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

[Stefan Kangas]

"Basil L. Contovounesios" <contovob@tcd.ie> writes:

> FWIW, emacs-27 and master behave differently in this respect;
> see e.g. https://github.com/abo-abo/swiper/issues/2709.
>
> The headings used to be inserted in the current buffer along with the
> bindings, but the headings alone are now printed to standard-output
> instead.
>
> Is that a problem?

Yes, it is a bug.  I have pushed a fix to master.  Could you please test
that it works for you?

(The fix should mean that you don't have to bind `standard-output' in
swiper.)