From f25d97fbd3e70e394c6328f2e847d7a26b7c0f91 Mon Sep 17 00:00:00 2001
From: NIC619 <twedusuck@gmail.com>
Date: Mon, 15 Jul 2019 16:32:05 +0800
Subject: [PATCH] Prevent self re-subscription

---
 libp2p/pubsub/pubsub.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libp2p/pubsub/pubsub.py b/libp2p/pubsub/pubsub.py
index 3e8f74c..07008ca 100644
--- a/libp2p/pubsub/pubsub.py
+++ b/libp2p/pubsub/pubsub.py
@@ -209,6 +209,10 @@ class Pubsub():
         :param topic_id: topic_id to subscribe to
         """
 
+        # Already subscribed
+        if topic_id in self.my_topics:
+            return self.my_topics[topic_id]
+
         # Map topic_id to blocking queue
         self.my_topics[topic_id] = asyncio.Queue()