Re: Git status parse error after v.2.22.0 upgrade

From: Jeff King <peff@peff.net>
Date: Jun 13, 2019, 19:00 UTC
Message-ID: <20190613190037.GA27217@sigill.intra.peff.net>
In-Reply-To: <8981e6c8-eb20-fde7-2b4c-1fbf2057caef@gmail.com>

On Thu, Jun 13, 2019 at 06:43:41PM +0100, Phillip Wood wrote:

Show 17 quoted lines

> >>  (2) make the sequencer machinery more careful to clean up after it
> >>      is done or it is aborted  (for example, "git reset --hard"
> >>      could remove these state files preemptively even when a rebase
> >>      is not in progress, I would think).
> >>
> >> I think we already had some patches toward the latter recently.
> > 
> > Maybe I am not understanding it correctly, but do you mean in (2) that
> > "git reset --hard" would always clear sequencer state?
> 
> I think the commit Junio is referring to is
> b07d9bfd17 ("commit/reset: try to clean up sequencer state", 2019-04-16)
> which will only remove the sequencer directory if it stops after the
> pick was the last one in the series. The idea is that if cherry-pick
> stops for a conflict resolution on the last pick user commits the result
> directly or run reset without running `cherry-pick --continue`
> afterwards the sequencer state gets cleaned up properly.

OK, that makes a lot more sense to me. It did make me wonder if doing an "e"dit on the final commit of a rebase followed by "reset HEAD^" would clear the sequencer state. But looking at that commit, this kicks in only for the cherry-pick and revert cases.

Thanks for explaining.

> If we do want to do something then maybe teaching gc not to collect
> commits listed in .git/sequencer/todo and
> .git/rebase-merge/git-rebase-todo would be useful.

IMHO that opens up a can of worms, because the reachability rules get more complicated (so for example people trying to prune away unwanted history get confused about what is still mentioning the objects). That's a reasonable rare case. OTOH, so is mentioning commits in an ongoing rebase that are not still reachable from the branch you are rebasing, nor the HEAD reflog.

-Peff