Fix auto set deadlines on publish

common/djangoapps/course_modes/models.py

@@ -159,6 +159,8 @@ class CourseMode(models.Model):
     @expiration_datetime.setter
     def expiration_datetime(self, new_datetime):
         """ Saves datetime to _expiration_datetime and sets the explicit flag. """
+        # Only set explicit flag if we are setting an actual date.
+        if new_datetime is not None:
             self.expiration_datetime_is_explicit = True
         self._expiration_datetime = new_datetime
 

common/djangoapps/course_modes/tests/test_models.py

@@ -421,3 +421,12 @@ class CourseModeModelTest(TestCase):
 
         self.assertFalse(verified_mode.expiration_datetime_is_explicit)
         self.assertEqual(verified_mode.expiration_datetime, now)
+
+    def test_expiration_datetime_explicitly_set_to_none(self):
+        """ Verify that setting the _expiration_date property does not set the explicit flag. """
+        verified_mode, __ = self.create_mode('verified', 'Verified Certificate')
+        self.assertFalse(verified_mode.expiration_datetime_is_explicit)
+
+        verified_mode.expiration_datetime = None
+        self.assertFalse(verified_mode.expiration_datetime_is_explicit)
+        self.assertIsNone(verified_mode.expiration_datetime)

lms/djangoapps/verify_student/signals.py

@@ -14,11 +14,11 @@ def _listen_for_course_publish(sender, course_key, **kwargs):  # pylint: disable
     Catches the signal that a course has been published in Studio and
     sets the verification deadline date to a default.
     """
+    course = modulestore().get_course(course_key)
+    if course:
         try:
             deadline = VerificationDeadline.objects.get(course_key=course_key)
-        if deadline and not deadline.deadline_is_explicit:
-            course = modulestore().get_course(course_key)
-            if course and deadline.deadline != course.end:
+            if not deadline.deadline_is_explicit and deadline.deadline != course.end:
                 VerificationDeadline.set_deadline(course_key, course.end)
         except ObjectDoesNotExist:
-        pass
+            VerificationDeadline.set_deadline(course_key, course.end)

lms/djangoapps/verify_student/tests/test_signals.py

@@ -24,13 +24,13 @@ class VerificationDeadlineSignalTest(ModuleStoreTestCase):
         VerificationDeadline.objects.all().delete()
 
     def test_no_deadline(self):
-        """ Verify the signal does not raise error when no deadlines found. """
+        """ Verify the signal sets deadline to course end when no deadline exists."""
         _listen_for_course_publish('store', self.course.id)
 
-        self.assertIsNone(_listen_for_course_publish('store', self.course.id))
+        self.assertEqual(VerificationDeadline.deadline_for_course(self.course.id), self.course.end)
 
     def test_deadline(self):
-        """ Verify deadline is set to course end date by signal. """
+        """ Verify deadline is set to course end date by signal when changed. """
         deadline = datetime.now(tz=UTC) - timedelta(days=7)
         VerificationDeadline.set_deadline(self.course.id, deadline)