Junio C Hamano <gitster@xxxxxxxxx> writes:
> I have been disturbed by this for a long time, but not strongly
> enough to do anything to it.
>
> This sequence works
>
> $ git checkout -b newbranch
> $ git commit --allow-empty -m one
> $ git show -s newbranch@{1}
>
> and shows the state that was immediately after the newbranch was
> created.
>
> But then if you do
>
> $ git reflog expire --expire=now refs/heads/newbranch
> $ git commit --allow=empty -m two
> $ git show -s newbranch@{1}
>
> you'd be scolded with
>
> fatal: log for 'newbranch' only has 1 entries
>
> While it is true that it has only 1 entry, we have enough
> information in that single entry that records the transition between
> the state in which the tip of the branch was pointing at commit
> 'one' to the new commit 'two' built on it, so we should be able to
> answer "what object newbranch was pointing at?". But we refuse to
> do so.
>
> And it is unintuitive. It is understandable to the users that all
> the ref history before "reflog expire" is lost---it was what the end
> user asked Git to do. But after creating one commit on the state
> (or do anything else that moves the ref) and finding it regrettable,
> "git reset --hard @{1}" should be a viable way to recover from the
> mistake made _after_ the reflog entries were expired.
>
> Opinions?
Makes sense. The first solution that comes to mind is immediately record
current state after "reflog expire", so that there will be 2 entries for
the case in question.
-- Sergey
