commit 600c236e2111a770e478040a8a78bb62ef27ac39
Author: Brant Knudson <[email protected]>
Date:   Fri Dec 19 14:11:00 2014 -0600

    Fix to not use empty IN clause
    
    When an empty IN clause is used with sqlalchemy, a warning is
    printed:
    
     SAWarning: The IN-predicate on "assignment.actor_id" was invoked
     with an empty sequence. ...
    
    With this fix, these warnings should no longer be printed.
    
    The tests are changed to convert these warnings into errors.
    
    Change-Id: I58c7e5f11fdac9bbc1e9a970ce690ea113e2bd95
    Closes-Bug: #1404354

--- keystone-2014.2.2/keystone/assignment/backends/sql.py.orig	2014-12-04 21:03:56.000000000 -0800
+++ keystone-2014.2.2/keystone/assignment/backends/sql.py	2015-01-25 20:44:40.377007906 -0800
@@ -356,6 +356,10 @@ class Assignment(keystone_assignment.Dri

     def _get_group_project_roles(self, session, groups, project_id,
                                  project_domain_id):
+        if not groups:
+            # If there's no groups then there will be no project roles.
+            return []
+
         sql_constraints = sqlalchemy.and_(
             RoleAssignment.type == AssignmentType.GROUP_PROJECT,
             RoleAssignment.target_id == project_id)