send OverlappingStreamData errors for overlapping StreamFrame data

fixes #115

session_test.go

@@ -214,12 +214,9 @@ var _ = Describe("Session", func() {
 
 		It("closes empty streams with error", func() {
 			testErr := errors.New("test")
-			session.handleStreamFrame(&frames.StreamFrame{
+			session.newStreamImpl(5)
-				StreamID: 5,
-			})
 			Expect(session.streams).To(HaveLen(2))
 			Expect(session.streams[5]).ToNot(BeNil())
-			Expect(streamCallbackCalled).To(BeTrue())
 			session.closeStreamsWithError(testErr)
 			_, err := session.streams[5].Read([]byte{0})
 			Expect(err).To(MatchError(testErr))

stream.go

@@ -254,8 +254,11 @@ func (s *stream) AddStreamFrame(frame *frames.StreamFrame) error {
 	}
 
 	s.mutex.Lock()
-	s.frameQueue.Push(frame)
+	defer s.mutex.Unlock()
-	s.mutex.Unlock()
+	err := s.frameQueue.Push(frame)
+	if err != nil && err != errDuplicateStreamData {
+		return err
+	}
 	s.newFrameOrErrCond.Signal()
 	return nil
 }

stream_test.go

@@ -190,14 +190,14 @@ var _ = Describe("Stream", func() {
 			Expect(b).To(Equal([]byte{0xDE, 0xAD, 0xBE, 0xEF}))
 		})
 
-		It("handles duplicate StreamFrames", func() {
+		It("ignores duplicate StreamFrames", func() {
 			frame1 := frames.StreamFrame{
 				Offset: 0,
 				Data:   []byte{0xDE, 0xAD},
 			}
 			frame2 := frames.StreamFrame{
 				Offset: 0,
-				Data:   []byte{0xDE, 0xAD},
+				Data:   []byte{0x13, 0x37},
 			}
 			frame3 := frames.StreamFrame{
 				Offset: 2,
@@ -216,7 +216,7 @@ var _ = Describe("Stream", func() {
 			Expect(b).To(Equal([]byte{0xDE, 0xAD, 0xBE, 0xEF}))
 		})
 
-		PIt("discards unneeded str frames", func() {
+		It("rejects a StreamFrames with an overlapping data range", func() {
 			frame1 := frames.StreamFrame{
 				Offset: 0,
 				Data:   []byte("ab"),
@@ -225,21 +225,10 @@ var _ = Describe("Stream", func() {
 				Offset: 1,
 				Data:   []byte("xy"),
 			}
-			frame3 := frames.StreamFrame{
-				Offset: 2,
-				Data:   []byte("cd"),
-			}
 			err := str.AddStreamFrame(&frame1)
 			Expect(err).ToNot(HaveOccurred())
 			err = str.AddStreamFrame(&frame2)
-			Expect(err).ToNot(HaveOccurred())
+			Expect(err).To(MatchError(errOverlappingStreamData))
-			err = str.AddStreamFrame(&frame3)
-			Expect(err).ToNot(HaveOccurred())
-			b := make([]byte, 4)
-			n, err := str.Read(b)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(n).To(Equal(4))
-			Expect(b).To(Equal([]byte("abyd")))
 		})
 
 		Context("flow control", func() {