test rows for validity

Change-Id: I501c1c18df96b5b2ad628e86cfb724a541d5c4b6
Reviewed-on: https://gerrit.libreoffice.org/13170
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>