bug#28182: maybe implement CTRL++ to zoom text

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Sun, 29 Sep 2019 03:40:05 +0200
> Cc: Eli Zaretskii <eliz@gnu.org>, Tak Kunihiro <homeros.misasa@gmail.com>, 
>       Juri Linkov <juri@linkov.net>, 28182@debbugs.gnu.org, 
>       積丹尼 Dan Jacobson <jidanni@jidanni.org>
> 
> Richard Stallman <rms@gnu.org> writes:
> 
> >   > I think it's a better default, since it's more in line with user
> >   > expectations.  The "Ctrl+mouse whell changes font size" behaviour is
> >   > pretty ubiquitous in browsers, text editors and IDEs.
> >
> > I proposed CTRL +, but you're talking about the mouse wheel.
> > They are not the same: my laptop has no mouse wheel.
> 
> Earlier in this thread, Eli objected to that proposal because it would
> be backwards incompatible.

The problem is not with C-+, which is undefined by default.  The
problem is with C--, which is used for numeric arguments.  It makes
little sense to me to use C-+ for increasing the font size without
also using C-- for decreasing it.