Broken Redirect on Form Submit

Sometimes when the form to create or update a promo is submitted, the user is taken to a page that displays only the just-submitted promo along with all its promo icons.

The URL for that page is in the form /promos/remove/97/1?path=node/173. I believe 97 is the idea of the promo, 1 is its delta, and 173 is the ID of the base node for the promo.

So far as I can tell, this occurs when "undefined" is appended to the end of the URL.

I am not positive, but I believe the attached patch fixes this problem. It definitely addresses one place in JavaScript which can incorrectly append "undefined" to the end of a URL, and since I have implemented this patch, I have not seen the problem described above. I believe this patch should be committed either way since it fixes a definite problem in the JavaScript, and seems to fix the redirect problem I have described.