Re: New names for VC local version backups

[Andre Spiegel]

Sorry, I was offline yesterday and couldn't reply.

Eli Zaretskii <address@hidden> writes:

> > The change is installed.

> Sigh.  Is it possible to try to discuss important changes here
> *before* they get installed?  I thought that's what we started
> this forum for, no?

It is always a matter of personal judgement; sorry if I erred to the
wrong side this time.  I had discussed this with Stefan; also this is
a change in a very recently added feature that people cannot be
relying very intimately on as of yet :-).

First, let me clarify that this feature has nothing whatsoever to do
with ordinary Emacs backups (file~) or numbered backups (file~num~).
It is a new feature that creates temporary, local backups of
repository versions, and so I called these "version backups".  The
question is what naming convention to use for them.  When I introduced
this feature a week or so ago, I chose to use file.~x.y~, the same
convention that is used by C-x v ~ (vc-version-other-window).  (Note
that I am writing ~x.y~ instead of ~rev~ to make it clear that this is
_not_ a numbered backup, sometimes called a "backup version" in the
Emacs manual.  I am talking about files where there is not a single
number between the tildes, but a revision with at least one dot in
it.)

The problem is that we need to delete the automatic version backups
automatically as well, especially when a number of them piles up due
to mixed VC/non-VC editing.  But we must not delete any files that the
user created himself via C-x v ~.  So Stefan and I figured we need to
use different names for the automatic version backups.

I don't like the idea of putting them into CVS/Base, because this
feature is backend-independent in VC, even if it's only used for
remote CVS right now.

It is true that file.~x.y~ will not work on 8.3 file systems, but
neither has C-x v ~ ever been working on such file systems, then.
Maybe because the new feature is more important (and more implicitly
employed by VC), we need to find a solution for this now.

Apart from that, Stefan had the neat idea of making the files almost
look like those from C-x v ~ by inserting another `.' before the
revision (file.~.x.y~).  This would probably be ok with file type
recognition and we could still spot the "automatic" files reliably.

Thoughts?

(BTW. If anyone is in desperate need of getting rid of that file.#x.y#
thing, it is all defined in a single place,
vc-version-backup-file-name in vc-hooks.el.  Until we have agreed on a
solution, you can patch this to your liking :-)