We have an TII assignment which has submissions. One of those submissions is for a non-moodle user (not sure how a non-moodle user would even manage to submit anything!).

Viewing the assignment works fine until you view the list of submissions (/mod/turnitintool/view.php?id=2930&do=allsubmissions). At this point, the turnitintool_choice_user cookie is set.
This cookie appears to contain the userid for each of the users with submissions.
Because there is a non-moodle user present, the cookie include a userid of nm-xxxxxxx making the total cookie something akin to:

123_456_nm-123_789

When a user views subsequent pages within mod/turnitintool - for example the Intro page (/mod/turnitintool/view.php?id=2930&do=intro), they are shown an 'Error reading from database'. The only way to rid themselves of this error is to clear the cookie from their browser.

To replicate:

• Create a new Turnitin assignment
  • Enable Anonymous marking
• Either:
  • Upload an assignment for an enrolled user and then Unenrol that user; or
  • Upload an assignment for an unenrolled user using the web interface
• Update the assignment part
  • Make the due date and the post date to something now passed (or wait until your post date has naturally past... could take a while)

• View the Submission Inbox
• Hit the 'Refresh Submissions' button for good measure
• Open your browsers inspector and look at the cookie
  • The cookie now include a user with nm-XXXX
• View the Summary Page
  • BANG:

    Debug info: ERROR: invalid input syntax for integer: "nm-3703529"

    SELECT COUNT('x') FROM mdl_turnitintool_submissions WHERE submission_part = $1 AND turnitintoolid = $2 AND userid IS NULL

    [array (

    0 => 'nm-3703529',

    1 => '2',

    )]

    Error code: dmlreadexception

    Stack trace:

    line 407 of /lib/dml/moodle_database.php: dml_read_exception thrown

    line 239 of /lib/dml/pgsql_native_moodle_database.php: call to moodle_database->query_end()

    line 699 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->query_end()

    line 1337 of /lib/dml/moodle_database.php: call to pgsql_native_moodle_database->get_records_sql()

    line 1410 of /lib/dml/moodle_database.php: call to moodle_database->get_record_sql()

    line 1581 of /lib/dml/moodle_database.php: call to moodle_database->get_field_sql()

    line 1564 of /lib/dml/moodle_database.php: call to moodle_database->count_records_sql()

    line 1547 of /lib/dml/moodle_database.php: call to moodle_database->count_records_select()

    line 6763 of /mod/turnitintool/lib.php: call to moodle_database->count_records()

    line 4859 of /mod/turnitintool/lib.php: call to turnitintool_count_records()

    line 67 of /mod/turnitintool/view.php: call to turnitintool_update_choice_cookie()