diff --git a/lib/completionlib.php b/lib/completionlib.php
index 262c1e811f0..de9b8a4e639 100644
--- a/lib/completionlib.php
+++ b/lib/completionlib.php
@@ -158,7 +158,7 @@ function completion_can_view_data($userid, $course = null) {
 
     if (!is_object($course)) {
         $cid = $course;
-        $course = new object();
+        $course = new stdClass();
         $course->id = $cid;
     }
 
diff --git a/lib/setuplib.php b/lib/setuplib.php
index ee6b8ee61aa..155704ce576 100644
--- a/lib/setuplib.php
+++ b/lib/setuplib.php
@@ -63,7 +63,14 @@ define('MEMORY_HUGE', -4);
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @deprecated since 2.0
  */
-class object extends stdClass {};
+class object extends stdClass {
+    /**
+     * Constructor.
+     */
+    public function __construct() {
+        debugging("'object' class has been deprecated, please use stdClass instead.", DEBUG_DEVELOPER);
+    }
+};
 
 /**
  * Base Moodle Exception class
diff --git a/lib/tests/completionlib_test.php b/lib/tests/completionlib_test.php
index f126735a56e..d9a75de7af5 100644
--- a/lib/tests/completionlib_test.php
+++ b/lib/tests/completionlib_test.php
@@ -59,15 +59,7 @@ class core_completionlib_testcase extends advanced_testcase {
         // Create a course with activities.
         $this->course = $this->getDataGenerator()->create_course(array('enablecompletion' => true));
         $this->user = $this->getDataGenerator()->create_user();
-        $studentrole = $DB->get_record('role', array('shortname' => 'student'));
-        $this->assertNotEmpty($studentrole);
-
-        // Get manual enrolment plugin and enrol user.
-        require_once($CFG->dirroot.'/enrol/manual/locallib.php');
-        $manplugin = enrol_get_plugin('manual');
-        $maninstance = $DB->get_record('enrol', array('courseid' => $this->course->id, 'enrol' => 'manual'), '*', MUST_EXIST);
-        $manplugin->enrol_user($maninstance, $this->user->id, $studentrole->id);
-        $this->assertEquals(1, $DB->count_records('user_enrolments'));
+        $this->getDataGenerator()->enrol_user($this->user->id, $this->course->id);
 
         $this->module1 = $this->getDataGenerator()->create_module('forum', array('course' => $this->course->id));
         $this->module2 = $this->getDataGenerator()->create_module('forum', array('course' => $this->course->id));
@@ -858,6 +850,17 @@ class core_completionlib_testcase extends advanced_testcase {
         $expectedlegacylog = array($this->course->id, 'course', 'completion updated', 'completion.php?id='.$this->course->id);
         $this->assertEventLegacyLogData($expectedlegacylog, $event);
     }
+
+    public function test_completion_can_view_data() {
+        $this->setup_data();
+
+        $student = $this->getDataGenerator()->create_user();
+        $this->getDataGenerator()->enrol_user($student->id, $this->course->id);
+
+        $this->setUser($student);
+        $this->assertTrue(completion_can_view_data($student->id, $this->course->id));
+        $this->assertFalse(completion_can_view_data($this->user->id, $this->course->id));
+    }
 }
 
 class core_completionlib_fake_recordset implements Iterator {
diff --git a/lib/tests/setuplib_test.php b/lib/tests/setuplib_test.php
index b46cd645092..787e581adb8 100644
--- a/lib/tests/setuplib_test.php
+++ b/lib/tests/setuplib_test.php
@@ -460,4 +460,10 @@ class core_setuplib_testcase extends advanced_testcase {
             return get_exception_info($e);
         }
     }
+
+    public function test_object() {
+        $obj = new object();
+        $this->assertDebuggingCalled("'object' class has been deprecated, please use stdClass instead.");
+        $this->assertInstanceOf('stdClass', $obj);
+    }
 }
diff --git a/mod/quiz/attemptlib.php b/mod/quiz/attemptlib.php
index 5060db3472d..22819860871 100644
--- a/mod/quiz/attemptlib.php
+++ b/mod/quiz/attemptlib.php
@@ -1975,23 +1975,6 @@ class quiz_attempt {
         $event->trigger();
     }
 
-    /**
-     * Print the fields of the comment form for questions in this attempt.
-     * @param $slot which question to output the fields for.
-     * @param $prefix Prefix to add to all field names.
-     */
-    public function question_print_comment_fields($slot, $prefix) {
-        // Work out a nice title.
-        $student = get_record('user', 'id', $this->get_userid());
-        $a = new object();
-        $a->fullname = fullname($student, true);
-        $a->attempt = $this->get_attempt_number();
-
-        question_print_comment_fields($this->quba->get_question_attempt($slot),
-                $prefix, $this->get_display_options(true)->markdp,
-                get_string('gradingattempt', 'quiz_grading', $a));
-    }
-
     // Private methods =========================================================
 
     /**
diff --git a/mod/quiz/upgrade.txt b/mod/quiz/upgrade.txt
index 2c395e86287..78bee87a9d0 100644
--- a/mod/quiz/upgrade.txt
+++ b/mod/quiz/upgrade.txt
@@ -1,5 +1,9 @@
 This files describes API changes in the quiz code.
 
+=== 3.1 ===
+* quiz_attempt::question_print_comment_fields() has been removed. It was broken
+  since at least Moodle 2.0.
+
 === 2.9 ===
 
 * There have been changes in classes/output/edit_renderer.php for MDL-40990.