webdav: use an internal fork of encoding/xml.

The Go 1.5 version of the standard library's encoding/xml package was
rolled back to the 1.4 behavior. See #11841

Change-Id: I5a5d6636b90b19d59dbcfdc44adf54b4f0b3ccb7
Reviewed-on: https://go-review.googlesource.com/12772
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

webdav/file.go

@@ -5,7 +5,6 @@
 package webdav
 
 import (
-	"encoding/xml"
 	"io"
 	"net/http"
 	"os"
@@ -14,6 +13,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	"golang.org/x/net/webdav/internal/xml"
 )
 
 // slashClean is equivalent to but slightly more efficient than

webdav/file_test.go

@@ -5,7 +5,6 @@
 package webdav
 
 import (
-	"encoding/xml"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -17,6 +16,8 @@ import (
 	"strconv"
 	"strings"
 	"testing"
+
+	"golang.org/x/net/webdav/internal/xml"
 )
 
 func TestSlashClean(t *testing.T) {

webdav/internal/xml/README

@@ -0,0 +1,11 @@
+This is a fork of the encoding/xml package at ca1d6c4, the last commit before
+https://go.googlesource.com/go/+/c0d6d33 "encoding/xml: restore Go 1.4 name
+space behavior" made late in the lead-up to the Go 1.5 release.
+
+The list of encoding/xml changes is at
+https://go.googlesource.com/go/+log/master/src/encoding/xml
+
+This fork is temporary, and I (nigeltao) expect to revert it after Go 1.6 is
+released.
+
+See http://golang.org/issue/11841

webdav/internal/xml/atom_test.go

@@ -0,0 +1,56 @@
+// Copyright 2011 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.
+
+package xml
+
+import "time"
+
+var atomValue = &Feed{
+	XMLName: Name{"http://www.w3.org/2005/Atom", "feed"},
+	Title:   "Example Feed",
+	Link:    []Link{{Href: "http://example.org/"}},
+	Updated: ParseTime("2003-12-13T18:30:02Z"),
+	Author:  Person{Name: "John Doe"},
+	Id:      "urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6",
+
+	Entry: []Entry{
+		{
+			Title:   "Atom-Powered Robots Run Amok",
+			Link:    []Link{{Href: "http://example.org/2003/12/13/atom03"}},
+			Id:      "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a",
+			Updated: ParseTime("2003-12-13T18:30:02Z"),
+			Summary: NewText("Some text."),
+		},
+	},
+}
+
+var atomXml = `` +
+	`<feed xmlns="http://www.w3.org/2005/Atom" updated="2003-12-13T18:30:02Z">` +
+	`<title>Example Feed</title>` +
+	`<id>urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6</id>` +
+	`<link href="http://example.org/"></link>` +
+	`<author><name>John Doe</name><uri></uri><email></email></author>` +
+	`<entry>` +
+	`<title>Atom-Powered Robots Run Amok</title>` +
+	`<id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>` +
+	`<link href="http://example.org/2003/12/13/atom03"></link>` +
+	`<updated>2003-12-13T18:30:02Z</updated>` +
+	`<author><name></name><uri></uri><email></email></author>` +
+	`<summary>Some text.</summary>` +
+	`</entry>` +
+	`</feed>`
+
+func ParseTime(str string) time.Time {
+	t, err := time.Parse(time.RFC3339, str)
+	if err != nil {
+		panic(err)
+	}
+	return t
+}
+
+func NewText(text string) Text {
+	return Text{
+		Body: text,
+	}
+}

webdav/internal/xml/example_test.go

@@ -0,0 +1,151 @@
+// Copyright 2012 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.
+
+package xml_test
+
+import (
+	"encoding/xml"
+	"fmt"
+	"os"
+)
+
+func ExampleMarshalIndent() {
+	type Address struct {
+		City, State string
+	}
+	type Person struct {
+		XMLName   xml.Name `xml:"person"`
+		Id        int      `xml:"id,attr"`
+		FirstName string   `xml:"name>first"`
+		LastName  string   `xml:"name>last"`
+		Age       int      `xml:"age"`
+		Height    float32  `xml:"height,omitempty"`
+		Married   bool
+		Address
+		Comment string `xml:",comment"`
+	}
+
+	v := &Person{Id: 13, FirstName: "John", LastName: "Doe", Age: 42}
+	v.Comment = " Need more details. "
+	v.Address = Address{"Hanga Roa", "Easter Island"}
+
+	output, err := xml.MarshalIndent(v, "  ", "    ")
+	if err != nil {
+		fmt.Printf("error: %v\n", err)
+	}
+
+	os.Stdout.Write(output)
+	// Output:
+	//   <person id="13">
+	//       <name>
+	//           <first>John</first>
+	//           <last>Doe</last>
+	//       </name>
+	//       <age>42</age>
+	//       <Married>false</Married>
+	//       <City>Hanga Roa</City>
+	//       <State>Easter Island</State>
+	//       <!-- Need more details. -->
+	//   </person>
+}
+
+func ExampleEncoder() {
+	type Address struct {
+		City, State string
+	}
+	type Person struct {
+		XMLName   xml.Name `xml:"person"`
+		Id        int      `xml:"id,attr"`
+		FirstName string   `xml:"name>first"`
+		LastName  string   `xml:"name>last"`
+		Age       int      `xml:"age"`
+		Height    float32  `xml:"height,omitempty"`
+		Married   bool
+		Address
+		Comment string `xml:",comment"`
+	}
+
+	v := &Person{Id: 13, FirstName: "John", LastName: "Doe", Age: 42}
+	v.Comment = " Need more details. "
+	v.Address = Address{"Hanga Roa", "Easter Island"}
+
+	enc := xml.NewEncoder(os.Stdout)
+	enc.Indent("  ", "    ")
+	if err := enc.Encode(v); err != nil {
+		fmt.Printf("error: %v\n", err)
+	}
+
+	// Output:
+	//   <person id="13">
+	//       <name>
+	//           <first>John</first>
+	//           <last>Doe</last>
+	//       </name>
+	//       <age>42</age>
+	//       <Married>false</Married>
+	//       <City>Hanga Roa</City>
+	//       <State>Easter Island</State>
+	//       <!-- Need more details. -->
+	//   </person>
+}
+
+// This example demonstrates unmarshaling an XML excerpt into a value with
+// some preset fields. Note that the Phone field isn't modified and that
+// the XML <Company> element is ignored. Also, the Groups field is assigned
+// considering the element path provided in its tag.
+func ExampleUnmarshal() {
+	type Email struct {
+		Where string `xml:"where,attr"`
+		Addr  string
+	}
+	type Address struct {
+		City, State string
+	}
+	type Result struct {
+		XMLName xml.Name `xml:"Person"`
+		Name    string   `xml:"FullName"`
+		Phone   string
+		Email   []Email
+		Groups  []string `xml:"Group>Value"`
+		Address
+	}
+	v := Result{Name: "none", Phone: "none"}
+
+	data := `
+		<Person>
+			<FullName>Grace R. Emlin</FullName>
+			<Company>Example Inc.</Company>
+			<Email where="home">
+				<Addr>gre@example.com</Addr>
+			</Email>
+			<Email where='work'>
+				<Addr>gre@work.com</Addr>
+			</Email>
+			<Group>
+				<Value>Friends</Value>
+				<Value>Squash</Value>
+			</Group>
+			<City>Hanga Roa</City>
+			<State>Easter Island</State>
+		</Person>
+	`
+	err := xml.Unmarshal([]byte(data), &v)
+	if err != nil {
+		fmt.Printf("error: %v", err)
+		return
+	}
+	fmt.Printf("XMLName: %#v\n", v.XMLName)
+	fmt.Printf("Name: %q\n", v.Name)
+	fmt.Printf("Phone: %q\n", v.Phone)
+	fmt.Printf("Email: %v\n", v.Email)
+	fmt.Printf("Groups: %v\n", v.Groups)
+	fmt.Printf("Address: %v\n", v.Address)
+	// Output:
+	// XMLName: xml.Name{Space:"", Local:"Person"}
+	// Name: "Grace R. Emlin"
+	// Phone: "none"
+	// Email: [{home gre@example.com} {work gre@work.com}]
+	// Groups: [Friends Squash]
+	// Address: {Hanga Roa Easter Island}
+}

webdav/internal/xml/marshal.go

@@ -0,0 +1,1223 @@
+// Copyright 2011 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.
+
+package xml
+
+import (
+	"bufio"
+	"bytes"
+	"encoding"
+	"fmt"
+	"io"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+const (
+	// A generic XML header suitable for use with the output of Marshal.
+	// This is not automatically added to any output of this package,
+	// it is provided as a convenience.
+	Header = `<?xml version="1.0" encoding="UTF-8"?>` + "\n"
+)
+
+// Marshal returns the XML encoding of v.
+//
+// Marshal handles an array or slice by marshalling each of the elements.
+// Marshal handles a pointer by marshalling the value it points at or, if the
+// pointer is nil, by writing nothing.  Marshal handles an interface value by
+// marshalling the value it contains or, if the interface value is nil, by
+// writing nothing.  Marshal handles all other data by writing one or more XML
+// elements containing the data.
+//
+// The name for the XML elements is taken from, in order of preference:
+//     - the tag on the XMLName field, if the data is a struct
+//     - the value of the XMLName field of type xml.Name
+//     - the tag of the struct field used to obtain the data
+//     - the name of the struct field used to obtain the data
+//     - the name of the marshalled type
+//
+// The XML element for a struct contains marshalled elements for each of the
+// exported fields of the struct, with these exceptions:
+//     - the XMLName field, described above, is omitted.
+//     - a field with tag "-" is omitted.
+//     - a field with tag "name,attr" becomes an attribute with
+//       the given name in the XML element.
+//     - a field with tag ",attr" becomes an attribute with the
+//       field name in the XML element.
+//     - a field with tag ",chardata" is written as character data,
+//       not as an XML element.
+//     - a field with tag ",innerxml" is written verbatim, not subject
+//       to the usual marshalling procedure.
+//     - a field with tag ",comment" is written as an XML comment, not
+//       subject to the usual marshalling procedure. It must not contain
+//       the "--" string within it.
+//     - a field with a tag including the "omitempty" option is omitted
+//       if the field value is empty. The empty values are false, 0, any
+//       nil pointer or interface value, and any array, slice, map, or
+//       string of length zero.
+//     - an anonymous struct field is handled as if the fields of its
+//       value were part of the outer struct.
+//
+// If a field uses a tag "a>b>c", then the element c will be nested inside
+// parent elements a and b.  Fields that appear next to each other that name
+// the same parent will be enclosed in one XML element.
+//
+// See MarshalIndent for an example.
+//
+// Marshal will return an error if asked to marshal a channel, function, or map.
+func Marshal(v interface{}) ([]byte, error) {
+	var b bytes.Buffer
+	if err := NewEncoder(&b).Encode(v); err != nil {
+		return nil, err
+	}
+	return b.Bytes(), nil
+}
+
+// Marshaler is the interface implemented by objects that can marshal
+// themselves into valid XML elements.
+//
+// MarshalXML encodes the receiver as zero or more XML elements.
+// By convention, arrays or slices are typically encoded as a sequence
+// of elements, one per entry.
+// Using start as the element tag is not required, but doing so
+// will enable Unmarshal to match the XML elements to the correct
+// struct field.
+// One common implementation strategy is to construct a separate
+// value with a layout corresponding to the desired XML and then
+// to encode it using e.EncodeElement.
+// Another common strategy is to use repeated calls to e.EncodeToken
+// to generate the XML output one token at a time.
+// The sequence of encoded tokens must make up zero or more valid
+// XML elements.
+type Marshaler interface {
+	MarshalXML(e *Encoder, start StartElement) error
+}
+
+// MarshalerAttr is the interface implemented by objects that can marshal
+// themselves into valid XML attributes.
+//
+// MarshalXMLAttr returns an XML attribute with the encoded value of the receiver.
+// Using name as the attribute name is not required, but doing so
+// will enable Unmarshal to match the attribute to the correct
+// struct field.
+// If MarshalXMLAttr returns the zero attribute Attr{}, no attribute
+// will be generated in the output.
+// MarshalXMLAttr is used only for struct fields with the
+// "attr" option in the field tag.
+type MarshalerAttr interface {
+	MarshalXMLAttr(name Name) (Attr, error)
+}
+
+// MarshalIndent works like Marshal, but each XML element begins on a new
+// indented line that starts with prefix and is followed by one or more
+// copies of indent according to the nesting depth.
+func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
+	var b bytes.Buffer
+	enc := NewEncoder(&b)
+	enc.Indent(prefix, indent)
+	if err := enc.Encode(v); err != nil {
+		return nil, err
+	}
+	return b.Bytes(), nil
+}
+
+// An Encoder writes XML data to an output stream.
+type Encoder struct {
+	p printer
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+	e := &Encoder{printer{Writer: bufio.NewWriter(w)}}
+	e.p.encoder = e
+	return e
+}
+
+// Indent sets the encoder to generate XML in which each element
+// begins on a new indented line that starts with prefix and is followed by
+// one or more copies of indent according to the nesting depth.
+func (enc *Encoder) Indent(prefix, indent string) {
+	enc.p.prefix = prefix
+	enc.p.indent = indent
+}
+
+// Encode writes the XML encoding of v to the stream.
+//
+// See the documentation for Marshal for details about the conversion
+// of Go values to XML.
+//
+// Encode calls Flush before returning.
+func (enc *Encoder) Encode(v interface{}) error {
+	err := enc.p.marshalValue(reflect.ValueOf(v), nil, nil)
+	if err != nil {
+		return err
+	}
+	return enc.p.Flush()
+}
+
+// EncodeElement writes the XML encoding of v to the stream,
+// using start as the outermost tag in the encoding.
+//
+// See the documentation for Marshal for details about the conversion
+// of Go values to XML.
+//
+// EncodeElement calls Flush before returning.
+func (enc *Encoder) EncodeElement(v interface{}, start StartElement) error {
+	err := enc.p.marshalValue(reflect.ValueOf(v), nil, &start)
+	if err != nil {
+		return err
+	}
+	return enc.p.Flush()
+}
+
+var (
+	begComment   = []byte("<!--")
+	endComment   = []byte("-->")
+	endProcInst  = []byte("?>")
+	endDirective = []byte(">")
+)
+
+// EncodeToken writes the given XML token to the stream.
+// It returns an error if StartElement and EndElement tokens are not
+// properly matched.
+//
+// EncodeToken does not call Flush, because usually it is part of a
+// larger operation such as Encode or EncodeElement (or a custom
+// Marshaler's MarshalXML invoked during those), and those will call
+// Flush when finished. Callers that create an Encoder and then invoke
+// EncodeToken directly, without using Encode or EncodeElement, need to
+// call Flush when finished to ensure that the XML is written to the
+// underlying writer.
+//
+// EncodeToken allows writing a ProcInst with Target set to "xml" only
+// as the first token in the stream.
+//
+// When encoding a StartElement holding an XML namespace prefix
+// declaration for a prefix that is not already declared, contained
+// elements (including the StartElement itself) will use the declared
+// prefix when encoding names with matching namespace URIs.
+func (enc *Encoder) EncodeToken(t Token) error {
+
+	p := &enc.p
+	switch t := t.(type) {
+	case StartElement:
+		if err := p.writeStart(&t); err != nil {
+			return err
+		}
+	case EndElement:
+		if err := p.writeEnd(t.Name); err != nil {
+			return err
+		}
+	case CharData:
+		escapeText(p, t, false)
+	case Comment:
+		if bytes.Contains(t, endComment) {
+			return fmt.Errorf("xml: EncodeToken of Comment containing --> marker")
+		}
+		p.WriteString("<!--")
+		p.Write(t)
+		p.WriteString("-->")
+		return p.cachedWriteError()
+	case ProcInst:
+		// First token to be encoded which is also a ProcInst with target of xml
+		// is the xml declaration.  The only ProcInst where target of xml is allowed.
+		if t.Target == "xml" && p.Buffered() != 0 {
+			return fmt.Errorf("xml: EncodeToken of ProcInst xml target only valid for xml declaration, first token encoded")
+		}
+		if !isNameString(t.Target) {
+			return fmt.Errorf("xml: EncodeToken of ProcInst with invalid Target")
+		}
+		if bytes.Contains(t.Inst, endProcInst) {
+			return fmt.Errorf("xml: EncodeToken of ProcInst containing ?> marker")
+		}
+		p.WriteString("<?")
+		p.WriteString(t.Target)
+		if len(t.Inst) > 0 {
+			p.WriteByte(' ')
+			p.Write(t.Inst)
+		}
+		p.WriteString("?>")
+	case Directive:
+		if !isValidDirective(t) {
+			return fmt.Errorf("xml: EncodeToken of Directive containing wrong < or > markers")
+		}
+		p.WriteString("<!")
+		p.Write(t)
+		p.WriteString(">")
+	default:
+		return fmt.Errorf("xml: EncodeToken of invalid token type")
+
+	}
+	return p.cachedWriteError()
+}
+
+// isValidDirective reports whether dir is a valid directive text,
+// meaning angle brackets are matched, ignoring comments and strings.
+func isValidDirective(dir Directive) bool {
+	var (
+		depth     int
+		inquote   uint8
+		incomment bool
+	)
+	for i, c := range dir {
+		switch {
+		case incomment:
+			if c == '>' {
+				if n := 1 + i - len(endComment); n >= 0 && bytes.Equal(dir[n:i+1], endComment) {
+					incomment = false
+				}
+			}
+			// Just ignore anything in comment
+		case inquote != 0:
+			if c == inquote {
+				inquote = 0
+			}
+			// Just ignore anything within quotes
+		case c == '\'' || c == '"':
+			inquote = c
+		case c == '<':
+			if i+len(begComment) < len(dir) && bytes.Equal(dir[i:i+len(begComment)], begComment) {
+				incomment = true
+			} else {
+				depth++
+			}
+		case c == '>':
+			if depth == 0 {
+				return false
+			}
+			depth--
+		}
+	}
+	return depth == 0 && inquote == 0 && !incomment
+}
+
+// Flush flushes any buffered XML to the underlying writer.
+// See the EncodeToken documentation for details about when it is necessary.
+func (enc *Encoder) Flush() error {
+	return enc.p.Flush()
+}
+
+type printer struct {
+	*bufio.Writer
+	encoder    *Encoder
+	seq        int
+	indent     string
+	prefix     string
+	depth      int
+	indentedIn bool
+	putNewline bool
+	defaultNS  string
+	attrNS     map[string]string // map prefix -> name space
+	attrPrefix map[string]string // map name space -> prefix
+	prefixes   []printerPrefix
+	tags       []Name
+}
+
+// printerPrefix holds a namespace undo record.
+// When an element is popped, the prefix record
+// is set back to the recorded URL. The empty
+// prefix records the URL for the default name space.
+//
+// The start of an element is recorded with an element
+// that has mark=true.
+type printerPrefix struct {
+	prefix string
+	url    string
+	mark   bool
+}
+
+func (p *printer) prefixForNS(url string, isAttr bool) string {
+	// The "http://www.w3.org/XML/1998/namespace" name space is predefined as "xml"
+	// and must be referred to that way.
+	// (The "http://www.w3.org/2000/xmlns/" name space is also predefined as "xmlns",
+	// but users should not be trying to use that one directly - that's our job.)
+	if url == xmlURL {
+		return "xml"
+	}
+	if !isAttr && url == p.defaultNS {
+		// We can use the default name space.
+		return ""
+	}
+	return p.attrPrefix[url]
+}
+
+// defineNS pushes any namespace definition found in the given attribute.
+// If ignoreNonEmptyDefault is true, an xmlns="nonempty"
+// attribute will be ignored.
+func (p *printer) defineNS(attr Attr, ignoreNonEmptyDefault bool) error {
+	var prefix string
+	if attr.Name.Local == "xmlns" {
+		if attr.Name.Space != "" && attr.Name.Space != "xml" && attr.Name.Space != xmlURL {
+			return fmt.Errorf("xml: cannot redefine xmlns attribute prefix")
+		}
+	} else if attr.Name.Space == "xmlns" && attr.Name.Local != "" {
+		prefix = attr.Name.Local
+		if attr.Value == "" {
+			// Technically, an empty XML namespace is allowed for an attribute.
+			// From http://www.w3.org/TR/xml-names11/#scoping-defaulting:
+			//
+			// 	The attribute value in a namespace declaration for a prefix may be
+			//	empty. This has the effect, within the scope of the declaration, of removing
+			//	any association of the prefix with a namespace name.
+			//
+			// However our namespace prefixes here are used only as hints. There's
+			// no need to respect the removal of a namespace prefix, so we ignore it.
+			return nil
+		}
+	} else {
+		// Ignore: it's not a namespace definition
+		return nil
+	}
+	if prefix == "" {
+		if attr.Value == p.defaultNS {
+			// No need for redefinition.
+			return nil
+		}
+		if attr.Value != "" && ignoreNonEmptyDefault {
+			// We have an xmlns="..." value but
+			// it can't define a name space in this context,
+			// probably because the element has an empty
+			// name space. In this case, we just ignore
+			// the name space declaration.
+			return nil
+		}
+	} else if _, ok := p.attrPrefix[attr.Value]; ok {
+		// There's already a prefix for the given name space,
+		// so use that. This prevents us from
+		// having two prefixes for the same name space
+		// so attrNS and attrPrefix can remain bijective.
+		return nil
+	}
+	p.pushPrefix(prefix, attr.Value)
+	return nil
+}
+
+// createNSPrefix creates a name space prefix attribute
+// to use for the given name space, defining a new prefix
+// if necessary.
+// If isAttr is true, the prefix is to be created for an attribute
+// prefix, which means that the default name space cannot
+// be used.
+func (p *printer) createNSPrefix(url string, isAttr bool) {
+	if _, ok := p.attrPrefix[url]; ok {
+		// We already have a prefix for the given URL.
+		return
+	}
+	switch {
+	case !isAttr && url == p.defaultNS:
+		// We can use the default name space.
+		return
+	case url == "":
+		// The only way we can encode names in the empty
+		// name space is by using the default name space,
+		// so we must use that.
+		if p.defaultNS != "" {
+			// The default namespace is non-empty, so we
+			// need to set it to empty.
+			p.pushPrefix("", "")
+		}
+		return
+	case url == xmlURL:
+		return
+	}
+	// TODO If the URL is an existing prefix, we could
+	// use it as is. That would enable the
+	// marshaling of elements that had been unmarshaled
+	// and with a name space prefix that was not found.
+	// although technically it would be incorrect.
+
+	// Pick a name. We try to use the final element of the path
+	// but fall back to _.
+	prefix := strings.TrimRight(url, "/")
+	if i := strings.LastIndex(prefix, "/"); i >= 0 {
+		prefix = prefix[i+1:]
+	}
+	if prefix == "" || !isName([]byte(prefix)) || strings.Contains(prefix, ":") {
+		prefix = "_"
+	}
+	if strings.HasPrefix(prefix, "xml") {
+		// xmlanything is reserved.
+		prefix = "_" + prefix
+	}
+	if p.attrNS[prefix] != "" {
+		// Name is taken. Find a better one.
+		for p.seq++; ; p.seq++ {
+			if id := prefix + "_" + strconv.Itoa(p.seq); p.attrNS[id] == "" {
+				prefix = id
+				break
+			}
+		}
+	}
+
+	p.pushPrefix(prefix, url)
+}
+
+// writeNamespaces writes xmlns attributes for all the
+// namespace prefixes that have been defined in
+// the current element.
+func (p *printer) writeNamespaces() {
+	for i := len(p.prefixes) - 1; i >= 0; i-- {
+		prefix := p.prefixes[i]
+		if prefix.mark {
+			return
+		}
+		p.WriteString(" ")
+		if prefix.prefix == "" {
+			// Default name space.
+			p.WriteString(`xmlns="`)
+		} else {
+			p.WriteString("xmlns:")
+			p.WriteString(prefix.prefix)
+			p.WriteString(`="`)
+		}
+		EscapeText(p, []byte(p.nsForPrefix(prefix.prefix)))
+		p.WriteString(`"`)
+	}
+}
+
+// pushPrefix pushes a new prefix on the prefix stack
+// without checking to see if it is already defined.
+func (p *printer) pushPrefix(prefix, url string) {
+	p.prefixes = append(p.prefixes, printerPrefix{
+		prefix: prefix,
+		url:    p.nsForPrefix(prefix),
+	})
+	p.setAttrPrefix(prefix, url)
+}
+
+// nsForPrefix returns the name space for the given
+// prefix. Note that this is not valid for the
+// empty attribute prefix, which always has an empty
+// name space.
+func (p *printer) nsForPrefix(prefix string) string {
+	if prefix == "" {
+		return p.defaultNS
+	}
+	return p.attrNS[prefix]
+}
+
+// markPrefix marks the start of an element on the prefix
+// stack.
+func (p *printer) markPrefix() {
+	p.prefixes = append(p.prefixes, printerPrefix{
+		mark: true,
+	})
+}
+
+// popPrefix pops all defined prefixes for the current
+// element.
+func (p *printer) popPrefix() {
+	for len(p.prefixes) > 0 {
+		prefix := p.prefixes[len(p.prefixes)-1]
+		p.prefixes = p.prefixes[:len(p.prefixes)-1]
+		if prefix.mark {
+			break
+		}
+		p.setAttrPrefix(prefix.prefix, prefix.url)
+	}
+}
+
+// setAttrPrefix sets an attribute name space prefix.
+// If url is empty, the attribute is removed.
+// If prefix is empty, the default name space is set.
+func (p *printer) setAttrPrefix(prefix, url string) {
+	if prefix == "" {
+		p.defaultNS = url
+		return
+	}
+	if url == "" {
+		delete(p.attrPrefix, p.attrNS[prefix])
+		delete(p.attrNS, prefix)
+		return
+	}
+	if p.attrPrefix == nil {
+		// Need to define a new name space.
+		p.attrPrefix = make(map[string]string)
+		p.attrNS = make(map[string]string)
+	}
+	// Remove any old prefix value. This is OK because we maintain a
+	// strict one-to-one mapping between prefix and URL (see
+	// defineNS)
+	delete(p.attrPrefix, p.attrNS[prefix])
+	p.attrPrefix[url] = prefix
+	p.attrNS[prefix] = url
+}
+
+var (
+	marshalerType     = reflect.TypeOf((*Marshaler)(nil)).Elem()
+	marshalerAttrType = reflect.TypeOf((*MarshalerAttr)(nil)).Elem()
+	textMarshalerType = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
+)
+
+// marshalValue writes one or more XML elements representing val.
+// If val was obtained from a struct field, finfo must have its details.
+func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo, startTemplate *StartElement) error {
+	if startTemplate != nil && startTemplate.Name.Local == "" {
+		return fmt.Errorf("xml: EncodeElement of StartElement with missing name")
+	}
+
+	if !val.IsValid() {
+		return nil
+	}
+	if finfo != nil && finfo.flags&fOmitEmpty != 0 && isEmptyValue(val) {
+		return nil
+	}
+
+	// Drill into interfaces and pointers.
+	// This can turn into an infinite loop given a cyclic chain,
+	// but it matches the Go 1 behavior.
+	for val.Kind() == reflect.Interface || val.Kind() == reflect.Ptr {
+		if val.IsNil() {
+			return nil
+		}
+		val = val.Elem()
+	}
+
+	kind := val.Kind()
+	typ := val.Type()
+
+	// Check for marshaler.
+	if val.CanInterface() && typ.Implements(marshalerType) {
+		return p.marshalInterface(val.Interface().(Marshaler), p.defaultStart(typ, finfo, startTemplate))
+	}
+	if val.CanAddr() {
+		pv := val.Addr()
+		if pv.CanInterface() && pv.Type().Implements(marshalerType) {
+			return p.marshalInterface(pv.Interface().(Marshaler), p.defaultStart(pv.Type(), finfo, startTemplate))
+		}
+	}
+
+	// Check for text marshaler.
+	if val.CanInterface() && typ.Implements(textMarshalerType) {
+		return p.marshalTextInterface(val.Interface().(encoding.TextMarshaler), p.defaultStart(typ, finfo, startTemplate))
+	}
+	if val.CanAddr() {
+		pv := val.Addr()
+		if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
+			return p.marshalTextInterface(pv.Interface().(encoding.TextMarshaler), p.defaultStart(pv.Type(), finfo, startTemplate))
+		}
+	}
+
+	// Slices and arrays iterate over the elements. They do not have an enclosing tag.
+	if (kind == reflect.Slice || kind == reflect.Array) && typ.Elem().Kind() != reflect.Uint8 {
+		for i, n := 0, val.Len(); i < n; i++ {
+			if err := p.marshalValue(val.Index(i), finfo, startTemplate); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+
+	tinfo, err := getTypeInfo(typ)
+	if err != nil {
+		return err
+	}
+
+	// Create start element.
+	// Precedence for the XML element name is:
+	// 0. startTemplate
+	// 1. XMLName field in underlying struct;
+	// 2. field name/tag in the struct field; and
+	// 3. type name
+	var start StartElement
+
+	// explicitNS records whether the element's name space has been
+	// explicitly set (for example an XMLName field).
+	explicitNS := false
+
+	if startTemplate != nil {
+		start.Name = startTemplate.Name
+		explicitNS = true
+		start.Attr = append(start.Attr, startTemplate.Attr...)
+	} else if tinfo.xmlname != nil {
+		xmlname := tinfo.xmlname
+		if xmlname.name != "" {
+			start.Name.Space, start.Name.Local = xmlname.xmlns, xmlname.name
+		} else if v, ok := xmlname.value(val).Interface().(Name); ok && v.Local != "" {
+			start.Name = v
+		}
+		explicitNS = true
+	}
+	if start.Name.Local == "" && finfo != nil {
+		start.Name.Local = finfo.name
+		if finfo.xmlns != "" {
+			start.Name.Space = finfo.xmlns
+			explicitNS = true
+		}
+	}
+	if start.Name.Local == "" {
+		name := typ.Name()
+		if name == "" {
+			return &UnsupportedTypeError{typ}
+		}
+		start.Name.Local = name
+	}
+
+	// defaultNS records the default name space as set by a xmlns="..."
+	// attribute. We don't set p.defaultNS because we want to let
+	// the attribute writing code (in p.defineNS) be solely responsible
+	// for maintaining that.
+	defaultNS := p.defaultNS
+
+	// Attributes
+	for i := range tinfo.fields {
+		finfo := &tinfo.fields[i]
+		if finfo.flags&fAttr == 0 {
+			continue
+		}
+		attr, err := p.fieldAttr(finfo, val)
+		if err != nil {
+			return err
+		}
+		if attr.Name.Local == "" {
+			continue
+		}
+		start.Attr = append(start.Attr, attr)
+		if attr.Name.Space == "" && attr.Name.Local == "xmlns" {
+			defaultNS = attr.Value
+		}
+	}
+	if !explicitNS {
+		// Historic behavior: elements use the default name space
+		// they are contained in by default.
+		start.Name.Space = defaultNS
+	}
+	// Historic behaviour: an element that's in a namespace sets
+	// the default namespace for all elements contained within it.
+	start.setDefaultNamespace()
+
+	if err := p.writeStart(&start); err != nil {
+		return err
+	}
+
+	if val.Kind() == reflect.Struct {
+		err = p.marshalStruct(tinfo, val)
+	} else {
+		s, b, err1 := p.marshalSimple(typ, val)
+		if err1 != nil {
+			err = err1
+		} else if b != nil {
+			EscapeText(p, b)
+		} else {
+			p.EscapeString(s)
+		}
+	}
+	if err != nil {
+		return err
+	}
+
+	if err := p.writeEnd(start.Name); err != nil {
+		return err
+	}
+
+	return p.cachedWriteError()
+}
+
+// fieldAttr returns the attribute of the given field.
+// If the returned attribute has an empty Name.Local,
+// it should not be used.
+// The given value holds the value containing the field.
+func (p *printer) fieldAttr(finfo *fieldInfo, val reflect.Value) (Attr, error) {
+	fv := finfo.value(val)
+	name := Name{Space: finfo.xmlns, Local: finfo.name}
+	if finfo.flags&fOmitEmpty != 0 && isEmptyValue(fv) {
+		return Attr{}, nil
+	}
+	if fv.Kind() == reflect.Interface && fv.IsNil() {
+		return Attr{}, nil
+	}
+	if fv.CanInterface() && fv.Type().Implements(marshalerAttrType) {
+		attr, err := fv.Interface().(MarshalerAttr).MarshalXMLAttr(name)
+		return attr, err
+	}
+	if fv.CanAddr() {
+		pv := fv.Addr()
+		if pv.CanInterface() && pv.Type().Implements(marshalerAttrType) {
+			attr, err := pv.Interface().(MarshalerAttr).MarshalXMLAttr(name)
+			return attr, err
+		}
+	}
+	if fv.CanInterface() && fv.Type().Implements(textMarshalerType) {
+		text, err := fv.Interface().(encoding.TextMarshaler).MarshalText()
+		if err != nil {
+			return Attr{}, err
+		}
+		return Attr{name, string(text)}, nil
+	}
+	if fv.CanAddr() {
+		pv := fv.Addr()
+		if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
+			text, err := pv.Interface().(encoding.TextMarshaler).MarshalText()
+			if err != nil {
+				return Attr{}, err
+			}
+			return Attr{name, string(text)}, nil
+		}
+	}
+	// Dereference or skip nil pointer, interface values.
+	switch fv.Kind() {
+	case reflect.Ptr, reflect.Interface:
+		if fv.IsNil() {
+			return Attr{}, nil
+		}
+		fv = fv.Elem()
+	}
+	s, b, err := p.marshalSimple(fv.Type(), fv)
+	if err != nil {
+		return Attr{}, err
+	}
+	if b != nil {
+		s = string(b)
+	}
+	return Attr{name, s}, nil
+}
+
+// defaultStart returns the default start element to use,
+// given the reflect type, field info, and start template.
+func (p *printer) defaultStart(typ reflect.Type, finfo *fieldInfo, startTemplate *StartElement) StartElement {
+	var start StartElement
+	// Precedence for the XML element name is as above,
+	// except that we do not look inside structs for the first field.
+	if startTemplate != nil {
+		start.Name = startTemplate.Name
+		start.Attr = append(start.Attr, startTemplate.Attr...)
+	} else if finfo != nil && finfo.name != "" {
+		start.Name.Local = finfo.name
+		start.Name.Space = finfo.xmlns
+	} else if typ.Name() != "" {
+		start.Name.Local = typ.Name()
+	} else {
+		// Must be a pointer to a named type,
+		// since it has the Marshaler methods.
+		start.Name.Local = typ.Elem().Name()
+	}
+	// Historic behaviour: elements use the name space of
+	// the element they are contained in by default.
+	if start.Name.Space == "" {
+		start.Name.Space = p.defaultNS
+	}
+	start.setDefaultNamespace()
+	return start
+}
+
+// marshalInterface marshals a Marshaler interface value.
+func (p *printer) marshalInterface(val Marshaler, start StartElement) error {
+	// Push a marker onto the tag stack so that MarshalXML
+	// cannot close the XML tags that it did not open.
+	p.tags = append(p.tags, Name{})
+	n := len(p.tags)
+
+	err := val.MarshalXML(p.encoder, start)
+	if err != nil {
+		return err
+	}
+
+	// Make sure MarshalXML closed all its tags. p.tags[n-1] is the mark.
+	if len(p.tags) > n {
+		return fmt.Errorf("xml: %s.MarshalXML wrote invalid XML: <%s> not closed", receiverType(val), p.tags[len(p.tags)-1].Local)
+	}
+	p.tags = p.tags[:n-1]
+	return nil
+}
+
+// marshalTextInterface marshals a TextMarshaler interface value.
+func (p *printer) marshalTextInterface(val encoding.TextMarshaler, start StartElement) error {
+	if err := p.writeStart(&start); err != nil {
+		return err
+	}
+	text, err := val.MarshalText()
+	if err != nil {
+		return err
+	}
+	EscapeText(p, text)
+	return p.writeEnd(start.Name)
+}
+
+// writeStart writes the given start element.
+func (p *printer) writeStart(start *StartElement) error {
+	if start.Name.Local == "" {
+		return fmt.Errorf("xml: start tag with no name")
+	}
+
+	p.tags = append(p.tags, start.Name)
+	p.markPrefix()
+	// Define any name spaces explicitly declared in the attributes.
+	// We do this as a separate pass so that explicitly declared prefixes
+	// will take precedence over implicitly declared prefixes
+	// regardless of the order of the attributes.
+	ignoreNonEmptyDefault := start.Name.Space == ""
+	for _, attr := range start.Attr {
+		if err := p.defineNS(attr, ignoreNonEmptyDefault); err != nil {
+			return err
+		}
+	}
+	// Define any new name spaces implied by the attributes.
+	for _, attr := range start.Attr {
+		name := attr.Name
+		// From http://www.w3.org/TR/xml-names11/#defaulting
+		// "Default namespace declarations do not apply directly
+		// to attribute names; the interpretation of unprefixed
+		// attributes is determined by the element on which they
+		// appear."
+		// This means we don't need to create a new namespace
+		// when an attribute name space is empty.
+		if name.Space != "" && !name.isNamespace() {
+			p.createNSPrefix(name.Space, true)
+		}
+	}
+	p.createNSPrefix(start.Name.Space, false)
+
+	p.writeIndent(1)
+	p.WriteByte('<')
+	p.writeName(start.Name, false)
+	p.writeNamespaces()
+	for _, attr := range start.Attr {
+		name := attr.Name
+		if name.Local == "" || name.isNamespace() {
+			// Namespaces have already been written by writeNamespaces above.
+			continue
+		}
+		p.WriteByte(' ')
+		p.writeName(name, true)
+		p.WriteString(`="`)
+		p.EscapeString(attr.Value)
+		p.WriteByte('"')
+	}
+	p.WriteByte('>')
+	return nil
+}
+
+// writeName writes the given name. It assumes
+// that p.createNSPrefix(name) has already been called.
+func (p *printer) writeName(name Name, isAttr bool) {
+	if prefix := p.prefixForNS(name.Space, isAttr); prefix != "" {
+		p.WriteString(prefix)
+		p.WriteByte(':')
+	}
+	p.WriteString(name.Local)
+}
+
+func (p *printer) writeEnd(name Name) error {
+	if name.Local == "" {
+		return fmt.Errorf("xml: end tag with no name")
+	}
+	if len(p.tags) == 0 || p.tags[len(p.tags)-1].Local == "" {
+		return fmt.Errorf("xml: end tag </%s> without start tag", name.Local)
+	}
+	if top := p.tags[len(p.tags)-1]; top != name {
+		if top.Local != name.Local {
+			return fmt.Errorf("xml: end tag </%s> does not match start tag <%s>", name.Local, top.Local)
+		}
+		return fmt.Errorf("xml: end tag </%s> in namespace %s does not match start tag <%s> in namespace %s", name.Local, name.Space, top.Local, top.Space)
+	}
+	p.tags = p.tags[:len(p.tags)-1]
+
+	p.writeIndent(-1)
+	p.WriteByte('<')
+	p.WriteByte('/')
+	p.writeName(name, false)
+	p.WriteByte('>')
+	p.popPrefix()
+	return nil
+}
+
+func (p *printer) marshalSimple(typ reflect.Type, val reflect.Value) (string, []byte, error) {
+	switch val.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return strconv.FormatInt(val.Int(), 10), nil, nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return strconv.FormatUint(val.Uint(), 10), nil, nil
+	case reflect.Float32, reflect.Float64:
+		return strconv.FormatFloat(val.Float(), 'g', -1, val.Type().Bits()), nil, nil
+	case reflect.String:
+		return val.String(), nil, nil
+	case reflect.Bool:
+		return strconv.FormatBool(val.Bool()), nil, nil
+	case reflect.Array:
+		if typ.Elem().Kind() != reflect.Uint8 {
+			break
+		}
+		// [...]byte
+		var bytes []byte
+		if val.CanAddr() {
+			bytes = val.Slice(0, val.Len()).Bytes()
+		} else {
+			bytes = make([]byte, val.Len())
+			reflect.Copy(reflect.ValueOf(bytes), val)
+		}
+		return "", bytes, nil
+	case reflect.Slice:
+		if typ.Elem().Kind() != reflect.Uint8 {
+			break
+		}
+		// []byte
+		return "", val.Bytes(), nil
+	}
+	return "", nil, &UnsupportedTypeError{typ}
+}
+
+var ddBytes = []byte("--")
+
+func (p *printer) marshalStruct(tinfo *typeInfo, val reflect.Value) error {
+	s := parentStack{p: p}
+	for i := range tinfo.fields {
+		finfo := &tinfo.fields[i]
+		if finfo.flags&fAttr != 0 {
+			continue
+		}
+		vf := finfo.value(val)
+
+		// Dereference or skip nil pointer, interface values.
+		switch vf.Kind() {
+		case reflect.Ptr, reflect.Interface:
+			if !vf.IsNil() {
+				vf = vf.Elem()
+			}
+		}
+
+		switch finfo.flags & fMode {
+		case fCharData:
+			if err := s.setParents(&noField, reflect.Value{}); err != nil {
+				return err
+			}
+			if vf.CanInterface() && vf.Type().Implements(textMarshalerType) {
+				data, err := vf.Interface().(encoding.TextMarshaler).MarshalText()
+				if err != nil {
+					return err
+				}
+				Escape(p, data)
+				continue
+			}
+			if vf.CanAddr() {
+				pv := vf.Addr()
+				if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
+					data, err := pv.Interface().(encoding.TextMarshaler).MarshalText()
+					if err != nil {
+						return err
+					}
+					Escape(p, data)
+					continue
+				}
+			}
+			var scratch [64]byte
+			switch vf.Kind() {
+			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+				Escape(p, strconv.AppendInt(scratch[:0], vf.Int(), 10))
+			case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+				Escape(p, strconv.AppendUint(scratch[:0], vf.Uint(), 10))
+			case reflect.Float32, reflect.Float64:
+				Escape(p, strconv.AppendFloat(scratch[:0], vf.Float(), 'g', -1, vf.Type().Bits()))
+			case reflect.Bool:
+				Escape(p, strconv.AppendBool(scratch[:0], vf.Bool()))
+			case reflect.String:
+				if err := EscapeText(p, []byte(vf.String())); err != nil {
+					return err
+				}
+			case reflect.Slice:
+				if elem, ok := vf.Interface().([]byte); ok {
+					if err := EscapeText(p, elem); err != nil {
+						return err
+					}
+				}
+			}
+			continue
+
+		case fComment:
+			if err := s.setParents(&noField, reflect.Value{}); err != nil {
+				return err
+			}
+			k := vf.Kind()
+			if !(k == reflect.String || k == reflect.Slice && vf.Type().Elem().Kind() == reflect.Uint8) {
+				return fmt.Errorf("xml: bad type for comment field of %s", val.Type())
+			}
+			if vf.Len() == 0 {
+				continue
+			}
+			p.writeIndent(0)
+			p.WriteString("<!--")
+			dashDash := false
+			dashLast := false
+			switch k {
+			case reflect.String:
+				s := vf.String()
+				dashDash = strings.Index(s, "--") >= 0
+				dashLast = s[len(s)-1] == '-'
+				if !dashDash {
+					p.WriteString(s)
+				}
+			case reflect.Slice:
+				b := vf.Bytes()
+				dashDash = bytes.Index(b, ddBytes) >= 0
+				dashLast = b[len(b)-1] == '-'
+				if !dashDash {
+					p.Write(b)
+				}
+			default:
+				panic("can't happen")
+			}
+			if dashDash {
+				return fmt.Errorf(`xml: comments must not contain "--"`)
+			}
+			if dashLast {
+				// "--->" is invalid grammar. Make it "- -->"
+				p.WriteByte(' ')
+			}
+			p.WriteString("-->")
+			continue
+
+		case fInnerXml:
+			iface := vf.Interface()
+			switch raw := iface.(type) {
+			case []byte:
+				p.Write(raw)
+				continue
+			case string:
+				p.WriteString(raw)
+				continue
+			}
+
+		case fElement, fElement | fAny:
+			if err := s.setParents(finfo, vf); err != nil {
+				return err
+			}
+		}
+		if err := p.marshalValue(vf, finfo, nil); err != nil {
+			return err
+		}
+	}
+	if err := s.setParents(&noField, reflect.Value{}); err != nil {
+		return err
+	}
+	return p.cachedWriteError()
+}
+
+var noField fieldInfo
+
+// return the bufio Writer's cached write error
+func (p *printer) cachedWriteError() error {
+	_, err := p.Write(nil)
+	return err
+}
+
+func (p *printer) writeIndent(depthDelta int) {
+	if len(p.prefix) == 0 && len(p.indent) == 0 {
+		return
+	}
+	if depthDelta < 0 {
+		p.depth--
+		if p.indentedIn {
+			p.indentedIn = false
+			return
+		}
+		p.indentedIn = false
+	}
+	if p.putNewline {
+		p.WriteByte('\n')
+	} else {
+		p.putNewline = true
+	}
+	if len(p.prefix) > 0 {
+		p.WriteString(p.prefix)
+	}
+	if len(p.indent) > 0 {
+		for i := 0; i < p.depth; i++ {
+			p.WriteString(p.indent)
+		}
+	}
+	if depthDelta > 0 {
+		p.depth++
+		p.indentedIn = true
+	}
+}
+
+type parentStack struct {
+	p       *printer
+	xmlns   string
+	parents []string
+}
+
+// setParents sets the stack of current parents to those found in finfo.
+// It only writes the start elements if vf holds a non-nil value.
+// If finfo is &noField, it pops all elements.
+func (s *parentStack) setParents(finfo *fieldInfo, vf reflect.Value) error {
+	xmlns := s.p.defaultNS
+	if finfo.xmlns != "" {
+		xmlns = finfo.xmlns
+	}
+	commonParents := 0
+	if xmlns == s.xmlns {
+		for ; commonParents < len(finfo.parents) && commonParents < len(s.parents); commonParents++ {
+			if finfo.parents[commonParents] != s.parents[commonParents] {
+				break
+			}
+		}
+	}
+	// Pop off any parents that aren't in common with the previous field.
+	for i := len(s.parents) - 1; i >= commonParents; i-- {
+		if err := s.p.writeEnd(Name{
+			Space: s.xmlns,
+			Local: s.parents[i],
+		}); err != nil {
+			return err
+		}
+	}
+	s.parents = finfo.parents
+	s.xmlns = xmlns
+	if commonParents >= len(s.parents) {
+		// No new elements to push.
+		return nil
+	}
+	if (vf.Kind() == reflect.Ptr || vf.Kind() == reflect.Interface) && vf.IsNil() {
+		// The element is nil, so no need for the start elements.
+		s.parents = s.parents[:commonParents]
+		return nil
+	}
+	// Push any new parents required.
+	for _, name := range s.parents[commonParents:] {
+		start := &StartElement{
+			Name: Name{
+				Space: s.xmlns,
+				Local: name,
+			},
+		}
+		// Set the default name space for parent elements
+		// to match what we do with other elements.
+		if s.xmlns != s.p.defaultNS {
+			start.setDefaultNamespace()
+		}
+		if err := s.p.writeStart(start); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// A MarshalXMLError is returned when Marshal encounters a type
+// that cannot be converted into XML.
+type UnsupportedTypeError struct {
+	Type reflect.Type
+}
+
+func (e *UnsupportedTypeError) Error() string {
+	return "xml: unsupported type: " + e.Type.String()
+}
+
+func isEmptyValue(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+		return v.Len() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	}
+	return false
+}

webdav/internal/xml/marshal_test.go

@@ -0,0 +1,1939 @@
+// Copyright 2011 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.
+
+package xml
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+type DriveType int
+
+const (
+	HyperDrive DriveType = iota
+	ImprobabilityDrive
+)
+
+type Passenger struct {
+	Name   []string `xml:"name"`
+	Weight float32  `xml:"weight"`
+}
+
+type Ship struct {
+	XMLName struct{} `xml:"spaceship"`
+
+	Name      string       `xml:"name,attr"`
+	Pilot     string       `xml:"pilot,attr"`
+	Drive     DriveType    `xml:"drive"`
+	Age       uint         `xml:"age"`
+	Passenger []*Passenger `xml:"passenger"`
+	secret    string
+}
+
+type NamedType string
+
+type Port struct {
+	XMLName struct{} `xml:"port"`
+	Type    string   `xml:"type,attr,omitempty"`
+	Comment string   `xml:",comment"`
+	Number  string   `xml:",chardata"`
+}
+
+type Domain struct {
+	XMLName struct{} `xml:"domain"`
+	Country string   `xml:",attr,omitempty"`
+	Name    []byte   `xml:",chardata"`
+	Comment []byte   `xml:",comment"`
+}
+
+type Book struct {
+	XMLName struct{} `xml:"book"`
+	Title   string   `xml:",chardata"`
+}
+
+type Event struct {
+	XMLName struct{} `xml:"event"`
+	Year    int      `xml:",chardata"`
+}
+
+type Movie struct {
+	XMLName struct{} `xml:"movie"`
+	Length  uint     `xml:",chardata"`
+}
+
+type Pi struct {
+	XMLName       struct{} `xml:"pi"`
+	Approximation float32  `xml:",chardata"`
+}
+
+type Universe struct {
+	XMLName struct{} `xml:"universe"`
+	Visible float64  `xml:",chardata"`
+}
+
+type Particle struct {
+	XMLName struct{} `xml:"particle"`
+	HasMass bool     `xml:",chardata"`
+}
+
+type Departure struct {
+	XMLName struct{}  `xml:"departure"`
+	When    time.Time `xml:",chardata"`
+}
+
+type SecretAgent struct {
+	XMLName   struct{} `xml:"agent"`
+	Handle    string   `xml:"handle,attr"`
+	Identity  string
+	Obfuscate string `xml:",innerxml"`
+}
+
+type NestedItems struct {
+	XMLName struct{} `xml:"result"`
+	Items   []string `xml:">item"`
+	Item1   []string `xml:"Items>item1"`
+}
+
+type NestedOrder struct {
+	XMLName struct{} `xml:"result"`
+	Field1  string   `xml:"parent>c"`
+	Field2  string   `xml:"parent>b"`
+	Field3  string   `xml:"parent>a"`
+}
+
+type MixedNested struct {
+	XMLName struct{} `xml:"result"`
+	A       string   `xml:"parent1>a"`
+	B       string   `xml:"b"`
+	C       string   `xml:"parent1>parent2>c"`
+	D       string   `xml:"parent1>d"`
+}
+
+type NilTest struct {
+	A interface{} `xml:"parent1>parent2>a"`
+	B interface{} `xml:"parent1>b"`
+	C interface{} `xml:"parent1>parent2>c"`
+}
+
+type Service struct {
+	XMLName struct{} `xml:"service"`
+	Domain  *Domain  `xml:"host>domain"`
+	Port    *Port    `xml:"host>port"`
+	Extra1  interface{}
+	Extra2  interface{} `xml:"host>extra2"`
+}
+
+var nilStruct *Ship
+
+type EmbedA struct {
+	EmbedC
+	EmbedB EmbedB
+	FieldA string
+}
+
+type EmbedB struct {
+	FieldB string
+	*EmbedC
+}
+
+type EmbedC struct {
+	FieldA1 string `xml:"FieldA>A1"`
+	FieldA2 string `xml:"FieldA>A2"`
+	FieldB  string
+	FieldC  string
+}
+
+type NameCasing struct {
+	XMLName struct{} `xml:"casing"`
+	Xy      string
+	XY      string
+	XyA     string `xml:"Xy,attr"`
+	XYA     string `xml:"XY,attr"`
+}
+
+type NamePrecedence struct {
+	XMLName     Name              `xml:"Parent"`
+	FromTag     XMLNameWithoutTag `xml:"InTag"`
+	FromNameVal XMLNameWithoutTag
+	FromNameTag XMLNameWithTag
+	InFieldName string
+}
+
+type XMLNameWithTag struct {
+	XMLName Name   `xml:"InXMLNameTag"`
+	Value   string `xml:",chardata"`
+}
+
+type XMLNameWithNSTag struct {
+	XMLName Name   `xml:"ns InXMLNameWithNSTag"`
+	Value   string `xml:",chardata"`
+}
+
+type XMLNameWithoutTag struct {
+	XMLName Name
+	Value   string `xml:",chardata"`
+}
+
+type NameInField struct {
+	Foo Name `xml:"ns foo"`
+}
+
+type AttrTest struct {
+	Int   int     `xml:",attr"`
+	Named int     `xml:"int,attr"`
+	Float float64 `xml:",attr"`
+	Uint8 uint8   `xml:",attr"`
+	Bool  bool    `xml:",attr"`
+	Str   string  `xml:",attr"`
+	Bytes []byte  `xml:",attr"`
+}
+
+type OmitAttrTest struct {
+	Int   int     `xml:",attr,omitempty"`
+	Named int     `xml:"int,attr,omitempty"`
+	Float float64 `xml:",attr,omitempty"`
+	Uint8 uint8   `xml:",attr,omitempty"`
+	Bool  bool    `xml:",attr,omitempty"`
+	Str   string  `xml:",attr,omitempty"`
+	Bytes []byte  `xml:",attr,omitempty"`
+}
+
+type OmitFieldTest struct {
+	Int   int           `xml:",omitempty"`
+	Named int           `xml:"int,omitempty"`
+	Float float64       `xml:",omitempty"`
+	Uint8 uint8         `xml:",omitempty"`
+	Bool  bool          `xml:",omitempty"`
+	Str   string        `xml:",omitempty"`
+	Bytes []byte        `xml:",omitempty"`
+	Ptr   *PresenceTest `xml:",omitempty"`
+}
+
+type AnyTest struct {
+	XMLName  struct{}  `xml:"a"`
+	Nested   string    `xml:"nested>value"`
+	AnyField AnyHolder `xml:",any"`
+}
+
+type AnyOmitTest struct {
+	XMLName  struct{}   `xml:"a"`
+	Nested   string     `xml:"nested>value"`
+	AnyField *AnyHolder `xml:",any,omitempty"`
+}
+
+type AnySliceTest struct {
+	XMLName  struct{}    `xml:"a"`
+	Nested   string      `xml:"nested>value"`
+	AnyField []AnyHolder `xml:",any"`
+}
+
+type AnyHolder struct {
+	XMLName Name
+	XML     string `xml:",innerxml"`
+}
+
+type RecurseA struct {
+	A string
+	B *RecurseB
+}
+
+type RecurseB struct {
+	A *RecurseA
+	B string
+}
+
+type PresenceTest struct {
+	Exists *struct{}
+}
+
+type IgnoreTest struct {
+	PublicSecret string `xml:"-"`
+}
+
+type MyBytes []byte
+
+type Data struct {
+	Bytes  []byte
+	Attr   []byte `xml:",attr"`
+	Custom MyBytes
+}
+
+type Plain struct {
+	V interface{}
+}
+
+type MyInt int
+
+type EmbedInt struct {
+	MyInt
+}
+
+type Strings struct {
+	X []string `xml:"A>B,omitempty"`
+}
+
+type PointerFieldsTest struct {
+	XMLName  Name    `xml:"dummy"`
+	Name     *string `xml:"name,attr"`
+	Age      *uint   `xml:"age,attr"`
+	Empty    *string `xml:"empty,attr"`
+	Contents *string `xml:",chardata"`
+}
+
+type ChardataEmptyTest struct {
+	XMLName  Name    `xml:"test"`
+	Contents *string `xml:",chardata"`
+}
+
+type MyMarshalerTest struct {
+}
+
+var _ Marshaler = (*MyMarshalerTest)(nil)
+
+func (m *MyMarshalerTest) MarshalXML(e *Encoder, start StartElement) error {
+	e.EncodeToken(start)
+	e.EncodeToken(CharData([]byte("hello world")))
+	e.EncodeToken(EndElement{start.Name})
+	return nil
+}
+
+type MyMarshalerAttrTest struct{}
+
+var _ MarshalerAttr = (*MyMarshalerAttrTest)(nil)
+
+func (m *MyMarshalerAttrTest) MarshalXMLAttr(name Name) (Attr, error) {
+	return Attr{name, "hello world"}, nil
+}
+
+type MyMarshalerValueAttrTest struct{}
+
+var _ MarshalerAttr = MyMarshalerValueAttrTest{}
+
+func (m MyMarshalerValueAttrTest) MarshalXMLAttr(name Name) (Attr, error) {
+	return Attr{name, "hello world"}, nil
+}
+
+type MarshalerStruct struct {
+	Foo MyMarshalerAttrTest `xml:",attr"`
+}
+
+type MarshalerValueStruct struct {
+	Foo MyMarshalerValueAttrTest `xml:",attr"`
+}
+
+type InnerStruct struct {
+	XMLName Name `xml:"testns outer"`
+}
+
+type OuterStruct struct {
+	InnerStruct
+	IntAttr int `xml:"int,attr"`
+}
+
+type OuterNamedStruct struct {
+	InnerStruct
+	XMLName Name `xml:"outerns test"`
+	IntAttr int  `xml:"int,attr"`
+}
+
+type OuterNamedOrderedStruct struct {
+	XMLName Name `xml:"outerns test"`
+	InnerStruct
+	IntAttr int `xml:"int,attr"`
+}
+
+type OuterOuterStruct struct {
+	OuterStruct
+}
+
+type NestedAndChardata struct {
+	AB       []string `xml:"A>B"`
+	Chardata string   `xml:",chardata"`
+}
+
+type NestedAndComment struct {
+	AB      []string `xml:"A>B"`
+	Comment string   `xml:",comment"`
+}
+
+type XMLNSFieldStruct struct {
+	Ns   string `xml:"xmlns,attr"`
+	Body string
+}
+
+type NamedXMLNSFieldStruct struct {
+	XMLName struct{} `xml:"testns test"`
+	Ns      string   `xml:"xmlns,attr"`
+	Body    string
+}
+
+type XMLNSFieldStructWithOmitEmpty struct {
+	Ns   string `xml:"xmlns,attr,omitempty"`
+	Body string
+}
+
+type NamedXMLNSFieldStructWithEmptyNamespace struct {
+	XMLName struct{} `xml:"test"`
+	Ns      string   `xml:"xmlns,attr"`
+	Body    string
+}
+
+type RecursiveXMLNSFieldStruct struct {
+	Ns   string                     `xml:"xmlns,attr"`
+	Body *RecursiveXMLNSFieldStruct `xml:",omitempty"`
+	Text string                     `xml:",omitempty"`
+}
+
+func ifaceptr(x interface{}) interface{} {
+	return &x
+}
+
+var (
+	nameAttr     = "Sarah"
+	ageAttr      = uint(12)
+	contentsAttr = "lorem ipsum"
+)
+
+// Unless explicitly stated as such (or *Plain), all of the
+// tests below are two-way tests. When introducing new tests,
+// please try to make them two-way as well to ensure that
+// marshalling and unmarshalling are as symmetrical as feasible.
+var marshalTests = []struct {
+	Value         interface{}
+	ExpectXML     string
+	MarshalOnly   bool
+	UnmarshalOnly bool
+}{
+	// Test nil marshals to nothing
+	{Value: nil, ExpectXML: ``, MarshalOnly: true},
+	{Value: nilStruct, ExpectXML: ``, MarshalOnly: true},
+
+	// Test value types
+	{Value: &Plain{true}, ExpectXML: `<Plain><V>true</V></Plain>`},
+	{Value: &Plain{false}, ExpectXML: `<Plain><V>false</V></Plain>`},
+	{Value: &Plain{int(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{int8(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{int16(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{int32(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{uint(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{uint8(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{uint16(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{uint32(42)}, ExpectXML: `<Plain><V>42</V></Plain>`},
+	{Value: &Plain{float32(1.25)}, ExpectXML: `<Plain><V>1.25</V></Plain>`},
+	{Value: &Plain{float64(1.25)}, ExpectXML: `<Plain><V>1.25</V></Plain>`},
+	{Value: &Plain{uintptr(0xFFDD)}, ExpectXML: `<Plain><V>65501</V></Plain>`},
+	{Value: &Plain{"gopher"}, ExpectXML: `<Plain><V>gopher</V></Plain>`},
+	{Value: &Plain{[]byte("gopher")}, ExpectXML: `<Plain><V>gopher</V></Plain>`},
+	{Value: &Plain{"</>"}, ExpectXML: `<Plain><V>&lt;/&gt;</V></Plain>`},
+	{Value: &Plain{[]byte("</>")}, ExpectXML: `<Plain><V>&lt;/&gt;</V></Plain>`},
+	{Value: &Plain{[3]byte{'<', '/', '>'}}, ExpectXML: `<Plain><V>&lt;/&gt;</V></Plain>`},
+	{Value: &Plain{NamedType("potato")}, ExpectXML: `<Plain><V>potato</V></Plain>`},
+	{Value: &Plain{[]int{1, 2, 3}}, ExpectXML: `<Plain><V>1</V><V>2</V><V>3</V></Plain>`},
+	{Value: &Plain{[3]int{1, 2, 3}}, ExpectXML: `<Plain><V>1</V><V>2</V><V>3</V></Plain>`},
+	{Value: ifaceptr(true), MarshalOnly: true, ExpectXML: `<bool>true</bool>`},
+
+	// Test time.
+	{
+		Value:     &Plain{time.Unix(1e9, 123456789).UTC()},
+		ExpectXML: `<Plain><V>2001-09-09T01:46:40.123456789Z</V></Plain>`,
+	},
+
+	// A pointer to struct{} may be used to test for an element's presence.
+	{
+		Value:     &PresenceTest{new(struct{})},
+		ExpectXML: `<PresenceTest><Exists></Exists></PresenceTest>`,
+	},
+	{
+		Value:     &PresenceTest{},
+		ExpectXML: `<PresenceTest></PresenceTest>`,
+	},
+
+	// A pointer to struct{} may be used to test for an element's presence.
+	{
+		Value:     &PresenceTest{new(struct{})},
+		ExpectXML: `<PresenceTest><Exists></Exists></PresenceTest>`,
+	},
+	{
+		Value:     &PresenceTest{},
+		ExpectXML: `<PresenceTest></PresenceTest>`,
+	},
+
+	// A []byte field is only nil if the element was not found.
+	{
+		Value:         &Data{},
+		ExpectXML:     `<Data></Data>`,
+		UnmarshalOnly: true,
+	},
+	{
+		Value:         &Data{Bytes: []byte{}, Custom: MyBytes{}, Attr: []byte{}},
+		ExpectXML:     `<Data Attr=""><Bytes></Bytes><Custom></Custom></Data>`,
+		UnmarshalOnly: true,
+	},
+
+	// Check that []byte works, including named []byte types.
+	{
+		Value:     &Data{Bytes: []byte("ab"), Custom: MyBytes("cd"), Attr: []byte{'v'}},
+		ExpectXML: `<Data Attr="v"><Bytes>ab</Bytes><Custom>cd</Custom></Data>`,
+	},
+
+	// Test innerxml
+	{
+		Value: &SecretAgent{
+			Handle:    "007",
+			Identity:  "James Bond",
+			Obfuscate: "<redacted/>",
+		},
+		ExpectXML:   `<agent handle="007"><Identity>James Bond</Identity><redacted/></agent>`,
+		MarshalOnly: true,
+	},
+	{
+		Value: &SecretAgent{
+			Handle:    "007",
+			Identity:  "James Bond",
+			Obfuscate: "<Identity>James Bond</Identity><redacted/>",
+		},
+		ExpectXML:     `<agent handle="007"><Identity>James Bond</Identity><redacted/></agent>`,
+		UnmarshalOnly: true,
+	},
+
+	// Test structs
+	{Value: &Port{Type: "ssl", Number: "443"}, ExpectXML: `<port type="ssl">443</port>`},
+	{Value: &Port{Number: "443"}, ExpectXML: `<port>443</port>`},
+	{Value: &Port{Type: "<unix>"}, ExpectXML: `<port type="&lt;unix&gt;"></port>`},
+	{Value: &Port{Number: "443", Comment: "https"}, ExpectXML: `<port><!--https-->443</port>`},
+	{Value: &Port{Number: "443", Comment: "add space-"}, ExpectXML: `<port><!--add space- -->443</port>`, MarshalOnly: true},
+	{Value: &Domain{Name: []byte("google.com&friends")}, ExpectXML: `<domain>google.com&amp;friends</domain>`},
+	{Value: &Domain{Name: []byte("google.com"), Comment: []byte(" &friends ")}, ExpectXML: `<domain>google.com<!-- &friends --></domain>`},
+	{Value: &Book{Title: "Pride & Prejudice"}, ExpectXML: `<book>Pride &amp; Prejudice</book>`},
+	{Value: &Event{Year: -3114}, ExpectXML: `<event>-3114</event>`},
+	{Value: &Movie{Length: 13440}, ExpectXML: `<movie>13440</movie>`},
+	{Value: &Pi{Approximation: 3.14159265}, ExpectXML: `<pi>3.1415927</pi>`},
+	{Value: &Universe{Visible: 9.3e13}, ExpectXML: `<universe>9.3e+13</universe>`},
+	{Value: &Particle{HasMass: true}, ExpectXML: `<particle>true</particle>`},
+	{Value: &Departure{When: ParseTime("2013-01-09T00:15:00-09:00")}, ExpectXML: `<departure>2013-01-09T00:15:00-09:00</departure>`},
+	{Value: atomValue, ExpectXML: atomXml},
+	{
+		Value: &Ship{
+			Name:  "Heart of Gold",
+			Pilot: "Computer",
+			Age:   1,
+			Drive: ImprobabilityDrive,
+			Passenger: []*Passenger{
+				{
+					Name:   []string{"Zaphod", "Beeblebrox"},
+					Weight: 7.25,
+				},
+				{
+					Name:   []string{"Trisha", "McMillen"},
+					Weight: 5.5,
+				},
+				{
+					Name:   []string{"Ford", "Prefect"},
+					Weight: 7,
+				},
+				{
+					Name:   []string{"Arthur", "Dent"},
+					Weight: 6.75,
+				},
+			},
+		},
+		ExpectXML: `<spaceship name="Heart of Gold" pilot="Computer">` +
+			`<drive>` + strconv.Itoa(int(ImprobabilityDrive)) + `</drive>` +
+			`<age>1</age>` +
+			`<passenger>` +
+			`<name>Zaphod</name>` +
+			`<name>Beeblebrox</name>` +
+			`<weight>7.25</weight>` +
+			`</passenger>` +
+			`<passenger>` +
+			`<name>Trisha</name>` +
+			`<name>McMillen</name>` +
+			`<weight>5.5</weight>` +
+			`</passenger>` +
+			`<passenger>` +
+			`<name>Ford</name>` +
+			`<name>Prefect</name>` +
+			`<weight>7</weight>` +
+			`</passenger>` +
+			`<passenger>` +
+			`<name>Arthur</name>` +
+			`<name>Dent</name>` +
+			`<weight>6.75</weight>` +
+			`</passenger>` +
+			`</spaceship>`,
+	},
+
+	// Test a>b
+	{
+		Value: &NestedItems{Items: nil, Item1: nil},
+		ExpectXML: `<result>` +
+			`<Items>` +
+			`</Items>` +
+			`</result>`,
+	},
+	{
+		Value: &NestedItems{Items: []string{}, Item1: []string{}},
+		ExpectXML: `<result>` +
+			`<Items>` +
+			`</Items>` +
+			`</result>`,
+		MarshalOnly: true,
+	},
+	{
+		Value: &NestedItems{Items: nil, Item1: []string{"A"}},
+		ExpectXML: `<result>` +
+			`<Items>` +
+			`<item1>A</item1>` +
+			`</Items>` +
+			`</result>`,
+	},
+	{
+		Value: &NestedItems{Items: []string{"A", "B"}, Item1: nil},
+		ExpectXML: `<result>` +
+			`<Items>` +
+			`<item>A</item>` +
+			`<item>B</item>` +
+			`</Items>` +
+			`</result>`,
+	},
+	{
+		Value: &NestedItems{Items: []string{"A", "B"}, Item1: []string{"C"}},
+		ExpectXML: `<result>` +
+			`<Items>` +
+			`<item>A</item>` +
+			`<item>B</item>` +
+			`<item1>C</item1>` +
+			`</Items>` +
+			`</result>`,
+	},
+	{
+		Value: &NestedOrder{Field1: "C", Field2: "B", Field3: "A"},
+		ExpectXML: `<result>` +
+			`<parent>` +
+			`<c>C</c>` +
+			`<b>B</b>` +
+			`<a>A</a>` +
+			`</parent>` +
+			`</result>`,
+	},
+	{
+		Value: &NilTest{A: "A", B: nil, C: "C"},
+		ExpectXML: `<NilTest>` +
+			`<parent1>` +
+			`<parent2><a>A</a></parent2>` +
+			`<parent2><c>C</c></parent2>` +
+			`</parent1>` +
+			`</NilTest>`,
+		MarshalOnly: true, // Uses interface{}
+	},
+	{
+		Value: &MixedNested{A: "A", B: "B", C: "C", D: "D"},
+		ExpectXML: `<result>` +
+			`<parent1><a>A</a></parent1>` +
+			`<b>B</b>` +
+			`<parent1>` +
+			`<parent2><c>C</c></parent2>` +
+			`<d>D</d>` +
+			`</parent1>` +
+			`</result>`,
+	},
+	{
+		Value:     &Service{Port: &Port{Number: "80"}},
+		ExpectXML: `<service><host><port>80</port></host></service>`,
+	},
+	{
+		Value:     &Service{},
+		ExpectXML: `<service></service>`,
+	},
+	{
+		Value: &Service{Port: &Port{Number: "80"}, Extra1: "A", Extra2: "B"},
+		ExpectXML: `<service>` +
+			`<host><port>80</port></host>` +
+			`<Extra1>A</Extra1>` +
+			`<host><extra2>B</extra2></host>` +
+			`</service>`,
+		MarshalOnly: true,
+	},
+	{
+		Value: &Service{Port: &Port{Number: "80"}, Extra2: "example"},
+		ExpectXML: `<service>` +
+			`<host><port>80</port></host>` +
+			`<host><extra2>example</extra2></host>` +
+			`</service>`,
+		MarshalOnly: true,
+	},
+	{
+		Value: &struct {
+			XMLName struct{} `xml:"space top"`
+			A       string   `xml:"x>a"`
+			B       string   `xml:"x>b"`
+			C       string   `xml:"space x>c"`
+			C1      string   `xml:"space1 x>c"`
+			D1      string   `xml:"space1 x>d"`
+			E1      string   `xml:"x>e"`
+		}{
+			A:  "a",
+			B:  "b",
+			C:  "c",
+			C1: "c1",
+			D1: "d1",
+			E1: "e1",
+		},
+		ExpectXML: `<top xmlns="space">` +
+			`<x><a>a</a><b>b</b><c>c</c></x>` +
+			`<x xmlns="space1">` +
+			`<c>c1</c>` +
+			`<d>d1</d>` +
+			`</x>` +
+			`<x>` +
+			`<e>e1</e>` +
+			`</x>` +
+			`</top>`,
+	},
+	{
+		Value: &struct {
+			XMLName Name
+			A       string `xml:"x>a"`
+			B       string `xml:"x>b"`
+			C       string `xml:"space x>c"`
+			C1      string `xml:"space1 x>c"`
+			D1      string `xml:"space1 x>d"`
+		}{
+			XMLName: Name{
+				Space: "space0",
+				Local: "top",
+			},
+			A:  "a",
+			B:  "b",
+			C:  "c",
+			C1: "c1",
+			D1: "d1",
+		},
+		ExpectXML: `<top xmlns="space0">` +
+			`<x><a>a</a><b>b</b></x>` +
+			`<x xmlns="space"><c>c</c></x>` +
+			`<x xmlns="space1">` +
+			`<c>c1</c>` +
+			`<d>d1</d>` +
+			`</x>` +
+			`</top>`,
+	},
+	{
+		Value: &struct {
+			XMLName struct{} `xml:"top"`
+			B       string   `xml:"space x>b"`
+			B1      string   `xml:"space1 x>b"`
+		}{
+			B:  "b",
+			B1: "b1",
+		},
+		ExpectXML: `<top>` +
+			`<x xmlns="space"><b>b</b></x>` +
+			`<x xmlns="space1"><b>b1</b></x>` +
+			`</top>`,
+	},
+
+	// Test struct embedding
+	{
+		Value: &EmbedA{
+			EmbedC: EmbedC{
+				FieldA1: "", // Shadowed by A.A
+				FieldA2: "", // Shadowed by A.A
+				FieldB:  "A.C.B",
+				FieldC:  "A.C.C",
+			},
+			EmbedB: EmbedB{
+				FieldB: "A.B.B",
+				EmbedC: &EmbedC{
+					FieldA1: "A.B.C.A1",
+					FieldA2: "A.B.C.A2",
+					FieldB:  "", // Shadowed by A.B.B
+					FieldC:  "A.B.C.C",
+				},
+			},
+			FieldA: "A.A",
+		},
+		ExpectXML: `<EmbedA>` +
+			`<FieldB>A.C.B</FieldB>` +
+			`<FieldC>A.C.C</FieldC>` +
+			`<EmbedB>` +
+			`<FieldB>A.B.B</FieldB>` +
+			`<FieldA>` +
+			`<A1>A.B.C.A1</A1>` +
+			`<A2>A.B.C.A2</A2>` +
+			`</FieldA>` +
+			`<FieldC>A.B.C.C</FieldC>` +
+			`</EmbedB>` +
+			`<FieldA>A.A</FieldA>` +
+			`</EmbedA>`,
+	},
+
+	// Test that name casing matters
+	{
+		Value:     &NameCasing{Xy: "mixed", XY: "upper", XyA: "mixedA", XYA: "upperA"},
+		ExpectXML: `<casing Xy="mixedA" XY="upperA"><Xy>mixed</Xy><XY>upper</XY></casing>`,
+	},
+
+	// Test the order in which the XML element name is chosen
+	{
+		Value: &NamePrecedence{
+			FromTag:     XMLNameWithoutTag{Value: "A"},
+			FromNameVal: XMLNameWithoutTag{XMLName: Name{Local: "InXMLName"}, Value: "B"},
+			FromNameTag: XMLNameWithTag{Value: "C"},
+			InFieldName: "D",
+		},
+		ExpectXML: `<Parent>` +
+			`<InTag>A</InTag>` +
+			`<InXMLName>B</InXMLName>` +
+			`<InXMLNameTag>C</InXMLNameTag>` +
+			`<InFieldName>D</InFieldName>` +
+			`</Parent>`,
+		MarshalOnly: true,
+	},
+	{
+		Value: &NamePrecedence{
+			XMLName:     Name{Local: "Parent"},
+			FromTag:     XMLNameWithoutTag{XMLName: Name{Local: "InTag"}, Value: "A"},
+			FromNameVal: XMLNameWithoutTag{XMLName: Name{Local: "FromNameVal"}, Value: "B"},
+			FromNameTag: XMLNameWithTag{XMLName: Name{Local: "InXMLNameTag"}, Value: "C"},
+			InFieldName: "D",
+		},
+		ExpectXML: `<Parent>` +
+			`<InTag>A</InTag>` +
+			`<FromNameVal>B</FromNameVal>` +
+			`<InXMLNameTag>C</InXMLNameTag>` +
+			`<InFieldName>D</InFieldName>` +
+			`</Parent>`,
+		UnmarshalOnly: true,
+	},
+
+	// xml.Name works in a plain field as well.
+	{
+		Value:     &NameInField{Name{Space: "ns", Local: "foo"}},
+		ExpectXML: `<NameInField><foo xmlns="ns"></foo></NameInField>`,
+	},
+	{
+		Value:         &NameInField{Name{Space: "ns", Local: "foo"}},
+		ExpectXML:     `<NameInField><foo xmlns="ns"><ignore></ignore></foo></NameInField>`,
+		UnmarshalOnly: true,
+	},
+
+	// Marshaling zero xml.Name uses the tag or field name.
+	{
+		Value:       &NameInField{},
+		ExpectXML:   `<NameInField><foo xmlns="ns"></foo></NameInField>`,
+		MarshalOnly: true,
+	},
+
+	// Test attributes
+	{
+		Value: &AttrTest{
+			Int:   8,
+			Named: 9,
+			Float: 23.5,
+			Uint8: 255,
+			Bool:  true,
+			Str:   "str",
+			Bytes: []byte("byt"),
+		},
+		ExpectXML: `<AttrTest Int="8" int="9" Float="23.5" Uint8="255"` +
+			` Bool="true" Str="str" Bytes="byt"></AttrTest>`,
+	},
+	{
+		Value: &AttrTest{Bytes: []byte{}},
+		ExpectXML: `<AttrTest Int="0" int="0" Float="0" Uint8="0"` +
+			` Bool="false" Str="" Bytes=""></AttrTest>`,
+	},
+	{
+		Value: &OmitAttrTest{
+			Int:   8,
+			Named: 9,
+			Float: 23.5,
+			Uint8: 255,
+			Bool:  true,
+			Str:   "str",
+			Bytes: []byte("byt"),
+		},
+		ExpectXML: `<OmitAttrTest Int="8" int="9" Float="23.5" Uint8="255"` +
+			` Bool="true" Str="str" Bytes="byt"></OmitAttrTest>`,
+	},
+	{
+		Value:     &OmitAttrTest{},
+		ExpectXML: `<OmitAttrTest></OmitAttrTest>`,
+	},
+
+	// pointer fields
+	{
+		Value:       &PointerFieldsTest{Name: &nameAttr, Age: &ageAttr, Contents: &contentsAttr},
+		ExpectXML:   `<dummy name="Sarah" age="12">lorem ipsum</dummy>`,
+		MarshalOnly: true,
+	},
+
+	// empty chardata pointer field
+	{
+		Value:       &ChardataEmptyTest{},
+		ExpectXML:   `<test></test>`,
+		MarshalOnly: true,
+	},
+
+	// omitempty on fields
+	{
+		Value: &OmitFieldTest{
+			Int:   8,
+			Named: 9,
+			Float: 23.5,
+			Uint8: 255,
+			Bool:  true,
+			Str:   "str",
+			Bytes: []byte("byt"),
+			Ptr:   &PresenceTest{},
+		},
+		ExpectXML: `<OmitFieldTest>` +
+			`<Int>8</Int>` +
+			`<int>9</int>` +
+			`<Float>23.5</Float>` +
+			`<Uint8>255</Uint8>` +
+			`<Bool>true</Bool>` +
+			`<Str>str</Str>` +
+			`<Bytes>byt</Bytes>` +
+			`<Ptr></Ptr>` +
+			`</OmitFieldTest>`,
+	},
+	{
+		Value:     &OmitFieldTest{},
+		ExpectXML: `<OmitFieldTest></OmitFieldTest>`,
+	},
+
+	// Test ",any"
+	{
+		ExpectXML: `<a><nested><value>known</value></nested><other><sub>unknown</sub></other></a>`,
+		Value: &AnyTest{
+			Nested: "known",
+			AnyField: AnyHolder{
+				XMLName: Name{Local: "other"},
+				XML:     "<sub>unknown</sub>",
+			},
+		},
+	},
+	{
+		Value: &AnyTest{Nested: "known",
+			AnyField: AnyHolder{
+				XML:     "<unknown/>",
+				XMLName: Name{Local: "AnyField"},
+			},
+		},
+		ExpectXML: `<a><nested><value>known</value></nested><AnyField><unknown/></AnyField></a>`,
+	},
+	{
+		ExpectXML: `<a><nested><value>b</value></nested></a>`,
+		Value: &AnyOmitTest{
+			Nested: "b",
+		},
+	},
+	{
+		ExpectXML: `<a><nested><value>b</value></nested><c><d>e</d></c><g xmlns="f"><h>i</h></g></a>`,
+		Value: &AnySliceTest{
+			Nested: "b",
+			AnyField: []AnyHolder{
+				{
+					XMLName: Name{Local: "c"},
+					XML:     "<d>e</d>",
+				},
+				{
+					XMLName: Name{Space: "f", Local: "g"},
+					XML:     "<h>i</h>",
+				},
+			},
+		},
+	},
+	{
+		ExpectXML: `<a><nested><value>b</value></nested></a>`,
+		Value: &AnySliceTest{
+			Nested: "b",
+		},
+	},
+
+	// Test recursive types.
+	{
+		Value: &RecurseA{
+			A: "a1",
+			B: &RecurseB{
+				A: &RecurseA{"a2", nil},
+				B: "b1",
+			},
+		},
+		ExpectXML: `<RecurseA><A>a1</A><B><A><A>a2</A></A><B>b1</B></B></RecurseA>`,
+	},
+
+	// Test ignoring fields via "-" tag
+	{
+		ExpectXML: `<IgnoreTest></IgnoreTest>`,
+		Value:     &IgnoreTest{},
+	},
+	{
+		ExpectXML:   `<IgnoreTest></IgnoreTest>`,
+		Value:       &IgnoreTest{PublicSecret: "can't tell"},
+		MarshalOnly: true,
+	},
+	{
+		ExpectXML:     `<IgnoreTest><PublicSecret>ignore me</PublicSecret></IgnoreTest>`,
+		Value:         &IgnoreTest{},
+		UnmarshalOnly: true,
+	},
+
+	// Test escaping.
+	{
+		ExpectXML: `<a><nested><value>dquote: &#34;; squote: &#39;; ampersand: &amp;; less: &lt;; greater: &gt;;</value></nested><empty></empty></a>`,
+		Value: &AnyTest{
+			Nested:   `dquote: "; squote: '; ampersand: &; less: <; greater: >;`,
+			AnyField: AnyHolder{XMLName: Name{Local: "empty"}},
+		},
+	},
+	{
+		ExpectXML: `<a><nested><value>newline: &#xA;; cr: &#xD;; tab: &#x9;;</value></nested><AnyField></AnyField></a>`,
