frox - 7:59 am on Sep 2, 2013 (gmt 0)
The browser is not requesting ò, it's requesting
GET /%C3%B2.txt HTTP/1.1
(that's what I actually see from Live HTTP headers, and that's what I see in the server logs.)
So, the "in between area" is pretty safe, the request travels in a properly encoded form.
The problem is just server-side.
In this installation of Apache, the percent-encoded URLs are decoded using ISO8859-1, while in other installations I have the URLs are decoded using UTF-8.
In this installation, apache would require a request like "http://www.example.com/%f2.txt" to serve the file ò.txt (i.e., it decodes the percent-encoded URL with ISO8859 instead of UTF-8)
The problem is, the rest of the world is pretty consistent in encoding the URL in UTF-8, i.e. the request the server gets is "http://www.example.com/%C3%B2.txt"