Limit validation errors are not working

I did a quickscan of the Workflow code. It is possible , if there is an error in function workflow_form_alter().

But only if you have set the 'state list' to 'action buttons', not to radio_buttons.
How is your configuration on /admin/config/workflow/workflow/MY_WORKFLOW/edit under 'How to show the available states' ?

If possible debug the code of function workflow_form_alter() in file workflow.form.inc

I have the same situation with Workflow 7.x-2.10; when I set #limit_validation_errors in a workflow button, it stops saving any transition.

Any idea why is this happening?

So I figured this out. The reason why this is failing is that we're not using properly #limit_validation_errors. This issue has nothing to do with Workflow.

During the form validation, if this property is set (validation errors are limited), Drupal core will remove any non validated form values from the form state, so only values that passed validation will be left for submit callbacks.

For Drupal 8:
http://cgit.drupalcode.org/drupal/tree/core/lib/Drupal/Core/Form/FormVal...

For Drupal 7:
http://cgit.drupalcode.org/drupal/tree/includes/form.inc?h=7.x#n1193

My solution was to add a button validation that will be executed at end of all validations, and in there remove all form-related errors:

/**
 * Removes all validation errors that could happen when saving a draft
 *
 * @param $form
 * @param $form_state
 */
function my_custom_draft_validation($form, &$form_state) {
  $errors = form_get_errors();

  if (!empty($errors)) {
    $messages = drupal_get_messages('error', TRUE);

    // Remove error messages originated during the form validation
    foreach ($messages['error'] as $error) {
      if (!in_array($error, $errors)) {
        drupal_set_message('error', $error);
      }
    }

    // Remove all form errors
    form_clear_error();
  }
}

OK, thanks for the heads-up. So what is the status now?
Should something be changed in the Workflow module, or is all OK?
I didn't know about '#limit_validation_errors', but maybe it should be implmented?