check if the data stream is already closed after parsing an HTTP request

fixes #414

h2quic/server.go

@@ -154,6 +154,10 @@ func (s *Server) handleRequest(session streamCreator, headerStream utils.Stream,
 	if err != nil {
 		return err
 	}
+	// this can happen if the client immediately closes the data stream after sending the request and the runtime processes the reset before the request
+	if dataStream == nil {
+		return nil
+	}
 
 	var streamEnded bool
 	if h2headersFrame.StreamEnded() {

h2quic/server_test.go

@@ -25,7 +25,7 @@ import (
 type mockSession struct {
 	closed          bool
 	closedWithError error
-	dataStream      *mockStream
+	dataStream      utils.Stream
 }
 
 func (s *mockSession) GetOrOpenStream(id protocol.StreamID) (utils.Stream, error) {
@@ -153,6 +153,22 @@ var _ = Describe("H2 server", func() {
 			Expect(handlerCalled).To(BeTrue())
 		})
 
+		It("handles a request for which the client immediately resets the data stream", func() {
+			session.dataStream = nil
+			var handlerCalled bool
+			s.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				handlerCalled = true
+			})
+			headerStream.dataToRead.Write([]byte{
+				0x0, 0x0, 0x11, 0x1, 0x5, 0x0, 0x0, 0x0, 0x5,
+				// Taken from https://http2.github.io/http2-spec/compression.html#request.examples.with.huffman.coding
+				0x82, 0x86, 0x84, 0x41, 0x8c, 0xf1, 0xe3, 0xc2, 0xe5, 0xf2, 0x3a, 0x6b, 0xa0, 0xab, 0x90, 0xf4, 0xff,
+			})
+			err := s.handleRequest(session, headerStream, &sync.Mutex{}, hpackDecoder, h2framer)
+			Expect(err).NotTo(HaveOccurred())
+			Consistently(func() bool { return handlerCalled }).Should(BeFalse())
+		})
+
 		It("resets the dataStream when the body of POST request is not read, and the request handler replaces the request.Body", func() {
 			var handlerCalled bool
 			s.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {