Note a strange case for SOCKS streams.

src/or/connection_edge.c

@@ -2181,6 +2181,7 @@ connection_ap_handshake_socks_reply(entry_connection_t *conn, char *reply,
   if (status == SOCKS5_SUCCEEDED) {
     if(!conn->edge_.on_circuit ||
        !CIRCUIT_IS_ORIGIN(conn->edge_.on_circuit)) {
+      // XXX: Weird. We hit this a lot, and yet have no unusable_circs
       log_warn(LD_BUG, "No origin circuit for successful SOCKS stream");
     } else {
       TO_ORIGIN_CIRCUIT(conn->edge_.on_circuit)->any_streams_succeeded = 1;