net/http: update bundled http2

Update bundled x/net/http2 to x/net git rev 6c4ac8bd for:

   http2: fix Transport race sending RST_STREAM while reading DATA on cancels
   https://golang.org/cl/32571

   http2: remove h2-14 ALPN proto
   https://golang.org/cl/32576

Fixes #16974

Change-Id: I6ff8493a13d2641499fedf33e8005004735352ff
Reviewed-on: https://go-review.googlesource.com/32578
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/net/http/h2_bundle.go b/src/net/http/h2_bundle.go
index f8398adb9239bde4a9bf2688b76edfa22d0f41bc..71f511723a683d8631299ab5e36f9963673dfa5e 100644 (file)
--- a/src/net/http/h2_bundle.go
+++ b/src/net/http/h2_bundle.go
@@ -3035,8 +3035,6 @@ func http2ConfigureServer(s *Server, conf *http2Server) error {
                s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, http2NextProtoTLS)
        }
 
-       s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, "h2-14")
-
        if s.TLSNextProto == nil {
                s.TLSNextProto = map[string]func(*Server, *tls.Conn, Handler){}
        }
@@ -3050,7 +3048,6 @@ func http2ConfigureServer(s *Server, conf *http2Server) error {
                })
        }
        s.TLSNextProto[http2NextProtoTLS] = protoHandler
-       s.TLSNextProto["h2-14"] = protoHandler
        return nil
 }
 
@@ -5474,6 +5471,7 @@ type http2clientStream struct {
        bytesRemain int64     // -1 means unknown; owned by transportResponseBody.Read
        readErr     error     // sticky read error; owned by transportResponseBody.Read
        stopReqBody error     // if non-nil, stop writing req body; guarded by cc.mu
+       didReset    bool      // whether we sent a RST_STREAM to the server; guarded by cc.mu
 
        peerReset chan struct{} // closed on peer reset
        resetErr  error         // populated before peerReset is closed
@@ -5501,15 +5499,26 @@ func (cs *http2clientStream) awaitRequestCancel(req *Request) {
        }
        select {
        case <-req.Cancel:
+               cs.cancelStream()
                cs.bufPipe.CloseWithError(http2errRequestCanceled)
-               cs.cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
        case <-ctx.Done():
+               cs.cancelStream()
                cs.bufPipe.CloseWithError(ctx.Err())
-               cs.cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
        case <-cs.done:
        }
 }
 
+func (cs *http2clientStream) cancelStream() {
+       cs.cc.mu.Lock()
+       didReset := cs.didReset
+       cs.didReset = true
+       cs.cc.mu.Unlock()
+
+       if !didReset {
+               cs.cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
+       }
+}
+
 // checkResetOrDone reports any error sent in a RST_STREAM frame by the
 // server, or errStreamClosed if the stream is complete.
 func (cs *http2clientStream) checkResetOrDone() error {
@@ -6853,9 +6862,10 @@ func (rl *http2clientConnReadLoop) processData(f *http2DataFrame) error {
                        cc.bw.Flush()
                        cc.wmu.Unlock()
                }
+               didReset := cs.didReset
                cc.mu.Unlock()
 
-               if len(data) > 0 {
+               if len(data) > 0 && !didReset {
                        if _, err := cs.bufPipe.Write(data); err != nil {
                                rl.endStreamError(cs, err)
                                return err