net/http: update bundled x/net/http2

Updates x/net/http2 to git rev 1da14a5a36f220ea3f03470682b737b1dfd5de22 for:

    http2: make empty method mean GET
    https://golang.org/cl/169557 (Fixes golang/go#31061)

    http2: don't hang a stream if trailers values are not provided
    https://golang.org/cl/161958

Change-Id: I628af8c6d07d19e8f19ee37637243f6c242ef3a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/174677
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

src/net/http/h2_bundle.go

 // Code generated by golang.org/x/tools/cmd/bundle. DO NOT EDIT.
-//go:generate bundle -o h2_bundle.go -prefix http2 -underscore golang.org/x/net/http2
+//go:generate bundle -o h2_bundle.go -prefix http2 golang.org/x/net/http2
 
 // Package http2 implements the HTTP/2 protocol.
 //
@@ -1885,7 +1885,7 @@ func (f *http2Framer) WriteData(streamID uint32, endStream bool, data []byte) er
 	return f.WriteDataPadded(streamID, endStream, data, nil)
 }
 
-// WriteData writes a DATA frame with optional padding.
+// WriteDataPadded writes a DATA frame with optional padding.
 //
 // If pad is nil, the padding bit is not sent.
 // The length of pad must not exceed 255 bytes.
@@ -5870,7 +5870,16 @@ type http2chunkWriter struct{ rws *http2responseWriterState }
 
 func (cw http2chunkWriter) Write(p []byte) (n int, err error) { return cw.rws.writeChunk(p) }
 
-func (rws *http2responseWriterState) hasTrailers() bool { return len(rws.trailers) != 0 }
+func (rws *http2responseWriterState) hasTrailers() bool { return len(rws.trailers) > 0 }
+
+func (rws *http2responseWriterState) hasNonemptyTrailers() bool {
+	for _, trailer := range rws.trailers {
+		if _, ok := rws.handlerHeader[trailer]; ok {
+			return true
+		}
+	}
+	return false
+}
 
 // declareTrailer is called for each Trailer header when the
 // response header is written. It notes that a header will need to be
@@ -5970,7 +5979,10 @@ func (rws *http2responseWriterState) writeChunk(p []byte) (n int, err error) {
 		rws.promoteUndeclaredTrailers()
 	}
 
-	endStream := rws.handlerDone && !rws.hasTrailers()
+	// only send trailers if they have actually been defined by the
+	// server handler.
+	hasNonemptyTrailers := rws.hasNonemptyTrailers()
+	endStream := rws.handlerDone && !hasNonemptyTrailers
 	if len(p) > 0 || endStream {
 		// only send a 0 byte DATA frame if we're ending the stream.
 		if err := rws.conn.writeDataFromHandler(rws.stream, p, endStream); err != nil {
@@ -5979,7 +5991,7 @@ func (rws *http2responseWriterState) writeChunk(p []byte) (n int, err error) {
 		}
 	}
 
-	if rws.handlerDone && rws.hasTrailers() {
+	if rws.handlerDone && hasNonemptyTrailers {
 		err = rws.conn.writeHeaders(rws.stream, &http2writeResHeaders{
 			streamID:  rws.stream.id,
 			h:         rws.handlerHeader,
@@ -7834,7 +7846,11 @@ func (cc *http2ClientConn) encodeHeaders(req *Request, addGzipHeader bool, trail
 		// followed by the query production (see Sections 3.3 and 3.4 of
 		// [RFC3986]).
 		f(":authority", host)
-		f(":method", req.Method)
+		m := req.Method
+		if m == "" {
+			m = MethodGet
+		}
+		f(":method", m)
 		if req.Method != "CONNECT" {
 			f(":path", path)
 			f(":scheme", req.URL.Scheme)

src/net/http/socks_bundle.go

@@ -453,7 +453,7 @@ func (up *socksUsernamePassword) Authenticate(ctx context.Context, rw io.ReadWri
 		b = append(b, up.Username...)
 		b = append(b, byte(len(up.Password)))
 		b = append(b, up.Password...)
-		// TODO(mikio): handle IO deadlines and cancellation if
+		// TODO(mikio): handle IO deadlines and cancelation if
 		// necessary
 		if _, err := rw.Write(b); err != nil {
 			return err