From 57eabce89938bde420c1b6452dda571948cd1b07 Mon Sep 17 00:00:00 2001
From: Philip O'Toole <philip.otoole@yahoo.com>
Date: Sat, 2 Sep 2023 10:07:36 -0400
Subject: [PATCH] Protect against double-close of NodeTransport

---
 store/transport.go      | 8 +++++++-
 store/transport_test.go | 3 +++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/store/transport.go b/store/transport.go
index f9e41a7a..a4e6ce50 100644
--- a/store/transport.go
+++ b/store/transport.go
@@ -51,7 +51,8 @@ func (t *Transport) Addr() net.Addr {
 // custom configuration of the InstallSnapshot method.
 type NodeTransport struct {
 	*raft.NetworkTransport
-	done chan struct{}
+	done   chan struct{}
+	closed bool
 }
 
 // NewNodeTransport returns an initialized NodeTransport.
@@ -64,6 +65,11 @@ func NewNodeTransport(transport *raft.NetworkTransport) *NodeTransport {
 
 // Close closes the transport
 func (n *NodeTransport) Close() error {
+	if n.closed {
+		return nil
+	}
+	n.closed = true
+
 	close(n.done)
 	if n.NetworkTransport == nil {
 		return nil
diff --git a/store/transport_test.go b/store/transport_test.go
index 97520422..041168c9 100644
--- a/store/transport_test.go
+++ b/store/transport_test.go
@@ -18,4 +18,7 @@ func Test_NewNodeTransport(t *testing.T) {
 	if err := nt.Close(); err != nil {
 		t.Fatalf("failed to close NodeTransport: %s", err.Error())
 	}
+	if err := nt.Close(); err != nil {
+		t.Fatalf("failed to double-close NodeTransport: %s", err.Error())
+	}
 }