‘save_post’ hook not working in WP 3.5

attachment_fields_to_save is still called.

Just tried out this on my wordpress 3.5. installation and the following code killed wordpress when saving an image.

add_filter('attachment_fields_to_save', function() {
    die('attachment_fields_to_save');
});

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)