update module dependencies to latest version

vendor/golang.org/x/net/http2/server.go

@@ -143,7 +143,7 @@ type Server struct {
 }
 
 func (s *Server) initialConnRecvWindowSize() int32 {
-	if s.MaxUploadBufferPerConnection > initialWindowSize {
+	if s.MaxUploadBufferPerConnection >= initialWindowSize {
 		return s.MaxUploadBufferPerConnection
 	}
 	return 1 << 20
@@ -869,9 +869,7 @@ func (sc *serverConn) serve() {
 
 	// Each connection starts with initialWindowSize inflow tokens.
 	// If a higher value is configured, we add more tokens.
-	if diff := sc.srv.initialConnRecvWindowSize() - initialWindowSize; diff > 0 {
-		sc.sendWindowUpdate(nil, int(diff))
-	}
+	sc.sendWindowUpdate(nil)
 
 	if err := sc.readPreface(); err != nil {
 		sc.condlogf(err, "http2: server: error reading preface from client %v: %v", sc.conn.RemoteAddr(), err)
@@ -1588,7 +1586,7 @@ func (sc *serverConn) closeStream(st *stream, err error) {
 	if p := st.body; p != nil {
 		// Return any buffered unread bytes worth of conn-level flow control.
 		// See golang.org/issue/16481
-		sc.sendWindowUpdate(nil, p.Len())
+		sc.sendWindowUpdate(nil)
 
 		p.CloseWithError(err)
 	}
@@ -1736,7 +1734,7 @@ func (sc *serverConn) processData(f *DataFrame) error {
 		// sendWindowUpdate, which also schedules sending the
 		// frames.
 		sc.inflow.take(int32(f.Length))
-		sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
+		sc.sendWindowUpdate(nil) // conn-level
 
 		if st != nil && st.resetQueued {
 			// Already have a stream error in flight. Don't send another.
@@ -1754,7 +1752,7 @@ func (sc *serverConn) processData(f *DataFrame) error {
 			return sc.countError("data_flow", streamError(id, ErrCodeFlowControl))
 		}
 		sc.inflow.take(int32(f.Length))
-		sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
+		sc.sendWindowUpdate(nil) // conn-level
 
 		st.body.CloseWithError(fmt.Errorf("sender tried to send more than declared Content-Length of %d bytes", st.declBodyBytes))
 		// RFC 7540, sec 8.1.2.6: A request or response is also malformed if the
@@ -1772,7 +1770,7 @@ func (sc *serverConn) processData(f *DataFrame) error {
 		if len(data) > 0 {
 			wrote, err := st.body.Write(data)
 			if err != nil {
-				sc.sendWindowUpdate(nil, int(f.Length)-wrote)
+				sc.sendWindowUpdate32(nil, int32(f.Length)-int32(wrote))
 				return sc.countError("body_write_err", streamError(id, ErrCodeStreamClosed))
 			}
 			if wrote != len(data) {
@@ -2099,12 +2097,6 @@ func (sc *serverConn) newWriterAndRequest(st *stream, f *MetaHeadersFrame) (*res
 		return nil, nil, sc.countError("bad_path_method", streamError(f.StreamID, ErrCodeProtocol))
 	}
 
-	bodyOpen := !f.StreamEnded()
-	if rp.method == "HEAD" && bodyOpen {
-		// HEAD requests can't have bodies
-		return nil, nil, sc.countError("head_body", streamError(f.StreamID, ErrCodeProtocol))
-	}
-
 	rp.header = make(http.Header)
 	for _, hf := range f.RegularFields() {
 		rp.header.Add(sc.canonicalHeader(hf.Name), hf.Value)
@@ -2117,6 +2109,7 @@ func (sc *serverConn) newWriterAndRequest(st *stream, f *MetaHeadersFrame) (*res
 	if err != nil {
 		return nil, nil, err
 	}
+	bodyOpen := !f.StreamEnded()
 	if bodyOpen {
 		if vv, ok := rp.header["Content-Length"]; ok {
 			if cl, err := strconv.ParseUint(vv[0], 10, 63); err == nil {
@@ -2329,17 +2322,32 @@ func (sc *serverConn) noteBodyReadFromHandler(st *stream, n int, err error) {
 
 func (sc *serverConn) noteBodyRead(st *stream, n int) {
 	sc.serveG.check()
-	sc.sendWindowUpdate(nil, n) // conn-level
+	sc.sendWindowUpdate(nil) // conn-level
 	if st.state != stateHalfClosedRemote && st.state != stateClosed {
 		// Don't send this WINDOW_UPDATE if the stream is closed
 		// remotely.
-		sc.sendWindowUpdate(st, n)
+		sc.sendWindowUpdate(st)
 	}
 }
 
 // st may be nil for conn-level
-func (sc *serverConn) sendWindowUpdate(st *stream, n int) {
+func (sc *serverConn) sendWindowUpdate(st *stream) {
 	sc.serveG.check()
+
+	var n int32
+	if st == nil {
+		if avail, windowSize := sc.inflow.available(), sc.srv.initialConnRecvWindowSize(); avail > windowSize/2 {
+			return
+		} else {
+			n = windowSize - avail
+		}
+	} else {
+		if avail, windowSize := st.inflow.available(), sc.srv.initialStreamRecvWindowSize(); avail > windowSize/2 {
+			return
+		} else {
+			n = windowSize - avail
+		}
+	}
 	// "The legal range for the increment to the flow control
 	// window is 1 to 2^31-1 (2,147,483,647) octets."
 	// A Go Read call on 64-bit machines could in theory read
@@ -2505,6 +2513,10 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 		rws.writeHeader(200)
 	}
 
+	if rws.handlerDone {
+		rws.promoteUndeclaredTrailers()
+	}
+
 	isHeadResp := rws.req.Method == "HEAD"
 	if !rws.sentHeader {
 		rws.sentHeader = true
@@ -2576,10 +2588,6 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 		return 0, nil
 	}
 
-	if rws.handlerDone {
-		rws.promoteUndeclaredTrailers()
-	}
-
 	// only send trailers if they have actually been defined by the
 	// server handler.
 	hasNonemptyTrailers := rws.hasNonemptyTrailers()