Confluence allows Page to be renamed to a title that has already existed(and restricted)

Issue Summary

Confluence allows Parent Page to be renamed to a title that has already existed(and restricted)

Steps to Reproduce

1. Install Confluence
2. Create a New Space
3. Create a New Page in the space created above and name it "PAGE ONE" with UserA
4. Restrict "PAGE ONE" so that only UserA can view
   
5. Login with UserB and go to the parent page of "PAGE ONE" in the space (eg: the Home Page in this test)
6. Rename the parent page to "PAGE ONE"

Ref: CONFSERVER-75905.mp4

Expected Results

Any user is not supposed to rename a page to a page title that has already existed in the space

Actual Results

The parent page has successfully been renamed into "PAGE ONE", making this space have more than 1 page with the title of "PAGE ONE"

Information

This issue does not happen in the below situation:

• The original "PAGE ONE" is not restricted

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available