bug#4179: vc-merge with svn: syntax error in revision arg.

[Stefan Monnier]

> Stefan, how would you go about making these functions backend specific:

> (defun vc-trunk-p (rev)
> (defun vc-branch-p (rev)
> (defun vc-branch-part (rev)
> (defun vc-minor-part (rev)

Not sure: for some backends (svn, bzr, darcs at least), they simply
don't make any sense.

> It seems to me that only `vc-branch-p' needs to be backend specific, the
> rest are only used by RCS and CVS.

That sounds right.

> vc-default-{previous,next}-revision use them, but they can go into
> vc-rcs (or vc-cvs) and make one use the other (there's a precedent,
> vc-cvs-comment-history uses an RCS backend function...).

> Do you see an elegant way of dealing with this?

Move them to vc-rcs.


        Stefan