Check configured maximum user login length on user rename.

ticket 2587

tests/test_xmlrpc/test_user_plugin.py

@@ -685,6 +685,13 @@ class test_user(Declarative):
         ),
 
 
+        dict(
+            desc='Try to rename to a username that is too long %r' % user1,
+            command=('user_mod', [user1], dict(rename=invaliduser2)),
+            expected=errors.ValidationError(name='uid', error='can be at most 33 characters'),
+        ),
+
+
         dict(
             desc='Create %r' % group1,
             command=(