From 2a35f4e5d9b43f97cf3f134154638ea586fff548 Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Fri, 22 May 2020 16:55:56 +0200
Subject: [PATCH] Don't add duplicates in addLocal.

---
 group.go | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/group.go b/group.go
index 1827944..71ec353 100644
--- a/group.go
+++ b/group.go
@@ -52,6 +52,12 @@ func (up *upTrack) notifyLocal() {
 
 func (up *upTrack) addLocal(local *downTrack) {
 	up.mu.Lock()
+	for _, t := range up.local {
+		if t == local {
+			up.mu.Unlock()
+			return
+		}
+	}
 	up.local = append(up.local, local)
 	up.mu.Unlock()
 	up.notifyLocal()