bug#30699: 26.0.91; buffer contents flicker on macOS frames when frames are resized

[Alan Third]

On Tue, Mar 13, 2018 at 08:34:10AM -0700, Aaron Jensen wrote:
> mOn Sun, Mar 11, 2018 at 5:46 PM, Alan Third <alan@idiocy.org> wrote:
> >> The question is: can x_set_window_size be called without a redisplay
> >> happening soon enough, e.g. if Emacs is busy doing some lengthy
> >> calculation?
> >
> > OK, so this plan is a non‐starter.
> 
> Were you able to find a place where x_set_window_size can be called
> w/o a redisplay happening soon enough?
> 
> I haven't seen any glitches using this patch yet, fwiw.

I haven’t come across anything yet, but I’ve not been using this patch
much.

Watch out for macOS re‐enabling screen updates after ~1 second. It
does this automatically; I guess to stop buggy code from freezing the
application completely.

It should log a message to stderr when it does.

If we are going to use this code, as Eli pointed out, I’ll have to
catch every place where redisplay returns, so it’s not ready for
prime‐time yet.
-- 
Alan Third