+		Value: &AnyTest{
+			Nested:   "newline: \n; cr: \r; tab: \t;",
+			AnyField: AnyHolder{XMLName: Name{Local: "AnyField"}},
+		},
+	},
+	{
+		ExpectXML: "<a><nested><value>1\r2\r\n3\n\r4\n5</value></nested></a>",
+		Value: &AnyTest{
+			Nested: "1\n2\n3\n\n4\n5",
+		},
+		UnmarshalOnly: true,
+	},
+	{
+		ExpectXML: `<EmbedInt><MyInt>42</MyInt></EmbedInt>`,
+		Value: &EmbedInt{
+			MyInt: 42,
+		},
+	},
+	// Test omitempty with parent chain; see golang.org/issue/4168.
+	{
+		ExpectXML: `<Strings><A></A></Strings>`,
+		Value:     &Strings{},
+	},
+	// Custom marshalers.
+	{
+		ExpectXML: `<MyMarshalerTest>hello world</MyMarshalerTest>`,
+		Value:     &MyMarshalerTest{},
+	},
+	{
+		ExpectXML: `<MarshalerStruct Foo="hello world"></MarshalerStruct>`,
+		Value:     &MarshalerStruct{},
+	},
+	{
+		ExpectXML: `<MarshalerValueStruct Foo="hello world"></MarshalerValueStruct>`,
+		Value:     &MarshalerValueStruct{},
+	},
+	{
+		ExpectXML: `<outer xmlns="testns" int="10"></outer>`,
+		Value:     &OuterStruct{IntAttr: 10},
+	},
+	{
+		ExpectXML: `<test xmlns="outerns" int="10"></test>`,
+		Value:     &OuterNamedStruct{XMLName: Name{Space: "outerns", Local: "test"}, IntAttr: 10},
+	},
+	{
+		ExpectXML: `<test xmlns="outerns" int="10"></test>`,
+		Value:     &OuterNamedOrderedStruct{XMLName: Name{Space: "outerns", Local: "test"}, IntAttr: 10},
+	},
+	{
+		ExpectXML: `<outer xmlns="testns" int="10"></outer>`,
+		Value:     &OuterOuterStruct{OuterStruct{IntAttr: 10}},
+	},
+	{
+		ExpectXML: `<NestedAndChardata><A><B></B><B></B></A>test</NestedAndChardata>`,
+		Value:     &NestedAndChardata{AB: make([]string, 2), Chardata: "test"},
+	},
+	{
+		ExpectXML: `<NestedAndComment><A><B></B><B></B></A><!--test--></NestedAndComment>`,
+		Value:     &NestedAndComment{AB: make([]string, 2), Comment: "test"},
+	},
+	{
+		ExpectXML: `<XMLNSFieldStruct xmlns="http://example.com/ns"><Body>hello world</Body></XMLNSFieldStruct>`,
+		Value:     &XMLNSFieldStruct{Ns: "http://example.com/ns", Body: "hello world"},
+	},
+	{
+		ExpectXML: `<testns:test xmlns:testns="testns" xmlns="http://example.com/ns"><Body>hello world</Body></testns:test>`,
+		Value:     &NamedXMLNSFieldStruct{Ns: "http://example.com/ns", Body: "hello world"},
+	},
+	{
+		ExpectXML: `<testns:test xmlns:testns="testns"><Body>hello world</Body></testns:test>`,
+		Value:     &NamedXMLNSFieldStruct{Ns: "", Body: "hello world"},
+	},
+	{
+		ExpectXML: `<XMLNSFieldStructWithOmitEmpty><Body>hello world</Body></XMLNSFieldStructWithOmitEmpty>`,
+		Value:     &XMLNSFieldStructWithOmitEmpty{Body: "hello world"},
+	},
+	{
+		// The xmlns attribute must be ignored because the <test>
+		// element is in the empty namespace, so it's not possible
+		// to set the default namespace to something non-empty.
+		ExpectXML:   `<test><Body>hello world</Body></test>`,
+		Value:       &NamedXMLNSFieldStructWithEmptyNamespace{Ns: "foo", Body: "hello world"},
+		MarshalOnly: true,
+	},
+	{
+		ExpectXML: `<RecursiveXMLNSFieldStruct xmlns="foo"><Body xmlns=""><Text>hello world</Text></Body></RecursiveXMLNSFieldStruct>`,
+		Value: &RecursiveXMLNSFieldStruct{
+			Ns: "foo",
+			Body: &RecursiveXMLNSFieldStruct{
+				Text: "hello world",
+			},
+		},
+	},
+}
+
+func TestMarshal(t *testing.T) {
+	for idx, test := range marshalTests {
+		if test.UnmarshalOnly {
+			continue
+		}
+		data, err := Marshal(test.Value)
+		if err != nil {
+			t.Errorf("#%d: marshal(%#v): %s", idx, test.Value, err)
+			continue
+		}
+		if got, want := string(data), test.ExpectXML; got != want {
+			if strings.Contains(want, "\n") {
+				t.Errorf("#%d: marshal(%#v):\nHAVE:\n%s\nWANT:\n%s", idx, test.Value, got, want)
+			} else {
+				t.Errorf("#%d: marshal(%#v):\nhave %#q\nwant %#q", idx, test.Value, got, want)
+			}
+		}
+	}
+}
+
+type AttrParent struct {
+	X string `xml:"X>Y,attr"`
+}
+
+type BadAttr struct {
+	Name []string `xml:"name,attr"`
+}
+
+var marshalErrorTests = []struct {
+	Value interface{}
+	Err   string
+	Kind  reflect.Kind
+}{
+	{
+		Value: make(chan bool),
+		Err:   "xml: unsupported type: chan bool",
+		Kind:  reflect.Chan,
+	},
+	{
+		Value: map[string]string{
+			"question": "What do you get when you multiply six by nine?",
+			"answer":   "42",
+		},
+		Err:  "xml: unsupported type: map[string]string",
+		Kind: reflect.Map,
+	},
+	{
+		Value: map[*Ship]bool{nil: false},
+		Err:   "xml: unsupported type: map[*xml.Ship]bool",
+		Kind:  reflect.Map,
+	},
+	{
+		Value: &Domain{Comment: []byte("f--bar")},
+		Err:   `xml: comments must not contain "--"`,
+	},
+	// Reject parent chain with attr, never worked; see golang.org/issue/5033.
+	{
+		Value: &AttrParent{},
+		Err:   `xml: X>Y chain not valid with attr flag`,
+	},
+	{
+		Value: BadAttr{[]string{"X", "Y"}},
+		Err:   `xml: unsupported type: []string`,
+	},
+}
+
+var marshalIndentTests = []struct {
+	Value     interface{}
+	Prefix    string
+	Indent    string
+	ExpectXML string
+}{
+	{
+		Value: &SecretAgent{
+			Handle:    "007",
+			Identity:  "James Bond",
+			Obfuscate: "<redacted/>",
+		},
+		Prefix:    "",
+		Indent:    "\t",
+		ExpectXML: fmt.Sprintf("<agent handle=\"007\">\n\t<Identity>James Bond</Identity><redacted/>\n</agent>"),
+	},
+}
+
+func TestMarshalErrors(t *testing.T) {
+	for idx, test := range marshalErrorTests {
+		data, err := Marshal(test.Value)
+		if err == nil {
+			t.Errorf("#%d: marshal(%#v) = [success] %q, want error %v", idx, test.Value, data, test.Err)
+			continue
+		}
+		if err.Error() != test.Err {
+			t.Errorf("#%d: marshal(%#v) = [error] %v, want %v", idx, test.Value, err, test.Err)
+		}
+		if test.Kind != reflect.Invalid {
+			if kind := err.(*UnsupportedTypeError).Type.Kind(); kind != test.Kind {
+				t.Errorf("#%d: marshal(%#v) = [error kind] %s, want %s", idx, test.Value, kind, test.Kind)
+			}
+		}
+	}
+}
+
+// Do invertibility testing on the various structures that we test
+func TestUnmarshal(t *testing.T) {
+	for i, test := range marshalTests {
+		if test.MarshalOnly {
+			continue
+		}
+		if _, ok := test.Value.(*Plain); ok {
+			continue
+		}
+		vt := reflect.TypeOf(test.Value)
+		dest := reflect.New(vt.Elem()).Interface()
+		err := Unmarshal([]byte(test.ExpectXML), dest)
+
+		switch fix := dest.(type) {
+		case *Feed:
+			fix.Author.InnerXML = ""
+			for i := range fix.Entry {
+				fix.Entry[i].Author.InnerXML = ""
+			}
+		}
+
+		if err != nil {
+			t.Errorf("#%d: unexpected error: %#v", i, err)
+		} else if got, want := dest, test.Value; !reflect.DeepEqual(got, want) {
+			t.Errorf("#%d: unmarshal(%q):\nhave %#v\nwant %#v", i, test.ExpectXML, got, want)
+		}
+	}
+}
+
+func TestMarshalIndent(t *testing.T) {
+	for i, test := range marshalIndentTests {
+		data, err := MarshalIndent(test.Value, test.Prefix, test.Indent)
+		if err != nil {
+			t.Errorf("#%d: Error: %s", i, err)
+			continue
+		}
+		if got, want := string(data), test.ExpectXML; got != want {
+			t.Errorf("#%d: MarshalIndent:\nGot:%s\nWant:\n%s", i, got, want)
+		}
+	}
+}
+
+type limitedBytesWriter struct {
+	w      io.Writer
+	remain int // until writes fail
+}
+
+func (lw *limitedBytesWriter) Write(p []byte) (n int, err error) {
+	if lw.remain <= 0 {
+		println("error")
+		return 0, errors.New("write limit hit")
+	}
+	if len(p) > lw.remain {
+		p = p[:lw.remain]
+		n, _ = lw.w.Write(p)
+		lw.remain = 0
+		return n, errors.New("write limit hit")
+	}
+	n, err = lw.w.Write(p)
+	lw.remain -= n
+	return n, err
+}
+
+func TestMarshalWriteErrors(t *testing.T) {
+	var buf bytes.Buffer
+	const writeCap = 1024
+	w := &limitedBytesWriter{&buf, writeCap}
+	enc := NewEncoder(w)
+	var err error
+	var i int
+	const n = 4000
+	for i = 1; i <= n; i++ {
+		err = enc.Encode(&Passenger{
+			Name:   []string{"Alice", "Bob"},
+			Weight: 5,
+		})
+		if err != nil {
+			break
+		}
+	}
+	if err == nil {
+		t.Error("expected an error")
+	}
+	if i == n {
+		t.Errorf("expected to fail before the end")
+	}
+	if buf.Len() != writeCap {
+		t.Errorf("buf.Len() = %d; want %d", buf.Len(), writeCap)
+	}
+}
+
+func TestMarshalWriteIOErrors(t *testing.T) {
+	enc := NewEncoder(errWriter{})
+
+	expectErr := "unwritable"
+	err := enc.Encode(&Passenger{})
+	if err == nil || err.Error() != expectErr {
+		t.Errorf("EscapeTest = [error] %v, want %v", err, expectErr)
+	}
+}
+
+func TestMarshalFlush(t *testing.T) {
+	var buf bytes.Buffer
+	enc := NewEncoder(&buf)
+	if err := enc.EncodeToken(CharData("hello world")); err != nil {
+		t.Fatalf("enc.EncodeToken: %v", err)
+	}
+	if buf.Len() > 0 {
+		t.Fatalf("enc.EncodeToken caused actual write: %q", buf.Bytes())
+	}
+	if err := enc.Flush(); err != nil {
+		t.Fatalf("enc.Flush: %v", err)
+	}
+	if buf.String() != "hello world" {
+		t.Fatalf("after enc.Flush, buf.String() = %q, want %q", buf.String(), "hello world")
+	}
+}
+
+var encodeElementTests = []struct {
+	desc      string
+	value     interface{}
+	start     StartElement
+	expectXML string
+}{{
+	desc:  "simple string",
+	value: "hello",
+	start: StartElement{
+		Name: Name{Local: "a"},
+	},
+	expectXML: `<a>hello</a>`,
+}, {
+	desc:  "string with added attributes",
+	value: "hello",
+	start: StartElement{
+		Name: Name{Local: "a"},
+		Attr: []Attr{{
+			Name:  Name{Local: "x"},
+			Value: "y",
+		}, {
+			Name:  Name{Local: "foo"},
+			Value: "bar",
+		}},
+	},
+	expectXML: `<a x="y" foo="bar">hello</a>`,
+}, {
+	desc: "start element with default name space",
+	value: struct {
+		Foo XMLNameWithNSTag
+	}{
+		Foo: XMLNameWithNSTag{
+			Value: "hello",
+		},
+	},
+	start: StartElement{
+		Name: Name{Space: "ns", Local: "a"},
+		Attr: []Attr{{
+			Name: Name{Local: "xmlns"},
+			// "ns" is the name space defined in XMLNameWithNSTag
+			Value: "ns",
+		}},
+	},
+	expectXML: `<a xmlns="ns"><InXMLNameWithNSTag>hello</InXMLNameWithNSTag></a>`,
+}, {
+	desc: "start element in name space with different default name space",
+	value: struct {
+		Foo XMLNameWithNSTag
+	}{
+		Foo: XMLNameWithNSTag{
+			Value: "hello",
+		},
+	},
+	start: StartElement{
+		Name: Name{Space: "ns2", Local: "a"},
+		Attr: []Attr{{
+			Name: Name{Local: "xmlns"},
+			// "ns" is the name space defined in XMLNameWithNSTag
+			Value: "ns",
+		}},
+	},
+	expectXML: `<ns2:a xmlns:ns2="ns2" xmlns="ns"><InXMLNameWithNSTag>hello</InXMLNameWithNSTag></ns2:a>`,
+}, {
+	desc:  "XMLMarshaler with start element with default name space",
+	value: &MyMarshalerTest{},
+	start: StartElement{
+		Name: Name{Space: "ns2", Local: "a"},
+		Attr: []Attr{{
+			Name: Name{Local: "xmlns"},
+			// "ns" is the name space defined in XMLNameWithNSTag
+			Value: "ns",
+		}},
+	},
+	expectXML: `<ns2:a xmlns:ns2="ns2" xmlns="ns">hello world</ns2:a>`,
+}}
+
+func TestEncodeElement(t *testing.T) {
+	for idx, test := range encodeElementTests {
+		var buf bytes.Buffer
+		enc := NewEncoder(&buf)
+		err := enc.EncodeElement(test.value, test.start)
+		if err != nil {
+			t.Fatalf("enc.EncodeElement: %v", err)
+		}
+		err = enc.Flush()
+		if err != nil {
+			t.Fatalf("enc.Flush: %v", err)
+		}
+		if got, want := buf.String(), test.expectXML; got != want {
+			t.Errorf("#%d(%s): EncodeElement(%#v, %#v):\nhave %#q\nwant %#q", idx, test.desc, test.value, test.start, got, want)
+		}
+	}
+}
+
+func BenchmarkMarshal(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		Marshal(atomValue)
+	}
+}
+
+func BenchmarkUnmarshal(b *testing.B) {
+	b.ReportAllocs()
+	xml := []byte(atomXml)
+	for i := 0; i < b.N; i++ {
+		Unmarshal(xml, &Feed{})
+	}
+}
+
+// golang.org/issue/6556
+func TestStructPointerMarshal(t *testing.T) {
+	type A struct {
+		XMLName string `xml:"a"`
+		B       []interface{}
+	}
+	type C struct {
+		XMLName Name
+		Value   string `xml:"value"`
+	}
+
+	a := new(A)
+	a.B = append(a.B, &C{
+		XMLName: Name{Local: "c"},
+		Value:   "x",
+	})
+
+	b, err := Marshal(a)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if x := string(b); x != "<a><c><value>x</value></c></a>" {
+		t.Fatal(x)
+	}
+	var v A
+	err = Unmarshal(b, &v)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+var encodeTokenTests = []struct {
+	desc string
+	toks []Token
+	want string
+	err  string
+}{{
+	desc: "start element with name space",
+	toks: []Token{
+		StartElement{Name{"space", "local"}, nil},
+	},
+	want: `<space:local xmlns:space="space">`,
+}, {
+	desc: "start element with no name",
+	toks: []Token{
+		StartElement{Name{"space", ""}, nil},
+	},
+	err: "xml: start tag with no name",
+}, {
+	desc: "end element with no name",
+	toks: []Token{
+		EndElement{Name{"space", ""}},
+	},
+	err: "xml: end tag with no name",
+}, {
+	desc: "char data",
+	toks: []Token{
+		CharData("foo"),
+	},
+	want: `foo`,
+}, {
+	desc: "char data with escaped chars",
+	toks: []Token{
+		CharData(" \t\n"),
+	},
+	want: " &#x9;\n",
+}, {
+	desc: "comment",
+	toks: []Token{
+		Comment("foo"),
+	},
+	want: `<!--foo-->`,
+}, {
+	desc: "comment with invalid content",
+	toks: []Token{
+		Comment("foo-->"),
+	},
+	err: "xml: EncodeToken of Comment containing --> marker",
+}, {
+	desc: "proc instruction",
+	toks: []Token{
+		ProcInst{"Target", []byte("Instruction")},
+	},
+	want: `<?Target Instruction?>`,
+}, {
+	desc: "proc instruction with empty target",
+	toks: []Token{
+		ProcInst{"", []byte("Instruction")},
+	},
+	err: "xml: EncodeToken of ProcInst with invalid Target",
+}, {
+	desc: "proc instruction with bad content",
+	toks: []Token{
+		ProcInst{"", []byte("Instruction?>")},
+	},
+	err: "xml: EncodeToken of ProcInst with invalid Target",
+}, {
+	desc: "directive",
+	toks: []Token{
+		Directive("foo"),
+	},
+	want: `<!foo>`,
+}, {
+	desc: "more complex directive",
+	toks: []Token{
+		Directive("DOCTYPE doc [ <!ELEMENT doc '>'> <!-- com>ment --> ]"),
+	},
+	want: `<!DOCTYPE doc [ <!ELEMENT doc '>'> <!-- com>ment --> ]>`,
+}, {
+	desc: "directive instruction with bad name",
+	toks: []Token{
+		Directive("foo>"),
+	},
+	err: "xml: EncodeToken of Directive containing wrong < or > markers",
+}, {
+	desc: "end tag without start tag",
+	toks: []Token{
+		EndElement{Name{"foo", "bar"}},
+	},
+	err: "xml: end tag </bar> without start tag",
+}, {
+	desc: "mismatching end tag local name",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, nil},
+		EndElement{Name{"", "bar"}},
+	},
+	err:  "xml: end tag </bar> does not match start tag <foo>",
+	want: `<foo>`,
+}, {
+	desc: "mismatching end tag namespace",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, nil},
+		EndElement{Name{"another", "foo"}},
+	},
+	err:  "xml: end tag </foo> in namespace another does not match start tag <foo> in namespace space",
+	want: `<space:foo xmlns:space="space">`,
+}, {
+	desc: "start element with explicit namespace",
+	toks: []Token{
+		StartElement{Name{"space", "local"}, []Attr{
+			{Name{"xmlns", "x"}, "space"},
+			{Name{"space", "foo"}, "value"},
+		}},
+	},
+	want: `<x:local xmlns:x="space" x:foo="value">`,
+}, {
+	desc: "start element with explicit namespace and colliding prefix",
+	toks: []Token{
+		StartElement{Name{"space", "local"}, []Attr{
+			{Name{"xmlns", "x"}, "space"},
+			{Name{"space", "foo"}, "value"},
+			{Name{"x", "bar"}, "other"},
+		}},
+	},
+	want: `<x:local xmlns:x_1="x" xmlns:x="space" x:foo="value" x_1:bar="other">`,
+}, {
+	desc: "start element using previously defined namespace",
+	toks: []Token{
+		StartElement{Name{"", "local"}, []Attr{
+			{Name{"xmlns", "x"}, "space"},
+		}},
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"space", "x"}, "y"},
+		}},
+	},
+	want: `<local xmlns:x="space"><x:foo x:x="y">`,
+}, {
+	desc: "nested name space with same prefix",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"xmlns", "x"}, "space1"},
+		}},
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"xmlns", "x"}, "space2"},
+		}},
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"space1", "a"}, "space1 value"},
+			{Name{"space2", "b"}, "space2 value"},
+		}},
+		EndElement{Name{"", "foo"}},
+		EndElement{Name{"", "foo"}},
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"space1", "a"}, "space1 value"},
+			{Name{"space2", "b"}, "space2 value"},
+		}},
+	},
+	want: `<foo xmlns:x="space1"><foo xmlns:x="space2"><foo xmlns:space1="space1" space1:a="space1 value" x:b="space2 value"></foo></foo><foo xmlns:space2="space2" x:a="space1 value" space2:b="space2 value">`,
+}, {
+	desc: "start element defining several prefixes for the same name space",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"xmlns", "a"}, "space"},
+			{Name{"xmlns", "b"}, "space"},
+			{Name{"space", "x"}, "value"},
+		}},
+	},
+	want: `<a:foo xmlns:a="space" a:x="value">`,
+}, {
+	desc: "nested element redefines name space",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"xmlns", "x"}, "space"},
+		}},
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"xmlns", "y"}, "space"},
+			{Name{"space", "a"}, "value"},
+		}},
+	},
+	want: `<foo xmlns:x="space"><x:foo x:a="value">`,
+}, {
+	desc: "nested element creates alias for default name space",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+		}},
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"xmlns", "y"}, "space"},
+			{Name{"space", "a"}, "value"},
+		}},
+	},
+	want: `<foo xmlns="space"><foo xmlns:y="space" y:a="value">`,
+}, {
+	desc: "nested element defines default name space with existing prefix",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"xmlns", "x"}, "space"},
+		}},
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+			{Name{"space", "a"}, "value"},
+		}},
+	},
+	want: `<foo xmlns:x="space"><foo xmlns="space" x:a="value">`,
+}, {
+	desc: "nested element uses empty attribute name space when default ns defined",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+		}},
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "attr"}, "value"},
+		}},
+	},
+	want: `<foo xmlns="space"><foo attr="value">`,
+}, {
+	desc: "redefine xmlns",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"foo", "xmlns"}, "space"},
+		}},
+	},
+	err: `xml: cannot redefine xmlns attribute prefix`,
+}, {
+	desc: "xmlns with explicit name space #1",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"xml", "xmlns"}, "space"},
+		}},
+	},
+	want: `<foo xmlns="space">`,
+}, {
+	desc: "xmlns with explicit name space #2",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{xmlURL, "xmlns"}, "space"},
+		}},
+	},
+	want: `<foo xmlns="space">`,
+}, {
+	desc: "empty name space declaration is ignored",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"xmlns", "foo"}, ""},
+		}},
+	},
+	want: `<foo>`,
+}, {
+	desc: "attribute with no name is ignored",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"", ""}, "value"},
+		}},
+	},
+	want: `<foo>`,
+}, {
+	desc: "namespace URL with non-valid name",
+	toks: []Token{
+		StartElement{Name{"/34", "foo"}, []Attr{
+			{Name{"/34", "x"}, "value"},
+		}},
+	},
+	want: `<_:foo xmlns:_="/34" _:x="value">`,
+}, {
+	desc: "nested element resets default namespace to empty",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+		}},
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"", "xmlns"}, ""},
+			{Name{"", "x"}, "value"},
+			{Name{"space", "x"}, "value"},
+		}},
+	},
+	want: `<foo xmlns="space"><foo xmlns:space="space" xmlns="" x="value" space:x="value">`,
+}, {
+	desc: "nested element requires empty default name space",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+		}},
+		StartElement{Name{"", "foo"}, nil},
+	},
+	want: `<foo xmlns="space"><foo xmlns="">`,
+}, {
+	desc: "attribute uses name space from xmlns",
+	toks: []Token{
+		StartElement{Name{"some/space", "foo"}, []Attr{
+			{Name{"", "attr"}, "value"},
+			{Name{"some/space", "other"}, "other value"},
+		}},
+	},
+	want: `<space:foo xmlns:space="some/space" attr="value" space:other="other value">`,
+}, {
+	desc: "default name space should not be used by attributes",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+			{Name{"xmlns", "bar"}, "space"},
+			{Name{"space", "baz"}, "foo"},
+		}},
+		StartElement{Name{"space", "baz"}, nil},
+		EndElement{Name{"space", "baz"}},
+		EndElement{Name{"space", "foo"}},
+	},
+	want: `<foo xmlns:bar="space" xmlns="space" bar:baz="foo"><baz></baz></foo>`,
+}, {
+	desc: "default name space not used by attributes, not explicitly defined",
+	toks: []Token{
+		StartElement{Name{"space", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+			{Name{"space", "baz"}, "foo"},
+		}},
+		StartElement{Name{"space", "baz"}, nil},
+		EndElement{Name{"space", "baz"}},
+		EndElement{Name{"space", "foo"}},
+	},
+	want: `<foo xmlns:space="space" xmlns="space" space:baz="foo"><baz></baz></foo>`,
+}, {
+	desc: "impossible xmlns declaration",
+	toks: []Token{
+		StartElement{Name{"", "foo"}, []Attr{
+			{Name{"", "xmlns"}, "space"},
+		}},
+		StartElement{Name{"space", "bar"}, []Attr{
+			{Name{"space", "attr"}, "value"},
+		}},
+	},
+	want: `<foo><space:bar xmlns:space="space" space:attr="value">`,
+}}
+
+func TestEncodeToken(t *testing.T) {
+loop:
+	for i, tt := range encodeTokenTests {
+		var buf bytes.Buffer
+		enc := NewEncoder(&buf)
+		var err error
+		for j, tok := range tt.toks {
+			err = enc.EncodeToken(tok)
+			if err != nil && j < len(tt.toks)-1 {
+				t.Errorf("#%d %s token #%d: %v", i, tt.desc, j, err)
+				continue loop
+			}
+		}
+		errorf := func(f string, a ...interface{}) {
+			t.Errorf("#%d %s token #%d:%s", i, tt.desc, len(tt.toks)-1, fmt.Sprintf(f, a...))
+		}
+		switch {
+		case tt.err != "" && err == nil:
+			errorf(" expected error; got none")
+			continue
+		case tt.err == "" && err != nil:
+			errorf(" got error: %v", err)
+			continue
+		case tt.err != "" && err != nil && tt.err != err.Error():
+			errorf(" error mismatch; got %v, want %v", err, tt.err)
+			continue
+		}
+		if err := enc.Flush(); err != nil {
+			errorf(" %v", err)
+			continue
+		}
+		if got := buf.String(); got != tt.want {
+			errorf("\ngot  %v\nwant %v", got, tt.want)
+			continue
+		}
+	}
+}
+
+func TestProcInstEncodeToken(t *testing.T) {
+	var buf bytes.Buffer
+	enc := NewEncoder(&buf)
+
+	if err := enc.EncodeToken(ProcInst{"xml", []byte("Instruction")}); err != nil {
+		t.Fatalf("enc.EncodeToken: expected to be able to encode xml target ProcInst as first token, %s", err)
+	}
+
+	if err := enc.EncodeToken(ProcInst{"Target", []byte("Instruction")}); err != nil {
+		t.Fatalf("enc.EncodeToken: expected to be able to add non-xml target ProcInst")
+	}
+
+	if err := enc.EncodeToken(ProcInst{"xml", []byte("Instruction")}); err == nil {
+		t.Fatalf("enc.EncodeToken: expected to not be allowed to encode xml target ProcInst when not first token")
+	}
+}
+
+func TestDecodeEncode(t *testing.T) {
+	var in, out bytes.Buffer
+	in.WriteString(`<?xml version="1.0" encoding="UTF-8"?>
+<?Target Instruction?>
+<root>
+</root>	
+`)
+	dec := NewDecoder(&in)
+	enc := NewEncoder(&out)
+	for tok, err := dec.Token(); err == nil; tok, err = dec.Token() {
+		err = enc.EncodeToken(tok)
+		if err != nil {
+			t.Fatalf("enc.EncodeToken: Unable to encode token (%#v), %v", tok, err)
+		}
+	}
+}
+
+// Issue 9796. Used to fail with GORACE="halt_on_error=1" -race.
+func TestRace9796(t *testing.T) {
+	type A struct{}
+	type B struct {
+		C []A `xml:"X>Y"`
+	}
+	var wg sync.WaitGroup
+	for i := 0; i < 2; i++ {
+		wg.Add(1)
+		go func() {
+			Marshal(B{[]A{A{}}})
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+}
+
+func TestIsValidDirective(t *testing.T) {
+	testOK := []string{
+		"<>",
+		"< < > >",
+		"<!DOCTYPE '<' '>' '>' <!--nothing-->>",
+		"<!DOCTYPE doc [ <!ELEMENT doc ANY> <!ELEMENT doc ANY> ]>",
+		"<!DOCTYPE doc [ <!ELEMENT doc \"ANY> '<' <!E\" LEMENT '>' doc ANY> ]>",
+		"<!DOCTYPE doc <!-- just>>>> a < comment --> [ <!ITEM anything> ] >",
+	}
+	testKO := []string{
+		"<",
+		">",
+		"<!--",
+		"-->",
+		"< > > < < >",
+		"<!dummy <!-- > -->",
+		"<!DOCTYPE doc '>",
+		"<!DOCTYPE doc '>'",
+		"<!DOCTYPE doc <!--comment>",
+	}
+	for _, s := range testOK {
+		if !isValidDirective(Directive(s)) {
+			t.Errorf("Directive %q is expected to be valid", s)
+		}
+	}
+	for _, s := range testKO {
+		if isValidDirective(Directive(s)) {
+			t.Errorf("Directive %q is expected to be invalid", s)
+		}
+	}
+}
+
+// Issue 11719. EncodeToken used to silently eat tokens with an invalid type.
+func TestSimpleUseOfEncodeToken(t *testing.T) {
+	var buf bytes.Buffer
+	enc := NewEncoder(&buf)
+	if err := enc.EncodeToken(&StartElement{Name: Name{"", "object1"}}); err == nil {
+		t.Errorf("enc.EncodeToken: pointer type should be rejected")
+	}
+	if err := enc.EncodeToken(&EndElement{Name: Name{"", "object1"}}); err == nil {
+		t.Errorf("enc.EncodeToken: pointer type should be rejected")
+	}
+	if err := enc.EncodeToken(StartElement{Name: Name{"", "object2"}}); err != nil {
+		t.Errorf("enc.EncodeToken: StartElement %s", err)
+	}
+	if err := enc.EncodeToken(EndElement{Name: Name{"", "object2"}}); err != nil {
+		t.Errorf("enc.EncodeToken: EndElement %s", err)
+	}
+	if err := enc.EncodeToken(Universe{}); err == nil {
+		t.Errorf("enc.EncodeToken: invalid type not caught")
+	}
+	if err := enc.Flush(); err != nil {
+		t.Errorf("enc.Flush: %s", err)
+	}
+	if buf.Len() == 0 {
+		t.Errorf("enc.EncodeToken: empty buffer")
+	}
+	want := "<object2></object2>"
+	if buf.String() != want {
+		t.Errorf("enc.EncodeToken: expected %q; got %q", want, buf.String())
+	}
+}

