Orphaned menu links when nodes are deleted if menu_link_ui is not enabled

One of many more issues.

How to get all routes provided by a particular view (at the moment):

$routes = [];
$view_id = 'frontpage';
$executable = \Drupal\views\Views::getExecutable($executable);
$view_route_overrides = \Drupal::state()->get('views.view_route_names');
foreach ($executable->displayHandlers as $display_id => display) {
  if ($display instanceof \Drupal\views\Plugin\views\display\DisplayRouterInterface) {
    if (!isset("$view_route_overrides[$view_id.$display_id"])) {
      $routes[] = "views.$view_id.$display_id";
    }
    else {
      $routes[] = $view_route_overrides[$view_id.$display_id]
    }
  }
}

Thanks for checking if this was still valid.

Discussed with @alexpott, @cilefen, @cottser, @laurii, and @xjm and we think it's worth bumping this to critical since it's a data integrity bug (albeit leaving cruft as opposed to deleting too much). Looks to me like since the menu links will still be valid, we'd be trying to load the entity to check access every time, even though it's not there - as opposed to it only being extra rows in the db.

Rerolled after #2776975: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase, #2735005: Convert all Simpletest web tests to BrowserTestBase (or UnitTestBase/KernelTestBase), and probably some other change but I couldn't find the issue.

Reviewed the code and it makes sense. Here's a fix for the test and some cosmetic fixes.

Going straight to RTBC because my changes are minor.

Committed/pushed to 8.5.x and cherry-picked to 8.4.x. Thanks!

I've found a new problem that comes with this. Module uninstall is broken if configuration is being deleted during the uninstall. Here is one example how to reproduce:

1. Install Drupal using the standard installation profile
2. Download & Enable token contributed module
3. Try to uninstall menu_link_content module

This gives error Symfony\Component\Routing\Exception\MissingMandatoryParametersException: Some mandatory parameters are missing ("entity_type_id") to generate a URL for route "entity.entity_view_mode.add_form".

I was able to reproduce this with drush and from UI.

@mikran
Please create a new issue and link it from here. This way people don't need to read the old discussion ... Thank you

After this change was introduced I'm getting the following error when attempting to delete an entity belonging to a custom content entity type generated by Drupal console:

The website encountered an unexpected error. Please try again later.</br></br><em class="placeholder">Drupal\Core\Entity\EntityStorageException</em>: Parameter &quot;personnel_revision&quot; for route &quot;entity.personnel.revision_revert&quot; must match &quot;[^/]++&quot; (&quot;&quot; given) to generate a corresponding URL.

The link has the following form: "/admin/structure/personnel/{personnel}/revisions/{personnel_revision}/revert". The {personnel} parameter is populated properly, but the {personnel_revision} parameter is missing, hence the error. Is there something we should be doing in code to ensure the revision parameter is passed in? Not too familiar with the routing system.

It looks like the change here is now preventing the deletion of entities having custom link templates with mandatory parameters, which are not automatically set by \Drupal\Core\Entity\EntityInterface::toUrl(). I've created an issue for this - #2924338: Entity::uriRelationships() throws exceptions if an URL cannot be generated because of missing mandatory parameters, which is a major as it looks like an usual case when e.g. using the diff module and suddenly after an update inside 8.4.x it is not possible to delete entities.

In addition to the bug above, we now also lose unparameterized collection routes. For example, menu links that point at /admin/people disappear when a user is deleted.

#2926897: Deleting content entities also deletes collection menu items.