bug#63949: 30.0.50; `vc-print-log´ does not erase buffer when called from *vc-change-log* buffer, at least for CVS logs

[Eli Zaretskii]

> Date: Sat, 10 Jun 2023 23:18:01 +0200
> Cc: manuel@ledu-giraud.fr, 63949@debbugs.gnu.org
> From: Jens Schmidt <jschmidt4gnu@vodafonemail.de>
> 
> On 2023-06-10  19:23, Eli Zaretskii wrote:
> 
> > If the backend is a VCS that records changes per-file, what you want 
> > will happen automatically, since "C-x v l" and other operations must 
> > in general refer to a file with those VCSes.  For backends that
> > record changes per-repository, why does it make sense that typing
> > "C-x v l" from a buffer that already shows a log should produce the
> > same log again?
> 
> To get it updated, for example because I perform some operation outside
> of Emacs.  One of these habits ...

If there's more than one natural meaning of a command, the usual way
we solve the dilemma is by using a prefix argument.