Strict URL alias checking with optional 404 redirect

Question

When I create a node with "This is sample title" as title, the Pathauto module will create "this-is-sample-title" as URL alias and some "node/123" as real node URL. But we can browse the same content with a different URL such as

SERVER/this-is-sample-title
SERVER/this-is-sample-title/some-garbage-here

In node head source code canonical url is set to "/this-is-sample-title" and shortlink to "node/123". How do I make Drupal strict on the URL alias and redirect to 404 if URL garbage found (even if first URL segment is correct)?

Answer 1

You can use the url_inbound_alter hook to verify if the internal path of the request matches the used url alias. If not, trigger a 404.

function YOURMODULE_url_inbound_alter(&$path, $original_path, $path_language)
{   
    if ($path === $original_path) {
        // path is same as url alias - don't do anything
        return false;
    }

    $alias = drupal_get_path_alias($original_path);
    if ($alias && $alias === $original_path) {
        // alias is same as url alias - don't do anything
        return false;
    }

    drupal_not_found();
    drupal_exit();
}

I've tested on some projects which are using the most common contrib modules (Pathauto, Globalredirect, Views, Sitemapxml, Wysisywyg, ...), and I don't have the problem. Url alias verification is strict and returns 404 for non existing aliases. But I'm able to reproduce it with custom menu callbacks (custom code or views).