Refs #30449 -- Made RelatedOnlyFieldListFilter respect ModelAdmin.ordering.

django/contrib/admin/filters.py

@@ -193,11 +193,17 @@ class RelatedFieldListFilter(FieldListFilter):
     def expected_parameters(self):
         return [self.lookup_kwarg, self.lookup_kwarg_isnull]
 
-    def field_choices(self, field, request, model_admin):
-        ordering = ()
+    def field_admin_ordering(self, field, request, model_admin):
+        """
+        Return the model admin's ordering for related field, if provided.
+        """
         related_admin = model_admin.admin_site._registry.get(field.remote_field.model)
         if related_admin is not None:
-            ordering = related_admin.get_ordering(request)
+            return related_admin.get_ordering(request)
+        return ()
+
+    def field_choices(self, field, request, model_admin):
+        ordering = self.field_admin_ordering(field, request, model_admin)
         return field.get_choices(include_blank=False, ordering=ordering)
 
     def choices(self, changelist):
@@ -419,4 +425,5 @@ FieldListFilter.register(lambda f: True, AllValuesFieldListFilter)
 class RelatedOnlyFieldListFilter(RelatedFieldListFilter):
     def field_choices(self, field, request, model_admin):
         pk_qs = model_admin.get_queryset(request).distinct().values_list('%s__pk' % self.field_path, flat=True)
-        return field.get_choices(include_blank=False, limit_choices_to={'pk__in': pk_qs})
+        ordering = self.field_admin_ordering(field, request, model_admin)
+        return field.get_choices(include_blank=False, limit_choices_to={'pk__in': pk_qs}, ordering=ordering)

tests/admin_filters/tests.py

@@ -741,6 +741,33 @@ class ListFiltersTests(TestCase):
         expected = [(self.alfred.pk, 'alfred'), (self.bob.pk, 'bob')]
         self.assertEqual(sorted(filterspec.lookup_choices), sorted(expected))
 
+    def test_relatedonlyfieldlistfilter_foreignkey_ordering(self):
+        """RelatedOnlyFieldListFilter ordering respects ModelAdmin.ordering."""
+        class EmployeeAdminWithOrdering(ModelAdmin):
+            ordering = ('name',)
+
+        class BookAdmin(ModelAdmin):
+            list_filter = (
+                ('employee', RelatedOnlyFieldListFilter),
+            )
+
+        albert = Employee.objects.create(name='Albert Green', department=self.dev)
+        self.djangonaut_book.employee = albert
+        self.djangonaut_book.save()
+        self.bio_book.employee = self.jack
+        self.bio_book.save()
+
+        site.register(Employee, EmployeeAdminWithOrdering)
+        self.addCleanup(lambda: site.unregister(Employee))
+        modeladmin = BookAdmin(Book, site)
+
+        request = self.request_factory.get('/')
+        request.user = self.alfred
+        changelist = modeladmin.get_changelist_instance(request)
+        filterspec = changelist.get_filters(request)[0][0]
+        expected = [(albert.pk, 'Albert Green'), (self.jack.pk, 'Jack Red')]
+        self.assertEqual(filterspec.lookup_choices, expected)
+
     def test_relatedonlyfieldlistfilter_foreignkey_default_ordering(self):
         """RelatedOnlyFieldListFilter ordering respects Meta.ordering."""
         class BookAdmin(ModelAdmin):