bug#60585: 30.0.50; global-text-scale-adjust shrinks window (was not before)

[Gregory Heytings]

> > > But are your sure you launched these sessions with emacs -Q?  I see on 
> > > your video another Emacs running in the background, which is 
> > > configured.
> >
> > Very sure.
>
> Then I fear I'm lost.  I can apparently reproduce that problem, it can 
> apparently be fixed in the same way on your system and on mine by 
> turning scroll-bars off... but as I said I can reproduce the exact same 
> problem with older versions of Emacs (2017 and later) and with older 
> versions of IceWM (2020 and later).

Jean, can you please try to build Emacs on an earlier version of the 
repository, say at revision e0488f89d1 when the global-text-scale-adjust 
was introduced six months ago, and check if the same problem still exists?

(In case you don't know how to do that: type "git clone 
git://git.sv.gnu.org/emacs.git", "cd emacs", "git checkout e0488f89d1", 
"make".  Then type "./src/emacs -Q".)