Re: Simple git push --tags deleted all branches

[Mateusz Loskot <mateusz@loskot.net>]

On Thu, 29 Nov 2018 at 16:39, Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
> On Thu, Nov 29 2018, Mateusz Loskot wrote:
> > On Thu, 29 Nov 2018 at 16:03, Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
> >> On Wed, Nov 28 2018, Mateusz Loskot wrote:
> >> >
> >> > (using git version 2.19.2.windows.1)
> >> >
> >> > I've just encountered one of those WTH moments.
> >> >
> >> > I have a bare repository
> >> >
> >> > core.git (BARE:master) $ git branch
> >> >   1.0
> >> >   2.0
> >> > * master
> >> >
> >> > core.git (BARE:master) $ git tag
> >> > 1.0.1651
> >> > 1.0.766
> >> > 2.0.1103
> >> > 2.0.1200
> >> >
> >> > I published the repo using: git push --all --follow-tags
> >> >
> >> > This succeeded, but there seem to be no tags pushed, just branches.
> >> > So, I followed with
> >> >
> >> > core.git (BARE:master) $ git push --tags
> >> > To XXX
> >> >  - [deleted]               1.0
> >> >  - [deleted]               2.0
> >> >  ! [remote rejected]       master (refusing to delete the current
> >> > branch: refs/heads/master)
> >> > error: failed to push some refs to 'XXX'
> >> >
> >> > And, I've found out that all branches and tags have been
> >> > wiped in both, local repo and remote :)
> >> >
> >> > I restored the repo and tried out
> >> >
> >> > git push origin 1.0
> >> > git push origin --tags
> >> >
> >> > and this time both succeeded, without wiping out any refs.
> >> >
> >> > Could anyone help me to understand why remote-less
> >> >
> >> > git push --tags
> >> >
> >> > is/was so dangerous and unforgiving?!
> >>
> >> Since nobody's replied yet, I can't see what's going on here from the
> >> info you've provided. My guess is that you have something "mirror" set
> >> on the remote.
> >
> > Thank you for responding.
> >
> > The git push --tags hugely surprised me, and here is genuine screenshot
> > https://twitter.com/mloskot/status/1068072285846859776
> >
> >> It seems you can't share the repo or its URL, but could you share the
> >> scrubbed output of 'git config -l --show-origin' when run inside this
> >> repository?
> >
> > Here is complete output. I have not stripped the basics like aliases,
> > just in case.
>
> Right, it's because you used --mirror, the important bit:
>
> > file:config     remote.origin.url=https://xxx.com/core-external-metadata.git
> > file:config     remote.origin.fetch=+refs/*:refs/*
> > file:config     remote.origin.mirror=true
> > file:config
>
> I.e. you have cloned with the --mirror flag, this is what it's supposed
> to do: https://git-scm.com/docs/git-clone#git-clone---mirror
> https://git-scm.com/docs/git-fetch#git-fetch---prune
>
> I.e. you push and git tries to mirror the refs you have locally to the
> remote, including pruning stuff in the remote.

Thank you very much for diagnosing my issue.
I was not aware about how --mirror affects the workflow.
It all makes perfect sense now.

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net