Update x/net (#5169)

Gopkg.lock

@@ -746,7 +746,8 @@
   revision = "12dd70caea0268ac0d6c2707d0611ef601e7c64e"
 
 [[projects]]
-  digest = "1:47ea747d07fae720d749d06ac5dc5ded0df70c57e328b6549cf2d9c64698757e"
+  branch = "master"
+  digest = "1:6d5ed712653ea5321fe3e3475ab2188cf362a4e0d31e9fd3acbd4dfbbca0d680"
   name = "golang.org/x/net"
   packages = [
     "context",
@@ -755,7 +756,7 @@
     "html/charset",
   ]
   pruneopts = "NUT"
-  revision = "f2499483f923065a842d38eb4c7f1927e6fc6e6d"
+  revision = "9b4f9f5ad5197c79fd623a3638e70d8b26cef344"
 
 [[projects]]
   digest = "1:8159a9cda4b8810aaaeb0d60e2fa68e2fd86d8af4ec8f5059830839e3c8d93d5"

Gopkg.toml

@@ -27,7 +27,7 @@ ignored = ["google.golang.org/appengine*"]
   name = "golang.org/x/text"
 
 [[constraint]]
-  revision = "f2499483f923065a842d38eb4c7f1927e6fc6e6d"
+  branch = "master"
   name = "golang.org/x/net"
 
 [[override]]

vendor/golang.org/x/net/context/context.go

@@ -5,6 +5,8 @@
 // Package context defines the Context type, which carries deadlines,
 // cancelation signals, and other request-scoped values across API boundaries
 // and between processes.
+// As of Go 1.7 this package is available in the standard library under the
+// name context.  https://golang.org/pkg/context.
 //
 // Incoming requests to a server should create a Context, and outgoing calls to
 // servers should accept a Context. The chain of function calls between must
@@ -36,103 +38,6 @@
 // Contexts.
 package context // import "golang.org/x/net/context"
 
-import "time"
-
-// A Context carries a deadline, a cancelation signal, and other values across
-// API boundaries.
-//
-// Context's methods may be called by multiple goroutines simultaneously.
-type Context interface {
-	// Deadline returns the time when work done on behalf of this context
-	// should be canceled.  Deadline returns ok==false when no deadline is
-	// set.  Successive calls to Deadline return the same results.
-	Deadline() (deadline time.Time, ok bool)
-
-	// Done returns a channel that's closed when work done on behalf of this
-	// context should be canceled.  Done may return nil if this context can
-	// never be canceled.  Successive calls to Done return the same value.
-	//
-	// WithCancel arranges for Done to be closed when cancel is called;
-	// WithDeadline arranges for Done to be closed when the deadline
-	// expires; WithTimeout arranges for Done to be closed when the timeout
-	// elapses.
-	//
-	// Done is provided for use in select statements:
-	//
-	//  // Stream generates values with DoSomething and sends them to out
-	//  // until DoSomething returns an error or ctx.Done is closed.
-	//  func Stream(ctx context.Context, out chan<- Value) error {
-	//  	for {
-	//  		v, err := DoSomething(ctx)
-	//  		if err != nil {
-	//  			return err
-	//  		}
-	//  		select {
-	//  		case <-ctx.Done():
-	//  			return ctx.Err()
-	//  		case out <- v:
-	//  		}
-	//  	}
-	//  }
-	//
-	// See http://blog.golang.org/pipelines for more examples of how to use
-	// a Done channel for cancelation.
-	Done() <-chan struct{}
-
-	// Err returns a non-nil error value after Done is closed.  Err returns
-	// Canceled if the context was canceled or DeadlineExceeded if the
-	// context's deadline passed.  No other values for Err are defined.
-	// After Done is closed, successive calls to Err return the same value.
-	Err() error
-
-	// Value returns the value associated with this context for key, or nil
-	// if no value is associated with key.  Successive calls to Value with
-	// the same key returns the same result.
-	//
-	// Use context values only for request-scoped data that transits
-	// processes and API boundaries, not for passing optional parameters to
-	// functions.
-	//
-	// A key identifies a specific value in a Context.  Functions that wish
-	// to store values in Context typically allocate a key in a global
-	// variable then use that key as the argument to context.WithValue and
-	// Context.Value.  A key can be any type that supports equality;
-	// packages should define keys as an unexported type to avoid
-	// collisions.
-	//
-	// Packages that define a Context key should provide type-safe accessors
-	// for the values stores using that key:
-	//
-	// 	// Package user defines a User type that's stored in Contexts.
-	// 	package user
-	//
-	// 	import "golang.org/x/net/context"
-	//
-	// 	// User is the type of value stored in the Contexts.
-	// 	type User struct {...}
-	//
-	// 	// key is an unexported type for keys defined in this package.
-	// 	// This prevents collisions with keys defined in other packages.
-	// 	type key int
-	//
-	// 	// userKey is the key for user.User values in Contexts.  It is
-	// 	// unexported; clients use user.NewContext and user.FromContext
-	// 	// instead of using this key directly.
-	// 	var userKey key = 0
-	//
-	// 	// NewContext returns a new Context that carries value u.
-	// 	func NewContext(ctx context.Context, u *User) context.Context {
-	// 		return context.WithValue(ctx, userKey, u)
-	// 	}
-	//
-	// 	// FromContext returns the User value stored in ctx, if any.
-	// 	func FromContext(ctx context.Context) (*User, bool) {
-	// 		u, ok := ctx.Value(userKey).(*User)
-	// 		return u, ok
-	// 	}
-	Value(key interface{}) interface{}
-}
-
 // Background returns a non-nil, empty Context. It is never canceled, has no
 // values, and has no deadline. It is typically used by the main function,
 // initialization, and tests, and as the top-level Context for incoming
@@ -149,8 +54,3 @@ func Background() Context {
 func TODO() Context {
 	return todo
 }
-
-// A CancelFunc tells an operation to abandon its work.
-// A CancelFunc does not wait for the work to stop.
-// After the first call, subsequent calls to a CancelFunc do nothing.
-type CancelFunc func()

vendor/golang.org/x/net/context/go19.go

@@ -0,0 +1,20 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.9
+
+package context
+
+import "context" // standard library's context, as of Go 1.7
+
+// A Context carries a deadline, a cancelation signal, and other values across
+// API boundaries.
+//
+// Context's methods may be called by multiple goroutines simultaneously.
+type Context = context.Context
+
+// A CancelFunc tells an operation to abandon its work.
+// A CancelFunc does not wait for the work to stop.
+// After the first call, subsequent calls to a CancelFunc do nothing.
+type CancelFunc = context.CancelFunc