webdav/internal/xml/read.go

@@ -0,0 +1,692 @@
+// Copyright 2009 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.
+
+package xml
+
+import (
+	"bytes"
+	"encoding"
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+// BUG(rsc): Mapping between XML elements and data structures is inherently flawed:
+// an XML element is an order-dependent collection of anonymous
+// values, while a data structure is an order-independent collection
+// of named values.
+// See package json for a textual representation more suitable
+// to data structures.
+
+// Unmarshal parses the XML-encoded data and stores the result in
+// the value pointed to by v, which must be an arbitrary struct,
+// slice, or string. Well-formed data that does not fit into v is
+// discarded.
+//
+// Because Unmarshal uses the reflect package, it can only assign
+// to exported (upper case) fields.  Unmarshal uses a case-sensitive
+// comparison to match XML element names to tag values and struct
+// field names.
+//
+// Unmarshal maps an XML element to a struct using the following rules.
+// In the rules, the tag of a field refers to the value associated with the
+// key 'xml' in the struct field's tag (see the example above).
+//
+//   * If the struct has a field of type []byte or string with tag
+//      ",innerxml", Unmarshal accumulates the raw XML nested inside the
+//      element in that field.  The rest of the rules still apply.
+//
+//   * If the struct has a field named XMLName of type xml.Name,
+//      Unmarshal records the element name in that field.
+//
+//   * If the XMLName field has an associated tag of the form
+//      "name" or "namespace-URL name", the XML element must have
+//      the given name (and, optionally, name space) or else Unmarshal
+//      returns an error.
+//
+//   * If the XML element has an attribute whose name matches a
+//      struct field name with an associated tag containing ",attr" or
+//      the explicit name in a struct field tag of the form "name,attr",
+//      Unmarshal records the attribute value in that field.
+//
+//   * If the XML element contains character data, that data is
+//      accumulated in the first struct field that has tag ",chardata".
+//      The struct field may have type []byte or string.
+//      If there is no such field, the character data is discarded.
+//
+//   * If the XML element contains comments, they are accumulated in
+//      the first struct field that has tag ",comment".  The struct
+//      field may have type []byte or string.  If there is no such
+//      field, the comments are discarded.
+//
+//   * If the XML element contains a sub-element whose name matches
+//      the prefix of a tag formatted as "a" or "a>b>c", unmarshal
+//      will descend into the XML structure looking for elements with the
+//      given names, and will map the innermost elements to that struct
+//      field. A tag starting with ">" is equivalent to one starting
+//      with the field name followed by ">".
+//
+//   * If the XML element contains a sub-element whose name matches
+//      a struct field's XMLName tag and the struct field has no
+//      explicit name tag as per the previous rule, unmarshal maps
+//      the sub-element to that struct field.
+//
+//   * If the XML element contains a sub-element whose name matches a
+//      field without any mode flags (",attr", ",chardata", etc), Unmarshal
+//      maps the sub-element to that struct field.
+//
+//   * If the XML element contains a sub-element that hasn't matched any
+//      of the above rules and the struct has a field with tag ",any",
+//      unmarshal maps the sub-element to that struct field.
+//
+//   * An anonymous struct field is handled as if the fields of its
+//      value were part of the outer struct.
+//
+//   * A struct field with tag "-" is never unmarshalled into.
+//
+// Unmarshal maps an XML element to a string or []byte by saving the
+// concatenation of that element's character data in the string or
+// []byte. The saved []byte is never nil.
+//
+// Unmarshal maps an attribute value to a string or []byte by saving
+// the value in the string or slice.
+//
+// Unmarshal maps an XML element to a slice by extending the length of
+// the slice and mapping the element to the newly created value.
+//
+// Unmarshal maps an XML element or attribute value to a bool by
+// setting it to the boolean value represented by the string.
+//
+// Unmarshal maps an XML element or attribute value to an integer or
+// floating-point field by setting the field to the result of
+// interpreting the string value in decimal.  There is no check for
+// overflow.
+//
+// Unmarshal maps an XML element to an xml.Name by recording the
+// element name.
+//
+// Unmarshal maps an XML element to a pointer by setting the pointer
+// to a freshly allocated value and then mapping the element to that value.
+//
+func Unmarshal(data []byte, v interface{}) error {
+	return NewDecoder(bytes.NewReader(data)).Decode(v)
+}
+
+// Decode works like xml.Unmarshal, except it reads the decoder
+// stream to find the start element.
+func (d *Decoder) Decode(v interface{}) error {
+	return d.DecodeElement(v, nil)
+}
+
+// DecodeElement works like xml.Unmarshal except that it takes
+// a pointer to the start XML element to decode into v.
+// It is useful when a client reads some raw XML tokens itself
+// but also wants to defer to Unmarshal for some elements.
+func (d *Decoder) DecodeElement(v interface{}, start *StartElement) error {
+	val := reflect.ValueOf(v)
+	if val.Kind() != reflect.Ptr {
+		return errors.New("non-pointer passed to Unmarshal")
+	}
+	return d.unmarshal(val.Elem(), start)
+}
+
+// An UnmarshalError represents an error in the unmarshalling process.
+type UnmarshalError string
+
+func (e UnmarshalError) Error() string { return string(e) }
+
+// Unmarshaler is the interface implemented by objects that can unmarshal
+// an XML element description of themselves.
+//
+// UnmarshalXML decodes a single XML element
+// beginning with the given start element.
+// If it returns an error, the outer call to Unmarshal stops and
+// returns that error.
+// UnmarshalXML must consume exactly one XML element.
+// One common implementation strategy is to unmarshal into
+// a separate value with a layout matching the expected XML
+// using d.DecodeElement,  and then to copy the data from
+// that value into the receiver.
+// Another common strategy is to use d.Token to process the
+// XML object one token at a time.
+// UnmarshalXML may not use d.RawToken.
+type Unmarshaler interface {
+	UnmarshalXML(d *Decoder, start StartElement) error
+}
+
+// UnmarshalerAttr is the interface implemented by objects that can unmarshal
+// an XML attribute description of themselves.
+//
+// UnmarshalXMLAttr decodes a single XML attribute.
+// If it returns an error, the outer call to Unmarshal stops and
+// returns that error.
+// UnmarshalXMLAttr is used only for struct fields with the
+// "attr" option in the field tag.
+type UnmarshalerAttr interface {
+	UnmarshalXMLAttr(attr Attr) error
+}
+
+// receiverType returns the receiver type to use in an expression like "%s.MethodName".
+func receiverType(val interface{}) string {
+	t := reflect.TypeOf(val)
+	if t.Name() != "" {
+		return t.String()
+	}
+	return "(" + t.String() + ")"
+}
+
+// unmarshalInterface unmarshals a single XML element into val.
+// start is the opening tag of the element.
+func (p *Decoder) unmarshalInterface(val Unmarshaler, start *StartElement) error {
+	// Record that decoder must stop at end tag corresponding to start.
+	p.pushEOF()
+
+	p.unmarshalDepth++
+	err := val.UnmarshalXML(p, *start)
+	p.unmarshalDepth--
+	if err != nil {
+		p.popEOF()
+		return err
+	}
+
+	if !p.popEOF() {
+		return fmt.Errorf("xml: %s.UnmarshalXML did not consume entire <%s> element", receiverType(val), start.Name.Local)
+	}
+
+	return nil
+}
+
+// unmarshalTextInterface unmarshals a single XML element into val.
+// The chardata contained in the element (but not its children)
+// is passed to the text unmarshaler.
+func (p *Decoder) unmarshalTextInterface(val encoding.TextUnmarshaler, start *StartElement) error {
+	var buf []byte
+	depth := 1
+	for depth > 0 {
+		t, err := p.Token()
+		if err != nil {
+			return err
+		}
+		switch t := t.(type) {
+		case CharData:
+			if depth == 1 {
+				buf = append(buf, t...)
+			}
+		case StartElement:
+			depth++
+		case EndElement:
+			depth--
+		}
+	}
+	return val.UnmarshalText(buf)
+}
+
+// unmarshalAttr unmarshals a single XML attribute into val.
+func (p *Decoder) unmarshalAttr(val reflect.Value, attr Attr) error {
+	if val.Kind() == reflect.Ptr {
+		if val.IsNil() {
+			val.Set(reflect.New(val.Type().Elem()))
+		}
+		val = val.Elem()
+	}
+
+	if val.CanInterface() && val.Type().Implements(unmarshalerAttrType) {
+		// This is an unmarshaler with a non-pointer receiver,
+		// so it's likely to be incorrect, but we do what we're told.
+		return val.Interface().(UnmarshalerAttr).UnmarshalXMLAttr(attr)
+	}
+	if val.CanAddr() {
+		pv := val.Addr()
+		if pv.CanInterface() && pv.Type().Implements(unmarshalerAttrType) {
+			return pv.Interface().(UnmarshalerAttr).UnmarshalXMLAttr(attr)
+		}
+	}
+
+	// Not an UnmarshalerAttr; try encoding.TextUnmarshaler.
+	if val.CanInterface() && val.Type().Implements(textUnmarshalerType) {
+		// This is an unmarshaler with a non-pointer receiver,
+		// so it's likely to be incorrect, but we do what we're told.
+		return val.Interface().(encoding.TextUnmarshaler).UnmarshalText([]byte(attr.Value))
+	}
+	if val.CanAddr() {
+		pv := val.Addr()
+		if pv.CanInterface() && pv.Type().Implements(textUnmarshalerType) {
+			return pv.Interface().(encoding.TextUnmarshaler).UnmarshalText([]byte(attr.Value))
+		}
+	}
+
+	copyValue(val, []byte(attr.Value))
+	return nil
+}
+
+var (
+	unmarshalerType     = reflect.TypeOf((*Unmarshaler)(nil)).Elem()
+	unmarshalerAttrType = reflect.TypeOf((*UnmarshalerAttr)(nil)).Elem()
+	textUnmarshalerType = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+)
+
+// Unmarshal a single XML element into val.
+func (p *Decoder) unmarshal(val reflect.Value, start *StartElement) error {
+	// Find start element if we need it.
+	if start == nil {
+		for {
+			tok, err := p.Token()
+			if err != nil {
+				return err
+			}
+			if t, ok := tok.(StartElement); ok {
+				start = &t
+				break
+			}
+		}
+	}
+
+	// Load value from interface, but only if the result will be
+	// usefully addressable.
+	if val.Kind() == reflect.Interface && !val.IsNil() {
+		e := val.Elem()
+		if e.Kind() == reflect.Ptr && !e.IsNil() {
+			val = e
+		}
+	}
+
+	if val.Kind() == reflect.Ptr {
+		if val.IsNil() {
+			val.Set(reflect.New(val.Type().Elem()))
+		}
+		val = val.Elem()
+	}
+
+	if val.CanInterface() && val.Type().Implements(unmarshalerType) {
+		// This is an unmarshaler with a non-pointer receiver,
+		// so it's likely to be incorrect, but we do what we're told.
+		return p.unmarshalInterface(val.Interface().(Unmarshaler), start)
+	}
+
+	if val.CanAddr() {
+		pv := val.Addr()
+		if pv.CanInterface() && pv.Type().Implements(unmarshalerType) {
+			return p.unmarshalInterface(pv.Interface().(Unmarshaler), start)
+		}
+	}
+
+	if val.CanInterface() && val.Type().Implements(textUnmarshalerType) {
+		return p.unmarshalTextInterface(val.Interface().(encoding.TextUnmarshaler), start)
+	}
+
+	if val.CanAddr() {
+		pv := val.Addr()
+		if pv.CanInterface() && pv.Type().Implements(textUnmarshalerType) {
+			return p.unmarshalTextInterface(pv.Interface().(encoding.TextUnmarshaler), start)
+		}
+	}
+
+	var (
+		data         []byte
+		saveData     reflect.Value
+		comment      []byte
+		saveComment  reflect.Value
+		saveXML      reflect.Value
+		saveXMLIndex int
+		saveXMLData  []byte
+		saveAny      reflect.Value
+		sv           reflect.Value
+		tinfo        *typeInfo
+		err          error
+	)
+
+	switch v := val; v.Kind() {
+	default:
+		return errors.New("unknown type " + v.Type().String())
+
+	case reflect.Interface:
+		// TODO: For now, simply ignore the field. In the near
+		//       future we may choose to unmarshal the start
+		//       element on it, if not nil.
+		return p.Skip()
+
+	case reflect.Slice:
+		typ := v.Type()
+		if typ.Elem().Kind() == reflect.Uint8 {
+			// []byte
+			saveData = v
+			break
+		}
+
+		// Slice of element values.
+		// Grow slice.
+		n := v.Len()
+		if n >= v.Cap() {
+			ncap := 2 * n
+			if ncap < 4 {
+				ncap = 4
+			}
+			new := reflect.MakeSlice(typ, n, ncap)
+			reflect.Copy(new, v)
+			v.Set(new)
+		}
+		v.SetLen(n + 1)
+
+		// Recur to read element into slice.
+		if err := p.unmarshal(v.Index(n), start); err != nil {
+			v.SetLen(n)
+			return err
+		}
+		return nil
+
+	case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr, reflect.String:
+		saveData = v
+
+	case reflect.Struct:
+		typ := v.Type()
+		if typ == nameType {
+			v.Set(reflect.ValueOf(start.Name))
+			break
+		}
+
+		sv = v
+		tinfo, err = getTypeInfo(typ)
+		if err != nil {
+			return err
+		}
+
+		// Validate and assign element name.
+		if tinfo.xmlname != nil {
+			finfo := tinfo.xmlname
+			if finfo.name != "" && finfo.name != start.Name.Local {
+				return UnmarshalError("expected element type <" + finfo.name + "> but have <" + start.Name.Local + ">")
+			}
+			if finfo.xmlns != "" && finfo.xmlns != start.Name.Space {
+				e := "expected element <" + finfo.name + "> in name space " + finfo.xmlns + " but have "
+				if start.Name.Space == "" {
+					e += "no name space"
+				} else {
+					e += start.Name.Space
+				}
+				return UnmarshalError(e)
+			}
+			fv := finfo.value(sv)
+			if _, ok := fv.Interface().(Name); ok {
+				fv.Set(reflect.ValueOf(start.Name))
+			}
+		}
+
+		// Assign attributes.
+		// Also, determine whether we need to save character data or comments.
+		for i := range tinfo.fields {
+			finfo := &tinfo.fields[i]
+			switch finfo.flags & fMode {
+			case fAttr:
+				strv := finfo.value(sv)
+				// Look for attribute.
+				for _, a := range start.Attr {
+					if a.Name.Local == finfo.name && (finfo.xmlns == "" || finfo.xmlns == a.Name.Space) {
+						if err := p.unmarshalAttr(strv, a); err != nil {
+							return err
+						}
+						break
+					}
+				}
+
+			case fCharData:
+				if !saveData.IsValid() {
+					saveData = finfo.value(sv)
+				}
+
+			case fComment:
+				if !saveComment.IsValid() {
+					saveComment = finfo.value(sv)
+				}
+
+			case fAny, fAny | fElement:
+				if !saveAny.IsValid() {
+					saveAny = finfo.value(sv)
+				}
+
+			case fInnerXml:
+				if !saveXML.IsValid() {
+					saveXML = finfo.value(sv)
+					if p.saved == nil {
+						saveXMLIndex = 0
+						p.saved = new(bytes.Buffer)
+					} else {
+						saveXMLIndex = p.savedOffset()
+					}
+				}
+			}
+		}
+	}
+
+	// Find end element.
+	// Process sub-elements along the way.
+Loop:
+	for {
+		var savedOffset int
+		if saveXML.IsValid() {
+			savedOffset = p.savedOffset()
+		}
+		tok, err := p.Token()
+		if err != nil {
+			return err
+		}
+		switch t := tok.(type) {
+		case StartElement:
+			consumed := false
+			if sv.IsValid() {
+				consumed, err = p.unmarshalPath(tinfo, sv, nil, &t)
+				if err != nil {
+					return err
+				}
+				if !consumed && saveAny.IsValid() {
+					consumed = true
+					if err := p.unmarshal(saveAny, &t); err != nil {
+						return err
+					}
+				}
+			}
+			if !consumed {
+				if err := p.Skip(); err != nil {
+					return err
+				}
+			}
+
+		case EndElement:
+			if saveXML.IsValid() {
+				saveXMLData = p.saved.Bytes()[saveXMLIndex:savedOffset]
+				if saveXMLIndex == 0 {
+					p.saved = nil
+				}
+			}
+			break Loop
+
+		case CharData:
+			if saveData.IsValid() {
+				data = append(data, t...)
+			}
+
+		case Comment:
+			if saveComment.IsValid() {
+				comment = append(comment, t...)
+			}
+		}
+	}
+
+	if saveData.IsValid() && saveData.CanInterface() && saveData.Type().Implements(textUnmarshalerType) {
+		if err := saveData.Interface().(encoding.TextUnmarshaler).UnmarshalText(data); err != nil {
+			return err
+		}
+		saveData = reflect.Value{}
+	}
+
+	if saveData.IsValid() && saveData.CanAddr() {
+		pv := saveData.Addr()
+		if pv.CanInterface() && pv.Type().Implements(textUnmarshalerType) {
+			if err := pv.Interface().(encoding.TextUnmarshaler).UnmarshalText(data); err != nil {
+				return err
+			}
+			saveData = reflect.Value{}
+		}
+	}
+
+	if err := copyValue(saveData, data); err != nil {
+		return err
+	}
+
+	switch t := saveComment; t.Kind() {
+	case reflect.String:
+		t.SetString(string(comment))
+	case reflect.Slice:
+		t.Set(reflect.ValueOf(comment))
+	}
+
+	switch t := saveXML; t.Kind() {
+	case reflect.String:
+		t.SetString(string(saveXMLData))
+	case reflect.Slice:
+		t.Set(reflect.ValueOf(saveXMLData))
+	}
+
+	return nil
+}
+
+func copyValue(dst reflect.Value, src []byte) (err error) {
+	dst0 := dst
+
+	if dst.Kind() == reflect.Ptr {
+		if dst.IsNil() {
+			dst.Set(reflect.New(dst.Type().Elem()))
+		}
+		dst = dst.Elem()
+	}
+
+	// Save accumulated data.
+	switch dst.Kind() {
+	case reflect.Invalid:
+		// Probably a comment.
+	default:
+		return errors.New("cannot unmarshal into " + dst0.Type().String())
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		itmp, err := strconv.ParseInt(string(src), 10, dst.Type().Bits())
+		if err != nil {
+			return err
+		}
+		dst.SetInt(itmp)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		utmp, err := strconv.ParseUint(string(src), 10, dst.Type().Bits())
+		if err != nil {
+			return err
+		}
+		dst.SetUint(utmp)
+	case reflect.Float32, reflect.Float64:
+		ftmp, err := strconv.ParseFloat(string(src), dst.Type().Bits())
+		if err != nil {
+			return err
+		}
+		dst.SetFloat(ftmp)
+	case reflect.Bool:
+		value, err := strconv.ParseBool(strings.TrimSpace(string(src)))
+		if err != nil {
+			return err
+		}
+		dst.SetBool(value)
+	case reflect.String:
+		dst.SetString(string(src))
+	case reflect.Slice:
+		if len(src) == 0 {
+			// non-nil to flag presence
+			src = []byte{}
+		}
+		dst.SetBytes(src)
+	}
+	return nil
+}
+
+// unmarshalPath walks down an XML structure looking for wanted
+// paths, and calls unmarshal on them.
+// The consumed result tells whether XML elements have been consumed
+// from the Decoder until start's matching end element, or if it's
+// still untouched because start is uninteresting for sv's fields.
+func (p *Decoder) unmarshalPath(tinfo *typeInfo, sv reflect.Value, parents []string, start *StartElement) (consumed bool, err error) {
+	recurse := false
+Loop:
+	for i := range tinfo.fields {
+		finfo := &tinfo.fields[i]
+		if finfo.flags&fElement == 0 || len(finfo.parents) < len(parents) || finfo.xmlns != "" && finfo.xmlns != start.Name.Space {
+			continue
+		}
+		for j := range parents {
+			if parents[j] != finfo.parents[j] {
+				continue Loop
+			}
+		}
+		if len(finfo.parents) == len(parents) && finfo.name == start.Name.Local {
+			// It's a perfect match, unmarshal the field.
+			return true, p.unmarshal(finfo.value(sv), start)
+		}
+		if len(finfo.parents) > len(parents) && finfo.parents[len(parents)] == start.Name.Local {
+			// It's a prefix for the field. Break and recurse
+			// since it's not ok for one field path to be itself
+			// the prefix for another field path.
+			recurse = true
+
+			// We can reuse the same slice as long as we
+			// don't try to append to it.
+			parents = finfo.parents[:len(parents)+1]
+			break
+		}
+	}
+	if !recurse {
+		// We have no business with this element.
+		return false, nil
+	}
+	// The element is not a perfect match for any field, but one
+	// or more fields have the path to this element as a parent
+	// prefix. Recurse and attempt to match these.
+	for {
+		var tok Token
+		tok, err = p.Token()
+		if err != nil {
+			return true, err
+		}
+		switch t := tok.(type) {
+		case StartElement:
+			consumed2, err := p.unmarshalPath(tinfo, sv, parents, &t)
+			if err != nil {
+				return true, err
+			}
+			if !consumed2 {
+				if err := p.Skip(); err != nil {
+					return true, err
+				}
+			}
+		case EndElement:
+			return true, nil
+		}
+	}
+}
+
+// Skip reads tokens until it has consumed the end element
+// matching the most recent start element already consumed.
+// It recurs if it encounters a start element, so it can be used to
+// skip nested structures.
+// It returns nil if it finds an end element matching the start
+// element; otherwise it returns an error describing the problem.
+func (d *Decoder) Skip() error {
+	for {
+		tok, err := d.Token()
+		if err != nil {
+			return err
+		}
+		switch tok.(type) {
+		case StartElement:
+			if err := d.Skip(); err != nil {
+				return err
+			}
+		case EndElement:
+			return nil
+		}
+	}
+}

