From 57163c70a3646a3eb14100b6e6adf498f2cddf57 Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Fri, 22 May 2020 22:38:40 +0200
Subject: [PATCH] Better protection against duplicate connection ids.

---
 client.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/client.go b/client.go
index c68455f..2bdaaf2 100644
--- a/client.go
+++ b/client.go
@@ -320,7 +320,7 @@ func addUpConn(c *client, id string) (*upConnection, error) {
 	if c.up == nil {
 		c.up = make(map[string]*upConnection)
 	}
-	if c.up[id] != nil {
+	if c.up[id] != nil || (c.down != nil && c.down[id] != nil) {
 		conn.pc.Close()
 		return nil, errors.New("Adding duplicate connection")
 	}
@@ -697,7 +697,7 @@ func addDownConn(c *client, id string, remote *upConnection) (*downConnection, e
 
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	if c.down[id] != nil {
+	if c.down[id] != nil || (c.up != nil && c.up[id] != nil) {
 		conn.pc.Close()
 		return nil, errors.New("Adding duplicate connection")
 	}