Send END_STREAM_REASON_NOROUTE: clients that didn't grok it are now obsolete

changes/noroute

@@ -0,0 +1,5 @@
+  - Minor features
+    - Send END_STREAM_REASON_NOROUTE in response to EHOSTUNREACH errors.
+      Clients before 0.2.1.27 didn't handle NOROUTE correctly, but
+      such clients are already deprecated because of security bugs.
+

src/or/reasons.c

@@ -174,13 +174,7 @@ errno_to_stream_end_reason(int e)
     S_CASE(ENETUNREACH):
       return END_STREAM_REASON_INTERNAL;
     S_CASE(EHOSTUNREACH):
-      /* XXXX023
-       * The correct behavior is END_STREAM_REASON_NOROUTE, but older
-       * clients don't recognize it.  So we're going to continue sending
-       * "MISC" until 0.2.1.27 or later is "well established".
-       */
-      /* return END_STREAM_REASON_NOROUTE; */
-      return END_STREAM_REASON_MISC;
+      return END_STREAM_REASON_NOROUTE;
     S_CASE(ECONNREFUSED):
       return END_STREAM_REASON_CONNECTREFUSED;
     S_CASE(ECONNRESET):