Invalid redirect after editing URL slug in frontend (from permalink) / Automatic redirects when changing URL slug

If you click "Edit..." on a permalink / single item view in the frontent [1], there is a redirect_to param which points to the current URL.
If you change this URL, e.g. by editing the URL slug, the redirect (after pressing "Save") will go to a Not-Found page.

A nifty solution would be to automatically create a redirect post, at least for some time (can be cleaned by maintenance task).

This is really useful in general, since you often notice a typo in the title, but editing the URL slug is more difficult (since you have to manually setup some redirect).

[1] http://test.b2evo.net/HEAD/blogs/blog1.php/2009/09/21/welcome-to-b2evolution (Note: you must be logged in to see the edit link, of course)