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: Tue, 22 Sep 2020 17:51:20 +0200
> 
> (gdb) show height
> Number of lines gdb thinks are in a page is unlimited.
> (gdb) show environment INSIDE_EMACS
> INSIDE_EMACS = 28.0.50,comint
> 
> It is indeed unlimited...  but if I change the size of the frame:
> 
> (gdb) show height
> Number of lines gdb thinks are in a page is 35.
> 
> So Emacs is somehow telling gdb to set the height when the frame size
> changes.  I tried grepping for that yesterday, but I was unable to see
> what triggers that.

That's a different problem, then.  I think it is related to
window-adjust-process-window-size-function and
set-process-window-size, introduced in Emacs 25.  I guess gud-gdb
should disable that feature.