Ticket #28099: delete_on_update_bug_update.diff

django/db/models/deletion.py

@@ -285 +285 @@
 
             # update fields
             for model, instances_for_fieldvalues in self.field_updates.items():
-                query = sql.UpdateQuery(model)
                 for (field, value), instances in instances_for_fieldvalues.items():
+                    query = sql.UpdateQuery(model)
                     query.update_batch([obj.pk for obj in instances],
                                        {field.name: value}, self.using)
 

tests/delete_regress/models.py

@@ -139 +139 @@
 
     class Meta:
         ordering = ['name']
+
+def status_on_delete(collector, field, sub_objs, using):
+    priority1 = sub_objs.filter(priority=1)
+    priority2 = sub_objs.filter(priority=2)
+
+    levelA_field = field.model._meta.get_field('levelA')
+    levelB_field = field.model._meta.get_field('levelB')
+
+    collector.add_field_update(levelA_field, 11, priority1)
+    collector.add_field_update(levelB_field, 12, priority2)
+
+    models.SET_NULL(collector, field, sub_objs, using)
+    
+
+class Status(models.Model):
+    pass
+
+
+class Report(models.Model):
+    status = models.ForeignKey(Status, null=True, blank=True,
+                               on_delete=status_on_delete)
+    priority = models.IntegerField()
+    levelA = models.IntegerField()
+    levelB = models.IntegerField()

tests/delete_regress/tests.py

@@ -7 +7 @@
     Award, AwardNote, Book, Child, Eaten, Email, File, Food, FooFile,
     FooFileProxy, FooImage, FooPhoto, House, Image, Item, Location, Login,
     OrderedPerson, OrgUnit, Person, Photo, PlayedWith, PlayedWithNote, Policy,
-    Researcher, Toy, Version,
-)
+    Researcher, Toy, Version, Status, Report)
 
 
 # Can't run this test under SQLite, because you can't
@@ -343 +342 @@
         OrderedPerson.objects.create(name='Bob', lives_in=h)
         OrderedPerson.objects.filter(lives_in__address='Foo').delete()
         self.assertEqual(OrderedPerson.objects.count(), 0)
+
+class CollectorUpdateTests(TestCase):
+    def test_delete_with_custom_handlers(self):
+
+        status, _ = Status.objects.get_or_create()
+
+        p1 = Report.objects.create(status=status, priority=1, levelA=1, levelB=0)
+
+        p2 = Report.objects.create(status=status, priority=2, levelA=2, levelB=0)
+
+        status.delete()
+
+        p1 = Report.objects.get(id=p1.pk)
+        self.assertEqual(p1.levelA, 11)
+        self.assertEqual(p1.levelB, 0)
+
+        p2 = Report.objects.get(id=p2.pk)
+        self.assertEqual(p2.levelA, 2)
+        self.assertEqual(p2.levelB, 12)