vendor/golang.org/x/net/context/pre_go19.go

@@ -0,0 +1,109 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.9
+
+package context
+
+import "time"
+
+// A Context carries a deadline, a cancelation signal, and other values across
+// API boundaries.
+//
+// Context's methods may be called by multiple goroutines simultaneously.
+type Context interface {
+	// Deadline returns the time when work done on behalf of this context
+	// should be canceled. Deadline returns ok==false when no deadline is
+	// set. Successive calls to Deadline return the same results.
+	Deadline() (deadline time.Time, ok bool)
+
+	// Done returns a channel that's closed when work done on behalf of this
+	// context should be canceled. Done may return nil if this context can
+	// never be canceled. Successive calls to Done return the same value.
+	//
+	// WithCancel arranges for Done to be closed when cancel is called;
+	// WithDeadline arranges for Done to be closed when the deadline
+	// expires; WithTimeout arranges for Done to be closed when the timeout
+	// elapses.
+	//
+	// Done is provided for use in select statements:
+	//
+	//  // Stream generates values with DoSomething and sends them to out
+	//  // until DoSomething returns an error or ctx.Done is closed.
+	//  func Stream(ctx context.Context, out chan<- Value) error {
+	//  	for {
+	//  		v, err := DoSomething(ctx)
+	//  		if err != nil {
+	//  			return err
+	//  		}
+	//  		select {
+	//  		case <-ctx.Done():
+	//  			return ctx.Err()
+	//  		case out <- v:
+	//  		}
+	//  	}
+	//  }
+	//
+	// See http://blog.golang.org/pipelines for more examples of how to use
+	// a Done channel for cancelation.
+	Done() <-chan struct{}
+
+	// Err returns a non-nil error value after Done is closed. Err returns
+	// Canceled if the context was canceled or DeadlineExceeded if the
+	// context's deadline passed. No other values for Err are defined.
+	// After Done is closed, successive calls to Err return the same value.
+	Err() error
+
+	// Value returns the value associated with this context for key, or nil
+	// if no value is associated with key. Successive calls to Value with
+	// the same key returns the same result.
+	//
+	// Use context values only for request-scoped data that transits
+	// processes and API boundaries, not for passing optional parameters to
+	// functions.
+	//
+	// A key identifies a specific value in a Context. Functions that wish
+	// to store values in Context typically allocate a key in a global
+	// variable then use that key as the argument to context.WithValue and
+	// Context.Value. A key can be any type that supports equality;
+	// packages should define keys as an unexported type to avoid
+	// collisions.
+	//
+	// Packages that define a Context key should provide type-safe accessors
+	// for the values stores using that key:
+	//
+	// 	// Package user defines a User type that's stored in Contexts.
+	// 	package user
+	//
+	// 	import "golang.org/x/net/context"
+	//
+	// 	// User is the type of value stored in the Contexts.
+	// 	type User struct {...}
+	//
+	// 	// key is an unexported type for keys defined in this package.
+	// 	// This prevents collisions with keys defined in other packages.
+	// 	type key int
+	//
+	// 	// userKey is the key for user.User values in Contexts. It is
+	// 	// unexported; clients use user.NewContext and user.FromContext
+	// 	// instead of using this key directly.
+	// 	var userKey key = 0
+	//
+	// 	// NewContext returns a new Context that carries value u.
+	// 	func NewContext(ctx context.Context, u *User) context.Context {
+	// 		return context.WithValue(ctx, userKey, u)
+	// 	}
+	//
+	// 	// FromContext returns the User value stored in ctx, if any.
+	// 	func FromContext(ctx context.Context) (*User, bool) {
+	// 		u, ok := ctx.Value(userKey).(*User)
+	// 		return u, ok
+	// 	}
+	Value(key interface{}) interface{}
+}
+
+// A CancelFunc tells an operation to abandon its work.
+// A CancelFunc does not wait for the work to stop.
+// After the first call, subsequent calls to a CancelFunc do nothing.
+type CancelFunc func()

vendor/golang.org/x/net/html/atom/gen.go

@@ -4,17 +4,17 @@
 
 // +build ignore
 
+//go:generate go run gen.go
+//go:generate go run gen.go -test
+
 package main
 
-// This program generates table.go and table_test.go.
-// Invoke as
-//
-//	go run gen.go |gofmt >table.go
-//	go run gen.go -test |gofmt >table_test.go
-
 import (
+	"bytes"
 	"flag"
 	"fmt"
+	"go/format"
+	"io/ioutil"
 	"math/rand"
 	"os"
 	"sort"
@@ -42,6 +42,18 @@ func identifier(s string) string {
 
 var test = flag.Bool("test", false, "generate table_test.go")
 
+func genFile(name string, buf *bytes.Buffer) {
+	b, err := format.Source(buf.Bytes())
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	if err := ioutil.WriteFile(name, b, 0644); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
 func main() {
 	flag.Parse()
 
@@ -52,32 +64,31 @@ func main() {
 	all = append(all, extra...)
 	sort.Strings(all)
 
-	if *test {
-		fmt.Printf("// generated by go run gen.go -test; DO NOT EDIT\n\n")
-		fmt.Printf("package atom\n\n")
-		fmt.Printf("var testAtomList = []string{\n")
-		for _, s := range all {
-			fmt.Printf("\t%q,\n", s)
-		}
-		fmt.Printf("}\n")
-		return
-	}
-
 	// uniq - lists have dups
-	// compute max len too
-	maxLen := 0
 	w := 0
 	for _, s := range all {
 		if w == 0 || all[w-1] != s {
-			if maxLen < len(s) {
-				maxLen = len(s)
-			}
 			all[w] = s
 			w++
 		}
 	}
 	all = all[:w]
 
+	if *test {
+		var buf bytes.Buffer
+		fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n")
+		fmt.Fprintln(&buf, "//go:generate go run gen.go -test\n")
+		fmt.Fprintln(&buf, "package atom\n")
+		fmt.Fprintln(&buf, "var testAtomList = []string{")
+		for _, s := range all {
+			fmt.Fprintf(&buf, "\t%q,\n", s)
+		}
+		fmt.Fprintln(&buf, "}")
+
+		genFile("table_test.go", &buf)
+		return
+	}
+
 	// Find hash that minimizes table size.
 	var best *table
 	for i := 0; i < 1000000; i++ {
@@ -163,36 +174,46 @@ func main() {
 		atom[s] = uint32(off<<8 | len(s))
 	}
 
+	var buf bytes.Buffer
 	// Generate the Go code.
-	fmt.Printf("// generated by go run gen.go; DO NOT EDIT\n\n")
+	fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n")
-	fmt.Printf("package atom\n\nconst (\n")
+	fmt.Fprintln(&buf, "//go:generate go run gen.go\n")
+	fmt.Fprintln(&buf, "package atom\n\nconst (")
+
+	// compute max len
+	maxLen := 0
 	for _, s := range all {
-		fmt.Printf("\t%s Atom = %#x\n", identifier(s), atom[s])
+		if maxLen < len(s) {
+			maxLen = len(s)
 		}
-	fmt.Printf(")\n\n")
+		fmt.Fprintf(&buf, "\t%s Atom = %#x\n", identifier(s), atom[s])
+	}
+	fmt.Fprintln(&buf, ")\n")
 
-	fmt.Printf("const hash0 = %#x\n\n", best.h0)
+	fmt.Fprintf(&buf, "const hash0 = %#x\n\n", best.h0)
-	fmt.Printf("const maxAtomLen = %d\n\n", maxLen)
+	fmt.Fprintf(&buf, "const maxAtomLen = %d\n\n", maxLen)
 
-	fmt.Printf("var table = [1<<%d]Atom{\n", best.k)
+	fmt.Fprintf(&buf, "var table = [1<<%d]Atom{\n", best.k)
 	for i, s := range best.tab {
 		if s == "" {
 			continue
 		}
-		fmt.Printf("\t%#x: %#x, // %s\n", i, atom[s], s)
+		fmt.Fprintf(&buf, "\t%#x: %#x, // %s\n", i, atom[s], s)
 	}
-	fmt.Printf("}\n")
+	fmt.Fprintf(&buf, "}\n")
 	datasize := (1 << best.k) * 4
 
