Issue #3326204: When no choice is selected you get 2 error messages

tests/src/Functional/CckSelectOtherRequiredTest.php

@@ -97,6 +97,13 @@ class CckSelectOtherRequiredTest extends CckSelectOtherTestBase {
         '_none',
         '',
       ],
+      'required list value is empty' => [
+        'An illegal choice has been detected. Please contact the site administrator.',
+        FALSE,
+        1,
+        '',
+        '',
+      ],
     ];
   }