Nobody calls the function like this currently, but we neither prohibit
or cope with this behavior. I decided to make the function cope with it.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>