From 6a8f754117e20bf2f9dfb3394fa8e16e22649092 Mon Sep 17 00:00:00 2001
From: Dominik Meyer <dmeyer@hsu-hh.de>
Date: Thu, 27 Jul 2023 23:46:51 +0200
Subject: [PATCH] FIX: only subscripe to topic if not yet subscribed

---
 src/WhisperCom/Router.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/WhisperCom/Router.cpp b/src/WhisperCom/Router.cpp
index 0945205..316c45a 100644
--- a/src/WhisperCom/Router.cpp
+++ b/src/WhisperCom/Router.cpp
@@ -283,10 +283,18 @@ void WhisperCom::Router::processLocalMessage_(zmq::message_t &msg)
     } 
     else if (rmsg.type() == WhisperCom::Protobuf::RouterMessageType::SUBSCRIBE)
     { 
+        DLOG_S(INFO) << "subscription request from " << sender << " topic: " << rmsg.topic();
         std::lock_guard<std::mutex> guard{mutexSubscription_};
         typeName="Subscribe";
+        
+        auto it = subscription_.find(rmsg.topic());
+        if (it == subscription_.end() || (*it).second.empty())
+        {
+            listening_.join(rmsg.topic().c_str());
+        }
+
         subscription_[rmsg.topic()].push_back(sender);
-        listening_.join(rmsg.topic().c_str());
+        
     }
     else if (rmsg.type() == WhisperCom::Protobuf::RouterMessageType::UNSUBSCRIBE)
     {