bug#23858: 25.0.95; window-state-get doesn't preserve side window status

[Eli Zaretskii]

> From: bmag bmag <bmagamb@gmail.com>
> Date: Sat, 2 Jul 2016 21:39:10 +0300
> Cc: 23858@debbugs.gnu.org
> 
> > It would be a (slight) penalty for the majority of users who never use
> > side windows.
> 
> Can you elaborate? AFAIU it only affects saving and loading of window
> configurations, which isn't used all that much, and we're only talking
> about reading and setting a window parameter. I could be mistaken, but
> the penalty sounds negligible to me.

Not necessarily: these functions are used by frameset.el, which is
used by desktop.el, and the latter auto-saves the window and frame
configurations every 30 sec by default.