switch to using get() rather than get_or_create(). Also add a test case with a…

switch to using get() rather than get_or_create(). Also add a test case with a different casing on the courseId

cms/djangoapps/contentstore/tests/test_contentstore.py

@@ -1297,8 +1297,19 @@ class ContentStoreTest(ModuleStoreTestCase):
     def test_forum_unseeding(self):
         """Test new course creation and verify forum seeding """
         test_course_data = self.assert_created_course(number_suffix=uuid4().hex)
-        unseed_permissions_roles(self._get_course_id(test_course_data))
-        self.assertFalse(are_permissions_roles_seeded(self._get_course_id(test_course_data)))
+        course_id = self._get_course_id(test_course_data)
+        unseed_permissions_roles(course_id)
+        self.assertFalse(are_permissions_roles_seeded(course_id))
+
+    def test_forum_unseeding_with_different_casing(self):
+        """Test new course creation and verify forum seeding """
+        test_course_data = self.assert_created_course(number_suffix=uuid4().hex)
+        # make sure we don't delete a forum permissions set with different casing
+        # than the passed in course_id. This is because Mongo and MySQL are using different collations
+        course_id = self._get_course_id(test_course_data)
+        unseed_permissions_roles(course_id.upper())
+        # permissions should still be there!
+        self.assertTrue(are_permissions_roles_seeded(course_id))
 
     def _get_course_id(self, test_course_data):
         """Returns the course ID (org/number/run)."""

common/djangoapps/django_comment_common/utils.py

@@ -36,28 +36,40 @@ def unseed_permissions_roles(course_id):
     """
     A utility method to clean up all forum related permissions and roles
     """
-    administrator_role = Role.objects.get_or_create(name="Administrator", course_id=course_id)[0]
-    moderator_role = Role.objects.get_or_create(name="Moderator", course_id=course_id)[0]
-    community_ta_role = Role.objects.get_or_create(name="Community TA", course_id=course_id)[0]
-    student_role = Role.objects.get_or_create(name="Student", course_id=course_id)[0]
-
-    # safety switches in case the casing does not match
+    try:
+        administrator_role = Role.objects.get(name="Administrator", course_id=course_id)
+        if administrator_role.course_id == course_id:
+            administrator_role.delete()
+    except Role.DoesNotExist:
+        pass
 
-    if administrator_role.course_id == course_id:
-        administrator_role.delete()
+    try:
+        moderator_role = Role.objects.get(name="Moderator", course_id=course_id)
+        if moderator_role.course_id == course_id:
+            moderator_role.delete()
+    except Role.DoesNotExist:
+        pass
 
-    if moderator_role.course_id == course_id:
-        moderator_role.delete()
+    try:
+        community_ta_role = Role.objects.get(name="Community TA", course_id=course_id)
+        if community_ta_role.course_id == course_id:
+            community_ta_role.delete()
+    except Role.DoesNotExist:
+        pass
 
-    if community_ta_role.course_id == course_id:
-        community_ta_role.delete()
-    
-    if student_role.course_id == course_id:
-        student_role.delete()
+    try:
+        student_role = Role.objects.get(name="Student", course_id=course_id)
+        if student_role.course_id == course_id:
+            student_role.delete()
+    except Role.DoesNotExist:
+        pass
 
 
 def are_permissions_roles_seeded(course_id):
-
+    """
+    Returns whether the forums permissions for a course have been provisioned in
+    the database
+    """
     try:
         administrator_role = Role.objects.get(name="Administrator", course_id=course_id)
         moderator_role = Role.objects.get(name="Moderator", course_id=course_id)