Copying a page should also copy its restrictions

When a restricted page is copied, the created page is unrestricted. That is not what I would have expected as a user.

There are various complicating factors to consider:

• What if the user copying the page doesn't have "restrict page" permission? Are the restrictions removed on the new page in that case? Should the user be warned somehow?
• What if the user copying the page doesn't have permissions to edit the original page? I would expect them to have them included in the restrictions automatically.