fdo#73698 check for empty aOut

Change-Id: I0da26ef746553618bd8aee69f21ff0d1261efbf6
Reviewed-on: https://gerrit.libreoffice.org/7474
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>