[ILUG] Handling of double encoded strings when a server works as counter / redirector - RFC 3986 2.4 When to Encode or Decode

[Klaus Fleck]

Hi all,

By checking out the RFC 3986 I was wondering, if a server which works as 
a redirector / counter and gets a double encoded URL like

http%3A%2F%2Fr.ligatus.de%2F%3Fz%3DltOEcHbBpB1rFZe5UK7Y%252Bpxi5dzT60BXue2TeOVFkMQ9CSYAcCHXLgQlXKMhb3b6RrsghoihzdOXtNurIWwmrNxcvBGmu8uq%252ByQ%253D

as a parameter should decode this one before passing it to the users 
browser or just do nothing (and cause an error), because the last 
sentence in the RFC 3986 2.4 says:

    "Implementations must not
    percent-encode or decode the same string more than once, as decoding
    an already decoded string might lead to misinterpreting a percent
    data octet as the beginning of a percent-encoding, or vice versa in
    the case of percent-encoding an already percent-encoded string."

Does anyone know where I could find something about this?

Thanks

Klaus