Re: [PATCH v2 22/29] commit_packed_refs(): use a staging file separate from the lockfile

> >>  out:
> >> +	rollback_lock_file(&refs->lock);
> > 
> > We always rollback the lockfile regardless, because committing it would
> > overwrite our new content with an empty file. There's no real safety
> > against somebody calling commit_lock_file() on it, but it also seems
> > like an uncommon error to make.
> 
> If this seems too dangerous, we could add a `LOCK_NO_COMMIT` flag for
> `hold_lock_file_for_update()` and `hold_lock_file_for_update_timeout()`,
> which would die() if somebody tries to commit the associated lockfile. I
> think we can live without it. I hope that any such bugs would be caught
> immediately by CI. But I admit that the prospect of renaming an empty
> file on top of a `packed-refs` file is quite sobering, so if anybody is
> worried about this, let me know and I'll implement it.