bug#29279: Sharing the margins

[Dmitry Gutov]

On 11/16/17 5:39 PM, Eli Zaretskii wrote:

> > > 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.

Could you clarify what is the exact issue, BTW?

> > 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.

Are window-size-change-functions really supposed to be called when only 
the margin size has changed, but not the window's outer dimensions?