webdav/internal/xml/read_test.go

@@ -0,0 +1,744 @@
+// Copyright 2009 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.
+
+package xml
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Stripped down Atom feed data structures.
+
+func TestUnmarshalFeed(t *testing.T) {
+	var f Feed
+	if err := Unmarshal([]byte(atomFeedString), &f); err != nil {
+		t.Fatalf("Unmarshal: %s", err)
+	}
+	if !reflect.DeepEqual(f, atomFeed) {
+		t.Fatalf("have %#v\nwant %#v", f, atomFeed)
+	}
+}
+
+// hget http://codereview.appspot.com/rss/mine/rsc
+const atomFeedString = `
+<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en-us" updated="2009-10-04T01:35:58+00:00"><title>Code Review - My issues</title><link href="http://codereview.appspot.com/" rel="alternate"></link><link href="http://codereview.appspot.com/rss/mine/rsc" rel="self"></link><id>http://codereview.appspot.com/</id><author><name>rietveld&lt;&gt;</name></author><entry><title>rietveld: an attempt at pubsubhubbub
+</title><link href="http://codereview.appspot.com/126085" rel="alternate"></link><updated>2009-10-04T01:35:58+00:00</updated><author><name>email-address-removed</name></author><id>urn:md5:134d9179c41f806be79b3a5f7877d19a</id><summary type="html">
+  An attempt at adding pubsubhubbub support to Rietveld.
+http://code.google.com/p/pubsubhubbub
+http://code.google.com/p/rietveld/issues/detail?id=155
+
+The server side of the protocol is trivial:
+  1. add a &amp;lt;link rel=&amp;quot;hub&amp;quot; href=&amp;quot;hub-server&amp;quot;&amp;gt; tag to all
+     feeds that will be pubsubhubbubbed.
+  2. every time one of those feeds changes, tell the hub
+     with a simple POST request.
+
+I have tested this by adding debug prints to a local hub
+server and checking that the server got the right publish
+requests.
+
+I can&amp;#39;t quite get the server to work, but I think the bug
+is not in my code.  I think that the server expects to be
+able to grab the feed and see the feed&amp;#39;s actual URL in
+the link rel=&amp;quot;self&amp;quot;, but the default value for that drops
+the :port from the URL, and I cannot for the life of me
+figure out how to get the Atom generator deep inside
+django not to do that, or even where it is doing that,
+or even what code is running to generate the Atom feed.
+(I thought I knew but I added some assert False statements
+and it kept running!)
+
+Ignoring that particular problem, I would appreciate
+feedback on the right way to get the two values at
+the top of feeds.py marked NOTE(rsc).
+
+
+</summary></entry><entry><title>rietveld: correct tab handling
+</title><link href="http://codereview.appspot.com/124106" rel="alternate"></link><updated>2009-10-03T23:02:17+00:00</updated><author><name>email-address-removed</name></author><id>urn:md5:0a2a4f19bb815101f0ba2904aed7c35a</id><summary type="html">
+  This fixes the buggy tab rendering that can be seen at
+http://codereview.appspot.com/116075/diff/1/2
+
+The fundamental problem was that the tab code was
+not being told what column the text began in, so it
+didn&amp;#39;t know where to put the tab stops.  Another problem
+was that some of the code assumed that string byte
+offsets were the same as column offsets, which is only
+true if there are no tabs.
+
+In the process of fixing this, I cleaned up the arguments
+to Fold and ExpandTabs and renamed them Break and
+_ExpandTabs so that I could be sure that I found all the
+call sites.  I also wanted to verify that ExpandTabs was
+not being used from outside intra_region_diff.py.
+
+
+</summary></entry></feed> 	   `
+
+type Feed struct {
+	XMLName Name      `xml:"http://www.w3.org/2005/Atom feed"`
+	Title   string    `xml:"title"`
+	Id      string    `xml:"id"`
+	Link    []Link    `xml:"link"`
+	Updated time.Time `xml:"updated,attr"`
+	Author  Person    `xml:"author"`
+	Entry   []Entry   `xml:"entry"`
+}
+
+type Entry struct {
+	Title   string    `xml:"title"`
+	Id      string    `xml:"id"`
+	Link    []Link    `xml:"link"`
+	Updated time.Time `xml:"updated"`
+	Author  Person    `xml:"author"`
+	Summary Text      `xml:"summary"`
+}
+
+type Link struct {
+	Rel  string `xml:"rel,attr,omitempty"`
+	Href string `xml:"href,attr"`
+}
+
+type Person struct {
+	Name     string `xml:"name"`
+	URI      string `xml:"uri"`
+	Email    string `xml:"email"`
+	InnerXML string `xml:",innerxml"`
+}
+
+type Text struct {
+	Type string `xml:"type,attr,omitempty"`
+	Body string `xml:",chardata"`
+}
+
+var atomFeed = Feed{
+	XMLName: Name{"http://www.w3.org/2005/Atom", "feed"},
+	Title:   "Code Review - My issues",
+	Link: []Link{
+		{Rel: "alternate", Href: "http://codereview.appspot.com/"},
+		{Rel: "self", Href: "http://codereview.appspot.com/rss/mine/rsc"},
+	},
+	Id:      "http://codereview.appspot.com/",
+	Updated: ParseTime("2009-10-04T01:35:58+00:00"),
+	Author: Person{
+		Name:     "rietveld<>",
+		InnerXML: "<name>rietveld&lt;&gt;</name>",
+	},
+	Entry: []Entry{
+		{
+			Title: "rietveld: an attempt at pubsubhubbub\n",
+			Link: []Link{
+				{Rel: "alternate", Href: "http://codereview.appspot.com/126085"},
+			},
+			Updated: ParseTime("2009-10-04T01:35:58+00:00"),
+			Author: Person{
+				Name:     "email-address-removed",
+				InnerXML: "<name>email-address-removed</name>",
+			},
+			Id: "urn:md5:134d9179c41f806be79b3a5f7877d19a",
+			Summary: Text{
+				Type: "html",
+				Body: `
+  An attempt at adding pubsubhubbub support to Rietveld.
+http://code.google.com/p/pubsubhubbub
+http://code.google.com/p/rietveld/issues/detail?id=155
+
+The server side of the protocol is trivial:
+  1. add a &lt;link rel=&quot;hub&quot; href=&quot;hub-server&quot;&gt; tag to all
+     feeds that will be pubsubhubbubbed.
+  2. every time one of those feeds changes, tell the hub
+     with a simple POST request.
+
+I have tested this by adding debug prints to a local hub
+server and checking that the server got the right publish
+requests.
+
+I can&#39;t quite get the server to work, but I think the bug
+is not in my code.  I think that the server expects to be
+able to grab the feed and see the feed&#39;s actual URL in
+the link rel=&quot;self&quot;, but the default value for that drops
+the :port from the URL, and I cannot for the life of me
+figure out how to get the Atom generator deep inside
+django not to do that, or even where it is doing that,
+or even what code is running to generate the Atom feed.
+(I thought I knew but I added some assert False statements
+and it kept running!)
+
+Ignoring that particular problem, I would appreciate
+feedback on the right way to get the two values at
+the top of feeds.py marked NOTE(rsc).
+
+
+`,
+			},
+		},
+		{
+			Title: "rietveld: correct tab handling\n",
+			Link: []Link{
+				{Rel: "alternate", Href: "http://codereview.appspot.com/124106"},
+			},
+			Updated: ParseTime("2009-10-03T23:02:17+00:00"),
+			Author: Person{
+				Name:     "email-address-removed",
+				InnerXML: "<name>email-address-removed</name>",
+			},
+			Id: "urn:md5:0a2a4f19bb815101f0ba2904aed7c35a",
+			Summary: Text{
+				Type: "html",
+				Body: `
+  This fixes the buggy tab rendering that can be seen at
+http://codereview.appspot.com/116075/diff/1/2
+
+The fundamental problem was that the tab code was
+not being told what column the text began in, so it
+didn&#39;t know where to put the tab stops.  Another problem
+was that some of the code assumed that string byte
+offsets were the same as column offsets, which is only
+true if there are no tabs.
+
+In the process of fixing this, I cleaned up the arguments
+to Fold and ExpandTabs and renamed them Break and
+_ExpandTabs so that I could be sure that I found all the
+call sites.  I also wanted to verify that ExpandTabs was
+not being used from outside intra_region_diff.py.
+
+
+`,
+			},
+		},
+	},
+}
+
+const pathTestString = `
+<Result>
+    <Before>1</Before>
+    <Items>
+        <Item1>
+            <Value>A</Value>
+        </Item1>
+        <Item2>
+            <Value>B</Value>
+        </Item2>
+        <Item1>
+            <Value>C</Value>
+            <Value>D</Value>
+        </Item1>
+        <_>
+            <Value>E</Value>
+        </_>
+    </Items>
+    <After>2</After>
+</Result>
+`
+
+type PathTestItem struct {
+	Value string
+}
+
+type PathTestA struct {
+	Items         []PathTestItem `xml:">Item1"`
+	Before, After string
+}
+
+type PathTestB struct {
+	Other         []PathTestItem `xml:"Items>Item1"`
+	Before, After string
+}
+
+type PathTestC struct {
+	Values1       []string `xml:"Items>Item1>Value"`
+	Values2       []string `xml:"Items>Item2>Value"`
+	Before, After string
+}
+
+type PathTestSet struct {
+	Item1 []PathTestItem
+}
+
+type PathTestD struct {
+	Other         PathTestSet `xml:"Items"`
+	Before, After string
+}
+
+type PathTestE struct {
+	Underline     string `xml:"Items>_>Value"`
+	Before, After string
+}
+
+var pathTests = []interface{}{
+	&PathTestA{Items: []PathTestItem{{"A"}, {"D"}}, Before: "1", After: "2"},
+	&PathTestB{Other: []PathTestItem{{"A"}, {"D"}}, Before: "1", After: "2"},
+	&PathTestC{Values1: []string{"A", "C", "D"}, Values2: []string{"B"}, Before: "1", After: "2"},
+	&PathTestD{Other: PathTestSet{Item1: []PathTestItem{{"A"}, {"D"}}}, Before: "1", After: "2"},
+	&PathTestE{Underline: "E", Before: "1", After: "2"},
+}
+
+func TestUnmarshalPaths(t *testing.T) {
+	for _, pt := range pathTests {
+		v := reflect.New(reflect.TypeOf(pt).Elem()).Interface()
+		if err := Unmarshal([]byte(pathTestString), v); err != nil {
+			t.Fatalf("Unmarshal: %s", err)
+		}
+		if !reflect.DeepEqual(v, pt) {
+			t.Fatalf("have %#v\nwant %#v", v, pt)
+		}
+	}
+}
+
+type BadPathTestA struct {
+	First  string `xml:"items>item1"`
+	Other  string `xml:"items>item2"`
+	Second string `xml:"items"`
+}
+
+type BadPathTestB struct {
+	Other  string `xml:"items>item2>value"`
+	First  string `xml:"items>item1"`
+	Second string `xml:"items>item1>value"`
+}
+
+type BadPathTestC struct {
+	First  string
+	Second string `xml:"First"`
+}
+
+type BadPathTestD struct {
+	BadPathEmbeddedA
+	BadPathEmbeddedB
+}
+
+type BadPathEmbeddedA struct {
+	First string
+}
+
+type BadPathEmbeddedB struct {
+	Second string `xml:"First"`
+}
+
+var badPathTests = []struct {
+	v, e interface{}
+}{
+	{&BadPathTestA{}, &TagPathError{reflect.TypeOf(BadPathTestA{}), "First", "items>item1", "Second", "items"}},
+	{&BadPathTestB{}, &TagPathError{reflect.TypeOf(BadPathTestB{}), "First", "items>item1", "Second", "items>item1>value"}},
+	{&BadPathTestC{}, &TagPathError{reflect.TypeOf(BadPathTestC{}), "First", "", "Second", "First"}},
+	{&BadPathTestD{}, &TagPathError{reflect.TypeOf(BadPathTestD{}), "First", "", "Second", "First"}},
+}
+
+func TestUnmarshalBadPaths(t *testing.T) {
+	for _, tt := range badPathTests {
+		err := Unmarshal([]byte(pathTestString), tt.v)
+		if !reflect.DeepEqual(err, tt.e) {
+			t.Fatalf("Unmarshal with %#v didn't fail properly:\nhave %#v,\nwant %#v", tt.v, err, tt.e)
+		}
+	}
+}
+
+const OK = "OK"
+const withoutNameTypeData = `
+<?xml version="1.0" charset="utf-8"?>
+<Test3 Attr="OK" />`
+
+type TestThree struct {
+	XMLName Name   `xml:"Test3"`
+	Attr    string `xml:",attr"`
+}
+
+func TestUnmarshalWithoutNameType(t *testing.T) {
+	var x TestThree
+	if err := Unmarshal([]byte(withoutNameTypeData), &x); err != nil {
+		t.Fatalf("Unmarshal: %s", err)
+	}
+	if x.Attr != OK {
+		t.Fatalf("have %v\nwant %v", x.Attr, OK)
+	}
+}
+
+func TestUnmarshalAttr(t *testing.T) {
+	type ParamVal struct {
+		Int int `xml:"int,attr"`
+	}
+
+	type ParamPtr struct {
+		Int *int `xml:"int,attr"`
+	}
+
+	type ParamStringPtr struct {
+		Int *string `xml:"int,attr"`
+	}
+
+	x := []byte(`<Param int="1" />`)
+
+	p1 := &ParamPtr{}
+	if err := Unmarshal(x, p1); err != nil {
+		t.Fatalf("Unmarshal: %s", err)
+	}
+	if p1.Int == nil {
+		t.Fatalf("Unmarshal failed in to *int field")
+	} else if *p1.Int != 1 {
+		t.Fatalf("Unmarshal with %s failed:\nhave %#v,\n want %#v", x, p1.Int, 1)
+	}
+
+	p2 := &ParamVal{}
+	if err := Unmarshal(x, p2); err != nil {
+		t.Fatalf("Unmarshal: %s", err)
+	}
+	if p2.Int != 1 {
+		t.Fatalf("Unmarshal with %s failed:\nhave %#v,\n want %#v", x, p2.Int, 1)
+	}
+
+	p3 := &ParamStringPtr{}
+	if err := Unmarshal(x, p3); err != nil {
+		t.Fatalf("Unmarshal: %s", err)
+	}
+	if p3.Int == nil {
+		t.Fatalf("Unmarshal failed in to *string field")
+	} else if *p3.Int != "1" {
+		t.Fatalf("Unmarshal with %s failed:\nhave %#v,\n want %#v", x, p3.Int, 1)
+	}
+}
+
+type Tables struct {
+	HTable string `xml:"http://www.w3.org/TR/html4/ table"`
+	FTable string `xml:"http://www.w3schools.com/furniture table"`
+}
+
+var tables = []struct {
+	xml string
+	tab Tables
+	ns  string
+}{
+	{
+		xml: `<Tables>` +
+			`<table xmlns="http://www.w3.org/TR/html4/">hello</table>` +
+			`<table xmlns="http://www.w3schools.com/furniture">world</table>` +
+			`</Tables>`,
+		tab: Tables{"hello", "world"},
+	},
+	{
+		xml: `<Tables>` +
+			`<table xmlns="http://www.w3schools.com/furniture">world</table>` +
+			`<table xmlns="http://www.w3.org/TR/html4/">hello</table>` +
+			`</Tables>`,
+		tab: Tables{"hello", "world"},
+	},
+	{
+		xml: `<Tables xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/">` +
+			`<f:table>world</f:table>` +
+			`<h:table>hello</h:table>` +
+			`</Tables>`,
+		tab: Tables{"hello", "world"},
+	},
+	{
+		xml: `<Tables>` +
+			`<table>bogus</table>` +
+			`</Tables>`,
+		tab: Tables{},
+	},
+	{
+		xml: `<Tables>` +
+			`<table>only</table>` +
+			`</Tables>`,
+		tab: Tables{HTable: "only"},
+		ns:  "http://www.w3.org/TR/html4/",
+	},
+	{
+		xml: `<Tables>` +
+			`<table>only</table>` +
+			`</Tables>`,
+		tab: Tables{FTable: "only"},
+		ns:  "http://www.w3schools.com/furniture",
+	},
+	{
+		xml: `<Tables>` +
+			`<table>only</table>` +
+			`</Tables>`,
+		tab: Tables{},
+		ns:  "something else entirely",
+	},
+}
+
+func TestUnmarshalNS(t *testing.T) {
+	for i, tt := range tables {
+		var dst Tables
+		var err error
+		if tt.ns != "" {
+			d := NewDecoder(strings.NewReader(tt.xml))
+			d.DefaultSpace = tt.ns
+			err = d.Decode(&dst)
+		} else {
+			err = Unmarshal([]byte(tt.xml), &dst)
+		}
+		if err != nil {
+			t.Errorf("#%d: Unmarshal: %v", i, err)
+			continue
+		}
+		want := tt.tab
+		if dst != want {
+			t.Errorf("#%d: dst=%+v, want %+v", i, dst, want)
+		}
+	}
+}
+
+func TestRoundTrip(t *testing.T) {
+	// From issue 7535
+	const s = `<ex:element xmlns:ex="http://example.com/schema"></ex:element>`
+	in := bytes.NewBufferString(s)
+	for i := 0; i < 10; i++ {
+		out := &bytes.Buffer{}
+		d := NewDecoder(in)
+		e := NewEncoder(out)
+
+		for {
+			t, err := d.Token()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				fmt.Println("failed:", err)
+				return
+			}
+			e.EncodeToken(t)
+		}
+		e.Flush()
+		in = out
+	}
+	if got := in.String(); got != s {
+		t.Errorf("have: %q\nwant: %q\n", got, s)
+	}
+}
+
+func TestMarshalNS(t *testing.T) {
+	dst := Tables{"hello", "world"}
+	data, err := Marshal(&dst)
+	if err != nil {
+		t.Fatalf("Marshal: %v", err)
+	}
+	want := `<Tables><table xmlns="http://www.w3.org/TR/html4/">hello</table><table xmlns="http://www.w3schools.com/furniture">world</table></Tables>`
+	str := string(data)
+	if str != want {
+		t.Errorf("have: %q\nwant: %q\n", str, want)
+	}
+}
+
+type TableAttrs struct {
+	TAttr TAttr
+}
+
+type TAttr struct {
+	HTable string `xml:"http://www.w3.org/TR/html4/ table,attr"`
+	FTable string `xml:"http://www.w3schools.com/furniture table,attr"`
+	Lang   string `xml:"http://www.w3.org/XML/1998/namespace lang,attr,omitempty"`
+	Other1 string `xml:"http://golang.org/xml/ other,attr,omitempty"`
+	Other2 string `xml:"http://golang.org/xmlfoo/ other,attr,omitempty"`
+	Other3 string `xml:"http://golang.org/json/ other,attr,omitempty"`
+	Other4 string `xml:"http://golang.org/2/json/ other,attr,omitempty"`
+}
+
+var tableAttrs = []struct {
+	xml string
+	tab TableAttrs
+	ns  string
+}{
+	{
+		xml: `<TableAttrs xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/"><TAttr ` +
+			`h:table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: "world"}},
+	},
+	{
+		xml: `<TableAttrs><TAttr xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/" ` +
+			`h:table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: "world"}},
+	},
+	{
+		xml: `<TableAttrs><TAttr ` +
+			`h:table="hello" f:table="world" xmlns:f="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: "world"}},
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns="http://www.w3schools.com/furniture" xmlns:h="http://www.w3.org/TR/html4/"><TAttr ` +
+			`h:table="hello" table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: ""}},
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns:f="http://www.w3schools.com/furniture"><TAttr xmlns="http://www.w3.org/TR/html4/" ` +
+			`table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "", FTable: "world"}},
+	},
+	{
+		xml: `<TableAttrs><TAttr ` +
+			`table="bogus" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{},
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns:h="http://www.w3.org/TR/html4/"><TAttr ` +
+			`h:table="hello" table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "hello", FTable: ""}},
+		ns:  "http://www.w3schools.com/furniture",
+	},
+	{
+		// Default space does not apply to attribute names.
+		xml: `<TableAttrs xmlns:f="http://www.w3schools.com/furniture"><TAttr ` +
+			`table="hello" f:table="world" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{TAttr{HTable: "", FTable: "world"}},
+		ns:  "http://www.w3.org/TR/html4/",
+	},
+	{
+		xml: `<TableAttrs><TAttr ` +
+			`table="bogus" ` +
+			`/></TableAttrs>`,
+		tab: TableAttrs{},
+		ns:  "something else entirely",
+	},
+}
+
+func TestUnmarshalNSAttr(t *testing.T) {
+	for i, tt := range tableAttrs {
+		var dst TableAttrs
+		var err error
+		if tt.ns != "" {
+			d := NewDecoder(strings.NewReader(tt.xml))
+			d.DefaultSpace = tt.ns
+			err = d.Decode(&dst)
+		} else {
+			err = Unmarshal([]byte(tt.xml), &dst)
+		}
+		if err != nil {
+			t.Errorf("#%d: Unmarshal: %v", i, err)
+			continue
+		}
+		want := tt.tab
+		if dst != want {
+			t.Errorf("#%d: dst=%+v, want %+v", i, dst, want)
+		}
+	}
+}
+
+func TestMarshalNSAttr(t *testing.T) {
+	src := TableAttrs{TAttr{"hello", "world", "en_US", "other1", "other2", "other3", "other4"}}
+	data, err := Marshal(&src)
+	if err != nil {
+		t.Fatalf("Marshal: %v", err)
+	}
+	want := `<TableAttrs><TAttr xmlns:json_1="http://golang.org/2/json/" xmlns:json="http://golang.org/json/" xmlns:_xmlfoo="http://golang.org/xmlfoo/" xmlns:_xml="http://golang.org/xml/" xmlns:furniture="http://www.w3schools.com/furniture" xmlns:html4="http://www.w3.org/TR/html4/" html4:table="hello" furniture:table="world" xml:lang="en_US" _xml:other="other1" _xmlfoo:other="other2" json:other="other3" json_1:other="other4"></TAttr></TableAttrs>`
+	str := string(data)
+	if str != want {
+		t.Errorf("Marshal:\nhave: %#q\nwant: %#q\n", str, want)
+	}
+
+	var dst TableAttrs
+	if err := Unmarshal(data, &dst); err != nil {
+		t.Errorf("Unmarshal: %v", err)
+	}
+
+	if dst != src {
+		t.Errorf("Unmarshal = %q, want %q", dst, src)
+	}
+}
+
+type MyCharData struct {
+	body string
+}
+
+func (m *MyCharData) UnmarshalXML(d *Decoder, start StartElement) error {
+	for {
+		t, err := d.Token()
+		if err == io.EOF { // found end of element
+			break
+		}
+		if err != nil {
+			return err
+		}
+		if char, ok := t.(CharData); ok {
+			m.body += string(char)
+		}
+	}
+	return nil
+}
+
+var _ Unmarshaler = (*MyCharData)(nil)
+
+func (m *MyCharData) UnmarshalXMLAttr(attr Attr) error {
+	panic("must not call")
+}
+
+type MyAttr struct {
+	attr string
+}
+
+func (m *MyAttr) UnmarshalXMLAttr(attr Attr) error {
+	m.attr = attr.Value
+	return nil
+}
+
+var _ UnmarshalerAttr = (*MyAttr)(nil)
+
+type MyStruct struct {
+	Data *MyCharData
+	Attr *MyAttr `xml:",attr"`
+
+	Data2 MyCharData
+	Attr2 MyAttr `xml:",attr"`
+}
+
+func TestUnmarshaler(t *testing.T) {
+	xml := `<?xml version="1.0" encoding="utf-8"?>
+		<MyStruct Attr="attr1" Attr2="attr2">
+		<Data>hello <!-- comment -->world</Data>
+		<Data2>howdy <!-- comment -->world</Data2>
+		</MyStruct>
+	`
+
+	var m MyStruct
+	if err := Unmarshal([]byte(xml), &m); err != nil {
+		t.Fatal(err)
+	}
+
+	if m.Data == nil || m.Attr == nil || m.Data.body != "hello world" || m.Attr.attr != "attr1" || m.Data2.body != "howdy world" || m.Attr2.attr != "attr2" {
+		t.Errorf("m=%#+v\n", m)
+	}
+}
+
+type Pea struct {
+	Cotelydon string
+}
+
+type Pod struct {
+	Pea interface{} `xml:"Pea"`
+}
+
+// https://golang.org/issue/6836
+func TestUnmarshalIntoInterface(t *testing.T) {
+	pod := new(Pod)
+	pod.Pea = new(Pea)
+	xml := `<Pod><Pea><Cotelydon>Green stuff</Cotelydon></Pea></Pod>`
+	err := Unmarshal([]byte(xml), pod)
+	if err != nil {
+		t.Fatalf("failed to unmarshal %q: %v", xml, err)
+	}
+	pea, ok := pod.Pea.(*Pea)
+	if !ok {
+		t.Fatalf("unmarshalled into wrong type: have %T want *Pea", pod.Pea)
+	}
+	have, want := pea.Cotelydon, "Green stuff"
+	if have != want {
+		t.Errorf("failed to unmarshal into interface, have %q want %q", have, want)
+	}
+}

