Steps to Reproduce:
- Change the internal_name of a product to "Kochlöffel" (that's German for cooking spoon. Just in case you ever need one while in a German-speaking country and don't have a dictionary handy).
- Go to the catalog and use the product search box to the left to search for "Koch", you should see the product as a suggestion
- Clear the input field and search for "löffel" instead -> the product is not found.
The reason for this is that the special characters have to be url encoded for the GET request, but are never decoded. Easiest way to fix this is just to use a POST request instead.