bug#6513: vc-mtn broken with monotone 0.48 (can't even open files)

[Dan Nicolaescu]

Julio Merino <jmmv84@gmail.com> writes:

> The vc-mtn emacs module in emacs 23.2.1 does not work with monotone
> 0.48.  This prevents editing *any* file tracked by monotone.  Whenever
> I attempt to open a file that is tracked by monotone, emacs spits out
> the following in the minibuffer and fails to open the file:
>
> Wrong type argument: stringp, nil
>
> The problem is most likely related to some user interface changes that
> happened in monotone 0.48: some commands such as 'mtn status' have
> changed their output and thus the regular expressions bundled in
> vc-mtn do not yield the correct matches.

Yep, the regexp used by vc-mtn-workfile-branch no longer matches the
mtn status output.

> The fix is to stop using random mtn commands in vc-mtn and change the
> code to *only* use subcommands of 'mtn automate'.  'automate' is The
> interface to interact with monotone from other applications, because
> it exposes a stable interface with well-defined intput/output
> semantics.