diff -r 5ff1fc726848 -r c6bca38c1cbf parts/django/tests/regressiontests/delete_regress/tests.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/tests/regressiontests/delete_regress/tests.py	Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,116 @@
+import datetime
+
+from django.conf import settings
+from django.db import backend, connection, transaction, DEFAULT_DB_ALIAS
+from django.test import TestCase, TransactionTestCase
+
+from models import Book, Award, AwardNote, Person, Child, Toy, PlayedWith, PlayedWithNote
+
+# Can't run this test under SQLite, because you can't
+# get two connections to an in-memory database.
+if settings.DATABASES[DEFAULT_DB_ALIAS]['ENGINE'] != 'django.db.backends.sqlite3':
+    class DeleteLockingTest(TransactionTestCase):
+        def setUp(self):
+            # Create a second connection to the default database
+            conn_settings = settings.DATABASES[DEFAULT_DB_ALIAS]
+            self.conn2 = backend.DatabaseWrapper({
+                'HOST': conn_settings['HOST'],
+                'NAME': conn_settings['NAME'],
+                'OPTIONS': conn_settings['OPTIONS'],
+                'PASSWORD': conn_settings['PASSWORD'],
+                'PORT': conn_settings['PORT'],
+                'USER': conn_settings['USER'],
+                'TIME_ZONE': settings.TIME_ZONE,
+            })
+
+            # Put both DB connections into managed transaction mode
+            transaction.enter_transaction_management()
+            transaction.managed(True)
+            self.conn2._enter_transaction_management(True)
+
+        def tearDown(self):
+            # Close down the second connection.
+            transaction.leave_transaction_management()
+            self.conn2.close()
+
+        def test_concurrent_delete(self):
+            "Deletes on concurrent transactions don't collide and lock the database. Regression for #9479"
+
+            # Create some dummy data
+            b1 = Book(id=1, pagecount=100)
+            b2 = Book(id=2, pagecount=200)
+            b3 = Book(id=3, pagecount=300)
+            b1.save()
+            b2.save()
+            b3.save()
+
+            transaction.commit()
+
+            self.assertEquals(3, Book.objects.count())
+
+            # Delete something using connection 2.
+            cursor2 = self.conn2.cursor()
+            cursor2.execute('DELETE from delete_regress_book WHERE id=1')
+            self.conn2._commit();
+
+            # Now perform a queryset delete that covers the object
+            # deleted in connection 2. This causes an infinite loop
+            # under MySQL InnoDB unless we keep track of already
+            # deleted objects.
+            Book.objects.filter(pagecount__lt=250).delete()
+            transaction.commit()
+            self.assertEquals(1, Book.objects.count())
+
+class DeleteCascadeTests(TestCase):
+    def test_generic_relation_cascade(self):
+        """
+        Test that Django cascades deletes through generic-related
+        objects to their reverse relations.
+
+        This might falsely succeed if the database cascades deletes
+        itself immediately; the postgresql_psycopg2 backend does not
+        give such a false success because ForeignKeys are created with
+        DEFERRABLE INITIALLY DEFERRED, so its internal cascade is
+        delayed until transaction commit.
+
+        """
+        person = Person.objects.create(name='Nelson Mandela')
+        award = Award.objects.create(name='Nobel', content_object=person)
+        note = AwardNote.objects.create(note='a peace prize',
+                                        award=award)
+        self.assertEquals(AwardNote.objects.count(), 1)
+        person.delete()
+        self.assertEquals(Award.objects.count(), 0)
+        # first two asserts are just sanity checks, this is the kicker:
+        self.assertEquals(AwardNote.objects.count(), 0)
+
+    def test_fk_to_m2m_through(self):
+        """
+        Test that if a M2M relationship has an explicitly-specified
+        through model, and some other model has an FK to that through
+        model, deletion is cascaded from one of the participants in
+        the M2M, to the through model, to its related model.
+
+        Like the above test, this could in theory falsely succeed if
+        the DB cascades deletes itself immediately.
+
+        """
+        juan = Child.objects.create(name='Juan')
+        paints = Toy.objects.create(name='Paints')
+        played = PlayedWith.objects.create(child=juan, toy=paints,
+                                           date=datetime.date.today())
+        note = PlayedWithNote.objects.create(played=played,
+                                             note='the next Jackson Pollock')
+        self.assertEquals(PlayedWithNote.objects.count(), 1)
+        paints.delete()
+        self.assertEquals(PlayedWith.objects.count(), 0)
+        # first two asserts just sanity checks, this is the kicker:
+        self.assertEquals(PlayedWithNote.objects.count(), 0)
+
+class LargeDeleteTests(TestCase):
+    def test_large_deletes(self):
+        "Regression for #13309 -- if the number of objects > chunk size, deletion still occurs"
+        for x in range(300):
+            track = Book.objects.create(pagecount=x+100)
+        Book.objects.all().delete()
+        self.assertEquals(Book.objects.count(), 0)