Fixed #24576 -- Made deletion of related objects deterministic.

2 files changed, 4 insertions, 3 deletions

diff --git a/django/db/models/deletion.py b/django/db/models/deletion.py
index 831e3c03db..1c3b7203b5 100644
--- a/django/db/models/deletion.py
+++ b/django/db/models/deletion.py
@@ -64,7 +64,7 @@ class Collector(object):
     def __init__(self, using):
         self.using = using
         # Initially, {model: {instances}}, later values become lists.
-        self.data = {}
+        self.data = OrderedDict()
         self.field_updates = {}  # {model: {(field, value): {instances}}}
         # fast_deletes is a list of queryset-likes that can be deleted without
         # fetching the objects into memory.
diff --git a/tests/delete/tests.py b/tests/delete/tests.py
index 60c61ed281..9e383acb4e 100644
--- a/tests/delete/tests.py
+++ b/tests/delete/tests.py
@@ -224,12 +224,13 @@ class DeletionTests(TestCase):
         s2 = S.objects.create(pk=2, r=r)
         T.objects.create(pk=1, s=s1)
         T.objects.create(pk=2, s=s2)
+        RChild.objects.create(r_ptr=r)
         r.delete()
         self.assertEqual(
-            pre_delete_order, [(T, 2), (T, 1), (S, 2), (S, 1), (R, 1)]
+            pre_delete_order, [(T, 2), (T, 1), (RChild, 1), (S, 2), (S, 1), (R, 1)]
         )
         self.assertEqual(
-            post_delete_order, [(T, 1), (T, 2), (S, 1), (S, 2), (R, 1)]
+            post_delete_order, [(T, 1), (T, 2), (RChild, 1), (S, 1), (S, 2), (R, 1)]
         )
 
         models.signals.post_delete.disconnect(log_post_delete)