-	fmt.Printf("const atomText =\n")
+	fmt.Fprintln(&buf, "const atomText =")
 	textsize := len(text)
 	for len(text) > 60 {
-		fmt.Printf("\t%q +\n", text[:60])
+		fmt.Fprintf(&buf, "\t%q +\n", text[:60])
 		text = text[60:]
 	}
-	fmt.Printf("\t%q\n\n", text)
+	fmt.Fprintf(&buf, "\t%q\n\n", text)
 
-	fmt.Fprintf(os.Stderr, "%d atoms; %d string bytes + %d tables = %d total data\n", len(all), textsize, datasize, textsize+datasize)
+	genFile("table.go", &buf)
+
+	fmt.Fprintf(os.Stdout, "%d atoms; %d string bytes + %d tables = %d total data\n", len(all), textsize, datasize, textsize+datasize)
 }
 
 type byLen []string
@@ -285,8 +306,10 @@ func (t *table) push(i uint32, depth int) bool {
 
 // The lists of element names and attribute keys were taken from
 // https://html.spec.whatwg.org/multipage/indices.html#index
-// as of the "HTML Living Standard - Last Updated 21 February 2015" version.
+// as of the "HTML Living Standard - Last Updated 16 April 2018" version.
 
+// "command", "keygen" and "menuitem" have been removed from the spec,
+// but are kept here for backwards compatibility.
 var elements = []string{
 	"a",
 	"abbr",
@@ -349,6 +372,7 @@ var elements = []string{
 	"legend",
 	"li",
 	"link",
+	"main",
 	"map",
 	"mark",
 	"menu",
@@ -364,6 +388,7 @@ var elements = []string{
 	"output",
 	"p",
 	"param",
+	"picture",
 	"pre",
 	"progress",
 	"q",
@@ -375,6 +400,7 @@ var elements = []string{
 	"script",
 	"section",
 	"select",
+	"slot",
 	"small",
 	"source",
 	"span",
@@ -403,14 +429,21 @@ var elements = []string{
 }
 
 // https://html.spec.whatwg.org/multipage/indices.html#attributes-3
-
+//
+// "challenge", "command", "contextmenu", "dropzone", "icon", "keytype", "mediagroup",
+// "radiogroup", "spellcheck", "scoped", "seamless", "sortable" and "sorted" have been removed from the spec,
+// but are kept here for backwards compatibility.
 var attributes = []string{
 	"abbr",
 	"accept",
 	"accept-charset",
 	"accesskey",
 	"action",
+	"allowfullscreen",
+	"allowpaymentrequest",
+	"allowusermedia",
 	"alt",
+	"as",
 	"async",
 	"autocomplete",
 	"autofocus",
@@ -420,6 +453,7 @@ var attributes = []string{
 	"checked",
 	"cite",
 	"class",
+	"color",
 	"cols",
 	"colspan",
 	"command",
@@ -457,6 +491,8 @@ var attributes = []string{
 	"icon",
 	"id",
 	"inputmode",
+	"integrity",
+	"is",
 	"ismap",
 	"itemid",
 	"itemprop",
@@ -481,16 +517,20 @@ var attributes = []string{
 	"multiple",
 	"muted",
 	"name",
+	"nomodule",
+	"nonce",
 	"novalidate",
 	"open",
 	"optimum",
 	"pattern",
 	"ping",
 	"placeholder",
+	"playsinline",
 	"poster",
 	"preload",
 	"radiogroup",
 	"readonly",
+	"referrerpolicy",
 	"rel",
 	"required",
 	"reversed",
@@ -507,10 +547,13 @@ var attributes = []string{
 	"sizes",
 	"sortable",
 	"sorted",
+	"slot",
 	"span",
+	"spellcheck",
 	"src",
 	"srcdoc",
 	"srclang",
+	"srcset",
 	"start",
 	"step",
 	"style",
@@ -520,16 +563,22 @@ var attributes = []string{
 	"translate",
 	"type",
 	"typemustmatch",
+	"updateviacache",
 	"usemap",
 	"value",
 	"width",
+	"workertype",
 	"wrap",
 }
 
+// "onautocomplete", "onautocompleteerror", "onmousewheel",
+// "onshow" and "onsort" have been removed from the spec,
+// but are kept here for backwards compatibility.
 var eventHandlers = []string{
 	"onabort",
 	"onautocomplete",
 	"onautocompleteerror",
+	"onauxclick",
 	"onafterprint",
 	"onbeforeprint",
 	"onbeforeunload",
@@ -541,11 +590,14 @@ var eventHandlers = []string{
 	"onclick",
 	"onclose",
 	"oncontextmenu",
+	"oncopy",
 	"oncuechange",
+	"oncut",
 	"ondblclick",
 	"ondrag",
 	"ondragend",
 	"ondragenter",
+	"ondragexit",
 	"ondragleave",
 	"ondragover",
 	"ondragstart",
@@ -565,18 +617,24 @@ var eventHandlers = []string{
 	"onload",
 	"onloadeddata",
 	"onloadedmetadata",
+	"onloadend",
 	"onloadstart",
 	"onmessage",
+	"onmessageerror",
 	"onmousedown",
+	"onmouseenter",
+	"onmouseleave",
 	"onmousemove",
 	"onmouseout",
 	"onmouseover",
 	"onmouseup",
 	"onmousewheel",
+	"onwheel",
 	"onoffline",
 	"ononline",
 	"onpagehide",
 	"onpageshow",
+	"onpaste",
 	"onpause",
 	"onplay",
 	"onplaying",
@@ -585,7 +643,9 @@ var eventHandlers = []string{
 	"onratechange",
 	"onreset",
 	"onresize",
+	"onrejectionhandled",
 	"onscroll",
+	"onsecuritypolicyviolation",
 	"onseeked",
 	"onseeking",
 	"onselect",
@@ -597,6 +657,7 @@ var eventHandlers = []string{
 	"onsuspend",
 	"ontimeupdate",
 	"ontoggle",
+	"onunhandledrejection",
 	"onunload",
 	"onvolumechange",
 	"onwaiting",
@@ -604,6 +665,7 @@ var eventHandlers = []string{
 
