Gallery shortcode: display link to next image in the attachment page.

Hi.

I’d like the images in the attachment pages you reach via gallery shortcode thumbnails to link to the next attachment page of the post – now, they link to the media itself.

I know that I could just add the link in the image upload dialog, but I would like it to be automatic – editing the media.php file.

Has anyone any idea about how to do it? The gallery shortcode section of media.php seems to be screaming “danger! danger!” and I’m afraid to experiment.