4 files changed, 37 insertions, 31 deletions

diff --git a/vendor/golang.org/x/net/http2/headermap.go b/vendor/golang.org/x/net/http2/headermap.go
index c2805f6ac..c3ff3fa1c 100644
--- a/vendor/golang.org/x/net/http2/headermap.go
+++ b/vendor/golang.org/x/net/http2/headermap.go
@@ -7,15 +7,21 @@ package http2
 import (
 	"net/http"
 	"strings"
+	"sync"
 )
 
 var (
-	commonLowerHeader = map[string]string{} // Go-Canonical-Case -> lower-case
-	commonCanonHeader = map[string]string{} // lower-case -> Go-Canonical-Case
+	commonBuildOnce   sync.Once
+	commonLowerHeader map[string]string // Go-Canonical-Case -> lower-case
+	commonCanonHeader map[string]string // lower-case -> Go-Canonical-Case
 )
 
-func init() {
-	for _, v := range []string{
+func buildCommonHeaderMapsOnce() {
+	commonBuildOnce.Do(buildCommonHeaderMaps)
+}
+
+func buildCommonHeaderMaps() {
+	common := []string{
 		"accept",
 		"accept-charset",
 		"accept-encoding",
@@ -63,7 +69,10 @@ func init() {
 		"vary",
 		"via",
 		"www-authenticate",
-	} {
+	}
+	commonLowerHeader = make(map[string]string, len(common))
+	commonCanonHeader = make(map[string]string, len(common))
+	for _, v := range common {
 		chk := http.CanonicalHeaderKey(v)
 		commonLowerHeader[chk] = v
 		commonCanonHeader[v] = chk
@@ -71,6 +80,7 @@ func init() {
 }
 
 func lowerHeader(v string) string {
+	buildCommonHeaderMapsOnce()
 	if s, ok := commonLowerHeader[v]; ok {
 		return s
 	}
diff --git a/vendor/golang.org/x/net/http2/hpack/huffman.go b/vendor/golang.org/x/net/http2/hpack/huffman.go
index 8850e3946..b412a96c5 100644
--- a/vendor/golang.org/x/net/http2/hpack/huffman.go
+++ b/vendor/golang.org/x/net/http2/hpack/huffman.go
@@ -47,6 +47,7 @@ var ErrInvalidHuffman = errors.New("hpack: invalid Huffman-encoded data")
 // If maxLen is greater than 0, attempts to write more to buf than
 // maxLen bytes will return ErrStringLength.
 func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
+	rootHuffmanNode := getRootHuffmanNode()
 	n := rootHuffmanNode
 	// cur is the bit buffer that has not been fed into n.
 	// cbits is the number of low order bits in cur that are valid.
@@ -106,7 +107,7 @@ func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
 
 type node struct {
 	// children is non-nil for internal nodes
-	children []*node
+	children *[256]*node
 
 	// The following are only valid if children is nil:
 	codeLen uint8 // number of bits that led to the output of sym
@@ -114,22 +115,31 @@ type node struct {
 }
 
 func newInternalNode() *node {
-	return &node{children: make([]*node, 256)}
+	return &node{children: new([256]*node)}
 }
 
-var rootHuffmanNode = newInternalNode()
+var (
+	buildRootOnce       sync.Once
+	lazyRootHuffmanNode *node
+)
+
+func getRootHuffmanNode() *node {
+	buildRootOnce.Do(buildRootHuffmanNode)
+	return lazyRootHuffmanNode
+}
 
-func init() {
+func buildRootHuffmanNode() {
 	if len(huffmanCodes) != 256 {
 		panic("unexpected size")
 	}
+	lazyRootHuffmanNode = newInternalNode()
 	for i, code := range huffmanCodes {
 		addDecoderNode(byte(i), code, huffmanCodeLen[i])
 	}
 }
 
 func addDecoderNode(sym byte, code uint32, codeLen uint8) {
-	cur := rootHuffmanNode
+	cur := lazyRootHuffmanNode
 	for codeLen > 8 {
 		codeLen -= 8
 		i := uint8(code >> codeLen)
diff --git a/vendor/golang.org/x/net/http2/http2.go b/vendor/golang.org/x/net/http2/http2.go
index c82428254..bdaba1d46 100644
--- a/vendor/golang.org/x/net/http2/http2.go
+++ b/vendor/golang.org/x/net/http2/http2.go
@@ -201,19 +201,12 @@ func validWireHeaderFieldName(v string) bool {
 	return true
 }
 
-var httpCodeStringCommon = map[int]string{} // n -> strconv.Itoa(n)
-
-func init() {
-	for i := 100; i <= 999; i++ {
-		if v := http.StatusText(i); v != "" {
-			httpCodeStringCommon[i] = strconv.Itoa(i)
-		}
-	}
-}
-
 func httpCodeString(code int) string {
-	if s, ok := httpCodeStringCommon[code]; ok {
-		return s
+	switch code {
+	case 200:
+		return "200"
+	case 404:
+		return "404"
 	}
 	return strconv.Itoa(code)
 }
diff --git a/vendor/golang.org/x/net/http2/server.go b/vendor/golang.org/x/net/http2/server.go
index 22cb18e06..56859d1f8 100644
--- a/vendor/golang.org/x/net/http2/server.go
+++ b/vendor/golang.org/x/net/http2/server.go
@@ -663,6 +663,7 @@ func (sc *serverConn) condlogf(err error, format string, args ...interface{}) {
 
 func (sc *serverConn) canonicalHeader(v string) string {
 	sc.serveG.check()
+	buildCommonHeaderMapsOnce()
 	cv, ok := commonCanonHeader[v]
 	if ok {
 		return cv
@@ -2346,15 +2347,7 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 		}
 		_, hasContentType := rws.snapHeader["Content-Type"]
 		if !hasContentType && bodyAllowedForStatus(rws.status) && len(p) > 0 {
-			if cto := rws.snapHeader.Get("X-Content-Type-Options"); strings.EqualFold("nosniff", cto) {
-				// nosniff is an explicit directive not to guess a content-type.
-				// Content-sniffing is no less susceptible to polyglot attacks via
-				// hosted content when done on the server.
-				ctype = "application/octet-stream"
-				rws.conn.logf("http2: WriteHeader called with X-Content-Type-Options:nosniff but no Content-Type")
-			} else {
-				ctype = http.DetectContentType(p)
-			}
+			ctype = http.DetectContentType(p)
 		}
 		var date string
 		if _, ok := rws.snapHeader["Date"]; !ok {