From 89347be5265fe5bc83ea900d40f9b5adbdee39e5 Mon Sep 17 00:00:00 2001
From: NIC619 <twedusuck@gmail.com>
Date: Thu, 18 Jul 2019 13:26:31 +0800
Subject: [PATCH] Prevent self re-unsubscription

---
 libp2p/pubsub/pubsub.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libp2p/pubsub/pubsub.py b/libp2p/pubsub/pubsub.py
index 07008ca..f80ed97 100644
--- a/libp2p/pubsub/pubsub.py
+++ b/libp2p/pubsub/pubsub.py
@@ -238,9 +238,11 @@ class Pubsub():
         :param topic_id: topic_id to unsubscribe from
         """
 
+        # Return if we already unsubscribed from the topic
+        if topic_id not in self.my_topics:
+            return
         # Remove topic_id from map if present
-        if topic_id in self.my_topics:
-            del self.my_topics[topic_id]
+        del self.my_topics[topic_id]
 
         # Create unsubscribe message
         packet = rpc_pb2.RPC()