Fixed #22810 -- Corrected admin changelist count for list filters that filter by default.

django/contrib/admin/views/main.py

@@ -174,14 +174,8 @@ class ChangeList(object):
         result_count = paginator.count
 
         # Get the total number of objects, with no admin filters applied.
-        # Perform a slight optimization:
-        # full_result_count is equal to paginator.count if no filters
-        # were applied
         if self.model_admin.show_full_result_count:
-            if self.get_filters_params() or self.params.get(SEARCH_VAR):
-                full_result_count = self.root_queryset.count()
-            else:
-                full_result_count = result_count
+            full_result_count = self.root_queryset.count()
         else:
             full_result_count = None
         can_show_all = result_count <= self.list_max_show_all

tests/admin_filters/tests.py

@@ -43,6 +43,22 @@ class DecadeListFilter(SimpleListFilter):
             return queryset.filter(year__gte=2000, year__lte=2009)
 
 
+class NotNinetiesListFilter(SimpleListFilter):
+    title = "Not nineties books"
+    parameter_name = "book_year"
+
+    def lookups(self, request, model_admin):
+        return (
+            ('the 90s', "the 1990's"),
+        )
+
+    def queryset(self, request, queryset):
+        if self.value() == 'the 90s':
+            return queryset.filter(year__gte=1990, year__lte=1999)
+        else:
+            return queryset.exclude(year__gte=1990, year__lte=1999)
+
+
 class DecadeListFilterWithTitleAndParameter(DecadeListFilter):
     title = 'publication decade'
     parameter_name = 'publication-decade'
@@ -179,6 +195,10 @@ class DecadeFilterBookAdmin(ModelAdmin):
     ordering = ('-id',)
 
 
+class NotNinetiesListFilterAdmin(ModelAdmin):
+    list_filter = (NotNinetiesListFilter,)
+
+
 class DecadeFilterBookAdminWithoutTitle(ModelAdmin):
     list_filter = (DecadeListFilterWithoutTitle,)
 
@@ -1026,3 +1046,14 @@ class ListFiltersTests(TestCase):
 
         _test_choices(self.request_factory.get('/', {'publication-decade': 'the 90s'}),
                       ("All", "the 1980's"))
+
+    def test_list_filter_queryset_filtered_by_default(self):
+        """
+        A list filter that filters the queryset by default gives the correct
+        full_result_count.
+        """
+        modeladmin = NotNinetiesListFilterAdmin(Book, site)
+        request = self.request_factory.get('/', {})
+        changelist = self.get_changelist(request, Book, modeladmin)
+        changelist.get_results(request)
+        self.assertEqual(changelist.full_result_count, 4)

tests/admin_views/tests.py

@@ -3756,13 +3756,12 @@ class AdminCustomQuerysetTest(TestCase):
         Person.objects.create(name='person2', gender=2)
         changelist_url = reverse('admin:admin_views_person_changelist')
 
-        # 4 queries are expected: 1 for the session, 1 for the user,
-        # 1 for the count and 1 for the objects on the page
-        with self.assertNumQueries(4):
+        # 5 queries are expected: 1 for the session, 1 for the user,
+        # 2 for the counts and 1 for the objects on the page
+        with self.assertNumQueries(5):
             resp = self.client.get(changelist_url)
             self.assertEqual(resp.context['selection_note'], '0 of 2 selected')
             self.assertEqual(resp.context['selection_note_all'], 'All 2 selected')
-        # here one more count(*) query will run, because filters were applied
         with self.assertNumQueries(5):
             extra = {'q': 'not_in_name'}
             resp = self.client.get(changelist_url, extra)