From af46cf885d6f9f86bc144ef72235aa4dc87df8de Mon Sep 17 00:00:00 2001
From: Roderick Bovee <roderick@onecodex.com>
Date: Wed, 21 Sep 2016 10:58:27 -0700
Subject: [PATCH] Make PotionJSONEncoder serialize self-references (e.g. to
 re-serialize PotionJSONSchemaDecoder output)

---
 potion_client/converter.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/potion_client/converter.py b/potion_client/converter.py
index d528219..6f98537 100644
--- a/potion_client/converter.py
+++ b/potion_client/converter.py
@@ -32,6 +32,7 @@ def dst(self, dt):
 
 class PotionJSONEncoder(JSONEncoder):
     def encode(self, o):
+        root_id = id(o)
         if self.check_circular:
             markers = {}
         else:
@@ -42,6 +43,8 @@ def _encode(o):
                 if markers is not None:
                     marker_id = id(o)
                     if marker_id in markers:
+                        if marker_id == root_id:
+                            return {"$ref": "#"}
                         raise ValueError("Circular reference detected")
                     markers[marker_id] = o
                 try: