From 2024514380a812b982df9e33ea3dd7af78e6dcd5 Mon Sep 17 00:00:00 2001
From: kalo <24719519+KaloyanTanev@users.noreply.github.com>
Date: Mon, 6 Jul 2026 17:27:32 +0300
Subject: [PATCH 1/2] Do not error on close write, if stream was already
 canceled

---
 p2p/sender.go               | 21 ++++++++++++++++++---
 p2p/sender_internal_test.go |  7 +++++++
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/p2p/sender.go b/p2p/sender.go
index a36a69d15e..713aa86298 100644
--- a/p2p/sender.go
+++ b/p2p/sender.go
@@ -344,7 +344,15 @@ func SendReceive(ctx context.Context, p2pNode host.Host, peerID peer.ID,
 	}
 
 	if err := s.CloseWrite(); err != nil {
-		return errors.Wrap(err, "close write", z.Any("protocol", s.Protocol()))
+		// A canceled-stream error here is benign: the request was already written and
+		// delivered above, and the peer resetting our send-direction (STOP_SENDING) does
+		// not affect the receive-direction, so the response is still readable below.
+		// This happens much more frequently when QUIC is enabled.
+		if isCanceledStreamErr(err) {
+			log.Debug(ctx, "Closing write of canceled stream", z.Err(err), z.Any("protocol", s.Protocol()))
+		} else {
+			return errors.Wrap(err, "close write", z.Any("protocol", s.Protocol()))
+		}
 	}
 
 	if err = reader.ReadMsg(resp); err != nil {
@@ -355,7 +363,7 @@ func SendReceive(ctx context.Context, p2pNode host.Host, peerID peer.ID,
 		// This close error doesn't require a retry or warning mechanism since the message was
 		// correctly sent to the destination. However, it is still unknown what/who is causing the
 		// stream to be canceled. This error appears much more frequently when QUIC is enabled.
-		if strings.Contains(err.Error(), "close called for canceled stream") {
+		if isCanceledStreamErr(err) {
 			log.Debug(ctx, "Closing canceled stream", z.Err(err), z.Any("protocol", s.Protocol()))
 			return nil
 		}
@@ -412,7 +420,7 @@ func Send(ctx context.Context, p2pNode host.Host, protoID protocol.ID, peerID pe
 		// This close error doesn't require a retry or warning mechanism since the message was
 		// correctly sent to the destination. However, it is still unknown what/who is causing the
 		// stream to be canceled. This error appears much more frequently when QUIC is enabled.
-		if strings.Contains(err.Error(), "close called for canceled stream") {
+		if isCanceledStreamErr(err) {
 			log.Debug(ctx, "Closing canceled stream", z.Err(err), z.Any("protocol", s.Protocol()))
 			return nil
 		}
@@ -423,6 +431,13 @@ func Send(ctx context.Context, p2pNode host.Host, protoID protocol.ID, peerID pe
 	return nil
 }
 
+// isCanceledStreamErr returns true if the error is the benign QUIC stream error
+// returned when closing a stream whose send-direction the peer has already reset
+// (via STOP_SENDING). It occurs much more frequently when QUIC is enabled.
+func isCanceledStreamErr(err error) bool {
+	return err != nil && strings.Contains(err.Error(), "close called for canceled stream")
+}
+
 // protocolPrefix returns the common prefix of the provided protocol IDs.
 func protocolPrefix(pIDs ...protocol.ID) protocol.ID {
 	if len(pIDs) == 0 {
diff --git a/p2p/sender_internal_test.go b/p2p/sender_internal_test.go
index 88911c5f5d..bf60037b4d 100644
--- a/p2p/sender_internal_test.go
+++ b/p2p/sender_internal_test.go
@@ -160,3 +160,10 @@ func TestNonZeroResponse(t *testing.T) {
 	err := SendReceive(ctx, nil, "", nil, &pbv1.Duty{Slot: 1}, "")
 	require.ErrorContains(t, err, "bug: response proto must be zero value")
 }
+
+func TestIsCanceledStreamErr(t *testing.T) {
+	require.False(t, isCanceledStreamErr(nil))
+	require.False(t, isCanceledStreamErr(errors.New("some other error")))
+	require.True(t, isCanceledStreamErr(errors.New("close called for canceled stream 4")))
+	require.True(t, isCanceledStreamErr(errors.Wrap(errors.New("close called for canceled stream 4"), "close write")))
+}

From b486119b5c021a417b77a21c3c636154c34c8d49 Mon Sep 17 00:00:00 2001
From: kalo <24719519+KaloyanTanev@users.noreply.github.com>
Date: Mon, 6 Jul 2026 18:43:48 +0300
Subject: [PATCH 2/2] Nolint for revive

---
 p2p/sender.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/p2p/sender.go b/p2p/sender.go
index 713aa86298..3c88456e98 100644
--- a/p2p/sender.go
+++ b/p2p/sender.go
@@ -348,6 +348,8 @@ func SendReceive(ctx context.Context, p2pNode host.Host, peerID peer.ID,
 		// delivered above, and the peer resetting our send-direction (STOP_SENDING) does
 		// not affect the receive-direction, so the response is still readable below.
 		// This happens much more frequently when QUIC is enabled.
+		//
+		//nolint:revive // Prioritise readability.
 		if isCanceledStreamErr(err) {
 			log.Debug(ctx, "Closing write of canceled stream", z.Err(err), z.Any("protocol", s.Protocol()))
 		} else {