Page content, object properties and title leak on fully private wiki with xpages on the login action

Steps to reproduce:

• Make the wiki fully closed, i.e., check "Prevent unregistered users from viewing pages, regardless of the page rights" and the similar checkbox for editing in the rights administration.
• Go to <server>/xwiki/bin/login/Main/?xpage=view

Expected result:

You are redirected to login.

Actual result:

The page including title and content are displayed.

Note that this applies to any page but no sheets are applied. This also works with xpage=preview and xpage=print.

This issue most likely affects all versions of XWiki, I was able to reproduce on XWiki Enterprise 1.1.1, the oldest version that has a demo package available.