 // extra are ad-hoc values not covered by any of the lists above.
 var extra = []string{
+	"acronym",
 	"align",
 	"annotation",
 	"annotation-xml",
@@ -639,6 +701,8 @@ var extra = []string{
 	"plaintext",
 	"prompt",
 	"public",
+	"rb",
+	"rtc",
 	"spacer",
 	"strike",
 	"svg",

vendor/golang.org/x/net/html/const.go

@@ -4,7 +4,7 @@
 
 package html
 
-// Section 12.2.3.2 of the HTML5 specification says "The following elements
+// Section 12.2.4.2 of the HTML5 specification says "The following elements
 // have varying levels of special parsing rules".
 // https://html.spec.whatwg.org/multipage/syntax.html#the-stack-of-open-elements
 var isSpecialElementMap = map[string]bool{
@@ -52,10 +52,12 @@ var isSpecialElementMap = map[string]bool{
 	"iframe":     true,
 	"img":        true,
 	"input":      true,
-	"isindex":    true,
+	"isindex":    true, // The 'isindex' element has been removed, but keep it for backwards compatibility.
+	"keygen":     true,
 	"li":         true,
 	"link":       true,
 	"listing":    true,
+	"main":       true,
 	"marquee":    true,
 	"menu":       true,
 	"meta":       true,
@@ -95,8 +97,16 @@ func isSpecialElement(element *Node) bool {
 	switch element.Namespace {
 	case "", "html":
 		return isSpecialElementMap[element.Data]
+	case "math":
+		switch element.Data {
+		case "mi", "mo", "mn", "ms", "mtext", "annotation-xml":
+			return true
+		}
 	case "svg":
-		return element.Data == "foreignObject"
+		switch element.Data {
+		case "foreignObject", "desc", "title":
+			return true
+		}
 	}
 	return false
 }

vendor/golang.org/x/net/html/doc.go

@@ -49,18 +49,18 @@ call to Next. For example, to extract an HTML page's anchor text:
 	for {
 		tt := z.Next()
 		switch tt {
-		case ErrorToken:
+		case html.ErrorToken:
 			return z.Err()
-		case TextToken:
+		case html.TextToken:
 			if depth > 0 {
 				// emitBytes should copy the []byte it receives,
 				// if it doesn't process it immediately.
 				emitBytes(z.Text())
 			}
-		case StartTagToken, EndTagToken:
+		case html.StartTagToken, html.EndTagToken:
 			tn, _ := z.TagName()
 			if len(tn) == 1 && tn[0] == 'a' {
-				if tt == StartTagToken {
+				if tt == html.StartTagToken {
 					depth++
 				} else {
 					depth--

vendor/golang.org/x/net/html/foreign.go

@@ -67,7 +67,7 @@ func mathMLTextIntegrationPoint(n *Node) bool {
 	return false
 }
 
-// Section 12.2.5.5.
+// Section 12.2.6.5.
 var breakout = map[string]bool{
 	"b":          true,
 	"big":        true,
@@ -115,7 +115,7 @@ var breakout = map[string]bool{
 	"var":        true,
 }
 
-// Section 12.2.5.5.
+// Section 12.2.6.5.
 var svgTagNameAdjustments = map[string]string{
 	"altglyph":            "altGlyph",
 	"altglyphdef":         "altGlyphDef",
@@ -155,7 +155,7 @@ var svgTagNameAdjustments = map[string]string{
 	"textpath":            "textPath",
 }
 
-// Section 12.2.5.1
+// Section 12.2.6.1
 var mathMLAttributeAdjustments = map[string]string{
 	"definitionurl": "definitionURL",
 }

vendor/golang.org/x/net/html/node.go

@@ -21,9 +21,10 @@ const (
 	scopeMarkerNode
 )
 
-// Section 12.2.3.3 says "scope markers are inserted when entering applet
+// Section 12.2.4.3 says "The markers are inserted when entering applet,
-// elements, buttons, object elements, marquees, table cells, and table
+// object, marquee, template, td, th, and caption elements, and are used
-// captions, and are used to prevent formatting from 'leaking'".
+// to prevent formatting from "leaking" into applet, object, marquee,
+// template, td, th, and caption elements".
 var scopeMarker = Node{Type: scopeMarkerNode}
 
 // A Node consists of a NodeType and some Data (tag name for element nodes,
@@ -173,6 +174,16 @@ func (s *nodeStack) index(n *Node) int {
 	return -1
 }
 
+// contains returns whether a is within s.
+func (s *nodeStack) contains(a atom.Atom) bool {
+	for _, n := range *s {
+		if n.DataAtom == a {
+			return true
+		}
+	}
+	return false
+}
+
 // insert inserts a node at the given index.
 func (s *nodeStack) insert(i int, n *Node) {
 	(*s) = append(*s, nil)
@@ -191,3 +202,19 @@ func (s *nodeStack) remove(n *Node) {
 	(*s)[j] = nil
 	*s = (*s)[:j]
 }
+
+type insertionModeStack []insertionMode
+
+func (s *insertionModeStack) pop() (im insertionMode) {
+	i := len(*s)
+	im = (*s)[i-1]
+	*s = (*s)[:i-1]
+	return im
+}
+
+func (s *insertionModeStack) top() insertionMode {
+	if i := len(*s); i > 0 {
+		return (*s)[i-1]
+	}
+	return nil
+}

vendor/golang.org/x/net/html/parse.go

@@ -25,20 +25,22 @@ type parser struct {
 	hasSelfClosingToken bool
 	// doc is the document root element.
 	doc *Node
-	// The stack of open elements (section 12.2.3.2) and active formatting
+	// The stack of open elements (section 12.2.4.2) and active formatting
-	// elements (section 12.2.3.3).
+	// elements (section 12.2.4.3).
 	oe, afe nodeStack
-	// Element pointers (section 12.2.3.4).
+	// Element pointers (section 12.2.4.4).
 	head, form *Node
-	// Other parsing state flags (section 12.2.3.5).
+	// Other parsing state flags (section 12.2.4.5).
 	scripting, framesetOK bool
+	// The stack of template insertion modes
+	templateStack insertionModeStack
 	// im is the current insertion mode.
 	im insertionMode
 	// originalIM is the insertion mode to go back to after completing a text
 	// or inTableText insertion mode.
 	originalIM insertionMode
 	// fosterParenting is whether new elements should be inserted according to
-	// the foster parenting rules (section 12.2.5.3).
+	// the foster parenting rules (section 12.2.6.1).
 	fosterParenting bool
 	// quirks is whether the parser is operating in "quirks mode."
 	quirks bool
@@ -56,7 +58,7 @@ func (p *parser) top() *Node {
 	return p.doc
 }
 
-// Stop tags for use in popUntil. These come from section 12.2.3.2.
+// Stop tags for use in popUntil. These come from section 12.2.4.2.
 var (
 	defaultScopeStopTags = map[string][]a.Atom{
 		"":     {a.Applet, a.Caption, a.Html, a.Table, a.Td, a.Th, a.Marquee, a.Object, a.Template},
@@ -79,7 +81,7 @@ const (
 
 // popUntil pops the stack of open elements at the highest element whose tag
 // is in matchTags, provided there is no higher element in the scope's stop
-// tags (as defined in section 12.2.3.2). It returns whether or not there was
+// tags (as defined in section 12.2.4.2). It returns whether or not there was
 // such an element. If there was not, popUntil leaves the stack unchanged.
 //
 // For example, the set of stop tags for table scope is: "html", "table". If
@@ -126,7 +128,7 @@ func (p *parser) indexOfElementInScope(s scope, matchTags ...a.Atom) int {
 					return -1
 				}
 			case tableScope:
-				if tagAtom == a.Html || tagAtom == a.Table {
+				if tagAtom == a.Html || tagAtom == a.Table || tagAtom == a.Template {
 					return -1
 				}
 			case selectScope:
@@ -162,17 +164,17 @@ func (p *parser) clearStackToContext(s scope) {
 		tagAtom := p.oe[i].DataAtom
 		switch s {
 		case tableScope:
-			if tagAtom == a.Html || tagAtom == a.Table {
+			if tagAtom == a.Html || tagAtom == a.Table || tagAtom == a.Template {
 				p.oe = p.oe[:i+1]
 				return
 			}
 		case tableRowScope:
-			if tagAtom == a.Html || tagAtom == a.Tr {
+			if tagAtom == a.Html || tagAtom == a.Tr || tagAtom == a.Template {
 				p.oe = p.oe[:i+1]
 				return
 			}
 		case tableBodyScope:
-			if tagAtom == a.Html || tagAtom == a.Tbody || tagAtom == a.Tfoot || tagAtom == a.Thead {
+			if tagAtom == a.Html || tagAtom == a.Tbody || tagAtom == a.Tfoot || tagAtom == a.Thead || tagAtom == a.Template {
 				p.oe = p.oe[:i+1]
 				return
 			}
@@ -183,7 +185,7 @@ func (p *parser) clearStackToContext(s scope) {
 }
 
