Fixed #25883 -- Fixed admin deletion page summary counts for related objects.

django/contrib/admin/utils.py

@@ -163,8 +163,9 @@ def get_deleted_objects(objs, opts, user, admin_site, using):
     to_delete = collector.nested(format_callback)
 
     protected = [format_callback(obj) for obj in collector.protected]
+    model_count = {model._meta.verbose_name_plural: len(objs) for model, objs in collector.model_objs.items()}
 
-    return to_delete, collector.model_count, perms_needed, protected
+    return to_delete, model_count, perms_needed, protected
 
 
 class NestedObjects(Collector):
@@ -172,7 +173,7 @@ class NestedObjects(Collector):
         super(NestedObjects, self).__init__(*args, **kwargs)
         self.edges = {}  # {from_instance: [to_instances]}
         self.protected = set()
-        self.model_count = defaultdict(int)
+        self.model_objs = defaultdict(set)
 
     def add_edge(self, source, target):
         self.edges.setdefault(source, []).append(target)
@@ -187,7 +188,7 @@ class NestedObjects(Collector):
                 self.add_edge(getattr(obj, related_name), obj)
             else:
                 self.add_edge(None, obj)
-            self.model_count[obj._meta.verbose_name_plural] += 1
+            self.model_objs[obj._meta.model].add(obj)
         try:
             return super(NestedObjects, self).collect(objs, source_attr=source_attr, **kwargs)
         except models.ProtectedError as e:

docs/releases/1.9.1.txt

@@ -26,3 +26,6 @@ Bugfixes
 * Fixed missing ``varchar/text_pattern_ops`` index on ``CharField`` and
   ``TextField`` respectively when using ``AlterField`` on PostgreSQL
   (:ticket:`25412`).
+
+* Fixed admin's delete confirmation page's summary counts of related objects
+  (:ticket:`25883`).

tests/admin_views/models.py

@@ -40,6 +40,7 @@ class Article(models.Model):
     content = models.TextField()
     date = models.DateTimeField()
     section = models.ForeignKey(Section, models.CASCADE, null=True, blank=True)
+    another_section = models.ForeignKey(Section, models.CASCADE, null=True, blank=True, related_name='+')
     sub_section = models.ForeignKey(Section, models.SET_NULL, null=True, blank=True, related_name='+')
 
     def __str__(self):

tests/admin_views/tests.py

@@ -1292,7 +1292,8 @@ class AdminViewPermissionsTest(TestCase):
         )
         cls.s1 = Section.objects.create(name='Test section')
         cls.a1 = Article.objects.create(
-            content='<p>Middle content</p>', date=datetime.datetime(2008, 3, 18, 11, 54, 58), section=cls.s1
+            content='<p>Middle content</p>', date=datetime.datetime(2008, 3, 18, 11, 54, 58), section=cls.s1,
+            another_section=cls.s1,
         )
         cls.a2 = Article.objects.create(
             content='<p>Oldest content</p>', date=datetime.datetime(2000, 3, 18, 11, 54, 58), section=cls.s1
@@ -3203,7 +3204,7 @@ class AdminActionsTest(TestCase):
         self.assertIsInstance(confirmation, TemplateResponse)
         self.assertContains(confirmation, "Are you sure you want to delete the selected subscribers?")
         self.assertContains(confirmation, "<h2>Summary</h2>")
-        self.assertContains(confirmation, "<li>Subscribers: 3</li>")
+        self.assertContains(confirmation, "<li>Subscribers: 2</li>")
         self.assertContains(confirmation, "<li>External subscribers: 1</li>")
         self.assertContains(confirmation, ACTION_CHECKBOX_NAME, count=2)
         self.client.post(reverse('admin:admin_views_subscriber_changelist'), delete_confirmation_data)