I've compiled the latest trunk, the display property seems to be fixed, but line-prefix, and wrap-prefix are still affected.

On Sat, Jun 8, 2013 at 7:34 PM, Eli Zaretskii <eliz@gnu.org> wrote:

> Date: Sat, 8 Jun 2013 14:58:58 +0100
> From: E Sabof <esabof@gmail.com>
>
> Start emacs -Q
> M-:
>
> (progn
> (insert "some text")
> (let ((ov (make-overlay (- (point) 9) (point))))
> (overlay-put ov 'window (selected-window))
> (overlay-put ov 'display "different text"))
> (split-window-vertically))
>
> RET

Fixed in trunk revision 112896.

Thanks.