fix handling of unknown frames in the stream hijacker

http3/frames.go

@@ -33,11 +33,10 @@ func parseNextFrame(r io.Reader, unknownFrameHandler unknownFrameHandlerFunc) (f
 			if err != nil {
 				return nil, err
 			}
-			// If the unknownFrameHandler didn't process the frame, it is our responsibility to skip it.
 			if hijacked {
 				return nil, errHijacked
 			}
-			continue
+			// If the unknownFrameHandler didn't process the frame, it is our responsibility to skip it.
 		}
 		l, err := quicvarint.Read(qr)
 		if err != nil {

http3/frames_test.go

@@ -206,6 +206,7 @@ var _ = Describe("Frames", func() {
 			buf := &bytes.Buffer{}
 			quicvarint.Write(buf, 1337)
 			customFrameContents := []byte("custom frame")
+			quicvarint.Write(buf, uint64(len(customFrameContents)))
 			buf.Write(customFrameContents)
 			(&dataFrame{Length: 6}).Write(buf)
 			buf.WriteString("foobar")
@@ -214,10 +215,6 @@ var _ = Describe("Frames", func() {
 			frame, err := parseNextFrame(buf, func(ft FrameType) (hijacked bool, err error) {
 				Expect(ft).To(BeEquivalentTo(1337))
 				called = true
-				b := make([]byte, len(customFrameContents))
-				_, err = io.ReadFull(buf, b)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(b)).To(Equal(string(customFrameContents)))
 				return false, nil
 			})
 			Expect(err).ToNot(HaveOccurred())

http3/roundtrip.go

@@ -53,7 +53,7 @@ type RoundTripper struct {
 
 	// When set, this callback is called for the first unknown frame parsed on a bidirectional stream.
 	// It is called right after parsing the frame type.
-	// Callers can either process the frame and return control of the stream back to HTTP/3
+	// Callers can either ignore the frame and return control of the stream back to HTTP/3
 	// (by returning hijacked false).
 	// Alternatively, callers can take over the QUIC stream (by returning hijacked true).
 	StreamHijacker func(FrameType, quic.Connection, quic.Stream) (hijacked bool, err error)

http3/server.go

@@ -178,7 +178,7 @@ type Server struct {
 
 	// StreamHijacker, when set, is called for the first unknown frame parsed on a bidirectional stream.
 	// It is called right after parsing the frame type.
-	// Callers can either process the frame and return control of the stream back to HTTP/3
+	// Callers can either ignore the frame and return control of the stream back to HTTP/3
 	// (by returning hijacked false).
 	// Alternatively, callers can take over the QUIC stream (by returning hijacked true).
 	StreamHijacker func(FrameType, quic.Connection, quic.Stream) (hijacked bool, err error)