webdav/internal/xml/typeinfo.go

@@ -0,0 +1,371 @@
+// Copyright 2011 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.
+
+package xml
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+)
+
+// typeInfo holds details for the xml representation of a type.
+type typeInfo struct {
+	xmlname *fieldInfo
+	fields  []fieldInfo
+}
+
+// fieldInfo holds details for the xml representation of a single field.
+type fieldInfo struct {
+	idx     []int
+	name    string
+	xmlns   string
+	flags   fieldFlags
+	parents []string
+}
+
+type fieldFlags int
+
+const (
+	fElement fieldFlags = 1 << iota
+	fAttr
+	fCharData
+	fInnerXml
+	fComment
+	fAny
+
+	fOmitEmpty
+
+	fMode = fElement | fAttr | fCharData | fInnerXml | fComment | fAny
+)
+
+var tinfoMap = make(map[reflect.Type]*typeInfo)
+var tinfoLock sync.RWMutex
+
+var nameType = reflect.TypeOf(Name{})
+
+// getTypeInfo returns the typeInfo structure with details necessary
+// for marshalling and unmarshalling typ.
+func getTypeInfo(typ reflect.Type) (*typeInfo, error) {
+	tinfoLock.RLock()
+	tinfo, ok := tinfoMap[typ]
+	tinfoLock.RUnlock()
+	if ok {
+		return tinfo, nil
+	}
+	tinfo = &typeInfo{}
+	if typ.Kind() == reflect.Struct && typ != nameType {
+		n := typ.NumField()
+		for i := 0; i < n; i++ {
+			f := typ.Field(i)
+			if f.PkgPath != "" || f.Tag.Get("xml") == "-" {
+				continue // Private field
+			}
+
+			// For embedded structs, embed its fields.
+			if f.Anonymous {
+				t := f.Type
+				if t.Kind() == reflect.Ptr {
+					t = t.Elem()
+				}
+				if t.Kind() == reflect.Struct {
+					inner, err := getTypeInfo(t)
+					if err != nil {
+						return nil, err
+					}
+					if tinfo.xmlname == nil {
+						tinfo.xmlname = inner.xmlname
+					}
+					for _, finfo := range inner.fields {
+						finfo.idx = append([]int{i}, finfo.idx...)
+						if err := addFieldInfo(typ, tinfo, &finfo); err != nil {
+							return nil, err
+						}
+					}
+					continue
+				}
+			}
+
+			finfo, err := structFieldInfo(typ, &f)
+			if err != nil {
+				return nil, err
+			}
+
+			if f.Name == "XMLName" {
+				tinfo.xmlname = finfo
+				continue
+			}
+
+			// Add the field if it doesn't conflict with other fields.
+			if err := addFieldInfo(typ, tinfo, finfo); err != nil {
+				return nil, err
+			}
+		}
+	}
+	tinfoLock.Lock()
+	tinfoMap[typ] = tinfo
+	tinfoLock.Unlock()
+	return tinfo, nil
+}
+
+// structFieldInfo builds and returns a fieldInfo for f.
+func structFieldInfo(typ reflect.Type, f *reflect.StructField) (*fieldInfo, error) {
+	finfo := &fieldInfo{idx: f.Index}
+
+	// Split the tag from the xml namespace if necessary.
+	tag := f.Tag.Get("xml")
+	if i := strings.Index(tag, " "); i >= 0 {
+		finfo.xmlns, tag = tag[:i], tag[i+1:]
+	}
+
+	// Parse flags.
+	tokens := strings.Split(tag, ",")
+	if len(tokens) == 1 {
+		finfo.flags = fElement
+	} else {
+		tag = tokens[0]
+		for _, flag := range tokens[1:] {
+			switch flag {
+			case "attr":
+				finfo.flags |= fAttr
+			case "chardata":
+				finfo.flags |= fCharData
+			case "innerxml":
+				finfo.flags |= fInnerXml
+			case "comment":
+				finfo.flags |= fComment
+			case "any":
+				finfo.flags |= fAny
+			case "omitempty":
+				finfo.flags |= fOmitEmpty
+			}
+		}
+
+		// Validate the flags used.
+		valid := true
+		switch mode := finfo.flags & fMode; mode {
+		case 0:
+			finfo.flags |= fElement
+		case fAttr, fCharData, fInnerXml, fComment, fAny:
+			if f.Name == "XMLName" || tag != "" && mode != fAttr {
+				valid = false
+			}
+		default:
+			// This will also catch multiple modes in a single field.
+			valid = false
+		}
+		if finfo.flags&fMode == fAny {
+			finfo.flags |= fElement
+		}
+		if finfo.flags&fOmitEmpty != 0 && finfo.flags&(fElement|fAttr) == 0 {
+			valid = false
+		}
+		if !valid {
+			return nil, fmt.Errorf("xml: invalid tag in field %s of type %s: %q",
+				f.Name, typ, f.Tag.Get("xml"))
+		}
+	}
+
+	// Use of xmlns without a name is not allowed.
+	if finfo.xmlns != "" && tag == "" {
+		return nil, fmt.Errorf("xml: namespace without name in field %s of type %s: %q",
+			f.Name, typ, f.Tag.Get("xml"))
+	}
+
+	if f.Name == "XMLName" {
+		// The XMLName field records the XML element name. Don't
+		// process it as usual because its name should default to
+		// empty rather than to the field name.
+		finfo.name = tag
+		return finfo, nil
+	}
+
+	if tag == "" {
+		// If the name part of the tag is completely empty, get
+		// default from XMLName of underlying struct if feasible,
+		// or field name otherwise.
+		if xmlname := lookupXMLName(f.Type); xmlname != nil {
+			finfo.xmlns, finfo.name = xmlname.xmlns, xmlname.name
+		} else {
+			finfo.name = f.Name
+		}
+		return finfo, nil
+	}
+
+	if finfo.xmlns == "" && finfo.flags&fAttr == 0 {
+		// If it's an element no namespace specified, get the default
+		// from the XMLName of enclosing struct if possible.
+		if xmlname := lookupXMLName(typ); xmlname != nil {
+			finfo.xmlns = xmlname.xmlns
+		}
+	}
+
+	// Prepare field name and parents.
+	parents := strings.Split(tag, ">")
+	if parents[0] == "" {
+		parents[0] = f.Name
+	}
+	if parents[len(parents)-1] == "" {
+		return nil, fmt.Errorf("xml: trailing '>' in field %s of type %s", f.Name, typ)
+	}
+	finfo.name = parents[len(parents)-1]
+	if len(parents) > 1 {
+		if (finfo.flags & fElement) == 0 {
+			return nil, fmt.Errorf("xml: %s chain not valid with %s flag", tag, strings.Join(tokens[1:], ","))
+		}
+		finfo.parents = parents[:len(parents)-1]
+	}
+
+	// If the field type has an XMLName field, the names must match
+	// so that the behavior of both marshalling and unmarshalling
+	// is straightforward and unambiguous.
+	if finfo.flags&fElement != 0 {
+		ftyp := f.Type
+		xmlname := lookupXMLName(ftyp)
+		if xmlname != nil && xmlname.name != finfo.name {
+			return nil, fmt.Errorf("xml: name %q in tag of %s.%s conflicts with name %q in %s.XMLName",
+				finfo.name, typ, f.Name, xmlname.name, ftyp)
+		}
+	}
+	return finfo, nil
+}
+
+// lookupXMLName returns the fieldInfo for typ's XMLName field
+// in case it exists and has a valid xml field tag, otherwise
+// it returns nil.
+func lookupXMLName(typ reflect.Type) (xmlname *fieldInfo) {
+	for typ.Kind() == reflect.Ptr {
+		typ = typ.Elem()
+	}
+	if typ.Kind() != reflect.Struct {
+		return nil
+	}
+	for i, n := 0, typ.NumField(); i < n; i++ {
+		f := typ.Field(i)
+		if f.Name != "XMLName" {
+			continue
+		}
+		finfo, err := structFieldInfo(typ, &f)
+		if finfo.name != "" && err == nil {
+			return finfo
+		}
+		// Also consider errors as a non-existent field tag
+		// and let getTypeInfo itself report the error.
+		break
+	}
+	return nil
+}
+
+func min(a, b int) int {
+	if a <= b {
+		return a
+	}
+	return b
+}
+
+// addFieldInfo adds finfo to tinfo.fields if there are no
+// conflicts, or if conflicts arise from previous fields that were
+// obtained from deeper embedded structures than finfo. In the latter
+// case, the conflicting entries are dropped.
+// A conflict occurs when the path (parent + name) to a field is
+// itself a prefix of another path, or when two paths match exactly.
+// It is okay for field paths to share a common, shorter prefix.
+func addFieldInfo(typ reflect.Type, tinfo *typeInfo, newf *fieldInfo) error {
+	var conflicts []int
+Loop:
+	// First, figure all conflicts. Most working code will have none.
+	for i := range tinfo.fields {
+		oldf := &tinfo.fields[i]
+		if oldf.flags&fMode != newf.flags&fMode {
+			continue
+		}
+		if oldf.xmlns != "" && newf.xmlns != "" && oldf.xmlns != newf.xmlns {
+			continue
+		}
+		minl := min(len(newf.parents), len(oldf.parents))
+		for p := 0; p < minl; p++ {
+			if oldf.parents[p] != newf.parents[p] {
+				continue Loop
+			}
+		}
+		if len(oldf.parents) > len(newf.parents) {
+			if oldf.parents[len(newf.parents)] == newf.name {
+				conflicts = append(conflicts, i)
+			}
+		} else if len(oldf.parents) < len(newf.parents) {
+			if newf.parents[len(oldf.parents)] == oldf.name {
+				conflicts = append(conflicts, i)
+			}
+		} else {
+			if newf.name == oldf.name {
+				conflicts = append(conflicts, i)
+			}
+		}
+	}
+	// Without conflicts, add the new field and return.
+	if conflicts == nil {
+		tinfo.fields = append(tinfo.fields, *newf)
+		return nil
+	}
+
+	// If any conflict is shallower, ignore the new field.
+	// This matches the Go field resolution on embedding.
+	for _, i := range conflicts {
+		if len(tinfo.fields[i].idx) < len(newf.idx) {
+			return nil
+		}
+	}
+
+	// Otherwise, if any of them is at the same depth level, it's an error.
+	for _, i := range conflicts {
+		oldf := &tinfo.fields[i]
+		if len(oldf.idx) == len(newf.idx) {
+			f1 := typ.FieldByIndex(oldf.idx)
+			f2 := typ.FieldByIndex(newf.idx)
+			return &TagPathError{typ, f1.Name, f1.Tag.Get("xml"), f2.Name, f2.Tag.Get("xml")}
+		}
+	}
+
+	// Otherwise, the new field is shallower, and thus takes precedence,
+	// so drop the conflicting fields from tinfo and append the new one.
+	for c := len(conflicts) - 1; c >= 0; c-- {
+		i := conflicts[c]
+		copy(tinfo.fields[i:], tinfo.fields[i+1:])
+		tinfo.fields = tinfo.fields[:len(tinfo.fields)-1]
+	}
+	tinfo.fields = append(tinfo.fields, *newf)
+	return nil
+}
+
+// A TagPathError represents an error in the unmarshalling process
+// caused by the use of field tags with conflicting paths.
+type TagPathError struct {
+	Struct       reflect.Type
+	Field1, Tag1 string
+	Field2, Tag2 string
+}
+
+func (e *TagPathError) Error() string {
+	return fmt.Sprintf("%s field %q with tag %q conflicts with field %q with tag %q", e.Struct, e.Field1, e.Tag1, e.Field2, e.Tag2)
+}
+
+// value returns v's field value corresponding to finfo.
+// It's equivalent to v.FieldByIndex(finfo.idx), but initializes
+// and dereferences pointers as necessary.
+func (finfo *fieldInfo) value(v reflect.Value) reflect.Value {
+	for i, x := range finfo.idx {
+		if i > 0 {
+			t := v.Type()
+			if t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct {
+				if v.IsNil() {
+					v.Set(reflect.New(v.Type().Elem()))
+				}
+				v = v.Elem()
+			}
+		}
+		v = v.Field(x)
+	}
+	return v
+}

