Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2060 insertions, 0 deletions

diff --git a/src/encoding/xml/xml.go b/src/encoding/xml/xml.go
new file mode 100644
index 0000000..d121986
--- /dev/null
+++ b/src/encoding/xml/xml.go
@@ -0,0 +1,2060 @@
+// 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: https://www.xml.com/axml/testaxml.htm
+//    XML name spaces: https://www.w3.org/TR/REC-xml-names/
+
+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.
+type Name struct {
+	Space, Local string
+}
+
+// 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 any
+
+// A StartElement represents an XML start element.
+type StartElement struct {
+	Name Name
+	Attr []Attr
+}
+
+// Copy creates a new copy of StartElement.
+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}
+}
+
+// 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+// in which XML escape sequences have been replaced by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
+
+// Copy creates a new copy of CharData.
+func (c CharData) Copy() CharData { return CharData(bytes.Clone(c)) }
+
+// A Comment represents an XML comment of the form <!--comment-->.
+// The bytes do not include the <!-- and --> comment markers.
+type Comment []byte
+
+// Copy creates a new copy of Comment.
+func (c Comment) Copy() Comment { return Comment(bytes.Clone(c)) }
+
+// A ProcInst represents an XML processing instruction of the form <?target inst?>
+type ProcInst struct {
+	Target string
+	Inst   []byte
+}
+
+// Copy creates a new copy of ProcInst.
+func (p ProcInst) Copy() ProcInst {
+	p.Inst = bytes.Clone(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
+
+// Copy creates a new copy of Directive.
+func (d Directive) Copy() Directive { return Directive(bytes.Clone(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 TokenReader is anything that can decode a stream of XML tokens, including a
+// Decoder.
+//
+// When Token encounters an error or end-of-file condition after successfully
+// reading a token, it returns the token. It may return the (non-nil) error from
+// the same call or return the error (and a nil token) from a subsequent call.
+// An instance of this general case is that a TokenReader returning a non-nil
+// token at the end of the token stream may return either io.EOF or a nil error.
+// The next Read should return nil, io.EOF.
+//
+// Implementations of Token are discouraged from returning a nil token with a
+// nil error. Callers should treat a return of nil, nil as indicating that
+// nothing happened; in particular it does not indicate EOF.
+type TokenReader interface {
+	Token() (Token, error)
+}
+
+// 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 = xml.HTMLAutoClose
+	//	d.Entity = xml.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
+	// 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
+	t              TokenReader
+	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
+	linestart      int64
+	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
+}
+
+// NewTokenDecoder creates a new XML parser using an underlying token stream.
+func NewTokenDecoder(t TokenReader) *Decoder {
+	// Is it already a Decoder?
+	if d, ok := t.(*Decoder); ok {
+		return d
+	}
+	d := &Decoder{
+		ns:       make(map[string]string),
+		t:        t,
+		nextByte: -1,
+		line:     1,
+		Strict:   true,
+	}
+	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
+// or EOF before all expected end elements,
+// it will return an error.
+//
+// If CharsetReader is called and returns an error,
+// the error is wrapped and returned.
+//
+// Token implements XML name spaces as described by
+// https://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() (Token, error) {
+	var t Token
+	var err error
+	if d.stk != nil && d.stk.kind == stkEOF {
+		return nil, io.EOF
+	}
+	if d.nextToken != nil {
+		t = d.nextToken
+		d.nextToken = nil
+	} else {
+		if t, err = d.rawToken(); t == nil && err != nil {
+			if err == io.EOF && d.stk != nil && d.stk.kind != stkEOF {
+				err = d.syntaxError("unexpected EOF")
+			}
+			return nil, err
+		}
+		// We still have a token to process, so clear any
+		// errors (e.g. EOF) and proceed.
+		err = nil
+	}
+	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 == xmlnsPrefix {
+				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 == xmlnsPrefix {
+				// Default space for untagged names
+				v, ok := d.ns[""]
+				d.pushNs("", v, ok)
+				d.ns[""] = a.Value
+			}
+		}
+
+		d.pushElement(t1.Name)
+		d.translate(&t1.Name, true)
+		for i := range t1.Attr {
+			d.translate(&t1.Attr[i].Name, false)
+		}
+		t = t1
+
+	case EndElement:
+		if !d.popElement(&t1) {
+			return nil, d.err
+		}
+		t = t1
+	}
+	return t, err
+}
+
+const (
+	xmlURL      = "http://www.w3.org/XML/1998/namespace"
+	xmlnsPrefix = "xmlns"
+	xmlPrefix   = "xml"
+)
+
+// 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 == xmlnsPrefix:
+		return
+	case n.Space == "" && !isElementName:
+		return
+	case n.Space == xmlPrefix:
+		n.Space = xmlURL
+	case n.Space == "" && n.Local == xmlnsPrefix:
+		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
+	}
+
+	d.translate(&t.Name, true)
+
+	// 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
+	}
+	for _, s := range d.AutoClose {
+		if strings.EqualFold(s, d.stk.name.Local) {
+			// This one should be auto closed if t doesn't close it.
