Impossible to use method search_s in BaseLdap if attribute 'page_size' is not 0.

/opt/stack/keystone/keystone/common/ldap/core.py #493-520

def search_s(self, base, scope,
                 filterstr='(objectClass=*)', attrlist=None, attrsonly=0):
        # NOTE(morganfainberg): Remove "None" singletons from this list, which
        # allows us to set mapped attributes to "None" as defaults in config.
        # Without this filtering, the ldap query would raise a TypeError since
        # attrlist is expected to be an iterable of strings.
        if attrlist is not None:
            attrlist = [attr for attr in attrlist if attr is not None]
        LOG.debug('LDAP search: base=%s scope=%s filterstr=%s '
                  'attrs=%s attrsonly=%s',
                  base, scope, filterstr, attrlist, attrsonly)
        if self.page_size:
            ldap_result = self._paged_search_s(base, scope,
                                               filterstr, attrlist)
        else:
            base_utf8 = utf8_encode(base)
            filterstr_utf8 = utf8_encode(filterstr)
            if attrlist is None:
                attrlist_utf8 = None
            else:
                attrlist_utf8 = map(utf8_encode, attrlist)
            ldap_result = self.conn.search_s(base_utf8, scope,
                                             filterstr_utf8,
                                             attrlist_utf8, attrsonly)

            py_result = convert_ldap_result(ldap_result)

        return py_result

Variable 'py_result' can be not initialized if self.page_size > 0 because it's initialized only in the 'else' block.