Deprecated function: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated in Drupal\views\Plugin\views\display\DisplayPluginBase

Since there hasn't been a follow up to #9 going to close for now.

If still a bug please reopen adding steps to reproduce to the issue summary.

Thanks.

I have been able to reproduce this issue with the following:

1. Add a view to a global section of the site (Mine is an exposed form search block in the site header)
2. Go to a url that gives you a 404.

In the following, $route_name returns null and then fails the strpos.

  public function viewExposedFormBlocks() {
    // Avoid interfering with the admin forms.
    $route_name = \Drupal::routeMatch()->getRouteName();
    if (strpos($route_name, 'views_ui.') === 0) {
      return;
    }
    $this->view->initHandlers();

    if ($this->usesExposed() && $this->getOption('exposed_block')) {
      /** @var \Drupal\views\Plugin\views\exposed_form\ExposedFormPluginInterface $exposed_form */
      $exposed_form = $this->getPlugin('exposed_form');
      return $exposed_form->renderExposedForm(TRUE);
    }
  }

I am getting the same warning when images on the page have broken links and the exposed form search block in the site header is enabled. There are no warning upon disabling that block. I have to rebuild the cache each time.