Data exporter does not recover from failure

Setup

1. Login as admin
2. Open Site administration -> Users -> Define roles
3. Create a new role:
   1. Upload the attached dpo.xml preset
   2. Create the role a the system context
4. Open Site administration -> Users -> Assign system roles
5. Assign your admin user to the role

User requests

1. Place the attached runadhoc.php script in your Moodle directory
2. On the Command line, run:

   php runadhoc.php

3. Open Site administration -> Users -> Data requests
4. Create a new export request for any user
   1. It should be shown as "Pending"
5. Run runadhoc.php again
   1. Confirm that the output included detail of each component which was fetched
6. In the UI, refresh the page
7. Choose Actions => Approve request
8. Run runadhoc.php again
9. Cancel it just after it starts
10. Run runadhoc.php again
    1. Confirm that it finishes