Adding upstream version 9.0.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>

4 files changed, 729 insertions, 0 deletions

diff --git a/modules/markup/common/footnote.go b/modules/markup/common/footnote.go
new file mode 100644
index 0000000..0e75e2a
--- /dev/null
+++ b/modules/markup/common/footnote.go
@@ -0,0 +1,498 @@
+// Copyright 2019 Yusuke Inuzuka
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+// Most of what follows is a subtly changed version of github.com/yuin/goldmark/extension/footnote.go
+
+package common
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+	"unicode"
+
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+// CleanValue will clean a value to make it safe to be an id
+// This function is quite different from the original goldmark function
+// and more closely matches the output from the shurcooL sanitizer
+// In particular Unicode letters and numbers are a lot more than a-zA-Z0-9...
+func CleanValue(value []byte) []byte {
+	value = bytes.TrimSpace(value)
+	rs := bytes.Runes(value)
+	result := make([]rune, 0, len(rs))
+	needsDash := false
+	for _, r := range rs {
+		switch {
+		case unicode.IsLetter(r) || unicode.IsNumber(r) || r == '_':
+			if needsDash && len(result) > 0 {
+				result = append(result, '-')
+			}
+			needsDash = false
+			result = append(result, unicode.ToLower(r))
+		default:
+			needsDash = true
+		}
+	}
+	return []byte(string(result))
+}
+
+// Most of what follows is a subtly changed version of github.com/yuin/goldmark/extension/footnote.go
+
+// A FootnoteLink struct represents a link to a footnote of Markdown
+// (PHP Markdown Extra) text.
+type FootnoteLink struct {
+	ast.BaseInline
+	Index int
+	Name  []byte
+}
+
+// Dump implements Node.Dump.
+func (n *FootnoteLink) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["Index"] = fmt.Sprintf("%v", n.Index)
+	m["Name"] = fmt.Sprintf("%v", n.Name)
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// KindFootnoteLink is a NodeKind of the FootnoteLink node.
+var KindFootnoteLink = ast.NewNodeKind("GiteaFootnoteLink")
+
+// Kind implements Node.Kind.
+func (n *FootnoteLink) Kind() ast.NodeKind {
+	return KindFootnoteLink
+}
+
+// NewFootnoteLink returns a new FootnoteLink node.
+func NewFootnoteLink(index int, name []byte) *FootnoteLink {
+	return &FootnoteLink{
+		Index: index,
+		Name:  name,
+	}
+}
+
+// A FootnoteBackLink struct represents a link to a footnote of Markdown
+// (PHP Markdown Extra) text.
+type FootnoteBackLink struct {
+	ast.BaseInline
+	Index int
+	Name  []byte
+}
+
+// Dump implements Node.Dump.
+func (n *FootnoteBackLink) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["Index"] = fmt.Sprintf("%v", n.Index)
+	m["Name"] = fmt.Sprintf("%v", n.Name)
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// KindFootnoteBackLink is a NodeKind of the FootnoteBackLink node.
+var KindFootnoteBackLink = ast.NewNodeKind("GiteaFootnoteBackLink")
+
+// Kind implements Node.Kind.
+func (n *FootnoteBackLink) Kind() ast.NodeKind {
+	return KindFootnoteBackLink
+}
+
+// NewFootnoteBackLink returns a new FootnoteBackLink node.
+func NewFootnoteBackLink(index int, name []byte) *FootnoteBackLink {
+	return &FootnoteBackLink{
+		Index: index,
+		Name:  name,
+	}
+}
+
+// A Footnote struct represents a footnote of Markdown
+// (PHP Markdown Extra) text.
+type Footnote struct {
+	ast.BaseBlock
+	Ref   []byte
+	Index int
+	Name  []byte
+}
+
+// Dump implements Node.Dump.
+func (n *Footnote) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["Index"] = strconv.Itoa(n.Index)
+	m["Ref"] = string(n.Ref)
+	m["Name"] = string(n.Name)
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// KindFootnote is a NodeKind of the Footnote node.
+var KindFootnote = ast.NewNodeKind("GiteaFootnote")
+
+// Kind implements Node.Kind.