webdav/internal/xml/xml.go

@@ -0,0 +1,1998 @@
+// Copyright 2009 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.
+
+// Package xml implements a simple XML 1.0 parser that
+// understands XML name spaces.
+package xml
+
+// References:
+//    Annotated XML spec: http://www.xml.com/axml/testaxml.htm
+//    XML name spaces: http://www.w3.org/TR/REC-xml-names/
+
+// TODO(rsc):
+//	Test error handling.
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// A SyntaxError represents a syntax error in the XML input stream.
+type SyntaxError struct {
+	Msg  string
+	Line int
+}
+
+func (e *SyntaxError) Error() string {
+	return "XML syntax error on line " + strconv.Itoa(e.Line) + ": " + e.Msg
+}
+
+// A Name represents an XML name (Local) annotated with a name space
+// identifier (Space). In tokens returned by Decoder.Token, the Space
+// identifier is given as a canonical URL, not the short prefix used in
+// the document being parsed.
+//
+// As a special case, XML namespace declarations will use the literal
+// string "xmlns" for the Space field instead of the fully resolved URL.
+// See Encoder.EncodeToken for more information on namespace encoding
+// behaviour.
+type Name struct {
+	Space, Local string
+}
+
+// isNamespace reports whether the name is a namespace-defining name.
+func (name Name) isNamespace() bool {
+	return name.Local == "xmlns" || name.Space == "xmlns"
+}
+
+// An Attr represents an attribute in an XML element (Name=Value).
+type Attr struct {
+	Name  Name
+	Value string
+}
+
+// A Token is an interface holding one of the token types:
+// StartElement, EndElement, CharData, Comment, ProcInst, or Directive.
+type Token interface{}
+
+// A StartElement represents an XML start element.
+type StartElement struct {
+	Name Name
+	Attr []Attr
+}
+
+func (e StartElement) Copy() StartElement {
+	attrs := make([]Attr, len(e.Attr))
+	copy(attrs, e.Attr)
+	e.Attr = attrs
+	return e
+}
+
+// End returns the corresponding XML end element.
+func (e StartElement) End() EndElement {
+	return EndElement{e.Name}
+}
+
+// setDefaultNamespace sets the namespace of the element
+// as the default for all elements contained within it.
+func (e *StartElement) setDefaultNamespace() {
+	if e.Name.Space == "" {
+		// If there's no namespace on the element, don't
+		// set the default. Strictly speaking this might be wrong, as
+		// we can't tell if the element had no namespace set
+		// or was just using the default namespace.
+		return
+	}
+	// Don't add a default name space if there's already one set.
+	for _, attr := range e.Attr {
+		if attr.Name.Space == "" && attr.Name.Local == "xmlns" {
+			return
+		}
+	}
+	e.Attr = append(e.Attr, Attr{
+		Name: Name{
+			Local: "xmlns",
+		},
+		Value: e.Name.Space,
+	})
+}
+
+// An EndElement represents an XML end element.
+type EndElement struct {
+	Name Name
+}
+
+// A CharData represents XML character data (raw text),
+// in which XML escape sequences have been replaced by
+// the characters they represent.
+type CharData []byte
+
+func makeCopy(b []byte) []byte {
+	b1 := make([]byte, len(b))
+	copy(b1, b)
+	return b1
+}
+
+func (c CharData) Copy() CharData { return CharData(makeCopy(c)) }
+
+// A Comment represents an XML comment of the form <!--comment-->.
+// The bytes do not include the <!-- and --> comment markers.
+type Comment []byte
+
+func (c Comment) Copy() Comment { return Comment(makeCopy(c)) }
+
+// A ProcInst represents an XML processing instruction of the form <?target inst?>
+type ProcInst struct {
+	Target string
+	Inst   []byte
+}
+
+func (p ProcInst) Copy() ProcInst {
+	p.Inst = makeCopy(p.Inst)
+	return p
+}
+
+// A Directive represents an XML directive of the form <!text>.
+// The bytes do not include the <! and > markers.
+type Directive []byte
+
+func (d Directive) Copy() Directive { return Directive(makeCopy(d)) }
+
+// CopyToken returns a copy of a Token.
+func CopyToken(t Token) Token {
+	switch v := t.(type) {
+	case CharData:
+		return v.Copy()
+	case Comment:
+		return v.Copy()
+	case Directive:
+		return v.Copy()
+	case ProcInst:
+		return v.Copy()
+	case StartElement:
+		return v.Copy()
+	}
+	return t
+}
+
+// A Decoder represents an XML parser reading a particular input stream.
+// The parser assumes that its input is encoded in UTF-8.
+type Decoder struct {
+	// Strict defaults to true, enforcing the requirements
+	// of the XML specification.
+	// If set to false, the parser allows input containing common
+	// mistakes:
+	//	* If an element is missing an end tag, the parser invents
+	//	  end tags as necessary to keep the return values from Token
+	//	  properly balanced.
+	//	* In attribute values and character data, unknown or malformed
+	//	  character entities (sequences beginning with &) are left alone.
+	//
+	// Setting:
+	//
+	//	d.Strict = false;
+	//	d.AutoClose = HTMLAutoClose;
+	//	d.Entity = HTMLEntity
+	//
+	// creates a parser that can handle typical HTML.
+	//
+	// Strict mode does not enforce the requirements of the XML name spaces TR.
+	// In particular it does not reject name space tags using undefined prefixes.
+	// Such tags are recorded with the unknown prefix as the name space URL.
+	Strict bool
+
+	// When Strict == false, AutoClose indicates a set of elements to
+	// consider closed immediately after they are opened, regardless
+	// of whether an end element is present.
+	AutoClose []string
+
+	// Entity can be used to map non-standard entity names to string replacements.
+	// The parser behaves as if these standard mappings are present in the map,
+	// regardless of the actual map content:
+	//
+	//	"lt": "<",
+	//	"gt": ">",
+	//	"amp": "&",
+	//	"apos": "'",
+	//	"quot": `"`,
+	Entity map[string]string
+
+	// CharsetReader, if non-nil, defines a function to generate
+	// charset-conversion readers, converting from the provided
+	// non-UTF-8 charset into UTF-8. If CharsetReader is nil or
+	// returns an error, parsing stops with an error. One of the
+	// the CharsetReader's result values must be non-nil.
+	CharsetReader func(charset string, input io.Reader) (io.Reader, error)
+
+	// DefaultSpace sets the default name space used for unadorned tags,
+	// as if the entire XML stream were wrapped in an element containing
+	// the attribute xmlns="DefaultSpace".
+	DefaultSpace string
+
+	r              io.ByteReader
+	buf            bytes.Buffer
+	saved          *bytes.Buffer
+	stk            *stack
+	free           *stack
+	needClose      bool
+	toClose        Name
+	nextToken      Token
+	nextByte       int
+	ns             map[string]string
+	err            error
+	line           int
+	offset         int64
+	unmarshalDepth int
+}
+
+// NewDecoder creates a new XML parser reading from r.
+// If r does not implement io.ByteReader, NewDecoder will
+// do its own buffering.
+func NewDecoder(r io.Reader) *Decoder {
+	d := &Decoder{
+		ns:       make(map[string]string),
+		nextByte: -1,
+		line:     1,
+		Strict:   true,
+	}
+	d.switchToReader(r)
+	return d
+}
+
+// Token returns the next XML token in the input stream.
+// At the end of the input stream, Token returns nil, io.EOF.
+//
+// Slices of bytes in the returned token data refer to the
+// parser's internal buffer and remain valid only until the next
+// call to Token.  To acquire a copy of the bytes, call CopyToken
+// or the token's Copy method.
+//
+// Token expands self-closing elements such as <br/>
+// into separate start and end elements returned by successive calls.
+//
+// Token guarantees that the StartElement and EndElement
+// tokens it returns are properly nested and matched:
+// if Token encounters an unexpected end element,
+// it will return an error.
+//
+// Token implements XML name spaces as described by
+// http://www.w3.org/TR/REC-xml-names/.  Each of the
+// Name structures contained in the Token has the Space
+// set to the URL identifying its name space when known.
+// If Token encounters an unrecognized name space prefix,
+// it uses the prefix as the Space rather than report an error.
+func (d *Decoder) Token() (t Token, err error) {
+	if d.stk != nil && d.stk.kind == stkEOF {
+		err = io.EOF
+		return
+	}
+	if d.nextToken != nil {
+		t = d.nextToken
+		d.nextToken = nil
+	} else if t, err = d.rawToken(); err != nil {
+		return
+	}
+
+	if !d.Strict {
+		if t1, ok := d.autoClose(t); ok {
+			d.nextToken = t
+			t = t1
+		}
+	}
+	switch t1 := t.(type) {
+	case StartElement:
+		// In XML name spaces, the translations listed in the
+		// attributes apply to the element name and
+		// to the other attribute names, so process
+		// the translations first.
+		for _, a := range t1.Attr {
+			if a.Name.Space == "xmlns" {
+				v, ok := d.ns[a.Name.Local]
+				d.pushNs(a.Name.Local, v, ok)
+				d.ns[a.Name.Local] = a.Value
+			}
+			if a.Name.Space == "" && a.Name.Local == "xmlns" {
+				// Default space for untagged names
+				v, ok := d.ns[""]
+				d.pushNs("", v, ok)
+				d.ns[""] = a.Value
+			}
+		}
+
+		d.translate(&t1.Name, true)
+		for i := range t1.Attr {
+			d.translate(&t1.Attr[i].Name, false)
+		}
+		d.pushElement(t1.Name)
+		t = t1
+
+	case EndElement:
+		d.translate(&t1.Name, true)
+		if !d.popElement(&t1) {
+			return nil, d.err
+		}
+		t = t1
+	}
+	return
+}
+
+const xmlURL = "http://www.w3.org/XML/1998/namespace"
+
+// Apply name space translation to name n.
+// The default name space (for Space=="")
+// applies only to element names, not to attribute names.
+func (d *Decoder) translate(n *Name, isElementName bool) {
+	switch {
+	case n.Space == "xmlns":
+		return
+	case n.Space == "" && !isElementName:
+		return
+	case n.Space == "xml":
+		n.Space = xmlURL
+	case n.Space == "" && n.Local == "xmlns":
+		return
+	}
+	if v, ok := d.ns[n.Space]; ok {
+		n.Space = v
+	} else if n.Space == "" {
+		n.Space = d.DefaultSpace
+	}
+}
+
+func (d *Decoder) switchToReader(r io.Reader) {
+	// Get efficient byte at a time reader.
+	// Assume that if reader has its own
+	// ReadByte, it's efficient enough.
+	// Otherwise, use bufio.
+	if rb, ok := r.(io.ByteReader); ok {
+		d.r = rb
+	} else {
+		d.r = bufio.NewReader(r)
+	}
+}
+
+// Parsing state - stack holds old name space translations
+// and the current set of open elements.  The translations to pop when
+// ending a given tag are *below* it on the stack, which is
+// more work but forced on us by XML.
+type stack struct {
+	next *stack
+	kind int
+	name Name
+	ok   bool
+}
+
+const (
+	stkStart = iota
+	stkNs
+	stkEOF
+)
+
+func (d *Decoder) push(kind int) *stack {
+	s := d.free
+	if s != nil {
+		d.free = s.next
+	} else {
+		s = new(stack)
+	}
+	s.next = d.stk
+	s.kind = kind
+	d.stk = s
+	return s
+}
+
+func (d *Decoder) pop() *stack {
+	s := d.stk
+	if s != nil {
+		d.stk = s.next
+		s.next = d.free
+		d.free = s
+	}
+	return s
+}
+
+// Record that after the current element is finished
+// (that element is already pushed on the stack)
+// Token should return EOF until popEOF is called.
+func (d *Decoder) pushEOF() {
+	// Walk down stack to find Start.
+	// It might not be the top, because there might be stkNs
+	// entries above it.
+	start := d.stk
+	for start.kind != stkStart {
+		start = start.next
+	}
+	// The stkNs entries below a start are associated with that
+	// element too; skip over them.
+	for start.next != nil && start.next.kind == stkNs {
+		start = start.next
+	}
+	s := d.free
+	if s != nil {
+		d.free = s.next
+	} else {
+		s = new(stack)
+	}
+	s.kind = stkEOF
+	s.next = start.next
+	start.next = s
+}
+
+// Undo a pushEOF.
+// The element must have been finished, so the EOF should be at the top of the stack.
+func (d *Decoder) popEOF() bool {
+	if d.stk == nil || d.stk.kind != stkEOF {
+		return false
+	}
+	d.pop()
+	return true
+}
+
+// Record that we are starting an element with the given name.
+func (d *Decoder) pushElement(name Name) {
+	s := d.push(stkStart)
+	s.name = name
+}
+
+// Record that we are changing the value of ns[local].
+// The old value is url, ok.
+func (d *Decoder) pushNs(local string, url string, ok bool) {
+	s := d.push(stkNs)
+	s.name.Local = local
+	s.name.Space = url
+	s.ok = ok
+}
+
+// Creates a SyntaxError with the current line number.
+func (d *Decoder) syntaxError(msg string) error {
+	return &SyntaxError{Msg: msg, Line: d.line}
+}
+
+// Record that we are ending an element with the given name.
+// The name must match the record at the top of the stack,
+// which must be a pushElement record.
+// After popping the element, apply any undo records from
+// the stack to restore the name translations that existed
+// before we saw this element.
+func (d *Decoder) popElement(t *EndElement) bool {
+	s := d.pop()
+	name := t.Name
+	switch {
+	case s == nil || s.kind != stkStart:
+		d.err = d.syntaxError("unexpected end element </" + name.Local + ">")
+		return false
+	case s.name.Local != name.Local:
+		if !d.Strict {
+			d.needClose = true
+			d.toClose = t.Name
+			t.Name = s.name
+			return true
+		}
+		d.err = d.syntaxError("element <" + s.name.Local + "> closed by </" + name.Local + ">")
+		return false
+	case s.name.Space != name.Space:
+		d.err = d.syntaxError("element <" + s.name.Local + "> in space " + s.name.Space +
+			"closed by </" + name.Local + "> in space " + name.Space)
+		return false
+	}
+
+	// Pop stack until a Start or EOF is on the top, undoing the
+	// translations that were associated with the element we just closed.
+	for d.stk != nil && d.stk.kind != stkStart && d.stk.kind != stkEOF {
+		s := d.pop()
+		if s.ok {
+			d.ns[s.name.Local] = s.name.Space
+		} else {
+			delete(d.ns, s.name.Local)
+		}
+	}
+
+	return true
+}
+
+// If the top element on the stack is autoclosing and
+// t is not the end tag, invent the end tag.
+func (d *Decoder) autoClose(t Token) (Token, bool) {
+	if d.stk == nil || d.stk.kind != stkStart {
+		return nil, false
+	}
+	name := strings.ToLower(d.stk.name.Local)
+	for _, s := range d.AutoClose {
+		if strings.ToLower(s) == name {
+			// This one should be auto closed if t doesn't close it.
+			et, ok := t.(EndElement)
+			if !ok || et.Name.Local != name {
+				return EndElement{d.stk.name}, true
+			}
+			break
+		}
+	}
+	return nil, false
+}
+
+var errRawToken = errors.New("xml: cannot use RawToken from UnmarshalXML method")
+
+// RawToken is like Token but does not verify that
+// start and end elements match and does not translate
+// name space prefixes to their corresponding URLs.
+func (d *Decoder) RawToken() (Token, error) {
+	if d.unmarshalDepth > 0 {
+		return nil, errRawToken
+	}
+	return d.rawToken()
+}
+
+func (d *Decoder) rawToken() (Token, error) {
+	if d.err != nil {
+		return nil, d.err
+	}
+	if d.needClose {
+		// The last element we read was self-closing and
+		// we returned just the StartElement half.
+		// Return the EndElement half now.
+		d.needClose = false
+		return EndElement{d.toClose}, nil
+	}
+
+	b, ok := d.getc()
+	if !ok {
+		return nil, d.err
+	}
+
+	if b != '<' {
+		// Text section.
+		d.ungetc(b)
+		data := d.text(-1, false)
+		if data == nil {
+			return nil, d.err
+		}
+		return CharData(data), nil
+	}
+
+	if b, ok = d.mustgetc(); !ok {
+		return nil, d.err
+	}
+	switch b {
+	case '/':
+		// </: End element
+		var name Name
+		if name, ok = d.nsname(); !ok {
+			if d.err == nil {
+				d.err = d.syntaxError("expected element name after </")
+			}
+			return nil, d.err
+		}
+		d.space()
+		if b, ok = d.mustgetc(); !ok {
+			return nil, d.err
+		}
+		if b != '>' {
+			d.err = d.syntaxError("invalid characters between </" + name.Local + " and >")
+			return nil, d.err
+		}
+		return EndElement{name}, nil
+
+	case '?':
+		// <?: Processing instruction.
+		var target string
+		if target, ok = d.name(); !ok {
+			if d.err == nil {
+				d.err = d.syntaxError("expected target name after <?")
+			}
+			return nil, d.err
+		}
+		d.space()
+		d.buf.Reset()
+		var b0 byte
+		for {
+			if b, ok = d.mustgetc(); !ok {
+				return nil, d.err
+			}
+			d.buf.WriteByte(b)
+			if b0 == '?' && b == '>' {
+				break
+			}
+			b0 = b
+		}
+		data := d.buf.Bytes()
+		data = data[0 : len(data)-2] // chop ?>
+
+		if target == "xml" {
+			content := string(data)
+			ver := procInst("version", content)
+			if ver != "" && ver != "1.0" {
+				d.err = fmt.Errorf("xml: unsupported version %q; only version 1.0 is supported", ver)
+				return nil, d.err
+			}
+			enc := procInst("encoding", content)
+			if enc != "" && enc != "utf-8" && enc != "UTF-8" {
+				if d.CharsetReader == nil {
+					d.err = fmt.Errorf("xml: encoding %q declared but Decoder.CharsetReader is nil", enc)
+					return nil, d.err
+				}
+				newr, err := d.CharsetReader(enc, d.r.(io.Reader))
+				if err != nil {
+					d.err = fmt.Errorf("xml: opening charset %q: %v", enc, err)
+					return nil, d.err
+				}
+				if newr == nil {
+					panic("CharsetReader returned a nil Reader for charset " + enc)
+				}
+				d.switchToReader(newr)
+			}
+		}
+		return ProcInst{target, data}, nil
+
+	case '!':
+		// <!: Maybe comment, maybe CDATA.
+		if b, ok = d.mustgetc(); !ok {
+			return nil, d.err
+		}
+		switch b {
+		case '-': // <!-
+			// Probably <!-- for a comment.
+			if b, ok = d.mustgetc(); !ok {
+				return nil, d.err
+			}
+			if b != '-' {
+				d.err = d.syntaxError("invalid sequence <!- not part of <!--")
+				return nil, d.err
+			}
+			// Look for terminator.
+			d.buf.Reset()
+			var b0, b1 byte
+			for {
+				if b, ok = d.mustgetc(); !ok {
+					return nil, d.err
+				}
+				d.buf.WriteByte(b)
+				if b0 == '-' && b1 == '-' && b == '>' {
+					break
+				}
+				b0, b1 = b1, b
+			}
+			data := d.buf.Bytes()
+			data = data[0 : len(data)-3] // chop -->
+			return Comment(data), nil
+
+		case '[': // <![
+			// Probably <![CDATA[.
+			for i := 0; i < 6; i++ {
+				if b, ok = d.mustgetc(); !ok {
+					return nil, d.err
+				}
+				if b != "CDATA["[i] {
+					d.err = d.syntaxError("invalid <![ sequence")
+					return nil, d.err
+				}
+			}
+			// Have <![CDATA[.  Read text until ]]>.
+			data := d.text(-1, true)
+			if data == nil {
+				return nil, d.err
+			}
+			return CharData(data), nil
+		}
+
+		// Probably a directive: <!DOCTYPE ...>, <!ENTITY ...>, etc.
+		// We don't care, but accumulate for caller. Quoted angle
+		// brackets do not count for nesting.
+		d.buf.Reset()
+		d.buf.WriteByte(b)
+		inquote := uint8(0)
+		depth := 0
+		for {
+			if b, ok = d.mustgetc(); !ok {
+				return nil, d.err
+			}
+			if inquote == 0 && b == '>' && depth == 0 {
+				break
+			}
+		HandleB:
+			d.buf.WriteByte(b)
+			switch {
+			case b == inquote:
+				inquote = 0
+
+			case inquote != 0:
+				// in quotes, no special action
+
+			case b == '\'' || b == '"':
+				inquote = b
+
+			case b == '>' && inquote == 0:
+				depth--
+
+			case b == '<' && inquote == 0:
+				// Look for <!-- to begin comment.
+				s := "!--"
+				for i := 0; i < len(s); i++ {
+					if b, ok = d.mustgetc(); !ok {
+						return nil, d.err
+					}
+					if b != s[i] {
+						for j := 0; j < i; j++ {
+							d.buf.WriteByte(s[j])
+						}
+						depth++
+						goto HandleB
+					}
+				}
+
+				// Remove < that was written above.
+				d.buf.Truncate(d.buf.Len() - 1)
+
+				// Look for terminator.
+				var b0, b1 byte
+				for {
+					if b, ok = d.mustgetc(); !ok {
+						return nil, d.err
+					}
+					if b0 == '-' && b1 == '-' && b == '>' {
+						break
+					}
+					b0, b1 = b1, b
+				}
+			}
+		}
+		return Directive(d.buf.Bytes()), nil
+	}
+
+	// Must be an open element like <a href="foo">
+	d.ungetc(b)
+
+	var (
+		name  Name
+		empty bool
+		attr  []Attr
+	)
+	if name, ok = d.nsname(); !ok {
+		if d.err == nil {
+			d.err = d.syntaxError("expected element name after <")
+		}
+		return nil, d.err
+	}
+
+	attr = []Attr{}
+	for {
+		d.space()
+		if b, ok = d.mustgetc(); !ok {
+			return nil, d.err
+		}
+		if b == '/' {
+			empty = true
+			if b, ok = d.mustgetc(); !ok {
+				return nil, d.err
+			}
+			if b != '>' {
+				d.err = d.syntaxError("expected /> in element")
+				return nil, d.err
+			}
+			break
+		}
+		if b == '>' {
+			break
+		}
+		d.ungetc(b)
+
+		n := len(attr)
+		if n >= cap(attr) {
+			nCap := 2 * cap(attr)
+			if nCap == 0 {
+				nCap = 4
+			}
+			nattr := make([]Attr, n, nCap)
+			copy(nattr, attr)
+			attr = nattr
+		}
+		attr = attr[0 : n+1]
+		a := &attr[n]
+		if a.Name, ok = d.nsname(); !ok {
+			if d.err == nil {
+				d.err = d.syntaxError("expected attribute name in element")
+			}
+			return nil, d.err
+		}
+		d.space()
+		if b, ok = d.mustgetc(); !ok {
+			return nil, d.err
+		}
+		if b != '=' {
+			if d.Strict {
+				d.err = d.syntaxError("attribute name without = in element")
+				return nil, d.err
+			} else {
+				d.ungetc(b)
+				a.Value = a.Name.Local
+			}
+		} else {
+			d.space()
+			data := d.attrval()
+			if data == nil {
+				return nil, d.err
+			}
+			a.Value = string(data)
+		}
+	}
+	if empty {
+		d.needClose = true
+		d.toClose = name
+	}
+	return StartElement{name, attr}, nil
+}
+
+func (d *Decoder) attrval() []byte {
+	b, ok := d.mustgetc()
+	if !ok {
+		return nil
+	}
+	// Handle quoted attribute values
+	if b == '"' || b == '\'' {
+		return d.text(int(b), false)
+	}
+	// Handle unquoted attribute values for strict parsers
+	if d.Strict {
+		d.err = d.syntaxError("unquoted or missing attribute value in element")
+		return nil
+	}
+	// Handle unquoted attribute values for unstrict parsers
+	d.ungetc(b)
+	d.buf.Reset()
+	for {
+		b, ok = d.mustgetc()
+		if !ok {
+			return nil
+		}
+		// http://www.w3.org/TR/REC-html40/intro/sgmltut.html#h-3.2.2
+		if 'a' <= b && b <= 'z' || 'A' <= b && b <= 'Z' ||
+			'0' <= b && b <= '9' || b == '_' || b == ':' || b == '-' {
+			d.buf.WriteByte(b)
+		} else {
+			d.ungetc(b)
+			break
+		}
+	}
+	return d.buf.Bytes()
+}
+
+// Skip spaces if any
+func (d *Decoder) space() {
+	for {
+		b, ok := d.getc()
+		if !ok {
+			return
+		}
+		switch b {
+		case ' ', '\r', '\n', '\t':
+		default:
+			d.ungetc(b)
+			return
+		}
+	}
+}
+
+// Read a single byte.
+// If there is no byte to read, return ok==false
+// and leave the error in d.err.
+// Maintain line number.
+func (d *Decoder) getc() (b byte, ok bool) {
+	if d.err != nil {
+		return 0, false
+	}
+	if d.nextByte >= 0 {
+		b = byte(d.nextByte)
+		d.nextByte = -1
+	} else {
+		b, d.err = d.r.ReadByte()
+		if d.err != nil {
+			return 0, false
+		}
+		if d.saved != nil {
+			d.saved.WriteByte(b)
+		}
+	}
+	if b == '\n' {
+		d.line++
+	}
+	d.offset++
+	return b, true
+}
+
+// InputOffset returns the input stream byte offset of the current decoder position.
+// The offset gives the location of the end of the most recently returned token
+// and the beginning of the next token.
+func (d *Decoder) InputOffset() int64 {
+	return d.offset
+}
+
+// Return saved offset.
+// If we did ungetc (nextByte >= 0), have to back up one.
+func (d *Decoder) savedOffset() int {
+	n := d.saved.Len()
+	if d.nextByte >= 0 {
+		n--
+	}
+	return n
+}
+
+// Must read a single byte.
+// If there is no byte to read,
+// set d.err to SyntaxError("unexpected EOF")
+// and return ok==false
+func (d *Decoder) mustgetc() (b byte, ok bool) {
+	if b, ok = d.getc(); !ok {
+		if d.err == io.EOF {
+			d.err = d.syntaxError("unexpected EOF")
+		}
+	}
+	return
+}
+
+// Unread a single byte.
+func (d *Decoder) ungetc(b byte) {
+	if b == '\n' {
+		d.line--
+	}
+	d.nextByte = int(b)
+	d.offset--
+}
+
+var entity = map[string]int{
+	"lt":   '<',
+	"gt":   '>',
+	"amp":  '&',
+	"apos": '\'',
+	"quot": '"',
+}
+
+// Read plain text section (XML calls it character data).
+// If quote >= 0, we are in a quoted string and need to find the matching quote.
+// If cdata == true, we are in a <![CDATA[ section and need to find ]]>.
+// On failure return nil and leave the error in d.err.
+func (d *Decoder) text(quote int, cdata bool) []byte {
+	var b0, b1 byte
+	var trunc int
+	d.buf.Reset()
+Input:
+	for {
+		b, ok := d.getc()
+		if !ok {
+			if cdata {
+				if d.err == io.EOF {
+					d.err = d.syntaxError("unexpected EOF in CDATA section")
+				}
+				return nil
+			}
+			break Input
+		}
+
+		// <![CDATA[ section ends with ]]>.
+		// It is an error for ]]> to appear in ordinary text.
+		if b0 == ']' && b1 == ']' && b == '>' {
+			if cdata {
+				trunc = 2
+				break Input
+			}
+			d.err = d.syntaxError("unescaped ]]> not in CDATA section")
+			return nil
+		}
+
+		// Stop reading text if we see a <.
+		if b == '<' && !cdata {
+			if quote >= 0 {
+				d.err = d.syntaxError("unescaped < inside quoted string")
+				return nil
+			}
+			d.ungetc('<')
+			break Input
+		}
+		if quote >= 0 && b == byte(quote) {
+			break Input
+		}
+		if b == '&' && !cdata {
+			// Read escaped character expression up to semicolon.
+			// XML in all its glory allows a document to define and use
+			// its own character names with <!ENTITY ...> directives.
+			// Parsers are required to recognize lt, gt, amp, apos, and quot
+			// even if they have not been declared.
+			before := d.buf.Len()
+			d.buf.WriteByte('&')
+			var ok bool
+			var text string
+			var haveText bool
+			if b, ok = d.mustgetc(); !ok {
+				return nil
+			}
+			if b == '#' {
+				d.buf.WriteByte(b)
+				if b, ok = d.mustgetc(); !ok {
+					return nil
+				}
+				base := 10
+				if b == 'x' {
+					base = 16
+					d.buf.WriteByte(b)
+					if b, ok = d.mustgetc(); !ok {
+						return nil
+					}
+				}
+				start := d.buf.Len()
+				for '0' <= b && b <= '9' ||
+					base == 16 && 'a' <= b && b <= 'f' ||
+					base == 16 && 'A' <= b && b <= 'F' {
+					d.buf.WriteByte(b)
+					if b, ok = d.mustgetc(); !ok {
+						return nil
+					}
+				}
+				if b != ';' {
+					d.ungetc(b)
+				} else {
+					s := string(d.buf.Bytes()[start:])
+					d.buf.WriteByte(';')
+					n, err := strconv.ParseUint(s, base, 64)
+					if err == nil && n <= unicode.MaxRune {
+						text = string(n)
+						haveText = true
+					}
+				}
+			} else {
+				d.ungetc(b)
+				if !d.readName() {
+					if d.err != nil {
+						return nil
+					}
+					ok = false
+				}
+				if b, ok = d.mustgetc(); !ok {
+					return nil
+				}
+				if b != ';' {
+					d.ungetc(b)
+				} else {
+					name := d.buf.Bytes()[before+1:]
+					d.buf.WriteByte(';')
+					if isName(name) {
+						s := string(name)
+						if r, ok := entity[s]; ok {
+							text = string(r)
+							haveText = true
+						} else if d.Entity != nil {
+							text, haveText = d.Entity[s]
+						}
+					}
+				}
+			}
+
+			if haveText {
+				d.buf.Truncate(before)
+				d.buf.Write([]byte(text))
+				b0, b1 = 0, 0
+				continue Input
+			}
+			if !d.Strict {
+				b0, b1 = 0, 0
+				continue Input
+			}
+			ent := string(d.buf.Bytes()[before:])
+			if ent[len(ent)-1] != ';' {
+				ent += " (no semicolon)"
+			}
+			d.err = d.syntaxError("invalid character entity " + ent)
+			return nil
+		}
+
+		// We must rewrite unescaped \r and \r\n into \n.
+		if b == '\r' {
+			d.buf.WriteByte('\n')
+		} else if b1 == '\r' && b == '\n' {
+			// Skip \r\n--we already wrote \n.
+		} else {
+			d.buf.WriteByte(b)
+		}
+
+		b0, b1 = b1, b
+	}
+	data := d.buf.Bytes()
+	data = data[0 : len(data)-trunc]
+
+	// Inspect each rune for being a disallowed character.
+	buf := data
+	for len(buf) > 0 {
+		r, size := utf8.DecodeRune(buf)
+		if r == utf8.RuneError && size == 1 {
+			d.err = d.syntaxError("invalid UTF-8")
+			return nil
+		}
+		buf = buf[size:]
+		if !isInCharacterRange(r) {
+			d.err = d.syntaxError(fmt.Sprintf("illegal character code %U", r))
+			return nil
+		}
+	}
+
+	return data
+}
+
+// Decide whether the given rune is in the XML Character Range, per
+// the Char production of http://www.xml.com/axml/testaxml.htm,
+// Section 2.2 Characters.
+func isInCharacterRange(r rune) (inrange bool) {
+	return r == 0x09 ||
+		r == 0x0A ||
+		r == 0x0D ||
+		r >= 0x20 && r <= 0xDF77 ||
+		r >= 0xE000 && r <= 0xFFFD ||
+		r >= 0x10000 && r <= 0x10FFFF
+}
+
+// Get name space name: name with a : stuck in the middle.
+// The part before the : is the name space identifier.
+func (d *Decoder) nsname() (name Name, ok bool) {
+	s, ok := d.name()
+	if !ok {
+		return
+	}
+	i := strings.Index(s, ":")
+	if i < 0 {
+		name.Local = s
+	} else {
+		name.Space = s[0:i]
+		name.Local = s[i+1:]
+	}
+	return name, true
+}
+
+// Get name: /first(first|second)*/
+// Do not set d.err if the name is missing (unless unexpected EOF is received):
+// let the caller provide better context.
+func (d *Decoder) name() (s string, ok bool) {
+	d.buf.Reset()
+	if !d.readName() {
+		return "", false
+	}
+
+	// Now we check the characters.
+	b := d.buf.Bytes()
+	if !isName(b) {
+		d.err = d.syntaxError("invalid XML name: " + string(b))
+		return "", false
+	}
+	return string(b), true
+}
+
+// Read a name and append its bytes to d.buf.
+// The name is delimited by any single-byte character not valid in names.
+// All multi-byte characters are accepted; the caller must check their validity.
+func (d *Decoder) readName() (ok bool) {
+	var b byte
+	if b, ok = d.mustgetc(); !ok {
+		return
+	}
+	if b < utf8.RuneSelf && !isNameByte(b) {
+		d.ungetc(b)
+		return false
+	}
+	d.buf.WriteByte(b)
+
+	for {
+		if b, ok = d.mustgetc(); !ok {
+			return
+		}
+		if b < utf8.RuneSelf && !isNameByte(b) {
+			d.ungetc(b)
+			break
+		}
+		d.buf.WriteByte(b)
+	}
+	return true
+}
+
+func isNameByte(c byte) bool {
+	return 'A' <= c && c <= 'Z' ||
+		'a' <= c && c <= 'z' ||
+		'0' <= c && c <= '9' ||
+		c == '_' || c == ':' || c == '.' || c == '-'
+}
+
+func isName(s []byte) bool {
+	if len(s) == 0 {
+		return false
+	}
+	c, n := utf8.DecodeRune(s)
+	if c == utf8.RuneError && n == 1 {
+		return false
+	}
+	if !unicode.Is(first, c) {
+		return false
+	}
+	for n < len(s) {
+		s = s[n:]
+		c, n = utf8.DecodeRune(s)
+		if c == utf8.RuneError && n == 1 {
+			return false
+		}
+		if !unicode.Is(first, c) && !unicode.Is(second, c) {
+			return false
+		}
+	}
+	return true
+}
+
+func isNameString(s string) bool {
+	if len(s) == 0 {
+		return false
+	}
+	c, n := utf8.DecodeRuneInString(s)
+	if c == utf8.RuneError && n == 1 {
+		return false
+	}
+	if !unicode.Is(first, c) {
+		return false
+	}
+	for n < len(s) {
+		s = s[n:]
+		c, n = utf8.DecodeRuneInString(s)
+		if c == utf8.RuneError && n == 1 {
+			return false
+		}
+		if !unicode.Is(first, c) && !unicode.Is(second, c) {
+			return false
+		}
+	}
+	return true
+}
+
+// These tables were generated by cut and paste from Appendix B of
+// the XML spec at http://www.xml.com/axml/testaxml.htm
+// and then reformatting.  First corresponds to (Letter | '_' | ':')
+// and second corresponds to NameChar.
+
+var first = &unicode.RangeTable{
+	R16: []unicode.Range16{
+		{0x003A, 0x003A, 1},
+		{0x0041, 0x005A, 1},
+		{0x005F, 0x005F, 1},
+		{0x0061, 0x007A, 1},
+		{0x00C0, 0x00D6, 1},
+		{0x00D8, 0x00F6, 1},
+		{0x00F8, 0x00FF, 1},
+		{0x0100, 0x0131, 1},
+		{0x0134, 0x013E, 1},
+		{0x0141, 0x0148, 1},
+		{0x014A, 0x017E, 1},
+		{0x0180, 0x01C3, 1},
+		{0x01CD, 0x01F0, 1},
+		{0x01F4, 0x01F5, 1},
+		{0x01FA, 0x0217, 1},
+		{0x0250, 0x02A8, 1},
+		{0x02BB, 0x02C1, 1},
+		{0x0386, 0x0386, 1},
+		{0x0388, 0x038A, 1},
+		{0x038C, 0x038C, 1},
+		{0x038E, 0x03A1, 1},
+		{0x03A3, 0x03CE, 1},
+		{0x03D0, 0x03D6, 1},
+		{0x03DA, 0x03E0, 2},
+		{0x03E2, 0x03F3, 1},
+		{0x0401, 0x040C, 1},
+		{0x040E, 0x044F, 1},
+		{0x0451, 0x045C, 1},
+		{0x045E, 0x0481, 1},
+		{0x0490, 0x04C4, 1},
+		{0x04C7, 0x04C8, 1},
+		{0x04CB, 0x04CC, 1},
+		{0x04D0, 0x04EB, 1},
+		{0x04EE, 0x04F5, 1},
+		{0x04F8, 0x04F9, 1},
+		{0x0531, 0x0556, 1},
+		{0x0559, 0x0559, 1},
+		{0x0561, 0x0586, 1},
+		{0x05D0, 0x05EA, 1},
+		{0x05F0, 0x05F2, 1},
+		{0x0621, 0x063A, 1},
+		{0x0641, 0x064A, 1},
+		{0x0671, 0x06B7, 1},
+		{0x06BA, 0x06BE, 1},
+		{0x06C0, 0x06CE, 1},
+		{0x06D0, 0x06D3, 1},
+		{0x06D5, 0x06D5, 1},
+		{0x06E5, 0x06E6, 1},
+		{0x0905, 0x0939, 1},
+		{0x093D, 0x093D, 1},
+		{0x0958, 0x0961, 1},
+		{0x0985, 0x098C, 1},
+		{0x098F, 0x0990, 1},
+		{0x0993, 0x09A8, 1},
+		{0x09AA, 0x09B0, 1},
+		{0x09B2, 0x09B2, 1},
+		{0x09B6, 0x09B9, 1},
+		{0x09DC, 0x09DD, 1},
+		{0x09DF, 0x09E1, 1},
+		{0x09F0, 0x09F1, 1},
+		{0x0A05, 0x0A0A, 1},
+		{0x0A0F, 0x0A10, 1},
+		{0x0A13, 0x0A28, 1},
+		{0x0A2A, 0x0A30, 1},
+		{0x0A32, 0x0A33, 1},
+		{0x0A35, 0x0A36, 1},
+		{0x0A38, 0x0A39, 1},
+		{0x0A59, 0x0A5C, 1},
+		{0x0A5E, 0x0A5E, 1},
+		{0x0A72, 0x0A74, 1},
+		{0x0A85, 0x0A8B, 1},
+		{0x0A8D, 0x0A8D, 1},
+		{0x0A8F, 0x0A91, 1},
+		{0x0A93, 0x0AA8, 1},
+		{0x0AAA, 0x0AB0, 1},
+		{0x0AB2, 0x0AB3, 1},
+		{0x0AB5, 0x0AB9, 1},
+		{0x0ABD, 0x0AE0, 0x23},
+		{0x0B05, 0x0B0C, 1},
+		{0x0B0F, 0x0B10, 1},
+		{0x0B13, 0x0B28, 1},
+		{0x0B2A, 0x0B30, 1},
+		{0x0B32, 0x0B33, 1},
+		{0x0B36, 0x0B39, 1},
+		{0x0B3D, 0x0B3D, 1},
+		{0x0B5C, 0x0B5D, 1},
+		{0x0B5F, 0x0B61, 1},
+		{0x0B85, 0x0B8A, 1},
+		{0x0B8E, 0x0B90, 1},
+		{0x0B92, 0x0B95, 1},
+		{0x0B99, 0x0B9A, 1},
+		{0x0B9C, 0x0B9C, 1},
+		{0x0B9E, 0x0B9F, 1},
+		{0x0BA3, 0x0BA4, 1},
+		{0x0BA8, 0x0BAA, 1},
+		{0x0BAE, 0x0BB5, 1},
+		{0x0BB7, 0x0BB9, 1},
+		{0x0C05, 0x0C0C, 1},
+		{0x0C0E, 0x0C10, 1},
+		{0x0C12, 0x0C28, 1},
+		{0x0C2A, 0x0C33, 1},
+		{0x0C35, 0x0C39, 1},
+		{0x0C60, 0x0C61, 1},
+		{0x0C85, 0x0C8C, 1},
+		{0x0C8E, 0x0C90, 1},
+		{0x0C92, 0x0CA8, 1},
+		{0x0CAA, 0x0CB3, 1},
+		{0x0CB5, 0x0CB9, 1},
+		{0x0CDE, 0x0CDE, 1},
+		{0x0CE0, 0x0CE1, 1},
+		{0x0D05, 0x0D0C, 1},
+		{0x0D0E, 0x0D10, 1},
+		{0x0D12, 0x0D28, 1},
+		{0x0D2A, 0x0D39, 1},
+		{0x0D60, 0x0D61, 1},
+		{0x0E01, 0x0E2E, 1},
+		{0x0E30, 0x0E30, 1},
+		{0x0E32, 0x0E33, 1},
+		{0x0E40, 0x0E45, 1},
+		{0x0E81, 0x0E82, 1},
+		{0x0E84, 0x0E84, 1},
+		{0x0E87, 0x0E88, 1},
+		{0x0E8A, 0x0E8D, 3},
+		{0x0E94, 0x0E97, 1},
+		{0x0E99, 0x0E9F, 1},
+		{0x0EA1, 0x0EA3, 1},
+		{0x0EA5, 0x0EA7, 2},
+		{0x0EAA, 0x0EAB, 1},
+		{0x0EAD, 0x0EAE, 1},
+		{0x0EB0, 0x0EB0, 1},
+		{0x0EB2, 0x0EB3, 1},
+		{0x0EBD, 0x0EBD, 1},
+		{0x0EC0, 0x0EC4, 1},
+		{0x0F40, 0x0F47, 1},
+		{0x0F49, 0x0F69, 1},
+		{0x10A0, 0x10C5, 1},
+		{0x10D0, 0x10F6, 1},
+		{0x1100, 0x1100, 1},
+		{0x1102, 0x1103, 1},
+		{0x1105, 0x1107, 1},
+		{0x1109, 0x1109, 1},
+		{0x110B, 0x110C, 1},
+		{0x110E, 0x1112, 1},
+		{0x113C, 0x1140, 2},
+		{0x114C, 0x1150, 2},
+		{0x1154, 0x1155, 1},
+		{0x1159, 0x1159, 1},
+		{0x115F, 0x1161, 1},
+		{0x1163, 0x1169, 2},
+		{0x116D, 0x116E, 1},
+		{0x1172, 0x1173, 1},
+		{0x1175, 0x119E, 0x119E - 0x1175},
+		{0x11A8, 0x11AB, 0x11AB - 0x11A8},
+		{0x11AE, 0x11AF, 1},
+		{0x11B7, 0x11B8, 1},
+		{0x11BA, 0x11BA, 1},
+		{0x11BC, 0x11C2, 1},
+		{0x11EB, 0x11F0, 0x11F0 - 0x11EB},
+		{0x11F9, 0x11F9, 1},
+		{0x1E00, 0x1E9B, 1},
+		{0x1EA0, 0x1EF9, 1},
+		{0x1F00, 0x1F15, 1},
+		{0x1F18, 0x1F1D, 1},
+		{0x1F20, 0x1F45, 1},
+		{0x1F48, 0x1F4D, 1},
+		{0x1F50, 0x1F57, 1},
+		{0x1F59, 0x1F5B, 0x1F5B - 0x1F59},
+		{0x1F5D, 0x1F5D, 1},
+		{0x1F5F, 0x1F7D, 1},
+		{0x1F80, 0x1FB4, 1},
+		{0x1FB6, 0x1FBC, 1},
+		{0x1FBE, 0x1FBE, 1},
+		{0x1FC2, 0x1FC4, 1},
+		{0x1FC6, 0x1FCC, 1},
+		{0x1FD0, 0x1FD3, 1},
+		{0x1FD6, 0x1FDB, 1},
+		{0x1FE0, 0x1FEC, 1},
+		{0x1FF2, 0x1FF4, 1},
+		{0x1FF6, 0x1FFC, 1},
+		{0x2126, 0x2126, 1},
+		{0x212A, 0x212B, 1},
+		{0x212E, 0x212E, 1},
+		{0x2180, 0x2182, 1},
+		{0x3007, 0x3007, 1},
+		{0x3021, 0x3029, 1},
+		{0x3041, 0x3094, 1},
+		{0x30A1, 0x30FA, 1},
+		{0x3105, 0x312C, 1},
+		{0x4E00, 0x9FA5, 1},
+		{0xAC00, 0xD7A3, 1},
+	},
+}
+
+var second = &unicode.RangeTable{
+	R16: []unicode.Range16{
+		{0x002D, 0x002E, 1},
+		{0x0030, 0x0039, 1},
+		{0x00B7, 0x00B7, 1},
+		{0x02D0, 0x02D1, 1},
+		{0x0300, 0x0345, 1},
+		{0x0360, 0x0361, 1},
+		{0x0387, 0x0387, 1},
+		{0x0483, 0x0486, 1},
+		{0x0591, 0x05A1, 1},
+		{0x05A3, 0x05B9, 1},
+		{0x05BB, 0x05BD, 1},
+		{0x05BF, 0x05BF, 1},
+		{0x05C1, 0x05C2, 1},
+		{0x05C4, 0x0640, 0x0640 - 0x05C4},
+		{0x064B, 0x0652, 1},
+		{0x0660, 0x0669, 1},
+		{0x0670, 0x0670, 1},
+		{0x06D6, 0x06DC, 1},
+		{0x06DD, 0x06DF, 1},
+		{0x06E0, 0x06E4, 1},
+		{0x06E7, 0x06E8, 1},
+		{0x06EA, 0x06ED, 1},
+		{0x06F0, 0x06F9, 1},
+		{0x0901, 0x0903, 1},
+		{0x093C, 0x093C, 1},
+		{0x093E, 0x094C, 1},
+		{0x094D, 0x094D, 1},
+		{0x0951, 0x0954, 1},
+		{0x0962, 0x0963, 1},
+		{0x0966, 0x096F, 1},
+		{0x0981, 0x0983, 1},
+		{0x09BC, 0x09BC, 1},
+		{0x09BE, 0x09BF, 1},
+		{0x09C0, 0x09C4, 1},
+		{0x09C7, 0x09C8, 1},
+		{0x09CB, 0x09CD, 1},
+		{0x09D7, 0x09D7, 1},
+		{0x09E2, 0x09E3, 1},
+		{0x09E6, 0x09EF, 1},
+		{0x0A02, 0x0A3C, 0x3A},
+		{0x0A3E, 0x0A3F, 1},
+		{0x0A40, 0x0A42, 1},
+		{0x0A47, 0x0A48, 1},
+		{0x0A4B, 0x0A4D, 1},
+		{0x0A66, 0x0A6F, 1},
+		{0x0A70, 0x0A71, 1},
+		{0x0A81, 0x0A83, 1},
+		{0x0ABC, 0x0ABC, 1},
+		{0x0ABE, 0x0AC5, 1},
+		{0x0AC7, 0x0AC9, 1},
+		{0x0ACB, 0x0ACD, 1},
+		{0x0AE6, 0x0AEF, 1},
+		{0x0B01, 0x0B03, 1},
+		{0x0B3C, 0x0B3C, 1},
+		{0x0B3E, 0x0B43, 1},
+		{0x0B47, 0x0B48, 1},
+		{0x0B4B, 0x0B4D, 1},
+		{0x0B56, 0x0B57, 1},
+		{0x0B66, 0x0B6F, 1},
+		{0x0B82, 0x0B83, 1},
+		{0x0BBE, 0x0BC2, 1},
+		{0x0BC6, 0x0BC8, 1},
+		{0x0BCA, 0x0BCD, 1},
+		{0x0BD7, 0x0BD7, 1},
+		{0x0BE7, 0x0BEF, 1},
+		{0x0C01, 0x0C03, 1},
+		{0x0C3E, 0x0C44, 1},
+		{0x0C46, 0x0C48, 1},
+		{0x0C4A, 0x0C4D, 1},
+		{0x0C55, 0x0C56, 1},
+		{0x0C66, 0x0C6F, 1},
+		{0x0C82, 0x0C83, 1},
+		{0x0CBE, 0x0CC4, 1},
+		{0x0CC6, 0x0CC8, 1},
+		{0x0CCA, 0x0CCD, 1},
+		{0x0CD5, 0x0CD6, 1},
+		{0x0CE6, 0x0CEF, 1},
+		{0x0D02, 0x0D03, 1},
+		{0x0D3E, 0x0D43, 1},
+		{0x0D46, 0x0D48, 1},
+		{0x0D4A, 0x0D4D, 1},
+		{0x0D57, 0x0D57, 1},
+		{0x0D66, 0x0D6F, 1},
+		{0x0E31, 0x0E31, 1},
+		{0x0E34, 0x0E3A, 1},
+		{0x0E46, 0x0E46, 1},
+		{0x0E47, 0x0E4E, 1},
+		{0x0E50, 0x0E59, 1},
+		{0x0EB1, 0x0EB1, 1},
+		{0x0EB4, 0x0EB9, 1},
+		{0x0EBB, 0x0EBC, 1},
+		{0x0EC6, 0x0EC6, 1},
+		{0x0EC8, 0x0ECD, 1},
+		{0x0ED0, 0x0ED9, 1},
+		{0x0F18, 0x0F19, 1},
+		{0x0F20, 0x0F29, 1},
+		{0x0F35, 0x0F39, 2},
+		{0x0F3E, 0x0F3F, 1},
+		{0x0F71, 0x0F84, 1},
+		{0x0F86, 0x0F8B, 1},
+		{0x0F90, 0x0F95, 1},
+		{0x0F97, 0x0F97, 1},
+		{0x0F99, 0x0FAD, 1},
+		{0x0FB1, 0x0FB7, 1},
+		{0x0FB9, 0x0FB9, 1},
+		{0x20D0, 0x20DC, 1},
+		{0x20E1, 0x3005, 0x3005 - 0x20E1},
+		{0x302A, 0x302F, 1},
+		{0x3031, 0x3035, 1},
+		{0x3099, 0x309A, 1},
+		{0x309D, 0x309E, 1},
+		{0x30FC, 0x30FE, 1},
+	},
+}
+
+// HTMLEntity is an entity map containing translations for the
+// standard HTML entity characters.
+var HTMLEntity = htmlEntity
+
+var htmlEntity = map[string]string{
+	/*
+		hget http://www.w3.org/TR/html4/sgml/entities.html |
+		ssam '
+			,y /\&gt;/ x/\&lt;(.|\n)+/ s/\n/ /g
+			,x v/^\&lt;!ENTITY/d
+			,s/\&lt;!ENTITY ([^ ]+) .*U\+([0-9A-F][0-9A-F][0-9A-F][0-9A-F]) .+/	"\1": "\\u\2",/g
+		'
+	*/
+	"nbsp":     "\u00A0",
+	"iexcl":    "\u00A1",
+	"cent":     "\u00A2",
+	"pound":    "\u00A3",
+	"curren":   "\u00A4",
+	"yen":      "\u00A5",
+	"brvbar":   "\u00A6",
+	"sect":     "\u00A7",
+	"uml":      "\u00A8",
+	"copy":     "\u00A9",
+	"ordf":     "\u00AA",
+	"laquo":    "\u00AB",
+	"not":      "\u00AC",
+	"shy":      "\u00AD",
+	"reg":      "\u00AE",
+	"macr":     "\u00AF",
+	"deg":      "\u00B0",
+	"plusmn":   "\u00B1",
+	"sup2":     "\u00B2",
+	"sup3":     "\u00B3",
+	"acute":    "\u00B4",
+	"micro":    "\u00B5",
+	"para":     "\u00B6",
+	"middot":   "\u00B7",
+	"cedil":    "\u00B8",
+	"sup1":     "\u00B9",
+	"ordm":     "\u00BA",
+	"raquo":    "\u00BB",
+	"frac14":   "\u00BC",
+	"frac12":   "\u00BD",
+	"frac34":   "\u00BE",
+	"iquest":   "\u00BF",
+	"Agrave":   "\u00C0",
+	"Aacute":   "\u00C1",
+	"Acirc":    "\u00C2",
+	"Atilde":   "\u00C3",
+	"Auml":     "\u00C4",
+	"Aring":    "\u00C5",
+	"AElig":    "\u00C6",
+	"Ccedil":   "\u00C7",
+	"Egrave":   "\u00C8",
+	"Eacute":   "\u00C9",
+	"Ecirc":    "\u00CA",
+	"Euml":     "\u00CB",
+	"Igrave":   "\u00CC",
+	"Iacute":   "\u00CD",
+	"Icirc":    "\u00CE",
+	"Iuml":     "\u00CF",
+	"ETH":      "\u00D0",
+	"Ntilde":   "\u00D1",
+	"Ograve":   "\u00D2",
+	"Oacute":   "\u00D3",
+	"Ocirc":    "\u00D4",
+	"Otilde":   "\u00D5",
+	"Ouml":     "\u00D6",
+	"times":    "\u00D7",
+	"Oslash":   "\u00D8",
+	"Ugrave":   "\u00D9",
+	"Uacute":   "\u00DA",
+	"Ucirc":    "\u00DB",
+	"Uuml":     "\u00DC",
+	"Yacute":   "\u00DD",
+	"THORN":    "\u00DE",
+	"szlig":    "\u00DF",
+	"agrave":   "\u00E0",
+	"aacute":   "\u00E1",
+	"acirc":    "\u00E2",
+	"atilde":   "\u00E3",
+	"auml":     "\u00E4",
+	"aring":    "\u00E5",
+	"aelig":    "\u00E6",
+	"ccedil":   "\u00E7",
+	"egrave":   "\u00E8",
+	"eacute":   "\u00E9",
+	"ecirc":    "\u00EA",
+	"euml":     "\u00EB",
+	"igrave":   "\u00EC",
+	"iacute":   "\u00ED",
+	"icirc":    "\u00EE",
+	"iuml":     "\u00EF",
+	"eth":      "\u00F0",
+	"ntilde":   "\u00F1",
+	"ograve":   "\u00F2",
+	"oacute":   "\u00F3",
+	"ocirc":    "\u00F4",
+	"otilde":   "\u00F5",
+	"ouml":     "\u00F6",
+	"divide":   "\u00F7",
+	"oslash":   "\u00F8",
+	"ugrave":   "\u00F9",
+	"uacute":   "\u00FA",
+	"ucirc":    "\u00FB",
+	"uuml":     "\u00FC",
+	"yacute":   "\u00FD",
+	"thorn":    "\u00FE",
+	"yuml":     "\u00FF",
+	"fnof":     "\u0192",
+	"Alpha":    "\u0391",
+	"Beta":     "\u0392",
+	"Gamma":    "\u0393",
+	"Delta":    "\u0394",
+	"Epsilon":  "\u0395",
+	"Zeta":     "\u0396",
+	"Eta":      "\u0397",
+	"Theta":    "\u0398",
+	"Iota":     "\u0399",
+	"Kappa":    "\u039A",
+	"Lambda":   "\u039B",
+	"Mu":       "\u039C",
+	"Nu":       "\u039D",
+	"Xi":       "\u039E",
+	"Omicron":  "\u039F",
+	"Pi":       "\u03A0",
+	"Rho":      "\u03A1",
+	"Sigma":    "\u03A3",
+	"Tau":      "\u03A4",
+	"Upsilon":  "\u03A5",
+	"Phi":      "\u03A6",
+	"Chi":      "\u03A7",
+	"Psi":      "\u03A8",
+	"Omega":    "\u03A9",
+	"alpha":    "\u03B1",
+	"beta":     "\u03B2",
+	"gamma":    "\u03B3",
+	"delta":    "\u03B4",
+	"epsilon":  "\u03B5",
+	"zeta":     "\u03B6",
+	"eta":      "\u03B7",
+	"theta":    "\u03B8",
+	"iota":     "\u03B9",
+	"kappa":    "\u03BA",
+	"lambda":   "\u03BB",
+	"mu":       "\u03BC",
+	"nu":       "\u03BD",
+	"xi":       "\u03BE",
+	"omicron":  "\u03BF",
+	"pi":       "\u03C0",
+	"rho":      "\u03C1",
+	"sigmaf":   "\u03C2",
+	"sigma":    "\u03C3",
+	"tau":      "\u03C4",
+	"upsilon":  "\u03C5",
+	"phi":      "\u03C6",
+	"chi":      "\u03C7",
+	"psi":      "\u03C8",
+	"omega":    "\u03C9",
+	"thetasym": "\u03D1",
+	"upsih":    "\u03D2",
+	"piv":      "\u03D6",
+	"bull":     "\u2022",
+	"hellip":   "\u2026",
+	"prime":    "\u2032",
+	"Prime":    "\u2033",
+	"oline":    "\u203E",
+	"frasl":    "\u2044",
+	"weierp":   "\u2118",
+	"image":    "\u2111",
+	"real":     "\u211C",
+	"trade":    "\u2122",
+	"alefsym":  "\u2135",
+	"larr":     "\u2190",
+	"uarr":     "\u2191",
+	"rarr":     "\u2192",
+	"darr":     "\u2193",
+	"harr":     "\u2194",
+	"crarr":    "\u21B5",
+	"lArr":     "\u21D0",
+	"uArr":     "\u21D1",
+	"rArr":     "\u21D2",
+	"dArr":     "\u21D3",
+	"hArr":     "\u21D4",
+	"forall":   "\u2200",
+	"part":     "\u2202",
+	"exist":    "\u2203",
+	"empty":    "\u2205",
+	"nabla":    "\u2207",
+	"isin":     "\u2208",
+	"notin":    "\u2209",
+	"ni":       "\u220B",
+	"prod":     "\u220F",
+	"sum":      "\u2211",
+	"minus":    "\u2212",
+	"lowast":   "\u2217",
+	"radic":    "\u221A",
+	"prop":     "\u221D",
+	"infin":    "\u221E",
+	"ang":      "\u2220",
+	"and":      "\u2227",
+	"or":       "\u2228",
+	"cap":      "\u2229",
+	"cup":      "\u222A",
+	"int":      "\u222B",
+	"there4":   "\u2234",
+	"sim":      "\u223C",
+	"cong":     "\u2245",
+	"asymp":    "\u2248",
+	"ne":       "\u2260",
+	"equiv":    "\u2261",
+	"le":       "\u2264",
+	"ge":       "\u2265",
+	"sub":      "\u2282",
+	"sup":      "\u2283",
+	"nsub":     "\u2284",
+	"sube":     "\u2286",
+	"supe":     "\u2287",
+	"oplus":    "\u2295",
+	"otimes":   "\u2297",
+	"perp":     "\u22A5",
+	"sdot":     "\u22C5",
+	"lceil":    "\u2308",
+	"rceil":    "\u2309",
+	"lfloor":   "\u230A",
+	"rfloor":   "\u230B",
+	"lang":     "\u2329",
+	"rang":     "\u232A",
+	"loz":      "\u25CA",
+	"spades":   "\u2660",
+	"clubs":    "\u2663",
+	"hearts":   "\u2665",
+	"diams":    "\u2666",
+	"quot":     "\u0022",
+	"amp":      "\u0026",
+	"lt":       "\u003C",
+	"gt":       "\u003E",
+	"OElig":    "\u0152",
+	"oelig":    "\u0153",
+	"Scaron":   "\u0160",
+	"scaron":   "\u0161",
+	"Yuml":     "\u0178",
+	"circ":     "\u02C6",
+	"tilde":    "\u02DC",
+	"ensp":     "\u2002",
+	"emsp":     "\u2003",
+	"thinsp":   "\u2009",
+	"zwnj":     "\u200C",
+	"zwj":      "\u200D",
+	"lrm":      "\u200E",
+	"rlm":      "\u200F",
+	"ndash":    "\u2013",
+	"mdash":    "\u2014",
+	"lsquo":    "\u2018",
+	"rsquo":    "\u2019",
+	"sbquo":    "\u201A",
+	"ldquo":    "\u201C",
+	"rdquo":    "\u201D",
+	"bdquo":    "\u201E",
+	"dagger":   "\u2020",
+	"Dagger":   "\u2021",
+	"permil":   "\u2030",
+	"lsaquo":   "\u2039",
+	"rsaquo":   "\u203A",
+	"euro":     "\u20AC",
+}
+
+// HTMLAutoClose is the set of HTML elements that
+// should be considered to close automatically.
+var HTMLAutoClose = htmlAutoClose
+
+var htmlAutoClose = []string{
+	/*
+		hget http://www.w3.org/TR/html4/loose.dtd |
+		9 sed -n 's/<!ELEMENT ([^ ]*) +- O EMPTY.+/	"\1",/p' | tr A-Z a-z
+	*/
+	"basefont",
+	"br",
+	"area",
+	"link",
+	"img",
+	"param",
+	"hr",
+	"input",
+	"col",
+	"frame",
+	"isindex",
+	"base",
+	"meta",
+}
+
+var (
+	esc_quot = []byte("&#34;") // shorter than "&quot;"
+	esc_apos = []byte("&#39;") // shorter than "&apos;"
+	esc_amp  = []byte("&amp;")
+	esc_lt   = []byte("&lt;")
+	esc_gt   = []byte("&gt;")
+	esc_tab  = []byte("&#x9;")
+	esc_nl   = []byte("&#xA;")
+	esc_cr   = []byte("&#xD;")
+	esc_fffd = []byte("\uFFFD") // Unicode replacement character
+)
+
+// EscapeText writes to w the properly escaped XML equivalent
+// of the plain text data s.
+func EscapeText(w io.Writer, s []byte) error {
+	return escapeText(w, s, true)
+}
+
+// escapeText writes to w the properly escaped XML equivalent
+// of the plain text data s. If escapeNewline is true, newline
+// characters will be escaped.
+func escapeText(w io.Writer, s []byte, escapeNewline bool) error {
+	var esc []byte
+	last := 0
+	for i := 0; i < len(s); {
+		r, width := utf8.DecodeRune(s[i:])
+		i += width
+		switch r {
+		case '"':
+			esc = esc_quot
+		case '\'':
+			esc = esc_apos
+		case '&':
+			esc = esc_amp
+		case '<':
+			esc = esc_lt
+		case '>':
+			esc = esc_gt
+		case '\t':
+			esc = esc_tab
+		case '\n':
+			if !escapeNewline {
+				continue
+			}
+			esc = esc_nl
+		case '\r':
+			esc = esc_cr
+		default:
+			if !isInCharacterRange(r) || (r == 0xFFFD && width == 1) {
+				esc = esc_fffd
+				break
+			}
+			continue
+		}
+		if _, err := w.Write(s[last : i-width]); err != nil {
+			return err
+		}
+		if _, err := w.Write(esc); err != nil {
+			return err
+		}
+		last = i
+	}
+	if _, err := w.Write(s[last:]); err != nil {
+		return err
+	}
+	return nil
+}
+
+// EscapeString writes to p the properly escaped XML equivalent
+// of the plain text data s.
+func (p *printer) EscapeString(s string) {
+	var esc []byte
+	last := 0
+	for i := 0; i < len(s); {
+		r, width := utf8.DecodeRuneInString(s[i:])
+		i += width
+		switch r {
+		case '"':
+			esc = esc_quot
+		case '\'':
+			esc = esc_apos
+		case '&':
+			esc = esc_amp
+		case '<':
+			esc = esc_lt
+		case '>':
+			esc = esc_gt
+		case '\t':
+			esc = esc_tab
+		case '\n':
+			esc = esc_nl
+		case '\r':
+			esc = esc_cr
+		default:
+			if !isInCharacterRange(r) || (r == 0xFFFD && width == 1) {
+				esc = esc_fffd
+				break
+			}
+			continue
+		}
+		p.WriteString(s[last : i-width])
+		p.Write(esc)
+		last = i
+	}
+	p.WriteString(s[last:])
+}
+
+// Escape is like EscapeText but omits the error return value.
+// It is provided for backwards compatibility with Go 1.0.
+// Code targeting Go 1.1 or later should use EscapeText.
+func Escape(w io.Writer, s []byte) {
+	EscapeText(w, s)
+}
+
+// procInst parses the `param="..."` or `param='...'`
+// value out of the provided string, returning "" if not found.
+func procInst(param, s string) string {
+	// TODO: this parsing is somewhat lame and not exact.
+	// It works for all actual cases, though.
+	param = param + "="
+	idx := strings.Index(s, param)
+	if idx == -1 {
+		return ""
+	}
+	v := s[idx+len(param):]
+	if v == "" {
+		return ""
+	}
+	if v[0] != '\'' && v[0] != '"' {
+		return ""
+	}
+	idx = strings.IndexRune(v[1:], rune(v[0]))
+	if idx == -1 {
+		return ""
+	}
+	return v[1 : idx+1]
+}