 // generateImpliedEndTags pops nodes off the stack of open elements as long as
-// the top node has a tag name of dd, dt, li, option, optgroup, p, rp, or rt.
+// the top node has a tag name of dd, dt, li, optgroup, option, p, rb, rp, rt or rtc.
 // If exceptions are specified, nodes with that name will not be popped off.
 func (p *parser) generateImpliedEndTags(exceptions ...string) {
 	var i int
@@ -192,7 +194,7 @@ loop:
 		n := p.oe[i]
 		if n.Type == ElementNode {
 			switch n.DataAtom {
-			case a.Dd, a.Dt, a.Li, a.Option, a.Optgroup, a.P, a.Rp, a.Rt:
+			case a.Dd, a.Dt, a.Li, a.Optgroup, a.Option, a.P, a.Rb, a.Rp, a.Rt, a.Rtc:
 				for _, except := range exceptions {
 					if n.Data == except {
 						break loop
@@ -234,9 +236,9 @@ func (p *parser) shouldFosterParent() bool {
 }
 
 // fosterParent adds a child node according to the foster parenting rules.
-// Section 12.2.5.3, "foster parenting".
+// Section 12.2.6.1, "foster parenting".
 func (p *parser) fosterParent(n *Node) {
-	var table, parent, prev *Node
+	var table, parent, prev, template *Node
 	var i int
 	for i = len(p.oe) - 1; i >= 0; i-- {
 		if p.oe[i].DataAtom == a.Table {
@@ -245,6 +247,19 @@ func (p *parser) fosterParent(n *Node) {
 		}
 	}
 
+	var j int
+	for j = len(p.oe) - 1; j >= 0; j-- {
+		if p.oe[j].DataAtom == a.Template {
+			template = p.oe[j]
+			break
+		}
+	}
+
+	if template != nil && (table == nil || j > i) {
+		template.AppendChild(n)
+		return
+	}
+
 	if table == nil {
 		// The foster parent is the html element.
 		parent = p.oe[0]
@@ -304,7 +319,7 @@ func (p *parser) addElement() {
 	})
 }
 
-// Section 12.2.3.3.
+// Section 12.2.4.3.
 func (p *parser) addFormattingElement() {
 	tagAtom, attr := p.tok.DataAtom, p.tok.Attr
 	p.addElement()
@@ -351,7 +366,7 @@ findIdenticalElements:
 	p.afe = append(p.afe, p.top())
 }
 
-// Section 12.2.3.3.
+// Section 12.2.4.3.
 func (p *parser) clearActiveFormattingElements() {
 	for {
 		n := p.afe.pop()
@@ -361,7 +376,7 @@ func (p *parser) clearActiveFormattingElements() {
 	}
 }
 
-// Section 12.2.3.3.
+// Section 12.2.4.3.
 func (p *parser) reconstructActiveFormattingElements() {
 	n := p.afe.top()
 	if n == nil {
@@ -390,12 +405,12 @@ func (p *parser) reconstructActiveFormattingElements() {
 	}
 }
 
-// Section 12.2.4.
+// Section 12.2.5.
 func (p *parser) acknowledgeSelfClosingTag() {
 	p.hasSelfClosingToken = false
 }
 
-// An insertion mode (section 12.2.3.1) is the state transition function from
+// An insertion mode (section 12.2.4.1) is the state transition function from
 // a particular state in the HTML5 parser's state machine. It updates the
 // parser's fields depending on parser.tok (where ErrorToken means EOF).
 // It returns whether the token was consumed.
@@ -403,7 +418,7 @@ type insertionMode func(*parser) bool
 
 // setOriginalIM sets the insertion mode to return to after completing a text or
 // inTableText insertion mode.
-// Section 12.2.3.1, "using the rules for".
+// Section 12.2.4.1, "using the rules for".
 func (p *parser) setOriginalIM() {
 	if p.originalIM != nil {
 		panic("html: bad parser state: originalIM was set twice")
@@ -411,18 +426,38 @@ func (p *parser) setOriginalIM() {
 	p.originalIM = p.im
 }
 
-// Section 12.2.3.1, "reset the insertion mode".
+// Section 12.2.4.1, "reset the insertion mode".
 func (p *parser) resetInsertionMode() {
 	for i := len(p.oe) - 1; i >= 0; i-- {
 		n := p.oe[i]
-		if i == 0 && p.context != nil {
+		last := i == 0
+		if last && p.context != nil {
 			n = p.context
 		}
 
 		switch n.DataAtom {
 		case a.Select:
+			if !last {
+				for ancestor, first := n, p.oe[0]; ancestor != first; {
+					if ancestor == first {
+						break
+					}
+					ancestor = p.oe[p.oe.index(ancestor)-1]
+					switch ancestor.DataAtom {
+					case a.Template:
+						p.im = inSelectIM
+						return
+					case a.Table:
+						p.im = inSelectInTableIM
+						return
+					}
+				}
+			}
 			p.im = inSelectIM
 		case a.Td, a.Th:
+			// TODO: remove this divergence from the HTML5 spec.
+			//
+			// See https://bugs.chromium.org/p/chromium/issues/detail?id=829668
 			p.im = inCellIM
 		case a.Tr:
 			p.im = inRowIM
@@ -434,25 +469,41 @@ func (p *parser) resetInsertionMode() {
 			p.im = inColumnGroupIM
 		case a.Table:
 			p.im = inTableIM
+		case a.Template:
+			// TODO: remove this divergence from the HTML5 spec.
+			if n.Namespace != "" {
+				continue
+			}
+			p.im = p.templateStack.top()
 		case a.Head:
-			p.im = inBodyIM
+			// TODO: remove this divergence from the HTML5 spec.
+			//
+			// See https://bugs.chromium.org/p/chromium/issues/detail?id=829668
+			p.im = inHeadIM
 		case a.Body:
 			p.im = inBodyIM
 		case a.Frameset:
 			p.im = inFramesetIM
 		case a.Html:
+			if p.head == nil {
 				p.im = beforeHeadIM
+			} else {
+				p.im = afterHeadIM
+			}
 		default:
+			if last {
+				p.im = inBodyIM
+				return
+			}
 			continue
 		}
 		return
 	}
-	p.im = inBodyIM
 }
 
 const whitespace = " \t\r\n\f"
 
-// Section 12.2.5.4.1.
+// Section 12.2.6.4.1.
 func initialIM(p *parser) bool {
 	switch p.tok.Type {
 	case TextToken:
@@ -479,7 +530,7 @@ func initialIM(p *parser) bool {
 	return false
 }
 
