Page tree on side bar not rendering page title correctly when title contains path traversal strings

Issue Summary

This is reproducible on Data Center: (yes)

If the page title contains one of the following characters sets, the page tree displays as 

$htmlUtil.htmlEncode($content.displayTitle)

../ 
..\ 
/.. 
\..

Steps to Reproduce

• Create a page, with one of the above strings in the title.
• Publish/save
• Check the links in the Page Tree on side bar

Expected Results

All the links should display encoded results of displayTitle.

Actual Results

Title is not encoded correctly

Workaround

There is no obvious workaround found.