+func (n *Footnote) Kind() ast.NodeKind {
+	return KindFootnote
+}
+
+// NewFootnote returns a new Footnote node.
+func NewFootnote(ref []byte) *Footnote {
+	return &Footnote{
+		Ref:   ref,
+		Index: -1,
+		Name:  ref,
+	}
+}
+
+// A FootnoteList struct represents footnotes of Markdown
+// (PHP Markdown Extra) text.
+type FootnoteList struct {
+	ast.BaseBlock
+	Count int
+}
+
+// Dump implements Node.Dump.
+func (n *FootnoteList) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["Count"] = fmt.Sprintf("%v", n.Count)
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// KindFootnoteList is a NodeKind of the FootnoteList node.
+var KindFootnoteList = ast.NewNodeKind("GiteaFootnoteList")
+
+// Kind implements Node.Kind.
+func (n *FootnoteList) Kind() ast.NodeKind {
+	return KindFootnoteList
+}
+
+// NewFootnoteList returns a new FootnoteList node.
+func NewFootnoteList() *FootnoteList {
+	return &FootnoteList{
+		Count: 0,
+	}
+}
+
+var footnoteListKey = parser.NewContextKey()
+
+type footnoteBlockParser struct{}
+
+var defaultFootnoteBlockParser = &footnoteBlockParser{}
+
+// NewFootnoteBlockParser returns a new parser.BlockParser that can parse
+// footnotes of the Markdown(PHP Markdown Extra) text.
+func NewFootnoteBlockParser() parser.BlockParser {
+	return defaultFootnoteBlockParser
+}
+
+func (b *footnoteBlockParser) Trigger() []byte {
+	return []byte{'['}
+}
+
+func (b *footnoteBlockParser) Open(parent ast.Node, reader text.Reader, pc parser.Context) (ast.Node, parser.State) {
+	line, segment := reader.PeekLine()
+	pos := pc.BlockOffset()
+	if pos < 0 || line[pos] != '[' {
+		return nil, parser.NoChildren
+	}
+	pos++
+	if pos > len(line)-1 || line[pos] != '^' {
+		return nil, parser.NoChildren
+	}
+	open := pos + 1
+	closure := util.FindClosure(line[pos+1:], '[', ']', false, false) //nolint
+	closes := pos + 1 + closure
+	next := closes + 1
+	if closure > -1 {
+		if next >= len(line) || line[next] != ':' {
+			return nil, parser.NoChildren
+		}
+	} else {
+		return nil, parser.NoChildren
+	}
+	padding := segment.Padding
+	label := reader.Value(text.NewSegment(segment.Start+open-padding, segment.Start+closes-padding))
+	if util.IsBlank(label) {
+		return nil, parser.NoChildren
+	}
+	item := NewFootnote(label)
+
+	pos = next + 1 - padding
+	if pos >= len(line) {
+		reader.Advance(pos)
+		return item, parser.NoChildren
+	}
+	reader.AdvanceAndSetPadding(pos, padding)
+	return item, parser.HasChildren
+}
+
+func (b *footnoteBlockParser) Continue(node ast.Node, reader text.Reader, pc parser.Context) parser.State {
+	line, _ := reader.PeekLine()
+	if util.IsBlank(line) {
+		return parser.Continue | parser.HasChildren
+	}
+	childpos, padding := util.IndentPosition(line, reader.LineOffset(), 4)
+	if childpos < 0 {
+		return parser.Close
+	}
+	reader.AdvanceAndSetPadding(childpos, padding)
+	return parser.Continue | parser.HasChildren
+}
+
+func (b *footnoteBlockParser) Close(node ast.Node, reader text.Reader, pc parser.Context) {
+	var list *FootnoteList
+	if tlist := pc.Get(footnoteListKey); tlist != nil {
+		list = tlist.(*FootnoteList)
+	} else {
+		list = NewFootnoteList()
+		pc.Set(footnoteListKey, list)
+		node.Parent().InsertBefore(node.Parent(), node, list)
+	}
+	node.Parent().RemoveChild(node.Parent(), node)
+	list.AppendChild(list, node)
+}
+
+func (b *footnoteBlockParser) CanInterruptParagraph() bool {
+	return true
+}
+
+func (b *footnoteBlockParser) CanAcceptIndentedLine() bool {
+	return false
+}
+
+type footnoteParser struct{}
+
+var defaultFootnoteParser = &footnoteParser{}
+
+// NewFootnoteParser returns a new parser.InlineParser that can parse
+// footnote links of the Markdown(PHP Markdown Extra) text.
