Re: "after" variable watchers

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Eli Zaretskii <eliz@gnu.org>,  npostavs@gmail.com,  emacs-devel@gnu.org
> Date: Mon, 17 May 2021 14:36:28 -0400
> 
> > window_updeco_window is called indirectly from all places that change a
> > window's decorations, font or size.
> 
> Would it make sense to call it more lazily, e.g. as part of redisplay
> (basically, the watchpoints would just set some dirty bits and then at
> the beginning of redisplay you'd then run `window_updeco_window` on
> those windows with the dirty bit set)?

You don't need a watcher to set flags on windows.  Each change in the
dimensions of windows and their decorations is already preformed by
functions.