Fix list_limit doesn't work correctly for domain

This patch changed the sql query for domain list
to ensure the return count is correct if list_limit
is set for resource.

Closes-bug: #1760521

Change-Id: I690a9815fe2c35e6191ab3ac789e34736e0d637c

keystone/resource/backends/sql.py

@@ -81,9 +81,9 @@ class Resource(base.ResourceDriverBase):
                 f['value'] = base.NULL_DOMAIN_ID
         with sql.session_for_read() as session:
             query = session.query(Project)
+            query = query.filter(Project.id != base.NULL_DOMAIN_ID)
             project_refs = sql.filter_limit_query(Project, query, hints)
-            return [project_ref.to_dict() for project_ref in project_refs
-                    if not self._is_hidden_ref(project_ref)]
+            return [project_ref.to_dict() for project_ref in project_refs]
 
     def list_projects_from_ids(self, ids):
         if not ids:

keystone/tests/unit/identity/test_backends.py

@@ -24,7 +24,6 @@ from keystone import exception
 from keystone.tests import unit
 from keystone.tests.unit import default_fixtures
 from keystone.tests.unit import filtering
-from keystone.tests.unit import utils as test_utils
 
 
 CONF = keystone.conf.CONF
@@ -1107,8 +1106,6 @@ class IdentityTests(object):
                         matchers.StartsWith('domaingroup1'))
 
     @unit.skip_if_no_multiple_domains_support
-    @test_utils.wip('The root domain throws off the limit count by one',
-                    bug='#1760521')
     def test_list_limit_for_domains(self):
         def create_domains(count):
             for _ in range(count):

keystone/tests/unit/test_v3_resource.py

@@ -151,8 +151,6 @@ class ResourceTestCase(test_v3.RestfulTestCase,
                                            resource_url=resource_url)
         self.head(resource_url, expected_status=http_client.OK)
 
-    @test_utils.wip('The root domain throws off the limit count by one',
-                    bug='#1760521')
     def test_list_limit_for_domains(self):
         PROVIDERS.resource_api.create_domain(
             default_fixtures.ROOT_DOMAIN['id'], default_fixtures.ROOT_DOMAIN

releasenotes/notes/bug-1760521-fec5c88af214401f.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    [`bug 1760521 <https://bugs.launchpad.net/keystone/+bug/1760521>`_]
+    Fixed the bug that the result count for ``domain list`` may lack one if
+    the config option ``list_limit`` in [resource] is set.