+func NewFootnoteParser() parser.InlineParser {
+	return defaultFootnoteParser
+}
+
+func (s *footnoteParser) Trigger() []byte {
+	// footnote syntax probably conflict with the image syntax.
+	// So we need trigger this parser with '!'.
+	return []byte{'!', '['}
+}
+
+func (s *footnoteParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
+	line, segment := block.PeekLine()
+	pos := 1
+	if len(line) > 0 && line[0] == '!' {
+		pos++
+	}
+	if pos >= len(line) || line[pos] != '^' {
+		return nil
+	}
+	pos++
+	if pos >= len(line) {
+		return nil
+	}
+	open := pos
+	closure := util.FindClosure(line[pos:], '[', ']', false, false) //nolint
+	if closure < 0 {
+		return nil
+	}
+	closes := pos + closure
+	value := block.Value(text.NewSegment(segment.Start+open, segment.Start+closes))
+	block.Advance(closes + 1)
+
+	var list *FootnoteList
+	if tlist := pc.Get(footnoteListKey); tlist != nil {
+		list = tlist.(*FootnoteList)
+	}
+	if list == nil {
+		return nil
+	}
+	index := 0
+	name := []byte{}
+	for def := list.FirstChild(); def != nil; def = def.NextSibling() {
+		d := def.(*Footnote)
+		if bytes.Equal(d.Ref, value) {
+			if d.Index < 0 {
+				list.Count++
+				d.Index = list.Count
+				val := CleanValue(d.Name)
+				if len(val) == 0 {
+					val = []byte(strconv.Itoa(d.Index))
+				}
+				d.Name = pc.IDs().Generate(val, KindFootnote)
+			}
+			index = d.Index
+			name = d.Name
+			break
+		}
+	}
+	if index == 0 {
+		return nil
+	}
+
+	return NewFootnoteLink(index, name)
+}
+
+type footnoteASTTransformer struct{}
+
+var defaultFootnoteASTTransformer = &footnoteASTTransformer{}
+
+// NewFootnoteASTTransformer returns a new parser.ASTTransformer that
+// insert a footnote list to the last of the document.
+func NewFootnoteASTTransformer() parser.ASTTransformer {
+	return defaultFootnoteASTTransformer
+}
+
+func (a *footnoteASTTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
+	var list *FootnoteList
+	if tlist := pc.Get(footnoteListKey); tlist != nil {
+		list = tlist.(*FootnoteList)
+	} else {
+		return
+	}
+	pc.Set(footnoteListKey, nil)
+	for footnote := list.FirstChild(); footnote != nil; {
+		container := footnote
+		next := footnote.NextSibling()
+		if fc := container.LastChild(); fc != nil && ast.IsParagraph(fc) {
+			container = fc
+		}
+		footnoteNode := footnote.(*Footnote)
+		index := footnoteNode.Index
+		name := footnoteNode.Name
+		if index < 0 {
+			list.RemoveChild(list, footnote)
+		} else {
+			container.AppendChild(container, NewFootnoteBackLink(index, name))
+		}
+		footnote = next
+	}
+	list.SortChildren(func(n1, n2 ast.Node) int {
+		if n1.(*Footnote).Index < n2.(*Footnote).Index {
+			return -1
+		}
+		return 1
+	})
+	if list.Count <= 0 {
+		list.Parent().RemoveChild(list.Parent(), list)
+		return
+	}
+
+	node.AppendChild(node, list)
+}
+
+// FootnoteHTMLRenderer is a renderer.NodeRenderer implementation that
+// renders FootnoteLink nodes.
