Re: [RFC/PATCH] ignoring a fetch that overwrites local symref

On Tue, Dec 11, 2012 at 11:46 AM, Junio C Hamano [off-list ref] wrote:

This is a companion to an ancient thread

    http://thread.gmane.org/gmane.comp.version-control.git/145311/focus=145337

in which an error was dealt with while pushing into a "mirror"
repository that has a symbolic reference refs/remotes/origin/HEAD
pointing at refs/remotes/origin/master with "git push --mirror".
The issue was that the receiving end was told to update origin/HEAD
and origin/master separately; if origin/HEAD is updated, that would
update origin/master at the same time, and then when attempting to
update origin/master, it would notice that it no longer has the
expected old value and barf.  After the series, we started ignoring
such pushes to HEAD on the receiving end.

But you can suffer from a similar issue transferring objects in the
opposite direction.  If you run "fetch --mirror" in to such a
"mirror" repository, the other side would advertise both 'master'
and 'HEAD' under refs/remotes/origin/ hierarchy, and refs/*:refs/*
wildcard would try to grab both of them.

Work it around by noticing a wildcard match that attempts to update
a local symbolic ref and ignoring it.

At what point should we just support symrefs on the protocol? :-(