Even you create a page with an existing name you are not noticed under the name field

Steps to reproduce:

1. Create a page
2. Create a page with the same name as the first page created
3. You see that under the field the text is still "Ok" and when you press on "Save&View" button on your page it appears a box with the text: "The page X.Y already exists. You can fill in a new page name (or edit X.Y). "