bug#2604: 23.0.91; key bindings in vc-annotate incompatible w/ Emacs 22

[Dan Nicolaescu <dann@ics.uci.edu>]

Reiner Steib <reinersteib+gmane@imap.cc> writes:

  > On Mon, Mar 09 2009, Dan Nicolaescu wrote:
  > 
  > > Reiner Steib <reinersteib+gmane@imap.cc> writes:
  > >   > - D
  > >   > 
  > >   > Instead of showing diff of revision at line (as in Emacs 22), I get:
  > >   > 
  > >   > ,----[ *Messages* ]
  > >   > | vc-annotate-show-changeset-diff-revision-at-line:
  > >   > | The CVS backend does not support changeset diffs
  > >   > `----
  > >   > 
  > >   > Is this change intended?  
  > >
  > > It is. 
  > >
  > >   > I could understand that `D' should now work
  > >   > on change sets, but please at least mention it in NEWS and tell the
  > >   > user to try `d' instead or better just display the warning and than
  > >   > call `vc-annotate-show-diff-revision-at-line' if no change set
  > >   > operation is available.
  > >
  > > I am not sure that is better.  But if you can suggest a better wording
  > > for the error message, go for it.
  > 
  > How about this?  (Same in `log-view-diff-changeset', probably.)
  > 
  > --- vc-annotate.el	09 Jan 2009 09:52:59 +0100	1.7
  > +++ vc-annotate.el	09 Mar 2009 20:35:28 +0100	
  > @@ -506,7 +506,10 @@
  >    "Visit the diff of the revision at line from its previous revision for all files in the changeset."
  >    (interactive)
  >    (when (eq 'file (vc-call-backend vc-annotate-backend 'revision-granularity))
  > -    (error "The %s backend does not support changeset diffs" vc-annotate-backend))
  > +    (error
  > +     (substitute-command-keys "The %s backend does not support changeset diffs.  \
  > +Use \\[vc-annotate-show-diff-revision-at-line] to diff this file.")
  > +     vc-annotate-backend))
  >    (vc-annotate-show-diff-revision-at-line-internal nil))
  >  
  >  (defun vc-annotate-warp-revision (revspec)

I am not too convinced that this is better, but if you think it's
better, then feel free to go ahead and change it.

I added a note in NEWS about the key bindings.