Checkboxes type attribute fields do not work anymore after upgrading to Drupal 10.3.5

Migrated issue

Reported by: supreetam09

Related to !30

Problem/Motivation

Supporting checkboxes was introduced in this module's issue queue #3238246

After Drupal 10.3.5 upgrade (basically any version after #3427177 is committed to Drupal Core), it throws fatal error for any pages with menu item having multiple checkboxes type data:

InvalidArgumentException: "role_1" is an invalid render array key. Value should be an array but got a string. in Drupal\Core\Render\Element::children() (line 97 of core/lib/Drupal/Core/Render/Element.php).

It still supports single value checkbox, single select and radios. Seems like multi-value fields are affected.

Steps to reproduce

  • Add a checkboxes type attribute field in configuration.
    screenshot
  • Add a menu item with checkboxes attribute.
    screenshot
  • View a page that renders the menu item.
  • Bam!!!screenshot

Config schema

Also allow a sequence for default_value in config/schema/menu_link_attributes.schema.yml, as a checkboxes default can be a list (moved from #3590641 (closed)). The managed_file schema keys are handled in #3365618.

Edited by Norman Kämper-Leymann