Re: [PATCH 0/2] push: fix --force-if-includes consulting wrong ref

From: Ben Knoble <ben.knoble@gmail.com>
Date: Sep 5, 2026, 18:59 UTC
Message-ID: <D798198C-5F97-4701-9050-7868B6482214@gmail.com>
In-Reply-To: <20260904210122.431757-1-tyler@tylercipriani.com>

Show 11 quoted lines

> Le 4 sept. 2026 à 17:01, Tyler Cipriani <tyler@tylercipriani.com> a écrit :
> 
> --force-if-includes has been checking the reflog of the local branch named
> after the destination branch regardless of what's being pushed. This can cause
> false rejections or unintended data loss.
> 
> False rejection has been reported twice that I could find:
> 
> - 2023-07-26 - Stefan Haller reported local branch with a different name
>              false rejection[0]
> - 2025-05-08 - D. Ben Knoble reported detached HEAD false rejection[1]

Aha. I’d nearly forgotten that mail, and have since adjusted to some intuition of when to force-if-includes.

I’d be grateful to not need such potentially-buggy intuition :)

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> The same root cause can result in data loss: when a same-name local branch
> contains the remote tip but you --force-if-includes push an unrelated branch,
> clobbering the remote repo. PoCs are in t/t5533-push-cas.sh -- new test cases
> fail against maint, but pass with patches applied.
> 
> Existing tests covered refspecs with different names for --force-with-lease,
> but missed --force-if-includes. New patches cover:
> 
> - allow forced-update using refspec with different-named local branch
> - allow same as above, but with HEAD
> - reject force-update using refspec with different-named local branch lacking
> branch tip
> - reject same as above using HEAD
> - reject detached HEAD
> 
> Open question: the detached HEAD case. I opted to reject, since it seems like
> it might be surprising to allow in the case where you were just on a branch
> without the the tip of a remote ref, removed the last commit with git checkout
> HEAD^ and pushed with --force-if-includes and it allowed a destructive push.
> I made a separate patch showing different advice for that case (since a
> git pull won't help).
> 
> Based on maint since this is a bugfix. Happy to split patches any way
> that's helpful.
> 
> [0]: <https://lore.kernel.org/git/f51c73ed-eb03-83ca-fb31-d3e2645c9a63@haller-berlin.de>
> [1]: <https://lore.kernel.org/git/CALnO6CCk0SgwObQRnpd5Pt_DvCKF8dBmyVHivU6Nr_O-GusGLA@mail.gmail.com>
> 
> Tyler Cipriani (2):
> push: check pushed ref for --force-if-includes
> push: fix --force-if-includes detached HEAD advice

Thanks for the advice changes! One small nit on the first patch you can ignore if you choose.

At first I hoped we might be able to stop rejecting detached HEAD pushes, but some further thought begs the question: what reflog would we use? HEAD’s is too broad :)

So this may be all we can do for now.

At least I can replace my intuition with reading the error message again.