[1.1.X] Fixed #13309 -- Ensure that delete() deletes everything it should delete(). Thanks to craig.kimerer@gmail.com for the report

Backport of r12941 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@12955 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -388,13 +388,14 @@ class QuerySet(object):
         # Delete objects in chunks to prevent the list of related objects from
         # becoming too long.
         seen_objs = None
+        del_itr = iter(del_query)
         while 1:
             # Collect a chunk of objects to be deleted, and then all the
             # objects that are related to the objects that are to be deleted.
             # The chunking *isn't* done by slicing the del_query because we
             # need to maintain the query cache on del_query (see #12328)
             seen_objs = CollectedObjects(seen_objs)
-            for i, obj in izip(xrange(CHUNK_SIZE), del_query):
+            for i, obj in izip(xrange(CHUNK_SIZE), del_itr):
                 obj._collect_sub_objects(seen_objs)
 
             if not seen_objs:

tests/regressiontests/delete_regress/tests.py

@@ -0,0 +1,13 @@
+import datetime
+
+from django.test import TestCase
+
+from models import Book
+
+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)