net/http: update bundled x/net/http2

Updates x/net/http2 (and x/net/lex/httplex) to git rev 749a502 for:

   http2: don't sniff first Request.Body byte in Transport until we have a conn
   https://golang.org/cl/29074
   Fixes #17071

   http2: add Transport support for unicode domain names
   https://golang.org/cl/29071
   Updates #13835

   http2: don't send bogus :path pseudo headers if Request.URL.Opaque is set
   https://golang.org/cl/27632
     +
   http2: fix bug where '*' as a valid :path value in Transport
   https://golang.org/cl/29070
   Updates #16847

   http2: fix all vet warnings
   https://golang.org/cl/28344
   Updates #16228
   Updates #11041

Also uses the new -underscore flag to x/tools/cmd/bundle from
https://golang.org/cl/29086

Change-Id: Ica0f6bf6e33266237e37527a166a783d78c059c4
Reviewed-on: https://go-review.googlesource.com/29110
Run-TryBot: Brad Fitzpatrick <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Chris Broadfoot <[email protected]>

Author: bradfitz

src/go/build/deps_test.go

@@ -379,6 +379,7 @@ var pkgDeps = map[string][]string{
 		"mime/multipart", "runtime/debug",
 		"net/http/internal",
 		"golang_org/x/net/http2/hpack",
+		"golang_org/x/net/idna",
 		"golang_org/x/net/lex/httplex",
 		"internal/nettrace",
 		"net/http/httptrace",

src/net/http/h2_bundle.go

@@ -10,8 +10,11 @@
 package httplex
 
 import (
+	"net"
 	"strings"
 	"unicode/utf8"
+
+	"golang_org/x/net/idna"
 )
 
 var isTokenTable = [127]bool{
@@ -310,3 +313,39 @@ func ValidHeaderFieldValue(v string) bool {
 	}
 	return true
 }
+
+func isASCII(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] >= utf8.RuneSelf {
+			return false
+		}
+	}
+	return true
+}
+
+// PunycodeHostPort returns the IDNA Punycode version
+// of the provided "host" or "host:port" string.
+func PunycodeHostPort(v string) (string, error) {
+	if isASCII(v) {
+		return v, nil
+	}
+
+	host, port, err := net.SplitHostPort(v)
+	if err != nil {
+		// The input 'v' argument was just a "host" argument,
+		// without a port. This error should not be returned
+		// to the caller.
+		host = v
+		port = ""
+	}
+	host, err = idna.ToASCII(host)
+	if err != nil {
+		// Non-UTF-8? Not representable in Punycode, in any
+		// case.
+		return "", err
+	}
+	if port == "" {
+		return host, nil
+	}
+	return net.JoinHostPort(host, port), nil
+}

src/vendor/golang_org/x/net/lex/httplex/httplex.go

@@ -99,3 +99,21 @@ func TestHeaderValuesContainsToken(t *testing.T) {
 		}
 	}
 }
+
+func TestPunycodeHostPort(t *testing.T) {
+	tests := []struct {
+		in, want string
+	}{
+		{"www.google.com", "www.google.com"},
+		{"гофер.рф", "xn--c1ae0ajs.xn--p1ai"},
+		{"bücher.de", "xn--bcher-kva.de"},
+		{"bücher.de:8080", "xn--bcher-kva.de:8080"},
+		{"[1::6]:8080", "[1::6]:8080"},
+	}
+	for _, tt := range tests {
+		got, err := PunycodeHostPort(tt.in)
+		if tt.want != got || err != nil {
+			t.Errorf("PunycodeHostPort(%q) = %q, %v, want %q, nil", tt.in, got, err, tt.want)
+		}
+	}
+}