easy-handler errors out when raw bytes are passed as URL parameters

[Kevinpgalligan]

I'm running a dummy easy-handler that's just supposed to return a string, no matter what parameters I pass.

(hunchentoot:define-easy-handler (handle-announce :uri "/announce") ()
  "some string")

However, it returns a 400 when I request this URL:

http://127.0.0.1:4242/announce?field=%27%10%C5

I've confirmed that the issue is URL decoding -- it's trying to convert the raw bytes under the field parameter to UTF-8. This:

(hunchentoot::url-decode "http://127.0.0.1:4242/announce?field=%27%10%C5")

Causes the following error:

This sequence can't be decoded using UTF-8 as it is too short.  1 octet missing at the end.
   [Condition of type FLEXI-STREAMS:EXTERNAL-FORMAT-ENCODING-ERROR]
[...]
Backtrace:
  0: (FLEXI-STREAMS::SIGNAL-ENCODING-ERROR #<FLEXI-STREAMS::FLEXI-UTF-8-FORMAT (:UTF-8 :EOL-STYLE :LF) {1002051D53}> "This sequence can't be decoded ~ ..)
  1: ((:METHOD FLEXI-STREAMS::CHECK-END (T T T T)) #<unavailable argument> #<unused argument> #<unavailable argument> #<unavailable argument>) [fast-method]
  2: ((:METHOD FLEXI-STREAMS::COMPUTE-NUMBER-OF-CHARS (FLEXI-STREAMS::FLEXI-UTF-8-FORMAT T T T)) #<unavailable argument> #<unavailable argument> #<unavailable argument> #<unavailable argument>) [fast-metho..
  3: ((:METHOD FLEXI-STREAMS::OCTETS-TO-STRING* (FLEXI-STREAMS::FLEXI-UTF-8-FORMAT T T T)) #<FLEXI-STREAMS::FLEXI-UTF-8-FORMAT (:UTF-8 :EOL-STYLE :LF) {1002051D53}> #(104 116 116 112 58 47 ...) #<unavailab..

For context, part of the BitTorrent protocol sends raw bytes through URL parameters, which is how I ran into this issue.

Is this expected behaviour of Hunchentoot?

[Kevinpgalligan]

I'm not 100% sure where url-decode is getting called. I think the initialize-instance of requests calls form-url-encoded-list-to-alist on the parameters, which then uses url-decode.