Filters throw unrecoverable error when using relationships

Steps to reproduce:

1) Fresh 8.x-dev site
2) create a view that displays users
3) add the "content: authored" relationship
4) add the "Content: Type" filter

Notice: Trying to get property of non-object in Drupal\views\Plugin\views\HandlerBase->getEntityType() (line 771 of docroot/core/modules/views/lib/Drupal/views/Plugin/views/HandlerBase.php).

The function getEntityType() in core/modules/views/lib/Drupal/views/Plugin/views/HandlerBase.php has the problem:

  public function getEntityType() {
    // If the user has configured a relationship on the handler take that into
    // account.
    if (!empty($this->options['relationship']) && $this->options['relationship'] != 'none') {
      $views_data = $this->getViewsData()->get($this->view->relationship->table);
    }
    else {
      $views_data = $this->getViewsData()->get($this->view->storage->get('base_table'));
    }

    if (isset($views_data['table']['entity type'])) {
      return $views_data['table']['entity type'];
    }
    else {
      throw new \Exception(String::format('No entity type for field @field on view @view', array('@field' => $this->options['id'], '@view' => $this->view->storage->id())));
    }
  }

As best I can tell it appears that the code is using "$this->view->relationship->table" to determine the appropriate base table entity type for this filter. This however there presents 2 problems.

1) views can have many relationships, many of which can be against the same base for different reasons: I'd assume this means that using the variable "$this->view->relationship->table" is completely wrong
2) it doesn't take into account the $this->options['relationship'] configured value at all so it can't return the right relationship to build against.

An interesting thing about this (and probably why it has escaped testing) is that things work fine when the first entity matches the expected base. For example, creating a node view, adding a "content: author" relationship, and adding content:type will work fine. additionally, adding the "user: created" filter also works. In this situation its probably because there's only exactly one relationship that can work for this view.

To break this example in the same way, you can either add the "content: author" relationship again, or add the "Content: Authored" relationship (the one that relates users to content - not content to users). and the error will show up when you simply view the configuration of one of the two filters.

This was literally the 1st thing I've ever done in D8, and while I'm pretty good at navigating the code structure of 7.x-3.x views, the D8 code is a bit beyond me right now. I'm pretty sure that this is a one line fix that involves calling some sort of "->getRelationship($this->options['relationship']) " method and getting the base_table attribute, but after tons of digging I can't find it, or any way to get the properties of the selected relationship, so I'm leaving it up to you guys.

And lastly, this is also a problem with arguments, but seems to have been resolved with fields through UI fixes in a couple of other issues (noted in the related issues field).

Hopefully this is enough to go on. Thanks for the hard work!