ediff-revision doesn't recognize Mercurial-managed source

ediff-revision doesn't recognize Mercurial-managed source

[Skip Montanaro]

The core Python development team just switched from Subversion to Mercurial,
so I'm trying to get my tool chain back into working order.  I have been
using vc and ediff-revision from within XEmacs, but its Mercurial support
seemed lacking, so I thought I would try making the switch to GNU Emacs.

While it appears that the version of GNU Emacs (23.1) I downloaded from

    http://emacsformacosx.com/

has a vc-hg.el.gz file, executing vc-next-action (C-x v v) on a
Mercurial-managed file seems to have tried to register the file with bzr!
Trying to execute ediff-revision results in a "blah is not under version
control" message.

Do I need to sprinkle some sort of magic ~/.emacs magic pixie dust to get vc
to work?

Thanks,

Skip Montanaro

Re: ediff-revision doesn't recognize Mercurial-managed source

[Thierry Volpiatto]

Skip Montanaro <skip@pobox.com> writes:

> The core Python development team just switched from Subversion to Mercurial,
> so I'm trying to get my tool chain back into working order.  I have been
> using vc and ediff-revision from within XEmacs, but its Mercurial support
> seemed lacking, so I thought I would try making the switch to GNU Emacs.
>
> While it appears that the version of GNU Emacs (23.1) I downloaded from
>
>     http://emacsformacosx.com/
>
> has a vc-hg.el.gz file, executing vc-next-action (C-x v v) on a
> Mercurial-managed file seems to have tried to register the file with bzr!
> Trying to execute ediff-revision results in a "blah is not under version
> control" message.
>
> Do I need to sprinkle some sort of magic ~/.emacs magic pixie dust to get vc
> to work?
You should try DVC http://www.xsteve.at/prg/emacs_dvc/dvc.html
which have a very good support for hg.
It works fine since emacs22.

-- 
A+ Thierry
Get my Gnupg key:
gpg --keyserver pgp.mit.edu --recv-keys 59F29997 

Re: ediff-revision doesn't recognize Mercurial-managed source

[rusi]

On Mar 7, 8:23 am, Skip Montanaro <s...@pobox.com> wrote:
> The core Python development team just switched from Subversion to Mercurial,
> so I'm trying to get my tool chain back into working order.  I have been
> using vc and ediff-revision from within XEmacs, but its Mercurial support
> seemed lacking, so I thought I would try making the switch to GNU Emacs.
>
> While it appears that the version of GNU Emacs (23.1) I downloaded from
>
>    http://emacsformacosx.com/
>
> has a vc-hg.el.gz file, executing vc-next-action (C-x v v) on a
> Mercurial-managed file seems to have tried to register the file with bzr!
> Trying to execute ediff-revision results in a "blah is not under version
> control" message.
>
> Do I need to sprinkle some sort of magic ~/.emacs magic pixie dust to get vc
> to work?
>
> Thanks,
>
> Skip Montanaro

What happens if you set vc-handled-backends to the singleton list
(hg) ?

Re: ediff-revision doesn't recognize Mercurial-managed source

[Glenn Morris]

Skip Montanaro wrote:

> While it appears that the version of GNU Emacs (23.1) I downloaded from
>
>     http://emacsformacosx.com/
>
> has a vc-hg.el.gz file, executing vc-next-action (C-x v v) on a
> Mercurial-managed file seems to have tried to register the file with bzr!
> Trying to execute ediff-revision results in a "blah is not under version
> control" message.
>
> Do I need to sprinkle some sort of magic ~/.emacs magic pixie dust to get vc
> to work?

It should Just Work (though I'm not familiar with emacsformacosx.com).
On GNU/Linux, I tried:

hg clone http://www.selenic.com/repo/hello my-hello

emacs-23.1 -Q my-hello/hello.c

Making changes to the file and trying vc-next-action worked fine for me.
ediff-revision also seemed to work (normally I use C-x v =).

Re: ediff-revision doesn't recognize Mercurial-managed source

[Skip Montanaro]

> > Do I need to sprinkle some sort of magic ~/.emacs magic pixie dust to get vc
> > to work?
> 
> It should Just Work (though I'm not familiar with emacsformacosx.com).

Thanks.  I'll keep messing around with it.

Skip

Re: ediff-revision doesn't recognize Mercurial-managed source

[Skip Montanaro]

> > > Do I need to sprinkle some sort of magic ~/.emacs magic pixie dust to
> > > get vc to work?
> >
> > It should Just Work (though I'm not familiar with emacsformacosx.com).
>
> Thanks.  I'll keep messing around with it.

Okay, I figured out what's wrong.  The code to determine which vc backend is
in control often just travels up the directory tree looking for a key file
or directory.  For bzr it looks for a file named ".bzr", for hg, ".hg", etc.
The search is depth- (or rather height-) first.  My directory tree is broken
(obviously my fault), but managed to work for Subversion and CVS, the two
predominant version control systems in my coding past.  They happen to be
searched for earlier in the list of candidate backends.

Mercurial, alas, appears after Bazaar in the list of candidate backends.  Up
my directory tree (higher than my Mercurial repositories) lies a .bzr
directory dating from some long forgotten experiment with it in 2008.  The
search finds that and thinks that my Mercurial repository is actually part
of a Bazaar repo.

So, problem solved.  I need to do some house cleaning and probably a bit of
directory restructuring, but I should be able to get things squared away
without too much trouble.

For the vc maintainers: breadth-first search up the directory tree might be
something to consider.

Skip Montanaro

Re: ediff-revision doesn't recognize Mercurial-managed source

[Skip Montanaro]

> What happens if you set vc-handled-backends to the singleton list
> (hg) ?

Sorry, didn't see this before.  Given the fact that it found .bzr before .hg
I'm sure your suggestion would have worked, given my borked directory
structure.

S