net/http: update bundled http2, fixes TestConcurrentReadWriteReqBody_h2

Updates http2 to x/net git rev 520af5de654d for
https://golang.org/cl/18370

Fixes #13659

Change-Id: I920eaff6036ac22c500a97449826c6b12f873d7f
Reviewed-on: https://go-review.googlesource.com/18371
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>

src/net/http/clientserver_test.go

@@ -622,10 +622,7 @@ func testResponseBodyReadAfterClose(t *testing.T, h2 bool) {
 }
 
 func TestConcurrentReadWriteReqBody_h1(t *testing.T) { testConcurrentReadWriteReqBody(t, h1Mode) }
-func TestConcurrentReadWriteReqBody_h2(t *testing.T) {
-	t.Skip("known failing; golang.org/issue/13659")
-	testConcurrentReadWriteReqBody(t, h2Mode)
-}
+func TestConcurrentReadWriteReqBody_h2(t *testing.T) { testConcurrentReadWriteReqBody(t, h2Mode) }
 func testConcurrentReadWriteReqBody(t *testing.T, h2 bool) {
 	defer afterTest(t)
 	const reqBody = "some request body"
@@ -653,7 +650,7 @@ func testConcurrentReadWriteReqBody(t *testing.T, h2 bool) {
 				// our HTTP/1 implementation intentionally
 				// doesn't permit writes during read (mostly
 				// due to it being undefined); if that is ever
-				// relaxed, fix this.
+				// relaxed, change this.
 				<-didRead
 			}
 			io.WriteString(w, resBody)

src/net/http/h2_bundle.go

@@ -1406,10 +1406,6 @@ func http2parseContinuationFrame(fh http2FrameHeader, p []byte) (http2Frame, err
 	return &http2ContinuationFrame{fh, p}, nil
 }
 
-func (f *http2ContinuationFrame) StreamEnded() bool {
-	return f.http2FrameHeader.Flags.Has(http2FlagDataEndStream)
-}
-
 func (f *http2ContinuationFrame) HeaderBlockFragment() []byte {
 	f.checkValid()
 	return f.headerFragBuf
@@ -4222,8 +4218,8 @@ type http2clientStream struct {
 	done chan struct{} // closed when stream remove from cc.streams map; close calls guarded by cc.mu
 
 	// owned by clientConnReadLoop:
-	headersDone  bool // got HEADERS w/ END_HEADERS
-	trailersDone bool // got second HEADERS frame w/ END_HEADERS
+	pastHeaders  bool // got HEADERS w/ END_HEADERS
+	pastTrailers bool // got second HEADERS frame w/ END_HEADERS
 
 	trailer    Header // accumulated trailers
 	resTrailer Header // client's Response.Trailer
@@ -4926,6 +4922,7 @@ type http2clientConnReadLoop struct {
 	nextRes              *Response
 	sawRegHeader         bool  // saw non-pseudo header
 	reqMalformed         error // non-nil once known to be malformed
+	lastHeaderEndsStream bool
 }
 
 // readLoop runs in its own goroutine and reads and dispatches frames.
@@ -5018,26 +5015,28 @@ func (rl *http2clientConnReadLoop) run() error {
 func (rl *http2clientConnReadLoop) processHeaders(f *http2HeadersFrame) error {
 	rl.sawRegHeader = false
 	rl.reqMalformed = nil
+	rl.lastHeaderEndsStream = f.StreamEnded()
 	rl.nextRes = &Response{
 		Proto:      "HTTP/2.0",
 		ProtoMajor: 2,
 		Header:     make(Header),
 	}
-	return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded())
+	return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded())
 }
 
 func (rl *http2clientConnReadLoop) processContinuation(f *http2ContinuationFrame) error {
-	return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded())
+	return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded())
 }
 
-func (rl *http2clientConnReadLoop) processHeaderBlockFragment(frag []byte, streamID uint32, headersEnded, streamEnded bool) error {
+func (rl *http2clientConnReadLoop) processHeaderBlockFragment(frag []byte, streamID uint32, finalFrag bool) error {
 	cc := rl.cc
-	cs := cc.streamByID(streamID, streamEnded)
+	streamEnded := rl.lastHeaderEndsStream
+	cs := cc.streamByID(streamID, streamEnded && finalFrag)
 	if cs == nil {
 
 		return nil
 	}
-	if cs.headersDone {
+	if cs.pastHeaders {
 		rl.hdec.SetEmitFunc(cs.onNewTrailerField)
 	} else {
 		rl.hdec.SetEmitFunc(rl.onNewHeaderField)
@@ -5046,22 +5045,25 @@ func (rl *http2clientConnReadLoop) processHeaderBlockFragment(frag []byte, strea
 	if err != nil {
 		return http2ConnectionError(http2ErrCodeCompression)
 	}
+	if finalFrag {
 		if err := rl.hdec.Close(); err != nil {
 			return http2ConnectionError(http2ErrCodeCompression)
 		}
-	if !headersEnded {
+	}
+
+	if !finalFrag {
 		return nil
 	}
 
-	if !cs.headersDone {
-		cs.headersDone = true
+	if !cs.pastHeaders {
+		cs.pastHeaders = true
 	} else {
 
-		if cs.trailersDone {
+		if cs.pastTrailers {
 
 			return http2ConnectionError(http2ErrCodeProtocol)
 		}
-		cs.trailersDone = true
+		cs.pastTrailers = true
 		if !streamEnded {
 
 			return http2ConnectionError(http2ErrCodeProtocol)
@@ -5078,6 +5080,12 @@ func (rl *http2clientConnReadLoop) processHeaderBlockFragment(frag []byte, strea
 
 	res := rl.nextRes
 
+	if res.StatusCode == 100 {
+
+		cs.pastHeaders = false
+		return nil
+	}
+
 	if !streamEnded || cs.req.Method == "HEAD" {
 		res.ContentLength = -1
 		if clens := res.Header["Content-Length"]; len(clens) == 1 {