bug#39149: 27.0.50; describe-buffer-bindings is calling :filter function in wrong buffer

[Eli Zaretskii]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Sun, 15 Nov 2020 08:08:18 -0800
> Cc: larsi@gnus.org, yyoncho@gmail.com, 39149@debbugs.gnu.org
> 
> > If adding an argument is deemed not a good idea, how about binding a
> > special variable to convey that information to
> > describe-buffer-bindings?
> 
> Yes, that could be a third option c).  Personally, I like option b)
> better.

If we need to insert stuff into a buffer, why make it a string and
then insert? why not insert directly?  The latter means less consing,
so less GC.