Non ASCII characters in the url of a post/page lead to redirect

Overview of the issue

When you visit a post or a page that contains non-ASCII characters in its slug and respectfully, in its URL, a constant redirect is happening.

This is happening because of the way such characters are handled – they need to be properly converted and escaped so that they can be used as URL.

In order for this to be done, the urlencode and urldecode functions are used.

You can read more about this topic on the following two links:

• Why should I use urlencode? (Stack Overflow)
• Uniform Resource Identifiers (URI) (Internet Engineering Task Force)

Workaround

1. Go to wp-content/sitepress-multilingual-cms/classes/query-filtering/class-wpml-query-parser.php at line 421.
2. In the is_permalink_part_of_request(), replace

   return substr( trailingslashit( $request_uri ), 0, strlen( $permalink_path ) ) === $permalink_path;
   

   with this:

   return substr( trailingslashit( urldecode( $request_uri ) ), 0, strlen( $permalink_path ) ) === $permalink_path;