Ticket #14615: 14615.diff

django/db/models/base.py

@@ -585 +585 @@
         return force_unicode(dict(field.flatchoices).get(value, value), strings_only=True)
 
     def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):
-        if not self.pk:
+        if self._state.adding:
             raise ValueError("get_next/get_previous cannot be used on unsaved objects.")
         op = is_next and 'gt' or 'lt'
         order = not is_next and '-' or ''

django/db/models/fields/related.py

@@ -223 +223 @@
         try:
             return getattr(instance, self.cache_name)
         except AttributeError:
+            if instance._state.adding:
+                raise ValueError("Cannot retrieve related objects until the instance has been saved")
+
             params = {'%s__pk' % self.related.field.name: instance._get_pk_val()}
             db = router.db_for_read(self.related.model, instance=instance)
             rel_obj = self.related.model._base_manager.using(db).get(**params)
@@ -454 +457 @@
 
         manager = RelatedManager()
         attname = rel_field.rel.get_related_field().name
+
+        if instance._state.adding:
+            raise ValueError("Cannot retrieve related objects until the instance has been saved")
         manager.core_filters = {'%s__%s' % (rel_field.name, attname):
                 getattr(instance, attname)}
         manager.model = self.related.model
@@ -478 +484 @@
             self.through = through
             self._pk_val = self.instance.pk
             self.reverse = reverse
-            if self._pk_val is None:
-                raise ValueError("%r instance needs to have a primary key value before a many-to-many relationship can be used." % instance.__class__.__name__)
+            if self.instance._state.adding:
+                raise ValueError("%r instance needs to be saved before a many-to-many relationship can be used." % instance.__class__.__name__)
 
         def get_query_set(self):
             db = self._db or router.db_for_read(self.instance.__class__, instance=self.instance)

tests/modeltests/lookup/tests.py

@@ -350 +350 @@
                          '<Article: Article 2>')
         self.assertEqual(repr(self.a2.get_previous_by_pub_date()),
                          '<Article: Article 1>')
+        self.assertRaises(ValueError, lambda: Article().get_previous_by_pub_date())
 
     def test_escaping(self):
         # Underscores, percent signs and backslashes have special meaning in the

tests/modeltests/many_to_one/tests.py

@@ -370 +370 @@
         self.r.cached_query = Article.objects.filter(reporter=self.r)
         from copy import deepcopy
         self.assertEqual(repr(deepcopy(self.r)), "<Reporter: John Smith>")
+
+    def test_related_before_save(self):
+        # You cannot get the related objects before the main object is saved.
+        # See ticket #14615
+        self.assertRaises(ValueError, getattr, Reporter(), 'article_set')

tests/modeltests/one_to_one/tests.py

@@ -117 +117 @@
         mm = MultiModel(link1=self.p2, link2=o1, name="x1")
         self.assertRaises(IntegrityError, mm.save)
         transaction.savepoint_rollback(sid)
+
+    def test_related_before_save(self):
+        # You cannot get the related objects before the main object is saved.
+        # See ticket #14615
+        self.assertRaises(ValueError, getattr, Place(), 'restaurant')

tests/regressiontests/null_queries/tests.py

@@ -42 +42 @@
         # Can't use None on anything other than __exact
         self.assertRaises(ValueError, Choice.objects.filter, foo__gt=None)
 
-        # Related managers use __exact=None implicitly if the object hasn't been saved.
-        p2 = Poll(question="How?")
-        self.assertEquals(repr(p2.choice_set.all()), '[]')
-
     def test_reverse_relations(self):
         """
         Querying across reverse relations and then another relation should