🇦🇺Australia @merlin06

This patch restores the original else branch that is still required.

else {
  $views_data = $this->getViewsData()->get($this->view->storage->get('base_table'));
}

Patch 12 is incorrect.
Rolled patch 13 against original file.

Rolled a patch.

Credit for this snippet goes to https://www.drupal.org/u/bradtreloar → from https://www.drupal.org/australian-competition-and-consumer-commission-accc → and I modified the issue description with it.

$relationships = $this->displayHandler->getOption('relationships');
if(isset($relationships[$this->options['relationship']])) {
  $relationship = $relationships[$this->options['relationship']];
  $table_data = $this->getViewsData()->get($relationship['table']);
  $views_data = $this->getViewsData()->get($table_data[$relationship['field']]['relationship']['base']);
}
else {
  $views_data = $this->getViewsData()->get($this->view->storage->get('base_table'));
}

Preserving the original code

  /**
   * {@inheritdoc}
   */
  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') {
      $relationships = $this->displayHandler->getOption('relationships');
      if(isset($relationships[$this->options['relationship']])) {
        $relationship = $relationships[$this->options['relationship']];
        $table_data = $this->getViewsData()->get($relationship['table']);
        $views_data = $this->getViewsData()->get($table_data[$relationship['field']]['relationship']['base']);
      }
      else {
        $views_data = $this->getViewsData()->get($this->view->storage->get('base_table'));
      }
    }
    else {
      $views_data = $this->getViewsData()->get($this->view->storage->get('base_table'));
    }

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

merlin06 → created an issue.