Description:
------------
When the server receives a request for a URI that points to a
directory, it should issue a redirect with a trailing slash
appended, so that relative URIs in the delivered document work as
expected.

As it is now, when one requests http://localhost/foo, and there
is a file foo/index.html with a <link href="./styles.css">, the
stylesheet is requested as http://localhost/foo./styles.css
instead of http://localhost/foo/styles.css.

This issue was reported in #66191 as a bug, but the ticket was
closed before later comments revealed the actual cause of the
problem. I'm not sure if the current behavior can be regarded as
a bug, but it would be nice, if it will be solved by the built-in
webserver without requiring a custom router script.