On node add need to get the host entity for the field collection

Can you explain why this is necessary? It's already putting the field collection item itself in the host's field when the host is new. The code related to that is enough to get them saved together.

Directly below that change is this line:

field_attach_form('field_collection_item', $field_collection_item, $element, $form_state, $language);

That runs a whole host of code, not all of which is passed the $element (where the entity is stored).

For example, passing the field collection item to an 'allowed_values_function' without this patch will not allow the function to introspect the field collection's host entity.

Consider the following code:

/**
 * Returns the list of profile visibility options base on content type.
 * For publication we add the 'Featured' option
 */
function foo_get_allowed_profile_visibility($field, $instance, $entity_type, $entity, &$cacheable) {
  // This needs to be checked for every field.
  $cacheable = FALSE;

  // If this is a field collection item, use the bundle of the host entity.
  if ($entity instanceof FieldCollectionItemEntity) {
    $bundle = $entity->hostEntityBundle();
  }
  // Otherwise, extract it from the entity itself.
  elseif ($entity) {
    list(, , $bundle) = entity_extract_ids($entity_type, $entity);
  }
  else {
    $bundle = '';
  }

  if ($bundle != 'publication') {
    return array(
      0 => 'Hidden',
      1 => 'Visible',
    );
  }
  else {
    return array(
      0 => 'Hidden',
      1 => 'Visible',
      2 => 'Featured',
    );
  }
}

Makes sense, thanks gmercer for the patch and tim.plunkett for laying that out for me.

I verified the patch is needed for the call to hostEntityBundle() to succeed in an allowed_values_function and committed.