From ea7797402756a7d6ea596f978dc13f7da88a839b Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Mon, 18 Dec 2017 22:24:22 +0700
Subject: [PATCH] don't send data that was queue before the stream write
 deadline expired

---
 send_stream.go      |  5 ++++-
 send_stream_test.go | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/send_stream.go b/send_stream.go
index 4b349030b..d82dee14d 100644
--- a/send_stream.go
+++ b/send_stream.go
@@ -92,10 +92,13 @@ func (s *sendStream) Write(p []byte) (int, error) {
 	copy(s.dataForWriting, p)
 	s.onData()
 
+	var bytesWritten int
 	var err error
 	for {
+		bytesWritten = len(p) - len(s.dataForWriting)
 		deadline := s.writeDeadline
 		if !deadline.IsZero() && !time.Now().Before(deadline) {
+			s.dataForWriting = nil
 			err = errDeadline
 			break
 		}
@@ -120,7 +123,7 @@ func (s *sendStream) Write(p []byte) (int, error) {
 	} else if s.cancelWriteErr != nil {
 		err = s.cancelWriteErr
 	}
-	return len(p) - len(s.dataForWriting), err
+	return bytesWritten, err
 }
 
 // popStreamFrame returns the next STREAM frame that is supposed to be sent on this stream
diff --git a/send_stream_test.go b/send_stream_test.go
index f32cfb599..f8b77278c 100644
--- a/send_stream_test.go
+++ b/send_stream_test.go
@@ -245,6 +245,28 @@ var _ = Describe("Send Stream", func() {
 				Expect(n).To(BeEquivalentTo(frame.DataLen()))
 			})
 
+			It("doesn't pop any data after the deadline expired", func() {
+				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(10000)).AnyTimes()
+				mockFC.EXPECT().AddBytesSent(gomock.Any())
+				mockFC.EXPECT().IsNewlyBlocked()
+				deadline := time.Now().Add(scaleDuration(50 * time.Millisecond))
+				str.SetWriteDeadline(deadline)
+				writeReturned := make(chan struct{})
+				go func() {
+					defer GinkgoRecover()
+					_, err := strWithTimeout.Write(bytes.Repeat([]byte{0}, 100))
+					Expect(err).To(MatchError(errDeadline))
+					close(writeReturned)
+				}()
+				var frame *wire.StreamFrame
+				Eventually(func() *wire.StreamFrame {
+					frame = str.popStreamFrame(50)
+					return frame
+				}).ShouldNot(BeNil())
+				Eventually(writeReturned, scaleDuration(80*time.Millisecond)).Should(BeClosed())
+				Expect(str.popStreamFrame(50)).To(BeNil())
+			})
+
 			It("doesn't unblock if the deadline is changed before the first one expires", func() {
 				deadline1 := time.Now().Add(scaleDuration(50 * time.Millisecond))
 				deadline2 := time.Now().Add(scaleDuration(100 * time.Millisecond))