entity_views_handler_field_entity.inc does not handle entity properties of type 'entity'

Problem/Motivation

The views handler provided for entity properties / fields does not handle generic 'entity'-type properties. eg:

  $properties['referenced'] = array(
    'label' => t("Referenced item"),
    'type' => 'entity',
    'description' => t("The entity item referenced by this transaction."),
    'computed' => TRUE,
    'entity views field' => TRUE,
    'getter callback' => '_referenced_entity_callback', // Returns an EntityMetadataWrapper-wrapped entity
  );

This is because the entity_views_handler_field_entity::init() function sets 'entity', pulled from the property 'type' definition, as the entity type:

  /**
   * Initialize the entity type with the field's entity type.
   */
  public function init(&$view, &$options) {
    parent::init($view, $options);
    $this->field_entity_type = entity_property_extract_innermost_type($this->definition['type']);
  }

Down the line, 'entity' get passed as the entity type to entity_get_controller(), which dies as 'entity' is not a valid entity type.

Proposed resolution

While arguably, it's impossible to create a full featured entity handler that can handle arbitrary entity types, it *should* be possible to create a simplified handler that can use $entity->uri(), $entity->label() etc. to create links to these arbitrary entities.

Remaining tasks

User interface changes

API changes

Original report by @username

Hi,
I have a self-written entity type called 'A'. Entity type 'A' has 3 properties: entity_type, entity_id and revision_id. These 3 properties store the reference information to an exisiting entity.
Now I have used hook_entity_property_info() to define the property informations, including following snippet:

<?php
  $properties['entity']  = array(
    'label' => t('Entity'),
    'type' => 'entity',
    'computed' => TRUE,
    'getter callback' => 'my_getter_callback',
  );
?>

Providing the custom callback:

<?php
function my_getter_callback($data, array $options, $name, $type, $info) {
  return entity_metadata_wrapper($data->entity_type, $data->entity_id);
}
?>

With this, I'm able to directly access the referenced entity on my entities of type 'A' like:

<?php
entity_metadata_wrapper('A', $id)->entity->label();
?>

The API documentation about hook_entity_property_info() tells me:

entity views field: (optional) If enabled, the property is automatically exposed as views field available to all views query backends listing this entity-type. As the property value will always be generated from a loaded entity object, this is particularly useful for 'computed' properties. Defaults to FALSE.

I tried this with my 'entity' property to be able to use it in Views, that means i just added 'entity views field' => TRUE to my $properties['entity'] array. And the field even appears then in the Views configurations for entities of type 'A', so I can add the 'entity' field and I'm able to setup the display settings (Show label, show id, render full entity, link to the entity and so on).
Unfortunately, the view is not able to be rendered then. I just get a fatal error:

PHP Fatal error: Class name must be a valid object or a string in [...]\includes\common.inc on line 7809

I guess I did something wrong or have missed a point, but I can't find out what the problem is. If you could give me a hint or something, I'd be very thankful.
Thanks!