Compress deletes nodes so the flat list becomes invalid
This reverts commit d1b3571fba.
Change-Id: I70e52ac3988493a283ca83121bd2e4a67db6f5ed
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/110901
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>