Ticket #9994: to_field.diff

django/contrib/admin/filterspecs.py

@@ -74 +74 @@
             self.lookup_title = other_model._meta.verbose_name
         else:
             self.lookup_title = f.verbose_name # use field name
-        rel_name = other_model._meta.pk.name
+        rel_name = f.rel.get_related_field().name
         self.lookup_kwarg = '%s__%s__exact' % (self.field_path, rel_name)
         self.lookup_kwarg_isnull = '%s__isnull' % (self.field_path)
         self.lookup_val = request.GET.get(self.lookup_kwarg, None)

django/contrib/admin/options.py

@@ -229 +229 @@
         for part in parts[:-1]:
             field, _, _, _ = model._meta.get_field_by_name(part)
             if hasattr(field, 'rel'):
-                model = field.rel.to
-                pk_attr_name = model._meta.pk.name
+                pk_attr_name = field.rel.get_related_field().name
             elif isinstance(field, RelatedObject):
                 model = field.model
                 pk_attr_name = model._meta.pk.name