+type FootnoteHTMLRenderer struct {
+	html.Config
+}
+
+// NewFootnoteHTMLRenderer returns a new FootnoteHTMLRenderer.
+func NewFootnoteHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
+	r := &FootnoteHTMLRenderer{
+		Config: html.NewConfig(),
+	}
+	for _, opt := range opts {
+		opt.SetHTMLOption(&r.Config)
+	}
+	return r
+}
+
+// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
+func (r *FootnoteHTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(KindFootnoteLink, r.renderFootnoteLink)
+	reg.Register(KindFootnoteBackLink, r.renderFootnoteBackLink)
+	reg.Register(KindFootnote, r.renderFootnote)
+	reg.Register(KindFootnoteList, r.renderFootnoteList)
+}
+
+func (r *FootnoteHTMLRenderer) renderFootnoteLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	if entering {
+		n := node.(*FootnoteLink)
+		is := strconv.Itoa(n.Index)
+		_, _ = w.WriteString(`<sup id="fnref:`)
+		_, _ = w.Write(n.Name)
+		_, _ = w.WriteString(`"><a href="#fn:`)
+		_, _ = w.Write(n.Name)
+		_, _ = w.WriteString(`" class="footnote-ref" role="doc-noteref">`)
+		_, _ = w.WriteString(is)
+		_, _ = w.WriteString(`</a></sup>`)
+	}
+	return ast.WalkContinue, nil
+}
+
+func (r *FootnoteHTMLRenderer) renderFootnoteBackLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	if entering {
+		n := node.(*FootnoteBackLink)
+		_, _ = w.WriteString(` <a href="#fnref:`)
+		_, _ = w.Write(n.Name)
+		_, _ = w.WriteString(`" class="footnote-backref" role="doc-backlink">`)
+		_, _ = w.WriteString("&#x21a9;&#xfe0e;")
+		_, _ = w.WriteString(`</a>`)
+	}
+	return ast.WalkContinue, nil
+}
+
+func (r *FootnoteHTMLRenderer) renderFootnote(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*Footnote)
+	if entering {
+		_, _ = w.WriteString(`<li id="fn:`)
+		_, _ = w.Write(n.Name)
+		_, _ = w.WriteString(`" role="doc-endnote"`)
+		if node.Attributes() != nil {
+			html.RenderAttributes(w, node, html.ListItemAttributeFilter)
+		}
+		_, _ = w.WriteString(">\n")
+	} else {
+		_, _ = w.WriteString("</li>\n")
+	}
+	return ast.WalkContinue, nil
+}
+
+func (r *FootnoteHTMLRenderer) renderFootnoteList(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	tag := "div"
+	if entering {
+		_, _ = w.WriteString("<")
+		_, _ = w.WriteString(tag)
+		_, _ = w.WriteString(` class="footnotes" role="doc-endnotes"`)
+		if node.Attributes() != nil {
+			html.RenderAttributes(w, node, html.GlobalAttributeFilter)
+		}
+		_ = w.WriteByte('>')
+		if r.Config.XHTML {
+			_, _ = w.WriteString("\n<hr />\n")
+		} else {
+			_, _ = w.WriteString("\n<hr>\n")
+		}
+		_, _ = w.WriteString("<ol>\n")
+	} else {
+		_, _ = w.WriteString("</ol>\n")
+		_, _ = w.WriteString("</")
+		_, _ = w.WriteString(tag)
+		_, _ = w.WriteString(">\n")
+	}
+	return ast.WalkContinue, nil
+}
+
+type footnoteExtension struct{}
+
+// FootnoteExtension represents the Gitea Footnote
+var FootnoteExtension = &footnoteExtension{}
+
+// Extend extends the markdown converter with the Gitea Footnote parser
+func (e *footnoteExtension) Extend(m goldmark.Markdown) {
+	m.Parser().AddOptions(
+		parser.WithBlockParsers(
+			util.Prioritized(NewFootnoteBlockParser(), 999),
+		),
+		parser.WithInlineParsers(
+			util.Prioritized(NewFootnoteParser(), 101),
+		),
+		parser.WithASTTransformers(
+			util.Prioritized(NewFootnoteASTTransformer(), 999),
+		),
+	)
+	m.Renderer().AddOptions(renderer.WithNodeRenderers(
