When editing an object, in the "Manage versions" interface, the "copy" button does not do anything (see attached screenshot).

Steps to reproduce:

1. Prepare a test eZ Publish 4.6 installation, fully patched;
2. Create a new test article and publish;
3. Edit the article, and go to the "Manage versions" interface;
4. On the "Published version" section, click the "copy" button, and see that no copy is created.