From 599d93796636ff2256396682c7d99726e9f6f9eb Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 25 Mar 2020 16:48:32 +0700
Subject: [PATCH] make Stream.Close() a no-op after the stream was closed for
 shutdown

---
 send_stream.go      | 6 +++++-
 send_stream_test.go | 5 +++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/send_stream.go b/send_stream.go
index 59457042..df1b753b 100644
--- a/send_stream.go
+++ b/send_stream.go
@@ -311,9 +311,13 @@ func (s *sendStream) queueRetransmission(f wire.Frame) {
 
 func (s *sendStream) Close() error {
 	s.mutex.Lock()
+	if s.closedForShutdown {
+		s.mutex.Unlock()
+		return nil
+	}
 	if s.canceledWrite {
 		s.mutex.Unlock()
-		return fmt.Errorf("Close called for canceled stream %d", s.streamID)
+		return fmt.Errorf("close called for canceled stream %d", s.streamID)
 	}
 	s.ctxCancel()
 	s.finishedWriting = true
diff --git a/send_stream_test.go b/send_stream_test.go
index 911d4aca..3bb4421e 100644
--- a/send_stream_test.go
+++ b/send_stream_test.go
@@ -438,6 +438,11 @@ var _ = Describe("Send Stream", func() {
 				f, hasMoreData := str.popStreamFrame(1000)
 				Expect(f).To(BeNil())
 				Expect(hasMoreData).To(BeFalse())
+
+				Expect(str.Close()).To(Succeed())
+				f, hasMoreData = str.popStreamFrame(1000)
+				Expect(f).To(BeNil())
+				Expect(hasMoreData).To(BeFalse())
 			})
 
 			It("doesn't allow FIN twice", func() {