+		util.Prioritized(NewFootnoteHTMLRenderer(), 500),
+	))
+}
diff --git a/modules/markup/common/footnote_test.go b/modules/markup/common/footnote_test.go
new file mode 100644
index 0000000..62763c5
--- /dev/null
+++ b/modules/markup/common/footnote_test.go
@@ -0,0 +1,62 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// Copyright 2023 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCleanValue(t *testing.T) {
+	tests := []struct {
+		param  string
+		expect string
+	}{
+		// Github behavior test cases
+		{"", ""},
+		{"test.0.1", "test-0-1"},
+		{"test(0)", "test-0"},
+		{"test!1", "test-1"},
+		{"test:2", "test-2"},
+		{"test*3", "test-3"},
+		{"test！4", "test-4"},
+		{"test：5", "test-5"},
+		{"test*6", "test-6"},
+		{"test：6 a", "test-6-a"},
+		{"test：6 !b", "test-6-b"},
+		{"test：ad # df", "test-ad-df"},
+		{"test：ad #23 df 2*/*", "test-ad-23-df-2"},
+		{"test：ad 23 df 2*/*", "test-ad-23-df-2"},
+		{"test：ad # 23 df 2*/*", "test-ad-23-df-2"},
+		{"Anchors in Markdown", "anchors-in-markdown"},
+		{"a_b_c", "a_b_c"},
+		{"a-b-c", "a-b-c"},
+		{"a-b-c----", "a-b-c"},
+		{"test：6a", "test-6a"},
+		{"test：a6", "test-a6"},
+		{"tes a a   a  a", "tes-a-a-a-a"},
+		{"  tes a a   a  a  ", "tes-a-a-a-a"},
+		{"Header with \"double quotes\"", "header-with-double-quotes"},
+		{"Placeholder to force scrolling on link's click", "placeholder-to-force-scrolling-on-link-s-click"},
+		{"tes（）", "tes"},
+		{"tes（0）", "tes-0"},
+		{"tes{0}", "tes-0"},
+		{"tes[0]", "tes-0"},
+		{"test【0】", "test-0"},
+		{"tes…@a", "tes-a"},
+		{"tes￥& a", "tes-a"},
+		{"tes= a", "tes-a"},
+		{"tes|a", "tes-a"},
+		{"tes\\a", "tes-a"},
+		{"tes/a", "tes-a"},
+		{"a啊啊b", "a啊啊b"},
+		{"c🤔️🤔️d", "c-d"},
+		{"a⚡a", "a-a"},
+		{"e.~f", "e-f"},
+	}
+	for _, test := range tests {
+		assert.Equal(t, []byte(test.expect), CleanValue([]byte(test.param)), test.param)
+	}
+}
diff --git a/modules/markup/common/html.go b/modules/markup/common/html.go
new file mode 100644
index 0000000..5658839
--- /dev/null
+++ b/modules/markup/common/html.go
@@ -0,0 +1,16 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package common
+
+import (
+	"mvdan.cc/xurls/v2"
+)
+
+// NOTE: All below regex matching do not perform any extra validation.
+// Thus a link is produced even if the linked entity does not exist.
+// While fast, this is also incorrect and lead to false positives.
+// TODO: fix invalid linking issue
+
+// LinkRegex is a regexp matching a valid link
+var LinkRegex, _ = xurls.StrictMatchingScheme("https?://")
diff --git a/modules/markup/common/linkify.go b/modules/markup/common/linkify.go
new file mode 100644
index 0000000..f846802
--- /dev/null
+++ b/modules/markup/common/linkify.go
@@ -0,0 +1,153 @@
+// Copyright 2019 Yusuke Inuzuka
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+// Most of this file is a subtly changed version of github.com/yuin/goldmark/extension/linkify.go
+
+package common
+
+import (
+	"bytes"
+	"regexp"
+
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+var wwwURLRegxp = regexp.MustCompile(`^www\.[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}((?:/|[#?])[-a-zA-Z0-9@:%_\+.~#!?&//=\(\);,'">\^{}\[\]` + "`" + `]*)?`)
+
+type linkifyParser struct{}
+
+var defaultLinkifyParser = &linkifyParser{}
+
+// NewLinkifyParser return a new InlineParser can parse
+// text that seems like a URL.
