Subject: Re: [PATCH] Added --mirror-all to git-fetch.

From: Shawn Pearce <[email-masked]>
Date: Wed, 20 Sep 2006 12:49:12 -0400

Junio C Hamano <[email-masked]> wrote:
> I realize I am going around in circles, but Pasky's "remotes/"
> argument made me realize that this mirroring is not much more
> than "fetch --force --all".  I initially had an impression that
> this was for only strict mirroring where you do not even want
> your own "origin", but if you arrange the .git/remotes/origin
> file the right way, "fetch --force --all" (if you remembered to
> put '+' in front of the refspecs, even without --force) would
> what --mirror-all would do wouldn't it?

I started this change with '--all' and realized that ideally you
want '--all' to copy all available refs/heads/* from the remote to
refs/remotes/<name>/* here.  You want to create any new branches
which the remote has introduced since your last fetch.

You probably don't want to force a non-fast forward unless there's a
'+' in the corresponding Pull line of remotes/<name> or if --force is
used.  However you probably also want to delete any removed branches.

Which I think is quite different from a mirror.  A mirror wants to
replace the entire ref namespace with what's on the remote as it
has no need for a local namespace of its own.

Originally I gave Pasky a one-liner on #git:

  git fetch --force origin $(git ls-remote origin \
      | awk '{if(!/\^{}$/){print $2":"$2}}')

but he expressed interest in it being a native feature of the
core-Git fetch Porcelain.  To be honest I disagreed with him but
submitted the patch anyway.

I think --all copying into .git/refs/remotes/<name>/* makes perfect
sense.

And I think this mirror thing may make more sense as a small wrapper
around git-fetch.  A wrapper that checks for:

	- its running in a bare repository;
	- it has a single remote named origin;
	- HEAD isn't a symlink or a symref (its a normal ref in its
	  own right);
	- git-mirror.permitted is true in the config file.
 
-- 
Shawn.