[Orgmode] org-mode font-locking clobbers the rear-nonsticky text property; for other modes it doesn't

[Tom Weissmann]

I am trying to work out why font-lock for Org-mode changes the rear-nonsticky
property of text I insert, while it doesn't do it for other modes.

For example:

(with-current-buffer
    (get-buffer-create "foo")
  (insert (propertize ";;Try adding text after this ->" 
                      'read-only t 
                      'face 'underline 
                      'rear-nonsticky '(read-only))))

In the "foo" buffer you will be able to add text after the arrow. Turning on
lisp-interaction mode will fontify the text as a comment, but if you delete the
text you added you'll still be able to add some more - whereas in org-mode you
can't.

Does anyone know why this happens and how I can prevent it?

Cheers,
Tom SW