+			et, ok := t.(EndElement)
+			if !ok || !strings.EqualFold(et.Name.Local, d.stk.name.Local) {
+				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.t != nil {
+		return d.t.Token()
+	}
+	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" && !strings.EqualFold(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: %w", 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 == '-' {
+					if b != '>' {
+						d.err = d.syntaxError(
+							`invalid sequence "--" not allowed in comments`)
+						return nil, d.err
+					}
+					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
+				}
+
+				// Replace the comment with a space in the returned Directive
+				// body, so that markup parts that were separated by the comment
+				// (like a "<" and a "!") don't get joined when re-encoding the
+				// Directive, taking new semantic meaning.
+				d.buf.WriteByte(' ')
+			}
+		}
+		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)
+
+		a := Attr{}
+		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
+			}
+			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)
+		}
+		attr = append(attr, a)
+	}
+	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
+		}
+		// https://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.linestart = d.offset + 1
+	}
+	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
+}
+
+// InputPos returns the line of the current decoder position and the 1 based
+// input position of the line. The position gives the location of the end of the
+// most recently returned token.
+func (d *Decoder) InputPos() (line, column int) {
+	return d.line, int(d.offset-d.linestart) + 1
+}
+
+// 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]rune{
+	"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(rune(n))
+						haveText = true
+					}
+				}
+			} else {
+				d.ungetc(b)
+				if !d.readName() {
+					if d.err != nil {
+						return nil
+					}
+				}
+				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.WriteString(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 https://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 <= 0xD7FF ||
+		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
+	}
+	if strings.Count(s, ":") > 1 {
+		return name, false
+	} else if space, local, ok := strings.Cut(s, ":"); !ok || space == "" || local == "" {
+		name.Local = s
+	} else {
+		name.Space = space
+		name.Local = local
+	}
+	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 https://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.
+//
+// See the Decoder.Strict and Decoder.Entity fields' documentation.
+var HTMLEntity map[string]string = 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.
+//
+// See the Decoder.Strict and Decoder.Entity fields' documentation.
+var HTMLAutoClose []string = 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 (
+	escQuot = []byte("&#34;") // shorter than "&quot;"
+	escApos = []byte("&#39;") // shorter than "&apos;"
+	escAmp  = []byte("&amp;")
+	escLT   = []byte("&lt;")
+	escGT   = []byte("&gt;")
+	escTab  = []byte("&#x9;")
+	escNL   = []byte("&#xA;")
+	escCR   = []byte("&#xD;")
+	escFFFD = []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 = escQuot
+		case '\'':
+			esc = escApos
+		case '&':
+			esc = escAmp
+		case '<':
+			esc = escLT
+		case '>':
+			esc = escGT
+		case '\t':
+			esc = escTab
+		case '\n':
+			if !escapeNewline {
+				continue
+			}
+			esc = escNL
+		case '\r':
+			esc = escCR
+		default:
+			if !isInCharacterRange(r) || (r == 0xFFFD && width == 1) {
+				esc = escFFFD
+				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
+	}
+	_, err := w.Write(s[last:])
+	return err
+}
+
+// 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 = escQuot
+		case '\'':
+			esc = escApos
+		case '&':
+			esc = escAmp
+		case '<':
+			esc = escLT
+		case '>':
+			esc = escGT
+		case '\t':
+			esc = escTab
+		case '\n':
+			esc = escNL
+		case '\r':
+			esc = escCR
+		default:
+			if !isInCharacterRange(r) || (r == 0xFFFD && width == 1) {
+				esc = escFFFD
+				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)
+}
+
+var (
+	cdataStart  = []byte("<![CDATA[")
+	cdataEnd    = []byte("]]>")
+	cdataEscape = []byte("]]]]><![CDATA[>")
+)
+
+// emitCDATA writes to w the CDATA-wrapped plain text data s.
+// It escapes CDATA directives nested in s.
+func emitCDATA(w io.Writer, s []byte) error {
+	if len(s) == 0 {
+		return nil
+	}
+	if _, err := w.Write(cdataStart); err != nil {
+		return err
+	}
+
+	for {
+		before, after, ok := bytes.Cut(s, cdataEnd)
+		if !ok {
+			break
+		}
+		// Found a nested CDATA directive end.
+		if _, err := w.Write(before); err != nil {
+			return err
+		}
+		if _, err := w.Write(cdataEscape); err != nil {
+			return err
+		}
+		s = after
+	}
+
+	if _, err := w.Write(s); err != nil {
+		return err
+	}
+
+	_, err := w.Write(cdataEnd)
+	return err
+}
+
+// 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 + "="
+	_, v, _ := strings.Cut(s, param)
+	if v == "" {
+		return ""
+	}
+	if v[0] != '\'' && v[0] != '"' {
+		return ""
+	}
+	unquote, _, ok := strings.Cut(v[1:], v[:1])
+	if !ok {
+		return ""
+	}
+	return unquote
+}