When subsets are non-contiguous, we need to include the parts between
subsets.

Change-Id: I28214dccc75e6a6af5c65397b2126049a65bf79f
Reviewed-on: https://gerrit.libreoffice.org/56571
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
(cherry picked from commit 4600b07c)
Reviewed-on: https://gerrit.libreoffice.org/56687Reviewed-by: Aron Budea <aron.budea@collabora.com>
Tested-by: Aron Budea <aron.budea@collabora.com>