From 00fc76c01b59e26c8da6ac63797c33dc8951de16 Mon Sep 17 00:00:00 2001
From: Dirk McCormick <dirkmdev@gmail.com>
Date: Tue, 21 Mar 2023 08:59:42 +0100
Subject: [PATCH] fix: calling message queue Shutdown twice causes panic
 (because close is called twice on done channel)

---
 messagequeue/messagequeue.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/messagequeue/messagequeue.go b/messagequeue/messagequeue.go
index ea606423..cec616b4 100644
--- a/messagequeue/messagequeue.go
+++ b/messagequeue/messagequeue.go
@@ -68,6 +68,7 @@ type MessageQueue struct {
 
 	outgoingWork chan struct{}
 	done         chan struct{}
+	doneOnce     sync.Once
 
 	// internal do not touch outside go routines
 	sender             gsnet.MessageSender
@@ -144,7 +145,9 @@ func (mq *MessageQueue) Startup() {
 
 // Shutdown stops the processing of messages for a message queue.
 func (mq *MessageQueue) Shutdown() {
-	close(mq.done)
+	mq.doneOnce.Do(func() {
+		close(mq.done)
+	})
 }
 
 func (mq *MessageQueue) runQueue() {