-// Section 12.2.5.4.2.
+// Section 12.2.6.4.2.
 func beforeHTMLIM(p *parser) bool {
 	switch p.tok.Type {
 	case DoctypeToken:
@@ -517,7 +568,7 @@ func beforeHTMLIM(p *parser) bool {
 	return false
 }
 
-// Section 12.2.5.4.3.
+// Section 12.2.6.4.3.
 func beforeHeadIM(p *parser) bool {
 	switch p.tok.Type {
 	case TextToken:
@@ -560,7 +611,7 @@ func beforeHeadIM(p *parser) bool {
 	return false
 }
 
-// Section 12.2.5.4.4.
+// Section 12.2.6.4.4.
 func inHeadIM(p *parser) bool {
 	switch p.tok.Type {
 	case TextToken:
@@ -590,19 +641,41 @@ func inHeadIM(p *parser) bool {
 		case a.Head:
 			// Ignore the token.
 			return true
+		case a.Template:
+			p.addElement()
+			p.afe = append(p.afe, &scopeMarker)
+			p.framesetOK = false
+			p.im = inTemplateIM
+			p.templateStack = append(p.templateStack, inTemplateIM)
+			return true
 		}
 	case EndTagToken:
 		switch p.tok.DataAtom {
 		case a.Head:
-			n := p.oe.pop()
+			p.oe.pop()
-			if n.DataAtom != a.Head {
-				panic("html: bad parser state: <head> element not found, in the in-head insertion mode")
-			}
 			p.im = afterHeadIM
 			return true
 		case a.Body, a.Html, a.Br:
 			p.parseImpliedToken(EndTagToken, a.Head, a.Head.String())
 			return false
+		case a.Template:
+			if !p.oe.contains(a.Template) {
+				return true
+			}
+			// TODO: remove this divergence from the HTML5 spec.
+			//
+			// See https://bugs.chromium.org/p/chromium/issues/detail?id=829668
+			p.generateImpliedEndTags()
+			for i := len(p.oe) - 1; i >= 0; i-- {
+				if n := p.oe[i]; n.Namespace == "" && n.DataAtom == a.Template {
+					p.oe = p.oe[:i]
+					break
+				}
+			}
+			p.clearActiveFormattingElements()
+			p.templateStack.pop()
+			p.resetInsertionMode()
+			return true
 		default:
 			// Ignore the token.
 			return true
@@ -622,7 +695,7 @@ func inHeadIM(p *parser) bool {
 	return false
 }
 
-// Section 12.2.5.4.6.
+// Section 12.2.6.4.6.
 func afterHeadIM(p *parser) bool {
 	switch p.tok.Type {
 	case TextToken:
@@ -648,7 +721,7 @@ func afterHeadIM(p *parser) bool {
 			p.addElement()
 			p.im = inFramesetIM
 			return true
-		case a.Base, a.Basefont, a.Bgsound, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Title:
+		case a.Base, a.Basefont, a.Bgsound, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Template, a.Title:
 			p.oe = append(p.oe, p.head)
 			defer p.oe.remove(p.head)
 			return inHeadIM(p)
@@ -660,6 +733,8 @@ func afterHeadIM(p *parser) bool {
 		switch p.tok.DataAtom {
 		case a.Body, a.Html, a.Br:
 			// Drop down to creating an implied <body> tag.
+		case a.Template:
+			return inHeadIM(p)
 		default:
 			// Ignore the token.
 			return true
@@ -697,7 +772,7 @@ func copyAttributes(dst *Node, src Token) {
 	}
 }
 
-// Section 12.2.5.4.7.
+// Section 12.2.6.4.7.
 func inBodyIM(p *parser) bool {
 	switch p.tok.Type {
 	case TextToken:
@@ -727,10 +802,16 @@ func inBodyIM(p *parser) bool {
 	case StartTagToken:
 		switch p.tok.DataAtom {
 		case a.Html:
+			if p.oe.contains(a.Template) {
+				return true
+			}
 			copyAttributes(p.oe[0], p.tok)
-		case a.Base, a.Basefont, a.Bgsound, a.Command, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Title:
+		case a.Base, a.Basefont, a.Bgsound, a.Command, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Template, a.Title:
 			return inHeadIM(p)
 		case a.Body:
+			if p.oe.contains(a.Template) {
+				return true
+			}
 			if len(p.oe) >= 2 {
 				body := p.oe[1]
 				if body.Type == ElementNode && body.DataAtom == a.Body {
@@ -767,9 +848,13 @@ func inBodyIM(p *parser) bool {
 			// The newline, if any, will be dealt with by the TextToken case.
 			p.framesetOK = false
 		case a.Form:
-			if p.form == nil {
+			if p.form != nil && !p.oe.contains(a.Template) {
+				// Ignore the token
+				return true
+			}
 			p.popUntil(buttonScope, a.P)
 			p.addElement()
+			if !p.oe.contains(a.Template) {
 				p.form = p.top()
 			}
 		case a.Li:
@@ -903,6 +988,14 @@ func inBodyIM(p *parser) bool {
 			p.acknowledgeSelfClosingTag()
 			p.popUntil(buttonScope, a.P)
 			p.parseImpliedToken(StartTagToken, a.Form, a.Form.String())
+			if p.form == nil {
+				// NOTE: The 'isindex' element has been removed,
+				// and the 'template' element has not been designed to be
+				// collaborative with the index element.
+				//
+				// Ignore the token.
+				return true
+			}
 			if action != "" {
 				p.form.Attr = []Attribute{{Key: "action", Val: action}}
 			}
@@ -952,11 +1045,16 @@ func inBodyIM(p *parser) bool {
 			}
 			p.reconstructActiveFormattingElements()
 			p.addElement()
-		case a.Rp, a.Rt:
+		case a.Rb, a.Rtc:
 			if p.elementInScope(defaultScope, a.Ruby) {
 				p.generateImpliedEndTags()
 			}
 			p.addElement()
+		case a.Rp, a.Rt:
+			if p.elementInScope(defaultScope, a.Ruby) {
+				p.generateImpliedEndTags("rtc")
+			}
+			p.addElement()
 		case a.Math, a.Svg:
 			p.reconstructActiveFormattingElements()
 			if p.tok.DataAtom == a.Math {
@@ -993,6 +1091,19 @@ func inBodyIM(p *parser) bool {
 		case a.Address, a.Article, a.Aside, a.Blockquote, a.Button, a.Center, a.Details, a.Dir, a.Div, a.Dl, a.Fieldset, a.Figcaption, a.Figure, a.Footer, a.Header, a.Hgroup, a.Listing, a.Menu, a.Nav, a.Ol, a.Pre, a.Section, a.Summary, a.Ul:
 			p.popUntil(defaultScope, p.tok.DataAtom)
 		case a.Form:
+			if p.oe.contains(a.Template) {
+				i := p.indexOfElementInScope(defaultScope, a.Form)
+				if i == -1 {
+					// Ignore the token.
+					return true
+				}
+				p.generateImpliedEndTags()
+				if p.oe[i].DataAtom != a.Form {
+					// Ignore the token.
+					return true
+				}
+				p.popUntil(defaultScope, a.Form)
+			} else {
 				node := p.form
 				p.form = nil
 				i := p.indexOfElementInScope(defaultScope, a.Form)
@@ -1002,6 +1113,7 @@ func inBodyIM(p *parser) bool {
 				}
 				p.generateImpliedEndTags()
 				p.oe.remove(node)
+			}
 		case a.P:
 			if !p.elementInScope(buttonScope, a.P) {
 				p.parseImpliedToken(StartTagToken, a.P, a.P.String())
@@ -1022,6 +1134,8 @@ func inBodyIM(p *parser) bool {
 		case a.Br:
 			p.tok.Type = StartTagToken
 			return false
+		case a.Template:
+			return inHeadIM(p)
 		default:
 			p.inBodyEndTagOther(p.tok.DataAtom)
 		}
@@ -1030,6 +1144,21 @@ func inBodyIM(p *parser) bool {
 			Type: CommentNode,
 			Data: p.tok.Data,
 		})
+	case ErrorToken:
+		// TODO: remove this divergence from the HTML5 spec.
+		if len(p.templateStack) > 0 {
+			p.im = inTemplateIM
+			return false
+		} else {
+			for _, e := range p.oe {
+				switch e.DataAtom {
+				case a.Dd, a.Dt, a.Li, a.Optgroup, a.Option, a.P, a.Rb, a.Rp, a.Rt, a.Rtc, a.Tbody, a.Td, a.Tfoot, a.Th,
+					a.Thead, a.Tr, a.Body, a.Html:
+				default:
+					return true
+				}
+			}
+		}
 	}
 
