bug#60569: 29.0.60; vc-pull-and-push unsupported on non-git vcs

[Eli Zaretskii <eliz@gnu.org>]

> From: Juri Linkov <juri@linkov.net>
> Date: Sun, 22 Jan 2023 19:28:03 +0200
> 
> > Thanks for keeping VC generic.
> 
> Here is a one-line patch that adds support for vc-bzr.
> 
> Eli, is it ok to install this on the emacs-29 branch?
> I briefly tested it on bzr, so it should be quite safe.
> 
> diff --git a/lisp/vc/vc-bzr.el b/lisp/vc/vc-bzr.el
> index 6443f6d57aa..404800cb208 100644
> --- a/lisp/vc/vc-bzr.el
> +++ b/lisp/vc/vc-bzr.el
> @@ -381,7 +381,8 @@ vc-bzr--pushpull
>            (setq-local compile-command
>                        (concat vc-bzr-program " " command " "
>                                (if args (mapconcat #'identity args " ") "")))))
> -      (vc-set-async-update buf))))
> +      (vc-set-async-update buf)
> +      (get-buffer-process buf))))

Looks OK to me, but could you add some details regarding why this
change is needed?  Did we change our requirements from the return
value of the pushpull method?  Or did vc-set-async-update change its
behavior and no longer returns the process object?  Or something else?

Thanks.