TinyMCE: Link to internal page replaced if shortcut set on target page

Description

Steps to reproduce

1. Add a link in TinyMCE (XhtmlString) to a internal page.
2. Open the target page and add external link to the page.
3. Delete the target page. There a link between the xhtmlstring page and the internal page with the external link.
4. Add a new line in TinyMCE and publish.

Expected:
A connection between the Xhtmlstring and the target page. If you update the external link on the target page, the XhtmlString changes.

Actual:
No connection between the Xhtmlstring and the target page. If you update the external link on the target page, the XhtmlString does not change.