 	return true
@@ -1160,7 +1289,7 @@ func (p *parser) inBodyEndTagFormatting(tagAtom a.Atom) {
 }
 
 // inBodyEndTagOther performs the "any other end tag" algorithm for inBodyIM.
-// "Any other end tag" handling from 12.2.5.5 The rules for parsing tokens in foreign content
+// "Any other end tag" handling from 12.2.6.5 The rules for parsing tokens in foreign content
 // https://html.spec.whatwg.org/multipage/syntax.html#parsing-main-inforeign
 func (p *parser) inBodyEndTagOther(tagAtom a.Atom) {
 	for i := len(p.oe) - 1; i >= 0; i-- {
@@ -1174,7 +1303,7 @@ func (p *parser) inBodyEndTagOther(tagAtom a.Atom) {
 	}
 }
 
-// Section 12.2.5.4.8.
+// Section 12.2.6.4.8.
 func textIM(p *parser) bool {
 	switch p.tok.Type {
 	case ErrorToken:
@@ -1203,12 +1332,9 @@ func textIM(p *parser) bool {
 	return p.tok.Type == EndTagToken
 }
 
-// Section 12.2.5.4.9.
+// Section 12.2.6.4.9.
 func inTableIM(p *parser) bool {
 	switch p.tok.Type {
-	case ErrorToken:
-		// Stop parsing.
-		return true
 	case TextToken:
 		p.tok.Data = strings.Replace(p.tok.Data, "\x00", "", -1)
 		switch p.oe.top().DataAtom {
@@ -1249,7 +1375,7 @@ func inTableIM(p *parser) bool {
 			}
 			// Ignore the token.
 			return true
-		case a.Style, a.Script:
+		case a.Style, a.Script, a.Template:
 			return inHeadIM(p)
 		case a.Input:
 			for _, t := range p.tok.Attr {
@@ -1261,7 +1387,7 @@ func inTableIM(p *parser) bool {
 			}
 			// Otherwise drop down to the default action.
 		case a.Form:
-			if p.form != nil {
+			if p.oe.contains(a.Template) || p.form != nil {
 				// Ignore the token.
 				return true
 			}
@@ -1291,6 +1417,8 @@ func inTableIM(p *parser) bool {
 		case a.Body, a.Caption, a.Col, a.Colgroup, a.Html, a.Tbody, a.Td, a.Tfoot, a.Th, a.Thead, a.Tr:
 			// Ignore the token.
 			return true
+		case a.Template:
+			return inHeadIM(p)
 		}
 	case CommentToken:
 		p.addChild(&Node{
@@ -1301,6 +1429,8 @@ func inTableIM(p *parser) bool {
 	case DoctypeToken:
 		// Ignore the token.
 		return true
+	case ErrorToken:
+		return inBodyIM(p)
 	}
 
 	p.fosterParenting = true
@@ -1309,7 +1439,7 @@ func inTableIM(p *parser) bool {
 	return inBodyIM(p)
 }
 
-// Section 12.2.5.4.11.
+// Section 12.2.6.4.11.
 func inCaptionIM(p *parser) bool {
 	switch p.tok.Type {
 	case StartTagToken:
@@ -1355,7 +1485,7 @@ func inCaptionIM(p *parser) bool {
 	return inBodyIM(p)
 }
 
-// Section 12.2.5.4.12.
+// Section 12.2.6.4.12.
 func inColumnGroupIM(p *parser) bool {
 	switch p.tok.Type {
 	case TextToken:
@@ -1386,11 +1516,13 @@ func inColumnGroupIM(p *parser) bool {
 			p.oe.pop()
 			p.acknowledgeSelfClosingTag()
 			return true
+		case a.Template:
+			return inHeadIM(p)
 		}
 	case EndTagToken:
 		switch p.tok.DataAtom {
 		case a.Colgroup:
-			if p.oe.top().DataAtom != a.Html {
+			if p.oe.top().DataAtom == a.Colgroup {
 				p.oe.pop()
 				p.im = inTableIM
 			}
@@ -1398,17 +1530,21 @@ func inColumnGroupIM(p *parser) bool {
 		case a.Col:
 			// Ignore the token.
 			return true
+		case a.Template:
+			return inHeadIM(p)
 		}
+	case ErrorToken:
+		return inBodyIM(p)
+	}
+	if p.oe.top().DataAtom != a.Colgroup {
+		return true
 	}
-	if p.oe.top().DataAtom != a.Html {
 	p.oe.pop()
 	p.im = inTableIM
 	return false
-	}
-	return true
 }
 
-// Section 12.2.5.4.13.
+// Section 12.2.6.4.13.
 func inTableBodyIM(p *parser) bool {
 	switch p.tok.Type {
 	case StartTagToken:
@@ -1460,7 +1596,7 @@ func inTableBodyIM(p *parser) bool {
 	return inTableIM(p)
 }
 
-// Section 12.2.5.4.14.
+// Section 12.2.6.4.14.
 func inRowIM(p *parser) bool {
 	switch p.tok.Type {
 	case StartTagToken:
@@ -1511,7 +1647,7 @@ func inRowIM(p *parser) bool {
 	return inTableIM(p)
 }
 
-// Section 12.2.5.4.15.
+// Section 12.2.6.4.15.
 func inCellIM(p *parser) bool {
 	switch p.tok.Type {
 	case StartTagToken:
@@ -1560,12 +1696,9 @@ func inCellIM(p *parser) bool {
 	return inBodyIM(p)
 }
 
