Fixed #21870 -- Admin check for list_editable_item

During the admin check for list_editable _check_list_editable_item
should return an empty list if all checks pass. Additionally the
Testcase test_readonly_and_editable was changed to test what the
name implies instead of duplicating the logic of test_readonly.

1 files changed, 2 insertions, 0 deletions

diff --git a/django/contrib/admin/checks.py b/django/contrib/admin/checks.py
index 515cedcf69..f768374d54 100644
--- a/django/contrib/admin/checks.py
+++ b/django/contrib/admin/checks.py
@@ -791,6 +791,8 @@ class ModelAdminChecks(BaseModelAdminChecks):
                         id='admin.E126',
                     )
                 ]
+            else:
+                return []
 
     def _check_search_fields(self, cls, model):
         """ Check search_fields is a sequence. """