If Webware's ExtraPathInfo setting is true and you type a URL with a nonexistent directory component (e.g., http://site.com/dir/subdir/NONEXISTENT), WebKit returns the parent directory's index.py instead of a 404 Not Found error, because it thinks the invalid directory is actually extra path info. But the servlet, if it's not designed to use the extra path info, will just display its normal thing, which is wrong because it's the wrong servlet. Worse, any relative links on the page will loop back to that servlet, because they'll have the invalid pathname component(s) in the middle of the URL.
The consensus among Webware developers is, this is not a bug, it's a feature. It's just something to be aware of if you use ExtraPathInfo.
-- MikeOrr - 21 Feb 2002