bug#2157: 23.0.90; bzr support: vc-diff doesn't work with prefix argument on unchanged files

[Torsten Bronger <bronger@physik.rwth-aachen.de>]

Hallöchen!

Dan Nicolaescu writes:

> Torsten Bronger <bronger@physik.rwth-aachen.de> writes:
>
>> Dan Nicolaescu writes:
>> 
>>> Torsten Bronger <bronger@physik.rwth-aachen.de> writes:
>>>
>>>> If I visit an unchanged file under bzr revision control,
>>>> i.e. the modeline says "Bzr-" (NOT "Bzr:"), I can't use C-u C-x
>>>> v =, i.e. vc-diff but with explicit revision parameters.  The
>>>> error message is:
>>>> 
>>>> vc-bzr-previous-revision: Wrong type argument: stringp, nil
>
> [...]
>
> This shows that (vc-working-revision
> "/home/bronger/src/chantal/current/chantal/samples/remote_client/la2chantal.py")
>
> returns nil.  So probably for some reason
> (vc-bzr-working-revision
> "/home/bronger/src/chantal/current/chantal/samples/remote_client/la2chantal.py")
>
> returns nil.  Can you try to debug why that happens?

I don't know Lisp, but I hooked into the bzr executable and can
safely say that it isn't called for this action.  So apparently,
vc-bzr-working-revision tries to get the revno from the metadata in
the .bzr/ directory.  The branch format is "Bazaar Branch Format 7
(needs bzr 1.6)".

By the way, bug#618 is probably related to this.  Formerly, I had
missing revno in the modeline only in lightweight checkout, now I
have the same problem with all branches.  Maybe the branch metadata
format has diverged too much for vc-bzr?

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus
                   Jabber ID: torsten.bronger@jabber.rwth-aachen.de