Got crashes here in 5.0, seem to be gone in master, but better be safe
than sorry

Change-Id: I434800f0e4a465233024b6a1ae1f48b010319f5c
Reviewed-on: https://gerrit.libreoffice.org/27594Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>