Subject: Re: bug#18390: 24.4.50; REGRESSION: `split-window' error

From: Eli Zaretskii <[email-masked]>
Date: Mon, 03 Oct 2016 09:16:29 +0300

> Date: Sun, 2 Oct 2016 14:03:39 -0700 (PDT)
> From: Drew Adams <[email-masked]>
> Cc: [email-masked], [email-masked]
> 
> >   split-window(#<window 8 on Palette (Hue x Saturation)> 100 t)
> > 
> > This requests to split an 80-column window while leaving the original
> > window 100 columns, which is clearly impossible.  So why is this a
> > bug in Emacs and not in palette.el?
> 
> Uh, it works 100% of the time with builds prior to Emacs 24.4 -
> more precisely, it works perfectly with Emacs 22, 23, 24.1, 24.2
> and 24.3, as well as with pre-Emacs 24.4 builds through 2013-07-21.

That fact doesn't help with the above in any useful way.  If the Emacs
behavior have changed in some subtle ways since those versions, then
palette.el should have followed suit.

What I see in the failed code is quite clear: palette.el is asking
Emacs to do the impossible.  Why that happens is for the developer of
palette.el to investigate and tell.  It could be that eventually this
will lead to an Emacs bug, but in that case the bug should be found
where it really is and demonstrated to clearly indicate it's a core
bug, ideally without external packages at all.