Ticket #17294: 17294.patch

tests/modeltests/timezones/tests.py

@@ -25 +25 @@
 from django.utils.unittest import skipIf
 
 from .forms import EventForm, EventSplitForm, EventModelForm
-from .models import Event, Timestamp
+from .models import Event, MaybeEvent, Timestamp
 
 
 # These tests use the EAT (Eastern Africa Time) and ICT (Indochina Time)
@@ -403 +403 @@
                  datetime.datetime(2011, 1, 1, tzinfo=UTC)],
                 transform=lambda d: d)
 
+    def test_null_datetime(self):
+        # Regression for #17294
+        e = MaybeEvent.objects.create()
+        self.assertEqual(e.dt, None)
+
 NewDatabaseTests = override_settings(USE_TZ=True)(NewDatabaseTests)
 
 

tests/modeltests/timezones/models.py

@@ -3 +3 @@
 class Event(models.Model):
     dt = models.DateTimeField()
 
+class MaybeEvent(models.Model):
+    dt = models.DateTimeField(blank=True, null=True)
+
 class Timestamp(models.Model):
     created = models.DateTimeField(auto_now_add=True)
     updated = models.DateTimeField(auto_now=True)

tests/modeltests/timezones/forms.py

@@ -1 +1 @@
 from django import forms
 
-from .models import Event
+from .models import Event, MaybeEvent
 
 class EventForm(forms.Form):
     dt = forms.DateTimeField()

django/db/models/fields/__init__.py

@@ -786 +786 @@
 
     def get_prep_value(self, value):
         value = self.to_python(value)
-        if settings.USE_TZ and timezone.is_naive(value):
+        if value is not None and settings.USE_TZ and timezone.is_naive(value):
             # For backwards compatibility, interpret naive datetimes in local
             # time. This won't work during DST change, but we can't do much
             # about it, so we let the exceptions percolate up the call stack.