[repo] fix bug introduced by 4757:ec9c20c6b9f7, testing for select.selection is not enough to avoid the substep query, we should check there is no interesting restriction (test added)
# cube's specific schema
"""
:organization: Logilab
:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""