If the user assigning a permission is not "Administrator' or member of 'powerusers' or 'administrators', the entry in directory 'aceinfo' is not created

therefore the comment from the UI is not inserted in the notification mail.

How to reproduce:

• log in as Administrator
• create user1 and user2, members of members group only
• create a workspace workspace1 and assign the Everything permission to user1
• log in as user1
• navigate to workspace and assign Edit permission to user2 and specify a comment

Entry for this permission is not created in directory aceinfo and the notification mail does not contain the provided comment.
What is the consequence of not having the entry created in the directory?

Call to session.createEntry() in org.nuxeo.ecm.permissions.PermissionListener#handleUpdateACP returns null but no action is taken.