-// Section 12.2.5.4.16.
+// Section 12.2.6.4.16.
 func inSelectIM(p *parser) bool {
 	switch p.tok.Type {
-	case ErrorToken:
-		// Stop parsing.
-		return true
 	case TextToken:
 		p.addText(strings.Replace(p.tok.Data, "\x00", "", -1))
 	case StartTagToken:
@@ -1597,7 +1730,7 @@ func inSelectIM(p *parser) bool {
 			p.tokenizer.NextIsNotRawText()
 			// Ignore the token.
 			return true
-		case a.Script:
+		case a.Script, a.Template:
 			return inHeadIM(p)
 		}
 	case EndTagToken:
@@ -1618,6 +1751,8 @@ func inSelectIM(p *parser) bool {
 			if p.popUntil(selectScope, a.Select) {
 				p.resetInsertionMode()
 			}
+		case a.Template:
+			return inHeadIM(p)
 		}
 	case CommentToken:
 		p.addChild(&Node{
@@ -1627,12 +1762,14 @@ func inSelectIM(p *parser) bool {
 	case DoctypeToken:
 		// Ignore the token.
 		return true
+	case ErrorToken:
+		return inBodyIM(p)
 	}
 
 	return true
 }
 
-// Section 12.2.5.4.17.
+// Section 12.2.6.4.17.
 func inSelectInTableIM(p *parser) bool {
 	switch p.tok.Type {
 	case StartTagToken, EndTagToken:
@@ -1650,7 +1787,73 @@ func inSelectInTableIM(p *parser) bool {
 	return inSelectIM(p)
 }
 
-// Section 12.2.5.4.18.
+// Section 12.2.6.4.18.
+func inTemplateIM(p *parser) bool {
+	switch p.tok.Type {
+	case TextToken, CommentToken, DoctypeToken:
+		return inBodyIM(p)
+	case StartTagToken:
+		switch p.tok.DataAtom {
+		case a.Base, a.Basefont, a.Bgsound, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Template, a.Title:
+			return inHeadIM(p)
+		case a.Caption, a.Colgroup, a.Tbody, a.Tfoot, a.Thead:
+			p.templateStack.pop()
+			p.templateStack = append(p.templateStack, inTableIM)
+			p.im = inTableIM
+			return false
+		case a.Col:
+			p.templateStack.pop()
+			p.templateStack = append(p.templateStack, inColumnGroupIM)
+			p.im = inColumnGroupIM
+			return false
+		case a.Tr:
+			p.templateStack.pop()
+			p.templateStack = append(p.templateStack, inTableBodyIM)
+			p.im = inTableBodyIM
+			return false
+		case a.Td, a.Th:
+			p.templateStack.pop()
+			p.templateStack = append(p.templateStack, inRowIM)
+			p.im = inRowIM
+			return false
+		default:
+			p.templateStack.pop()
+			p.templateStack = append(p.templateStack, inBodyIM)
+			p.im = inBodyIM
+			return false
+		}
+	case EndTagToken:
+		switch p.tok.DataAtom {
+		case a.Template:
+			return inHeadIM(p)
+		default:
+			// Ignore the token.
+			return true
+		}
+	case ErrorToken:
+		if !p.oe.contains(a.Template) {
+			// Ignore the token.
+			return true
+		}
+		// TODO: remove this divergence from the HTML5 spec.
+		//
+		// See https://bugs.chromium.org/p/chromium/issues/detail?id=829668
+		p.generateImpliedEndTags()
+		for i := len(p.oe) - 1; i >= 0; i-- {
+			if n := p.oe[i]; n.Namespace == "" && n.DataAtom == a.Template {
+				p.oe = p.oe[:i]
+				break
+			}
+		}
+		p.clearActiveFormattingElements()
+		p.templateStack.pop()
+		p.resetInsertionMode()
+		return false
+	}
+	return false
+}
+
+// Section 12.2.6.4.19.
 func afterBodyIM(p *parser) bool {
 	switch p.tok.Type {
 	case ErrorToken:
@@ -1688,7 +1891,7 @@ func afterBodyIM(p *parser) bool {
 	return false
 }
 
-// Section 12.2.5.4.19.
+// Section 12.2.6.4.20.
 func inFramesetIM(p *parser) bool {
 	switch p.tok.Type {
 	case CommentToken:
@@ -1738,7 +1941,7 @@ func inFramesetIM(p *parser) bool {
 	return true
 }
 
-// Section 12.2.5.4.20.
+// Section 12.2.6.4.21.
 func afterFramesetIM(p *parser) bool {
 	switch p.tok.Type {
 	case CommentToken:
@@ -1777,7 +1980,7 @@ func afterFramesetIM(p *parser) bool {
 	return true
 }
 
-// Section 12.2.5.4.21.
+// Section 12.2.6.4.22.
 func afterAfterBodyIM(p *parser) bool {
 	switch p.tok.Type {
 	case ErrorToken:
@@ -1806,7 +2009,7 @@ func afterAfterBodyIM(p *parser) bool {
 	return false
 }
 
-// Section 12.2.5.4.22.
+// Section 12.2.6.4.23.
 func afterAfterFramesetIM(p *parser) bool {
 	switch p.tok.Type {
 	case CommentToken:
@@ -1844,7 +2047,7 @@ func afterAfterFramesetIM(p *parser) bool {
 
 const whitespaceOrNUL = whitespace + "\x00"
 
-// Section 12.2.5.5.
+// Section 12.2.6.5
 func parseForeignContent(p *parser) bool {
 	switch p.tok.Type {
 	case TextToken:
@@ -1924,7 +2127,7 @@ func parseForeignContent(p *parser) bool {
 	return true
 }
 
-// Section 12.2.5.
+// Section 12.2.6.
 func (p *parser) inForeignContent() bool {
 	if len(p.oe) == 0 {
 		return false
@@ -2012,6 +2215,15 @@ func (p *parser) parse() error {
 }
 
 // Parse returns the parse tree for the HTML from the given Reader.
+//
+// It implements the HTML5 parsing algorithm
+// (https://html.spec.whatwg.org/multipage/syntax.html#tree-construction),
+// which is very complicated. The resultant tree can contain implicitly created
+// nodes that have no explicit <tag> listed in r's data, and nodes' parents can
+// differ from the nesting implied by a naive processing of start and end
+// <tag>s. Conversely, explicit <tag>s in r's data can be silently dropped,
+// with no corresponding node in the resulting tree.
+//
 // The input is assumed to be UTF-8 encoded.
 func Parse(r io.Reader) (*Node, error) {
 	p := &parser{
@@ -2033,6 +2245,8 @@ func Parse(r io.Reader) (*Node, error) {
 // ParseFragment parses a fragment of HTML and returns the nodes that were
 // found. If the fragment is the InnerHTML for an existing element, pass that
 // element in context.
+//
+// It has the same intricacies as Parse.
 func ParseFragment(r io.Reader, context *Node) ([]*Node, error) {
 	contextTag := ""
 	if context != nil {
@@ -2064,6 +2278,9 @@ func ParseFragment(r io.Reader, context *Node) ([]*Node, error) {
 	}
 	p.doc.AppendChild(root)
 	p.oe = nodeStack{root}
+	if context != nil && context.DataAtom == a.Template {
+		p.templateStack = append(p.templateStack, inTemplateIM)
+	}
 	p.resetInsertionMode()
 
 	for n := context; n != nil; n = n.Parent {

vendor/golang.org/x/net/html/token.go

@@ -1161,8 +1161,8 @@ func (z *Tokenizer) TagAttr() (key, val []byte, moreAttr bool) {
 	return nil, nil, false
 }
 
-// Token returns the next Token. The result's Data and Attr values remain valid
+// Token returns the current Token. The result's Data and Attr values remain
-// after subsequent Next calls.
+// valid after subsequent Next calls.
 func (z *Tokenizer) Token() Token {
 	t := Token{Type: z.tt}
 	switch z.tt {