since...

commit d46c3214
Date:   Thu Jun 7 12:37:33 2018 +0200

    assert in BitmapInfoAccess if bitmap is empty or we can't read from it

Change-Id: I138a53e9ce0763d4e62cfbba594abb323e807378
Reviewed-on: https://gerrit.libreoffice.org/55704Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>