues as calling window-configuration-change-hook.
> 
> But margin size changes won't have to call window-size-change-functions, 
> right? Then it might be possible to move all the heavy consumers to this 
> hook, leaving window-configuration-change-hook relatively lightweight 
> (right)?

For some value of "lightweight".  The ones that I think about would
want to change window dimensions, e.g. by enlarging or shrinking the
margins, and that is not "lightweight", as I explained up-thread.