test rows for validity

Change-Id: I501c1c18df96b5b2ad628e86cfb724a541d5c4b6
(cherry picked from commit 1e514c8da8e37fc3cb26af6ddaf95a3ed8093a41)
Reviewed-on: https://gerrit.libreoffice.org/13171
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>