bug#21777: 25.0.50; gud-gdb uses a pager, which is harmful inside emacs

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: dima@secretsauce.net,  21777@debbugs.gnu.org,  schwab@linux-m68k.org
> Date: Wed, 23 Sep 2020 14:53:53 +0200
> 
> Andreas Schwab <schwab@linux-m68k.org> writes:
> 
> >> I'm not sure I agree: how is an unlimited setting different from any
> >> other setting?
> >
> > It is special, as it never matches any real terminal size.
> 
> Indeed.  If gdb has disabled the pager, then Emacs telling gdb about the
> changed size shouldn't enable the pager.

Such a change is already being considered for inclusion in GDB, see

  https://sourceware.org/pipermail/gdb-patches/2020-September/172031.html