short_url 404 issue

the short_url module should show a custom 404 page when no item is found.

If the wrong path ends with a slash or contains a slash, followed by something legal (a number when %path%/%page% is configured) a php Error occurs.

Similar to this issue: with a configuration %path%/%page% albums aren't recognized if the trailing slash misses.
A 301 redirect to the album with trailing slash would be more user-friendly.