+func NewLinkifyParser() parser.InlineParser {
+	return defaultLinkifyParser
+}
+
+func (s *linkifyParser) Trigger() []byte {
+	// ' ' indicates any white spaces and a line head
+	return []byte{' ', '*', '_', '~', '('}
+}
+
+var (
+	protoHTTP  = []byte("http:")
+	protoHTTPS = []byte("https:")
+	protoFTP   = []byte("ftp:")
+	domainWWW  = []byte("www.")
+)
+
+func (s *linkifyParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
+	if pc.IsInLinkLabel() {
+		return nil
+	}
+	line, segment := block.PeekLine()
+	consumes := 0
+	start := segment.Start
+	c := line[0]
+	// advance if current position is not a line head.
+	if c == ' ' || c == '*' || c == '_' || c == '~' || c == '(' {
+		consumes++
+		start++
+		line = line[1:]
+	}
+
+	var m []int
+	var protocol []byte
+	typ := ast.AutoLinkURL
+	if bytes.HasPrefix(line, protoHTTP) || bytes.HasPrefix(line, protoHTTPS) || bytes.HasPrefix(line, protoFTP) {
+		m = LinkRegex.FindSubmatchIndex(line)
+	}
+	if m == nil && bytes.HasPrefix(line, domainWWW) {
+		m = wwwURLRegxp.FindSubmatchIndex(line)
+		protocol = []byte("http")
+	}
+	if m != nil {
+		lastChar := line[m[1]-1]
+		if lastChar == '.' {
+			m[1]--
+		} else if lastChar == ')' {
+			closing := 0
+			for i := m[1] - 1; i >= m[0]; i-- {
+				if line[i] == ')' {
+					closing++
+				} else if line[i] == '(' {
+					closing--
+				}
+			}
+			if closing > 0 {
+				m[1] -= closing
+			}
+		} else if lastChar == ';' {
+			i := m[1] - 2
+			for ; i >= m[0]; i-- {
+				if util.IsAlphaNumeric(line[i]) {
+					continue
+				}
+				break
+			}
+			if i != m[1]-2 {
+				if line[i] == '&' {
+					m[1] -= m[1] - i
+				}
+			}
+		}
+	}
+	if m == nil {
+		if len(line) > 0 && util.IsPunct(line[0]) {
+			return nil
+		}
+		typ = ast.AutoLinkEmail
+		stop := util.FindEmailIndex(line)
+		if stop < 0 {
+			return nil
+		}
+		at := bytes.IndexByte(line, '@')
+		m = []int{0, stop, at, stop - 1}
+		if bytes.IndexByte(line[m[2]:m[3]], '.') < 0 {
+			return nil
+		}
+		lastChar := line[m[1]-1]
+		if lastChar == '.' {
+			m[1]--
+		}
+		if m[1] < len(line) {
+			nextChar := line[m[1]]
+			if nextChar == '-' || nextChar == '_' {
+				return nil
+			}
+		}
+	}
+
+	if consumes != 0 {
+		s := segment.WithStop(segment.Start + 1)
+		ast.MergeOrAppendTextSegment(parent, s)
+	}
+	consumes += m[1]
+	block.Advance(consumes)
+	n := ast.NewTextSegment(text.NewSegment(start, start+m[1]))
+	link := ast.NewAutoLink(typ, n)
+	link.Protocol = protocol
+	return link
+}
+
+func (s *linkifyParser) CloseBlock(parent ast.Node, pc parser.Context) {
+	// nothing to do
+}
+
+type linkify struct{}
+
+// Linkify is an extension that allow you to parse text that seems like a URL.
+var Linkify = &linkify{}
+
+func (e *linkify) Extend(m goldmark.Markdown) {
+	m.Parser().AddOptions(
+		parser.WithInlineParsers(
+			util.Prioritized(NewLinkifyParser(), 999),
+		),
+	)
+}