From 5ba0dd88808c67bbec937d0e4547dfff23e08513 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Wed, 15 Jan 2020 09:07:52 +0100
Subject: [PATCH] p2p: wait for goroutine exit, fixes #20558

---
 p2p/server.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/p2p/server.go b/p2p/server.go
index 9b9effaf6c..41453a0792 100644
--- a/p2p/server.go
+++ b/p2p/server.go
@@ -864,7 +864,6 @@ func (srv *Server) maxDialedConns() int {
 // listenLoop runs in its own goroutine and accepts
 // inbound connections.
 func (srv *Server) listenLoop() {
-	defer srv.loopWG.Done()
 	srv.log.Debug("TCP listener up", "addr", srv.listener.Addr())
 
 	tokens := defaultMaxPendingPeers
@@ -872,6 +871,12 @@ func (srv *Server) listenLoop() {
 		tokens = srv.MaxPendingPeers
 	}
 	slots := make(chan struct{}, tokens)
+	defer func() {
+		// Wait for a slot. This is to wait for any goroutine(s) doing srv.SetupConn
+		// to complete before exiting
+		<-slots
+		srv.loopWG.Done()
+	}()
 	for i := 0; i < tokens; i++ {
 		slots <- struct{}{}
 	}