In web as admin, login in a site with MDL-58712 applied and set a small userquota (something like 5MB). Site administration > Security > Site policies > User quota. In the app, login in that site using a student without any private file (you can delete them using the web interface). Go to private files and check that you don't see any message saying how much quota you have used. Upload any file with less than 5MB. Check that, after uploading it, you see a message saying you've used XMB of 5MB. Now try to upload a new file that surpasses the userquota combined with the previous file. Check that you see a warning telling you that you can't upload that file. Now login in the app using the admin user. Please notice you might have to manually create a token using the web interface: Site administration > Plugins > Web services > Manage tokens, click "Add" and create a token for the admin. Go to private files and check that you don't see the size warning even if you upload files.