If a non-interactive rebase of a ref fails at commit X and is aborted by
the user, the ref will be updated twice. First to point at X (with the
reflog message "rebase finished: $head_name onto $onto"), and then back
to $orig_head. It should not be updated at all.
Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>