lots of little fixes to make the logic less pessimistic

Change-Id: If368822984250b11b98c56f5890177a1402e8660
Reviewed-on: https://gerrit.libreoffice.org/44168Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>