Banners with no URL go to an empty page

When a banner has no URL (strange, but it lets you leave that field empty), it still has a valid link (banner/1, banner/2). But if you click, it goes to an empty page.

I think it would be great (and easy) if, when empty, the banner wouldn't point anywhere (like banner/1). I'm using the banner module to create a random image area, and that would make it work perfectly without any hack.

Maybe it's not its main objective. But if an user is using it in a "normal" way and leaves the URL field empty, that problems also appears.

Thanks in advance.