Re: New names for VC local version backups

[Eli Zaretskii]

> From: Andre Spiegel <address@hidden>
> Date: 25 Oct 2000 17:32:05 +0200
> > 
> >     version x.y.z or foobar.c -> versions/x_y_z/foobar.c
> > 
> 
> Hmm, this doesn't appeal to me.  It would result in an explosion of
> subdirectories under `versions'. 

Only for as long as you keep the relevant versions.

> It would be difficult to find a version of a particular file if you
> don't happen to know the version number.

I don't see anything that "find -name" couldn't solve.

> Completely unrelated files would end up in the same
> subdirectory only because they happen to have the same version number.

This happens today: we have *all* the files in the same directory.

Anyway, that was only a suggestion.

> A special kind of version backup is one that was created automatically
> (and should be temporary), this is identified by putting another `.'
> before rev, as Stefan suggested.  Gerd seems to agree with the idea,
> how about you, Eli?

I don't have any strong feelings.  If no one else object, I'd say go
ahead and do it.

> > The simplest solution would be to run the file name through
> > convert-standard-filename (it's a no-op on Unix).  The hard thing to
> > do is to make Emacs recognize such munged file names when it sees
> > them in the directory.  [...] It is possible to decide that this
> > feature won't work on 8+3 filesystems (e.g., numbered backups don't
> > work in that case), if it turns out too expensive to support.
> 
> I think that's what we should do.

What, the first alternative or the second?  They are mutually
exclusive.

> However, I think we need to make
> sure that Emacs does not even attempt to create a version backup on
> such a file system, effectively disabling the feature.  How could that
> be checked?

Like this:

  (when (and (fboundp 'msdos-long-file-names)
             (not (msdos-long-file-names)))
        ;; don't use numbered backups
        )

> Are numbered backups disabled automatically on MS-DOS?

Yes; see find-backup-file-name on files.el.