bug#38044: 27.0.50; There should be an easier way to look at a specific vc commit

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: larsi@gnus.org,  juri@linkov.net,  38044@debbugs.gnu.org,  
> dgutov@yandex.ru
> Date: Sun, 01 Dec 2019 14:13:06 +0100
> 
> >> Since one of the desiderata of this command, perhaps even the main
> >> one, is that it should act on the revision ID at point, how about
> >> making just `C-x v L' do that if it recognizes the word at point as
> >> a revision ID?
> >
> > We could do that, yes.
> 
> I haven't found a useful way to do this.

??? The current master AFAICS already does, but only if you invoke
"C-x v L" with an argument of 1.  Or am I missing something?

(It does so quite naively, though: it just picks up the word at point,
so I've seen it prompting with default being something like
"Copyright".  Perhaps we should use number-at-point instead?)

> There is, however, another option that is convenient (at least to me)
> and easy to implement.  Most of the time of I want to look up the log
> entry and/or diff of the revision ID at point the current buffer is not
> a version-controlled buffer (typically it's a Gnus buffer), so the
> default directory is wrong and I have to manually change to the
> version-controlled root directory.  For me this is almost always the
> Emacs master branch, so it would be convenient if typing `C-1 C-x v L'
> offered this directory as a default, as a user option.  The patch below
> does this.

The command prompts for a directory, so you can type whatever you
want.  Having a fixed default doesn't sound very wise to me (do you
never have to work with several repositories at the same time?), but
I'll defer to Dmitry's opinion here.

Thanks.