webdav/internal/xml/xml_test.go

@@ -0,0 +1,752 @@
+// Copyright 2009 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.
+
+package xml
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+	"unicode/utf8"
+)
+
+const testInput = `
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<body xmlns:foo="ns1" xmlns="ns2" xmlns:tag="ns3" ` +
+	"\r\n\t" + `  >
+  <hello lang="en">World &lt;&gt;&apos;&quot; &#x767d;&#40300;翔</hello>
+  <query>&何; &is-it;</query>
+  <goodbye />
+  <outer foo:attr="value" xmlns:tag="ns4">
+    <inner/>
+  </outer>
+  <tag:name>
+    <![CDATA[Some text here.]]>
+  </tag:name>
+</body><!-- missing final newline -->`
+
+var testEntity = map[string]string{"何": "What", "is-it": "is it?"}
+
+var rawTokens = []Token{
+	CharData("\n"),
+	ProcInst{"xml", []byte(`version="1.0" encoding="UTF-8"`)},
+	CharData("\n"),
+	Directive(`DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"`),
+	CharData("\n"),
+	StartElement{Name{"", "body"}, []Attr{{Name{"xmlns", "foo"}, "ns1"}, {Name{"", "xmlns"}, "ns2"}, {Name{"xmlns", "tag"}, "ns3"}}},
+	CharData("\n  "),
+	StartElement{Name{"", "hello"}, []Attr{{Name{"", "lang"}, "en"}}},
+	CharData("World <>'\" 白鵬翔"),
+	EndElement{Name{"", "hello"}},
+	CharData("\n  "),
+	StartElement{Name{"", "query"}, []Attr{}},
+	CharData("What is it?"),
+	EndElement{Name{"", "query"}},
+	CharData("\n  "),
+	StartElement{Name{"", "goodbye"}, []Attr{}},
+	EndElement{Name{"", "goodbye"}},
+	CharData("\n  "),
+	StartElement{Name{"", "outer"}, []Attr{{Name{"foo", "attr"}, "value"}, {Name{"xmlns", "tag"}, "ns4"}}},
+	CharData("\n    "),
+	StartElement{Name{"", "inner"}, []Attr{}},
+	EndElement{Name{"", "inner"}},
+	CharData("\n  "),
+	EndElement{Name{"", "outer"}},
+	CharData("\n  "),
+	StartElement{Name{"tag", "name"}, []Attr{}},
+	CharData("\n    "),
+	CharData("Some text here."),
+	CharData("\n  "),
+	EndElement{Name{"tag", "name"}},
+	CharData("\n"),
+	EndElement{Name{"", "body"}},
+	Comment(" missing final newline "),
+}
+
+var cookedTokens = []Token{
+	CharData("\n"),
+	ProcInst{"xml", []byte(`version="1.0" encoding="UTF-8"`)},
+	CharData("\n"),
+	Directive(`DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"`),
+	CharData("\n"),
+	StartElement{Name{"ns2", "body"}, []Attr{{Name{"xmlns", "foo"}, "ns1"}, {Name{"", "xmlns"}, "ns2"}, {Name{"xmlns", "tag"}, "ns3"}}},
+	CharData("\n  "),
+	StartElement{Name{"ns2", "hello"}, []Attr{{Name{"", "lang"}, "en"}}},
+	CharData("World <>'\" 白鵬翔"),
+	EndElement{Name{"ns2", "hello"}},
+	CharData("\n  "),
+	StartElement{Name{"ns2", "query"}, []Attr{}},
+	CharData("What is it?"),
+	EndElement{Name{"ns2", "query"}},
+	CharData("\n  "),
+	StartElement{Name{"ns2", "goodbye"}, []Attr{}},
+	EndElement{Name{"ns2", "goodbye"}},
+	CharData("\n  "),
+	StartElement{Name{"ns2", "outer"}, []Attr{{Name{"ns1", "attr"}, "value"}, {Name{"xmlns", "tag"}, "ns4"}}},
+	CharData("\n    "),
+	StartElement{Name{"ns2", "inner"}, []Attr{}},
+	EndElement{Name{"ns2", "inner"}},
+	CharData("\n  "),
+	EndElement{Name{"ns2", "outer"}},
+	CharData("\n  "),
+	StartElement{Name{"ns3", "name"}, []Attr{}},
+	CharData("\n    "),
+	CharData("Some text here."),
+	CharData("\n  "),
+	EndElement{Name{"ns3", "name"}},
+	CharData("\n"),
+	EndElement{Name{"ns2", "body"}},
+	Comment(" missing final newline "),
+}
+
+const testInputAltEncoding = `
+<?xml version="1.0" encoding="x-testing-uppercase"?>
+<TAG>VALUE</TAG>`
+
+var rawTokensAltEncoding = []Token{
+	CharData("\n"),
+	ProcInst{"xml", []byte(`version="1.0" encoding="x-testing-uppercase"`)},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("value"),
+	EndElement{Name{"", "tag"}},
+}
+
+var xmlInput = []string{
+	// unexpected EOF cases
+	"<",
+	"<t",
+	"<t ",
+	"<t/",
+	"<!",
+	"<!-",
+	"<!--",
+	"<!--c-",
+	"<!--c--",
+	"<!d",
+	"<t></",
+	"<t></t",
+	"<?",
+	"<?p",
+	"<t a",
+	"<t a=",
+	"<t a='",
+	"<t a=''",
+	"<t/><![",
+	"<t/><![C",
+	"<t/><![CDATA[d",
+	"<t/><![CDATA[d]",
+	"<t/><![CDATA[d]]",
+
+	// other Syntax errors
+	"<>",
+	"<t/a",
+	"<0 />",
+	"<?0 >",
+	//	"<!0 >",	// let the Token() caller handle
+	"</0>",
+	"<t 0=''>",
+	"<t a='&'>",
+	"<t a='<'>",
+	"<t>&nbspc;</t>",
+	"<t a>",
+	"<t a=>",
+	"<t a=v>",
+	//	"<![CDATA[d]]>",	// let the Token() caller handle
+	"<t></e>",
+	"<t></>",
+	"<t></t!",
+	"<t>cdata]]></t>",
+}
+
+func TestRawToken(t *testing.T) {
+	d := NewDecoder(strings.NewReader(testInput))
+	d.Entity = testEntity
+	testRawToken(t, d, testInput, rawTokens)
+}
+
+const nonStrictInput = `
+<tag>non&entity</tag>
+<tag>&unknown;entity</tag>
+<tag>&#123</tag>
+<tag>&#zzz;</tag>
+<tag>&なまえ3;</tag>
+<tag>&lt-gt;</tag>
+<tag>&;</tag>
+<tag>&0a;</tag>
+`
+
+var nonStringEntity = map[string]string{"": "oops!", "0a": "oops!"}
+
+var nonStrictTokens = []Token{
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("non&entity"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("&unknown;entity"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("&#123"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("&#zzz;"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("&なまえ3;"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("&lt-gt;"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("&;"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+	StartElement{Name{"", "tag"}, []Attr{}},
+	CharData("&0a;"),
+	EndElement{Name{"", "tag"}},
+	CharData("\n"),
+}
+
+func TestNonStrictRawToken(t *testing.T) {
+	d := NewDecoder(strings.NewReader(nonStrictInput))
+	d.Strict = false
+	testRawToken(t, d, nonStrictInput, nonStrictTokens)
+}
+
+type downCaser struct {
+	t *testing.T
+	r io.ByteReader
+}
+
+func (d *downCaser) ReadByte() (c byte, err error) {
+	c, err = d.r.ReadByte()
+	if c >= 'A' && c <= 'Z' {
+		c += 'a' - 'A'
+	}
+	return
+}
+
+func (d *downCaser) Read(p []byte) (int, error) {
+	d.t.Fatalf("unexpected Read call on downCaser reader")
+	panic("unreachable")
+}
+
+func TestRawTokenAltEncoding(t *testing.T) {
+	d := NewDecoder(strings.NewReader(testInputAltEncoding))
+	d.CharsetReader = func(charset string, input io.Reader) (io.Reader, error) {
+		if charset != "x-testing-uppercase" {
+			t.Fatalf("unexpected charset %q", charset)
+		}
+		return &downCaser{t, input.(io.ByteReader)}, nil
+	}
+	testRawToken(t, d, testInputAltEncoding, rawTokensAltEncoding)
+}
+
+func TestRawTokenAltEncodingNoConverter(t *testing.T) {
+	d := NewDecoder(strings.NewReader(testInputAltEncoding))
+	token, err := d.RawToken()
+	if token == nil {
+		t.Fatalf("expected a token on first RawToken call")
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	token, err = d.RawToken()
+	if token != nil {
+		t.Errorf("expected a nil token; got %#v", token)
+	}
+	if err == nil {
+		t.Fatalf("expected an error on second RawToken call")
+	}
+	const encoding = "x-testing-uppercase"
+	if !strings.Contains(err.Error(), encoding) {
+		t.Errorf("expected error to contain %q; got error: %v",
+			encoding, err)
+	}
+}
+
+func testRawToken(t *testing.T, d *Decoder, raw string, rawTokens []Token) {
+	lastEnd := int64(0)
+	for i, want := range rawTokens {
+		start := d.InputOffset()
+		have, err := d.RawToken()
+		end := d.InputOffset()
+		if err != nil {
+			t.Fatalf("token %d: unexpected error: %s", i, err)
+		}
+		if !reflect.DeepEqual(have, want) {
+			var shave, swant string
+			if _, ok := have.(CharData); ok {
+				shave = fmt.Sprintf("CharData(%q)", have)
+			} else {
+				shave = fmt.Sprintf("%#v", have)
+			}
+			if _, ok := want.(CharData); ok {
+				swant = fmt.Sprintf("CharData(%q)", want)
+			} else {
+				swant = fmt.Sprintf("%#v", want)
+			}
+			t.Errorf("token %d = %s, want %s", i, shave, swant)
+		}
+
+		// Check that InputOffset returned actual token.
+		switch {
+		case start < lastEnd:
+			t.Errorf("token %d: position [%d,%d) for %T is before previous token", i, start, end, have)
+		case start >= end:
+			// Special case: EndElement can be synthesized.
+			if start == end && end == lastEnd {
+				break
+			}
+			t.Errorf("token %d: position [%d,%d) for %T is empty", i, start, end, have)
+		case end > int64(len(raw)):
+			t.Errorf("token %d: position [%d,%d) for %T extends beyond input", i, start, end, have)
+		default:
+			text := raw[start:end]
+			if strings.ContainsAny(text, "<>") && (!strings.HasPrefix(text, "<") || !strings.HasSuffix(text, ">")) {
+				t.Errorf("token %d: misaligned raw token %#q for %T", i, text, have)
+			}
+		}
+		lastEnd = end
+	}
+}
+
+// Ensure that directives (specifically !DOCTYPE) include the complete
+// text of any nested directives, noting that < and > do not change
+// nesting depth if they are in single or double quotes.
+
+var nestedDirectivesInput = `
+<!DOCTYPE [<!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#">]>
+<!DOCTYPE [<!ENTITY xlt ">">]>
+<!DOCTYPE [<!ENTITY xlt "<">]>
+<!DOCTYPE [<!ENTITY xlt '>'>]>
+<!DOCTYPE [<!ENTITY xlt '<'>]>
+<!DOCTYPE [<!ENTITY xlt '">'>]>
+<!DOCTYPE [<!ENTITY xlt "'<">]>
+`
+
+var nestedDirectivesTokens = []Token{
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#">]`),
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY xlt ">">]`),
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY xlt "<">]`),
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY xlt '>'>]`),
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY xlt '<'>]`),
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY xlt '">'>]`),
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY xlt "'<">]`),
+	CharData("\n"),
+}
+
+func TestNestedDirectives(t *testing.T) {
+	d := NewDecoder(strings.NewReader(nestedDirectivesInput))
+
+	for i, want := range nestedDirectivesTokens {
+		have, err := d.Token()
+		if err != nil {
+			t.Fatalf("token %d: unexpected error: %s", i, err)
+		}
+		if !reflect.DeepEqual(have, want) {
+			t.Errorf("token %d = %#v want %#v", i, have, want)
+		}
+	}
+}
+
+func TestToken(t *testing.T) {
+	d := NewDecoder(strings.NewReader(testInput))
+	d.Entity = testEntity
+
+	for i, want := range cookedTokens {
+		have, err := d.Token()
+		if err != nil {
+			t.Fatalf("token %d: unexpected error: %s", i, err)
+		}
+		if !reflect.DeepEqual(have, want) {
+			t.Errorf("token %d = %#v want %#v", i, have, want)
+		}
+	}
+}
+
+func TestSyntax(t *testing.T) {
+	for i := range xmlInput {
+		d := NewDecoder(strings.NewReader(xmlInput[i]))
+		var err error
+		for _, err = d.Token(); err == nil; _, err = d.Token() {
+		}
+		if _, ok := err.(*SyntaxError); !ok {
+			t.Fatalf(`xmlInput "%s": expected SyntaxError not received`, xmlInput[i])
+		}
+	}
+}
+
+type allScalars struct {
+	True1     bool
+	True2     bool
+	False1    bool
+	False2    bool
+	Int       int
+	Int8      int8
+	Int16     int16
+	Int32     int32
+	Int64     int64
+	Uint      int
+	Uint8     uint8
+	Uint16    uint16
+	Uint32    uint32
+	Uint64    uint64
+	Uintptr   uintptr
+	Float32   float32
+	Float64   float64
+	String    string
+	PtrString *string
+}
+
+var all = allScalars{
+	True1:     true,
+	True2:     true,
+	False1:    false,
+	False2:    false,
+	Int:       1,
+	Int8:      -2,
+	Int16:     3,
+	Int32:     -4,
+	Int64:     5,
+	Uint:      6,
+	Uint8:     7,
+	Uint16:    8,
+	Uint32:    9,
+	Uint64:    10,
+	Uintptr:   11,
+	Float32:   13.0,
+	Float64:   14.0,
+	String:    "15",
+	PtrString: &sixteen,
+}
+
+var sixteen = "16"
+
+const testScalarsInput = `<allscalars>
+	<True1>true</True1>
+	<True2>1</True2>
+	<False1>false</False1>
+	<False2>0</False2>
+	<Int>1</Int>
+	<Int8>-2</Int8>
+	<Int16>3</Int16>
+	<Int32>-4</Int32>
+	<Int64>5</Int64>
+	<Uint>6</Uint>
+	<Uint8>7</Uint8>
+	<Uint16>8</Uint16>
+	<Uint32>9</Uint32>
+	<Uint64>10</Uint64>
+	<Uintptr>11</Uintptr>
+	<Float>12.0</Float>
+	<Float32>13.0</Float32>
+	<Float64>14.0</Float64>
+	<String>15</String>
+	<PtrString>16</PtrString>
+</allscalars>`
+
+func TestAllScalars(t *testing.T) {
+	var a allScalars
+	err := Unmarshal([]byte(testScalarsInput), &a)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(a, all) {
+		t.Errorf("have %+v want %+v", a, all)
+	}
+}
+
+type item struct {
+	Field_a string
+}
+
+func TestIssue569(t *testing.T) {
+	data := `<item><Field_a>abcd</Field_a></item>`
+	var i item
+	err := Unmarshal([]byte(data), &i)
+
+	if err != nil || i.Field_a != "abcd" {
+		t.Fatal("Expecting abcd")
+	}
+}
+
+func TestUnquotedAttrs(t *testing.T) {
+	data := "<tag attr=azAZ09:-_\t>"
+	d := NewDecoder(strings.NewReader(data))
+	d.Strict = false
+	token, err := d.Token()
+	if _, ok := err.(*SyntaxError); ok {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if token.(StartElement).Name.Local != "tag" {
+		t.Errorf("Unexpected tag name: %v", token.(StartElement).Name.Local)
+	}
+	attr := token.(StartElement).Attr[0]
+	if attr.Value != "azAZ09:-_" {
+		t.Errorf("Unexpected attribute value: %v", attr.Value)
+	}
+	if attr.Name.Local != "attr" {
+		t.Errorf("Unexpected attribute name: %v", attr.Name.Local)
+	}
+}
+
+func TestValuelessAttrs(t *testing.T) {
+	tests := [][3]string{
+		{"<p nowrap>", "p", "nowrap"},
+		{"<p nowrap >", "p", "nowrap"},
+		{"<input checked/>", "input", "checked"},
+		{"<input checked />", "input", "checked"},
+	}
+	for _, test := range tests {
+		d := NewDecoder(strings.NewReader(test[0]))
+		d.Strict = false
+		token, err := d.Token()
+		if _, ok := err.(*SyntaxError); ok {
+			t.Errorf("Unexpected error: %v", err)
+		}
+		if token.(StartElement).Name.Local != test[1] {
+			t.Errorf("Unexpected tag name: %v", token.(StartElement).Name.Local)
+		}
+		attr := token.(StartElement).Attr[0]
+		if attr.Value != test[2] {
+			t.Errorf("Unexpected attribute value: %v", attr.Value)
+		}
+		if attr.Name.Local != test[2] {
+			t.Errorf("Unexpected attribute name: %v", attr.Name.Local)
+		}
+	}
+}
+
+func TestCopyTokenCharData(t *testing.T) {
+	data := []byte("same data")
+	var tok1 Token = CharData(data)
+	tok2 := CopyToken(tok1)
+	if !reflect.DeepEqual(tok1, tok2) {
+		t.Error("CopyToken(CharData) != CharData")
+	}
+	data[1] = 'o'
+	if reflect.DeepEqual(tok1, tok2) {
+		t.Error("CopyToken(CharData) uses same buffer.")
+	}
+}
+
+func TestCopyTokenStartElement(t *testing.T) {
+	elt := StartElement{Name{"", "hello"}, []Attr{{Name{"", "lang"}, "en"}}}
+	var tok1 Token = elt
+	tok2 := CopyToken(tok1)
+	if tok1.(StartElement).Attr[0].Value != "en" {
+		t.Error("CopyToken overwrote Attr[0]")
+	}
+	if !reflect.DeepEqual(tok1, tok2) {
+		t.Error("CopyToken(StartElement) != StartElement")
+	}
+	tok1.(StartElement).Attr[0] = Attr{Name{"", "lang"}, "de"}
+	if reflect.DeepEqual(tok1, tok2) {
+		t.Error("CopyToken(CharData) uses same buffer.")
+	}
+}
+
+func TestSyntaxErrorLineNum(t *testing.T) {
+	testInput := "<P>Foo<P>\n\n<P>Bar</>\n"
+	d := NewDecoder(strings.NewReader(testInput))
+	var err error
+	for _, err = d.Token(); err == nil; _, err = d.Token() {
+	}
+	synerr, ok := err.(*SyntaxError)
+	if !ok {
+		t.Error("Expected SyntaxError.")
+	}
+	if synerr.Line != 3 {
+		t.Error("SyntaxError didn't have correct line number.")
+	}
+}
+
+func TestTrailingRawToken(t *testing.T) {
+	input := `<FOO></FOO>  `
+	d := NewDecoder(strings.NewReader(input))
+	var err error
+	for _, err = d.RawToken(); err == nil; _, err = d.RawToken() {
+	}
+	if err != io.EOF {
+		t.Fatalf("d.RawToken() = _, %v, want _, io.EOF", err)
+	}
+}
+
+func TestTrailingToken(t *testing.T) {
+	input := `<FOO></FOO>  `
+	d := NewDecoder(strings.NewReader(input))
+	var err error
+	for _, err = d.Token(); err == nil; _, err = d.Token() {
+	}
+	if err != io.EOF {
+		t.Fatalf("d.Token() = _, %v, want _, io.EOF", err)
+	}
+}
+
+func TestEntityInsideCDATA(t *testing.T) {
+	input := `<test><![CDATA[ &val=foo ]]></test>`
+	d := NewDecoder(strings.NewReader(input))
+	var err error
+	for _, err = d.Token(); err == nil; _, err = d.Token() {
+	}
+	if err != io.EOF {
+		t.Fatalf("d.Token() = _, %v, want _, io.EOF", err)
+	}
+}
+
+var characterTests = []struct {
+	in  string
+	err string
+}{
+	{"\x12<doc/>", "illegal character code U+0012"},
+	{"<?xml version=\"1.0\"?>\x0b<doc/>", "illegal character code U+000B"},
+	{"\xef\xbf\xbe<doc/>", "illegal character code U+FFFE"},
+	{"<?xml version=\"1.0\"?><doc>\r\n<hiya/>\x07<toots/></doc>", "illegal character code U+0007"},
+	{"<?xml version=\"1.0\"?><doc \x12='value'>what's up</doc>", "expected attribute name in element"},
+	{"<doc>&abc\x01;</doc>", "invalid character entity &abc (no semicolon)"},
+	{"<doc>&\x01;</doc>", "invalid character entity & (no semicolon)"},
+	{"<doc>&\xef\xbf\xbe;</doc>", "invalid character entity &\uFFFE;"},
+	{"<doc>&hello;</doc>", "invalid character entity &hello;"},
+}
+
+func TestDisallowedCharacters(t *testing.T) {
+
+	for i, tt := range characterTests {
+		d := NewDecoder(strings.NewReader(tt.in))
+		var err error
+
+		for err == nil {
+			_, err = d.Token()
+		}
+		synerr, ok := err.(*SyntaxError)
+		if !ok {
+			t.Fatalf("input %d d.Token() = _, %v, want _, *SyntaxError", i, err)
+		}
+		if synerr.Msg != tt.err {
+			t.Fatalf("input %d synerr.Msg wrong: want %q, got %q", i, tt.err, synerr.Msg)
+		}
+	}
+}
+
+type procInstEncodingTest struct {
+	expect, got string
+}
+
+var procInstTests = []struct {
+	input  string
+	expect [2]string
+}{
+	{`version="1.0" encoding="utf-8"`, [2]string{"1.0", "utf-8"}},
+	{`version="1.0" encoding='utf-8'`, [2]string{"1.0", "utf-8"}},
+	{`version="1.0" encoding='utf-8' `, [2]string{"1.0", "utf-8"}},
+	{`version="1.0" encoding=utf-8`, [2]string{"1.0", ""}},
+	{`encoding="FOO" `, [2]string{"", "FOO"}},
+}
+
+func TestProcInstEncoding(t *testing.T) {
+	for _, test := range procInstTests {
+		if got := procInst("version", test.input); got != test.expect[0] {
+			t.Errorf("procInst(version, %q) = %q; want %q", test.input, got, test.expect[0])
+		}
+		if got := procInst("encoding", test.input); got != test.expect[1] {
+			t.Errorf("procInst(encoding, %q) = %q; want %q", test.input, got, test.expect[1])
+		}
+	}
+}
+
+// Ensure that directives with comments include the complete
+// text of any nested directives.
+
+var directivesWithCommentsInput = `
+<!DOCTYPE [<!-- a comment --><!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#">]>
+<!DOCTYPE [<!ENTITY go "Golang"><!-- a comment-->]>
+<!DOCTYPE <!-> <!> <!----> <!-->--> <!--->--> [<!ENTITY go "Golang"><!-- a comment-->]>
+`
+
+var directivesWithCommentsTokens = []Token{
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#">]`),
+	CharData("\n"),
+	Directive(`DOCTYPE [<!ENTITY go "Golang">]`),
+	CharData("\n"),
+	Directive(`DOCTYPE <!-> <!>    [<!ENTITY go "Golang">]`),
+	CharData("\n"),
+}
+
+func TestDirectivesWithComments(t *testing.T) {
+	d := NewDecoder(strings.NewReader(directivesWithCommentsInput))
+
+	for i, want := range directivesWithCommentsTokens {
+		have, err := d.Token()
+		if err != nil {
+			t.Fatalf("token %d: unexpected error: %s", i, err)
+		}
+		if !reflect.DeepEqual(have, want) {
+			t.Errorf("token %d = %#v want %#v", i, have, want)
+		}
+	}
+}
+
+// Writer whose Write method always returns an error.
+type errWriter struct{}
+
+func (errWriter) Write(p []byte) (n int, err error) { return 0, fmt.Errorf("unwritable") }
+
+func TestEscapeTextIOErrors(t *testing.T) {
+	expectErr := "unwritable"
+	err := EscapeText(errWriter{}, []byte{'A'})
+
+	if err == nil || err.Error() != expectErr {
+		t.Errorf("have %v, want %v", err, expectErr)
+	}
+}
+
+func TestEscapeTextInvalidChar(t *testing.T) {
+	input := []byte("A \x00 terminated string.")
+	expected := "A \uFFFD terminated string."
+
+	buff := new(bytes.Buffer)
+	if err := EscapeText(buff, input); err != nil {
+		t.Fatalf("have %v, want nil", err)
+	}
+	text := buff.String()
+
+	if text != expected {
+		t.Errorf("have %v, want %v", text, expected)
+	}
+}
+
+func TestIssue5880(t *testing.T) {
+	type T []byte
+	data, err := Marshal(T{192, 168, 0, 1})
+	if err != nil {
+		t.Errorf("Marshal error: %v", err)
+	}
+	if !utf8.Valid(data) {
+		t.Errorf("Marshal generated invalid UTF-8: %x", data)
+	}
+}

webdav/prop.go

@@ -5,7 +5,6 @@
 package webdav
 
 import (
-	"encoding/xml"
 	"fmt"
 	"io"
 	"mime"
@@ -13,6 +12,8 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+
+	"golang.org/x/net/webdav/internal/xml"
 )
 
 // Proppatch describes a property update instruction as defined in RFC 4918.

webdav/prop_test.go

@@ -5,13 +5,14 @@
 package webdav
 
 import (
-	"encoding/xml"
 	"fmt"
 	"net/http"
 	"os"
 	"reflect"
 	"sort"
 	"testing"
+
+	"golang.org/x/net/webdav/internal/xml"
 )
 
 func TestMemPS(t *testing.T) {

webdav/xml.go

@@ -9,11 +9,12 @@ package webdav
 
 import (
 	"bytes"
-	"encoding/xml"
 	"fmt"
 	"io"
 	"net/http"
 	"time"
+
+	"golang.org/x/net/webdav/internal/xml"
 )
 
 // http://www.webdav.org/specs/rfc4918.html#ELEMENT_lockinfo

webdav/xml_test.go

@@ -6,7 +6,6 @@ package webdav
 
 import (
 	"bytes"
-	"encoding/xml"
 	"fmt"
 	"io"
 	"net/http"
@@ -15,6 +14,8 @@ import (
 	"sort"
 	"strings"
 	"testing"
+
+	"golang.org/x/net/webdav/internal/xml"
 )
 
 func TestReadLockInfo(t *testing.T) {