You could use <b>/error/kernel/20.tpl</b> and then have javascript handle the redirect.
Basically, assume the parent is valid and strip off the last element of the current url (in location.href), then you can use location.href="new url" to handle the redirect.
(Starting point - code in <b>/error/kernel/20.tpl</b>)
The error template would never be used, because there is no error.
I want the default (not overridden by my node templates) Folder view to do the redirect. So I should probably have a override for the Folder class as the last line in my override.ini.append. But what do I specify there, that is the question.
I would rather not use javascript, but generate a HTTP 301 redirect to the parent node. How to do that?
A little late to the party, but I was looking for something else and found this. On the off-chance this is still useful Marc, the way to do this would be to use the RedirectOperators extension: