Adding upstream version 9.0.3.

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

29 files changed, 3962 insertions, 0 deletions

diff --git a/modules/markup/markdown/ast.go b/modules/markup/markdown/ast.go
new file mode 100644
index 0000000..7f0ac6a
--- /dev/null
+++ b/modules/markup/markdown/ast.go
@@ -0,0 +1,176 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"strconv"
+
+	"github.com/yuin/goldmark/ast"
+)
+
+// Details is a block that contains Summary and details
+type Details struct {
+	ast.BaseBlock
+}
+
+// Dump implements Node.Dump .
+func (n *Details) Dump(source []byte, level int) {
+	ast.DumpHelper(n, source, level, nil, nil)
+}
+
+// KindDetails is the NodeKind for Details
+var KindDetails = ast.NewNodeKind("Details")
+
+// Kind implements Node.Kind.
+func (n *Details) Kind() ast.NodeKind {
+	return KindDetails
+}
+
+// NewDetails returns a new Paragraph node.
+func NewDetails() *Details {
+	return &Details{
+		BaseBlock: ast.BaseBlock{},
+	}
+}
+
+// IsDetails returns true if the given node implements the Details interface,
+// otherwise false.
+func IsDetails(node ast.Node) bool {
+	_, ok := node.(*Details)
+	return ok
+}
+
+// Summary is a block that contains the summary of details block
+type Summary struct {
+	ast.BaseBlock
+}
+
+// Dump implements Node.Dump .
+func (n *Summary) Dump(source []byte, level int) {
+	ast.DumpHelper(n, source, level, nil, nil)
+}
+
+// KindSummary is the NodeKind for Summary
+var KindSummary = ast.NewNodeKind("Summary")
+
+// Kind implements Node.Kind.
+func (n *Summary) Kind() ast.NodeKind {
+	return KindSummary
+}
+
+// NewSummary returns a new Summary node.
+func NewSummary() *Summary {
+	return &Summary{
+		BaseBlock: ast.BaseBlock{},
+	}
+}
+
+// IsSummary returns true if the given node implements the Summary interface,
+// otherwise false.
+func IsSummary(node ast.Node) bool {
+	_, ok := node.(*Summary)
+	return ok
+}
+
+// TaskCheckBoxListItem is a block that represents a list item of a markdown block with a checkbox
+type TaskCheckBoxListItem struct {
+	*ast.ListItem
+	IsChecked      bool
+	SourcePosition int
+}
+
+// KindTaskCheckBoxListItem is the NodeKind for TaskCheckBoxListItem
+var KindTaskCheckBoxListItem = ast.NewNodeKind("TaskCheckBoxListItem")
+
+// Dump implements Node.Dump .
+func (n *TaskCheckBoxListItem) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["IsChecked"] = strconv.FormatBool(n.IsChecked)
+	m["SourcePosition"] = strconv.FormatInt(int64(n.SourcePosition), 10)
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// Kind implements Node.Kind.
+func (n *TaskCheckBoxListItem) Kind() ast.NodeKind {
+	return KindTaskCheckBoxListItem
+}
+
+// NewTaskCheckBoxListItem returns a new TaskCheckBoxListItem node.
+func NewTaskCheckBoxListItem(listItem *ast.ListItem) *TaskCheckBoxListItem {
+	return &TaskCheckBoxListItem{
+		ListItem: listItem,
+	}
+}
+
+// IsTaskCheckBoxListItem returns true if the given node implements the TaskCheckBoxListItem interface,
+// otherwise false.
+func IsTaskCheckBoxListItem(node ast.Node) bool {
+	_, ok := node.(*TaskCheckBoxListItem)
+	return ok
+}
+
+// Icon is an inline for a fomantic icon
+type Icon struct {
+	ast.BaseInline
+	Name []byte
+}
+
+// Dump implements Node.Dump .
+func (n *Icon) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["Name"] = string(n.Name)
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// KindIcon is the NodeKind for Icon
+var KindIcon = ast.NewNodeKind("Icon")
+
+// Kind implements Node.Kind.
+func (n *Icon) Kind() ast.NodeKind {
+	return KindIcon
+}
+
+// NewIcon returns a new Paragraph node.
+func NewIcon(name string) *Icon {
+	return &Icon{
+		BaseInline: ast.BaseInline{},
+		Name:       []byte(name),
+	}
+}
+
+// IsIcon returns true if the given node implements the Icon interface,
+// otherwise false.
+func IsIcon(node ast.Node) bool {
+	_, ok := node.(*Icon)
+	return ok
+}
+
+// ColorPreview is an inline for a color preview
+type ColorPreview struct {
+	ast.BaseInline
+	Color []byte
+}
+
+// Dump implements Node.Dump.
+func (n *ColorPreview) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["Color"] = string(n.Color)
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// KindColorPreview is the NodeKind for ColorPreview
+var KindColorPreview = ast.NewNodeKind("ColorPreview")
+
+// Kind implements Node.Kind.
+func (n *ColorPreview) Kind() ast.NodeKind {
+	return KindColorPreview
+}
+
+// NewColorPreview returns a new Span node.
+func NewColorPreview(color []byte) *ColorPreview {
+	return &ColorPreview{
+		BaseInline: ast.BaseInline{},
+		Color:      color,
+	}
+}
diff --git a/modules/markup/markdown/callout/ast.go b/modules/markup/markdown/callout/ast.go
new file mode 100644
index 0000000..a5b1bbc
--- /dev/null
+++ b/modules/markup/markdown/callout/ast.go
@@ -0,0 +1,37 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package callout
+
+import (
+	"github.com/yuin/goldmark/ast"
+)
+
+// Attention is an inline for an attention
+type Attention struct {
+	ast.BaseInline
+	AttentionType string
+}
+
+// Dump implements Node.Dump.
+func (n *Attention) Dump(source []byte, level int) {
+	m := map[string]string{}
+	m["AttentionType"] = n.AttentionType
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// KindAttention is the NodeKind for Attention
+var KindAttention = ast.NewNodeKind("Attention")
+
+// Kind implements Node.Kind.
+func (n *Attention) Kind() ast.NodeKind {
+	return KindAttention
+}
+
+// NewAttention returns a new Attention node.
+func NewAttention(attentionType string) *Attention {
+	return &Attention{
+		BaseInline:    ast.BaseInline{},
+		AttentionType: attentionType,
+	}
+}
diff --git a/modules/markup/markdown/callout/github.go b/modules/markup/markdown/callout/github.go
new file mode 100644
index 0000000..9b8b611
--- /dev/null
+++ b/modules/markup/markdown/callout/github.go
@@ -0,0 +1,141 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Copyright 2024 The Forgejo Authors c/o Codeberg e.V.. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package callout
+
+import (
+	"strings"
+
+	"code.gitea.io/gitea/modules/svg"
+
+	"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"
+)
+
+type GitHubCalloutTransformer struct{}
+
+// Transform transforms the given AST tree.
+func (g *GitHubCalloutTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
+	supportedAttentionTypes := map[string]bool{
+		"note":      true,
+		"tip":       true,
+		"important": true,
+		"warning":   true,
+		"caution":   true,
+	}
+
+	_ = ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
+		if !entering {
+			return ast.WalkContinue, nil
+		}
+
+		if v, ok := n.(*ast.Blockquote); ok {
+			if v.ChildCount() == 0 {
+				return ast.WalkContinue, nil
+			}
+
+			// We only want attention blockquotes when the AST looks like:
+			// Text: "["
+			// Text: "!TYPE"
+			// Text(SoftLineBreak): "]"
+
+			// grab these nodes and make sure we adhere to the attention blockquote structure
+			firstParagraph := v.FirstChild()
+			if firstParagraph.ChildCount() < 3 {
+				return ast.WalkContinue, nil
+			}
+			firstTextNode, ok := firstParagraph.FirstChild().(*ast.Text)
+			if !ok || string(firstTextNode.Text(reader.Source())) != "[" {
+				return ast.WalkContinue, nil
+			}
+			secondTextNode, ok := firstTextNode.NextSibling().(*ast.Text)
+			if !ok {
+				return ast.WalkContinue, nil
+			}
+			// If the second node's text isn't one of the supported attention
+			// types, continue walking.
+			secondTextNodeText := secondTextNode.Text(reader.Source())
+			attentionType := strings.ToLower(strings.TrimPrefix(string(secondTextNodeText), "!"))
+			if _, has := supportedAttentionTypes[attentionType]; !has {
+				return ast.WalkContinue, nil
+			}
+
+			thirdTextNode, ok := secondTextNode.NextSibling().(*ast.Text)
+			if !ok || string(thirdTextNode.Text(reader.Source())) != "]" {
+				return ast.WalkContinue, nil
+			}
+
+			// color the blockquote
+			v.SetAttributeString("class", []byte("attention-header attention-"+attentionType))
+
+			// create an emphasis to make it bold
+			attentionParagraph := ast.NewParagraph()
+			attentionParagraph.SetAttributeString("class", []byte("attention-title"))
+			emphasis := ast.NewEmphasis(2)
+			emphasis.SetAttributeString("class", []byte("attention-"+attentionType))
+			firstParagraph.InsertBefore(firstParagraph, firstTextNode, emphasis)
+
+			// capitalize first letter
+			attentionText := ast.NewString([]byte(strings.ToUpper(string(attentionType[0])) + attentionType[1:]))
+
+			// replace the ![TYPE] with a dedicated paragraph of icon+Type
+			emphasis.AppendChild(emphasis, attentionText)
+			attentionParagraph.AppendChild(attentionParagraph, NewAttention(attentionType))
+			attentionParagraph.AppendChild(attentionParagraph, emphasis)
+			firstParagraph.Parent().InsertBefore(firstParagraph.Parent(), firstParagraph, attentionParagraph)
+			firstParagraph.RemoveChild(firstParagraph, firstTextNode)
+			firstParagraph.RemoveChild(firstParagraph, secondTextNode)
+			firstParagraph.RemoveChild(firstParagraph, thirdTextNode)
+		}
+		return ast.WalkContinue, nil
+	})
+}
+
+type GitHubCalloutHTMLRenderer struct {
+	html.Config
+}
+
+// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
+func (r *GitHubCalloutHTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(KindAttention, r.renderAttention)
+}
+
+// renderAttention renders a quote marked with i.e. "> **Note**" or "> **Warning**" with a corresponding svg
+func (r *GitHubCalloutHTMLRenderer) renderAttention(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	if entering {
+		n := node.(*Attention)
+
+		var octiconName string
+		switch n.AttentionType {
+		case "note":
+			octiconName = "info"
+		case "tip":
+			octiconName = "light-bulb"
+		case "important":
+			octiconName = "report"
+		case "warning":
+			octiconName = "alert"
+		case "caution":
+			octiconName = "stop"
+		default:
+			octiconName = "info"
+		}
+		_, _ = w.WriteString(string(svg.RenderHTML("octicon-"+octiconName, 16, "attention-icon attention-"+n.AttentionType)))
+	}
+	return ast.WalkContinue, nil
+}
+
+func NewGitHubCalloutHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
+	r := &GitHubCalloutHTMLRenderer{
+		Config: html.NewConfig(),
+	}
+	for _, opt := range opts {
+		opt.SetHTMLOption(&r.Config)
+	}
+	return r
+}
diff --git a/modules/markup/markdown/callout/github_legacy.go b/modules/markup/markdown/callout/github_legacy.go
new file mode 100644
index 0000000..96354b1
--- /dev/null
+++ b/modules/markup/markdown/callout/github_legacy.go
@@ -0,0 +1,78 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Copyright 2024 The Forgejo Authors c/o Codeberg e.V.. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package callout
+
+import (
+	"strings"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/text"
+)
+
+// Transformer for GitHub's legacy callout markup.
+type GitHubLegacyCalloutTransformer struct{}
+
+func (g *GitHubLegacyCalloutTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
+	supportedCalloutTypes := map[string]bool{"Note": true, "Warning": true}
+
+	_ = ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
+		if !entering {
+			return ast.WalkContinue, nil
+		}
+
+		if v, ok := n.(*ast.Blockquote); ok {
+			if v.ChildCount() == 0 {
+				return ast.WalkContinue, nil
+			}
+
+			// The first paragraph contains the callout type.
+			firstParagraph := v.FirstChild()
+			if firstParagraph.ChildCount() < 1 {
+				return ast.WalkContinue, nil
+			}
+
+			// In the legacy GitHub callout markup, the first node of the first
+			// paragraph should be an emphasis.
+			calloutNode, ok := firstParagraph.FirstChild().(*ast.Emphasis)
+			if !ok {
+				return ast.WalkContinue, nil
+			}
+			calloutText := string(calloutNode.Text(reader.Source()))
+			calloutType := strings.ToLower(calloutText)
+			// We only support "Note" and "Warning" callouts in legacy mode,
+			// match only those.
+			if _, has := supportedCalloutTypes[calloutText]; !has {
+				return ast.WalkContinue, nil
+			}
+
+			// Set the attention attribute on the emphasis
+			calloutNode.SetAttributeString("class", []byte("attention-"+calloutType))
+
+			// color the blockquote
+			v.SetAttributeString("class", []byte("attention-header attention-"+calloutType))
+
+			// Create new paragraph.
+			attentionParagraph := ast.NewParagraph()
+			attentionParagraph.SetAttributeString("class", []byte("attention-title"))
+
+			// Move the callout node to the paragraph and insert the paragraph.
+			attentionParagraph.AppendChild(attentionParagraph, NewAttention(calloutType))
+			attentionParagraph.AppendChild(attentionParagraph, calloutNode)
+			firstParagraph.Parent().InsertBefore(firstParagraph.Parent(), firstParagraph, attentionParagraph)
+			firstParagraph.RemoveChild(firstParagraph, calloutNode)
+
+			// Remove softbreak line if there's one.
+			if firstParagraph.ChildCount() >= 1 {
+				softBreakNode, ok := firstParagraph.FirstChild().(*ast.Text)
+				if ok && softBreakNode.SoftLineBreak() {
+					firstParagraph.RemoveChild(firstParagraph, softBreakNode)
+				}
+			}
+		}
+
+		return ast.WalkContinue, nil
+	})
+}
diff --git a/modules/markup/markdown/color_util.go b/modules/markup/markdown/color_util.go
new file mode 100644
index 0000000..355fef3
--- /dev/null
+++ b/modules/markup/markdown/color_util.go
@@ -0,0 +1,19 @@
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import "regexp"
+
+var (
+	hexRGB = regexp.MustCompile(`^#([0-9a-f]{3}|[0-9a-f]{6}|[0-9a-f]{8})$`)
+	hsl    = regexp.MustCompile(`^hsl\([ ]*([012]?[0-9]{1,2}|3[0-5][0-9]|360),[ ]*([0-9]{0,2}|100)\%,[ ]*([0-9]{0,2}|100)\%\)$`)
+	hsla   = regexp.MustCompile(`^hsla\(([ ]*[012]?[0-9]{1,2}|3[0-5][0-9]|360),[ ]*([0-9]{0,2}|100)\%,[ ]*([0-9]{0,2}|100)\%,[ ]*(1|1\.0|0|(0\.[0-9]+))\)$`)
+	rgb    = regexp.MustCompile(`^rgb\(([ ]*((([0-9]{1,2}|100)\%)|(([01]?[0-9]{1,2})|(2[0-4][0-9])|(25[0-5]))),){2}([ ]*((([0-9]{1,2}|100)\%)|(([01]?[0-9]{1,2})|(2[0-4][0-9])|(25[0-5]))))\)$`)
+	rgba   = regexp.MustCompile(`^rgba\(([ ]*((([0-9]{1,2}|100)\%)|(([01]?[0-9]{1,2})|(2[0-4][0-9])|(25[0-5]))),){3}[ ]*(1(\.0)?|0|(0\.[0-9]+))\)$`)
+)
+
+// matchColor return if color is in the form of hex RGB, HSL(A) or RGB(A).
+func matchColor(color string) bool {
+	return hexRGB.MatchString(color) || rgb.MatchString(color) || rgba.MatchString(color) || hsl.MatchString(color) || hsla.MatchString(color)
+}
diff --git a/modules/markup/markdown/color_util_test.go b/modules/markup/markdown/color_util_test.go
new file mode 100644
index 0000000..c6e0555
--- /dev/null
+++ b/modules/markup/markdown/color_util_test.go
@@ -0,0 +1,50 @@
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMatchColor(t *testing.T) {
+	testCases := []struct {
+		input    string
+		expected bool
+	}{
+		{"#ddeeffa0", true},
+		{"#ddeefe", true},
+		{"#abcdef", true},
+		{"#abcdeg", false},
+		{"#abcdefg0", false},
+		{"black", false},
+		{"violet", false},
+		{"rgb(255, 255, 255)", true},
+		{"rgb(0, 0, 0)", true},
+		{"rgb(256, 0, 0)", false},
+		{"rgb(0, 256, 0)", false},
+		{"rgb(0, 0, 256)", false},
+		{"rgb(0, 0, 0, 1)", false},
+		{"rgba(0, 0, 0)", false},
+		{"rgba(0, 255, 0, 1)", true},
+		{"rgba(32, 255, 12, 0.55)", true},
+		{"rgba(32, 256, 12, 0.55)", false},
+		{"hsl(0, 0%, 0%)", true},
+		{"hsl(360, 100%, 100%)", true},
+		{"hsl(361, 100%, 50%)", false},
+		{"hsl(360, 101%, 50%)", false},
+		{"hsl(360, 100%, 101%)", false},
+		{"hsl(0, 0%, 0%, 0)", false},
+		{"hsla(0, 0%, 0%)", false},
+		{"hsla(0, 0%, 0%, 0)", true},
+		{"hsla(0, 0%, 0%, 1)", true},
+		{"hsla(0, 0%, 0%, 0.5)", true},
+		{"hsla(0, 0%, 0%, 1.5)", false},
+	}
+	for _, testCase := range testCases {
+		actual := matchColor(testCase.input)
+		assert.Equal(t, testCase.expected, actual)
+	}
+}
diff --git a/modules/markup/markdown/convertyaml.go b/modules/markup/markdown/convertyaml.go
new file mode 100644
index 0000000..1675b68
--- /dev/null
+++ b/modules/markup/markdown/convertyaml.go
@@ -0,0 +1,83 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"github.com/yuin/goldmark/ast"
+	east "github.com/yuin/goldmark/extension/ast"
+	"gopkg.in/yaml.v3"
+)
+
+func nodeToTable(meta *yaml.Node) ast.Node {
+	for {
+		if meta == nil {
+			return nil
+		}
+		switch meta.Kind {
+		case yaml.DocumentNode:
+			meta = meta.Content[0]
+			continue
+		default:
+		}
+		break
+	}
+	switch meta.Kind {
+	case yaml.MappingNode:
+		return mappingNodeToTable(meta)
+	case yaml.SequenceNode:
+		return sequenceNodeToTable(meta)
+	default:
+		return ast.NewString([]byte(meta.Value))
+	}
+}
+
+func mappingNodeToTable(meta *yaml.Node) ast.Node {
+	table := east.NewTable()
+	alignments := make([]east.Alignment, 0, len(meta.Content)/2)
+	for i := 0; i < len(meta.Content); i += 2 {
+		alignments = append(alignments, east.AlignNone)
+	}
+
+	headerRow := east.NewTableRow(alignments)
+	valueRow := east.NewTableRow(alignments)
+	for i := 0; i < len(meta.Content); i += 2 {
+		cell := east.NewTableCell()
+
+		cell.AppendChild(cell, nodeToTable(meta.Content[i]))
+		headerRow.AppendChild(headerRow, cell)
+
+		if i+1 < len(meta.Content) {
+			cell = east.NewTableCell()
+			cell.AppendChild(cell, nodeToTable(meta.Content[i+1]))
+			valueRow.AppendChild(valueRow, cell)
+		}
+	}
+
+	table.AppendChild(table, east.NewTableHeader(headerRow))
+	table.AppendChild(table, valueRow)
+	return table
+}
+
+func sequenceNodeToTable(meta *yaml.Node) ast.Node {
+	table := east.NewTable()
+	alignments := []east.Alignment{east.AlignNone}
+	for _, item := range meta.Content {
+		row := east.NewTableRow(alignments)
+		cell := east.NewTableCell()
+		cell.AppendChild(cell, nodeToTable(item))
+		row.AppendChild(row, cell)
+		table.AppendChild(table, row)
+	}
+	return table
+}
+
+func nodeToDetails(meta *yaml.Node, icon string) ast.Node {
+	details := NewDetails()
+	summary := NewSummary()
+	summary.AppendChild(summary, NewIcon(icon))
+	details.AppendChild(details, summary)
+	details.AppendChild(details, nodeToTable(meta))
+
+	return details
+}
diff --git a/modules/markup/markdown/goldmark.go b/modules/markup/markdown/goldmark.go
new file mode 100644
index 0000000..0290e13
--- /dev/null
+++ b/modules/markup/markdown/goldmark.go
@@ -0,0 +1,213 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/yuin/goldmark/ast"
+	east "github.com/yuin/goldmark/extension/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"
+)
+
+var byteMailto = []byte("mailto:")
+
+// ASTTransformer is a default transformer of the goldmark tree.
+type ASTTransformer struct{}
+
+func (g *ASTTransformer) applyElementDir(n ast.Node) {
+	if markup.DefaultProcessorHelper.ElementDir != "" {
+		n.SetAttributeString("dir", []byte(markup.DefaultProcessorHelper.ElementDir))
+	}
+}
+
+// Transform transforms the given AST tree.
+func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
+	firstChild := node.FirstChild()
+	tocMode := ""
+	ctx := pc.Get(renderContextKey).(*markup.RenderContext)
+	rc := pc.Get(renderConfigKey).(*RenderConfig)
+
+	tocList := make([]markup.Header, 0, 20)
+	if rc.yamlNode != nil {
+		metaNode := rc.toMetaNode()
+		if metaNode != nil {
+			node.InsertBefore(node, firstChild, metaNode)
+		}
+		tocMode = rc.TOC
+	}
+
+	_ = ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
+		if !entering {
+			return ast.WalkContinue, nil
+		}
+
+		switch v := n.(type) {
+		case *ast.Heading:
+			g.transformHeading(ctx, v, reader, &tocList)
+		case *ast.Paragraph:
+			g.applyElementDir(v)
+		case *ast.Image:
+			g.transformImage(ctx, v)
+		case *ast.Link:
+			g.transformLink(ctx, v)
+		case *ast.List:
+			g.transformList(ctx, v, rc)
+		case *ast.Text:
+			if v.SoftLineBreak() && !v.HardLineBreak() {
+				if ctx.Metas["mode"] != "document" {
+					v.SetHardLineBreak(setting.Markdown.EnableHardLineBreakInComments)
+				} else {
+					v.SetHardLineBreak(setting.Markdown.EnableHardLineBreakInDocuments)
+				}
+			}
+		case *ast.CodeSpan:
+			g.transformCodeSpan(ctx, v, reader)
+		}
+		return ast.WalkContinue, nil
+	})
+
+	showTocInMain := tocMode == "true" /* old behavior, in main view */ || tocMode == "main"
+	showTocInSidebar := !showTocInMain && tocMode != "false" // not hidden, not main, then show it in sidebar
+	if len(tocList) > 0 && (showTocInMain || showTocInSidebar) {
+		if showTocInMain {
+			tocNode := createTOCNode(tocList, rc.Lang, nil)
+			node.InsertBefore(node, firstChild, tocNode)
+		} else {
+			tocNode := createTOCNode(tocList, rc.Lang, map[string]string{"open": "open"})
+			ctx.SidebarTocNode = tocNode
+		}
+	}
+
+	if len(rc.Lang) > 0 {
+		node.SetAttributeString("lang", []byte(rc.Lang))
+	}
+}
+
+// NewHTMLRenderer creates a HTMLRenderer to render
+// in the gitea form.
+func NewHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
+	r := &HTMLRenderer{
+		Config: html.NewConfig(),
+	}
+	for _, opt := range opts {
+		opt.SetHTMLOption(&r.Config)
+	}
+	return r
+}
+
+// HTMLRenderer is a renderer.NodeRenderer implementation that
+// renders gitea specific features.
+type HTMLRenderer struct {
+	html.Config
+}
+
+// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
+func (r *HTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(ast.KindDocument, r.renderDocument)
+	reg.Register(KindDetails, r.renderDetails)
+	reg.Register(KindSummary, r.renderSummary)
+	reg.Register(KindIcon, r.renderIcon)
+	reg.Register(ast.KindCodeSpan, r.renderCodeSpan)
+	reg.Register(KindTaskCheckBoxListItem, r.renderTaskCheckBoxListItem)
+	reg.Register(east.KindTaskCheckBox, r.renderTaskCheckBox)
+}
+
+func (r *HTMLRenderer) renderDocument(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*ast.Document)
+
+	if val, has := n.AttributeString("lang"); has {
+		var err error
+		if entering {
+			_, err = w.WriteString("<div")
+			if err == nil {
+				_, err = w.WriteString(fmt.Sprintf(` lang=%q`, val))
+			}
+			if err == nil {
+				_, err = w.WriteRune('>')
+			}
+		} else {
+			_, err = w.WriteString("</div>")
+		}
+
+		if err != nil {
+			return ast.WalkStop, err
+		}
+	}
+
+	return ast.WalkContinue, nil
+}
+
+func (r *HTMLRenderer) renderDetails(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	var err error
+	if entering {
+		if _, err = w.WriteString("<details"); err != nil {
+			return ast.WalkStop, err
+		}
+		html.RenderAttributes(w, node, nil)
+		_, err = w.WriteString(">")
+	} else {
+		_, err = w.WriteString("</details>")
+	}
+
+	if err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkContinue, nil
+}
+
+func (r *HTMLRenderer) renderSummary(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	var err error
+	if entering {
+		_, err = w.WriteString("<summary>")
+	} else {
+		_, err = w.WriteString("</summary>")
+	}
+
+	if err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkContinue, nil
+}
+
+var validNameRE = regexp.MustCompile("^[a-z ]+$")
+
+func (r *HTMLRenderer) renderIcon(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	if !entering {
+		return ast.WalkContinue, nil
+	}
+
+	n := node.(*Icon)
+
+	name := strings.TrimSpace(strings.ToLower(string(n.Name)))
+
+	if len(name) == 0 {
+		// skip this
+		return ast.WalkContinue, nil
+	}
+
+	if !validNameRE.MatchString(name) {
+		// skip this
+		return ast.WalkContinue, nil
+	}
+
+	var err error
+	_, err = w.WriteString(fmt.Sprintf(`<i class="icon %s"></i>`, name))
+	if err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkContinue, nil
+}
diff --git a/modules/markup/markdown/markdown.go b/modules/markup/markdown/markdown.go
new file mode 100644
index 0000000..d249d25
--- /dev/null
+++ b/modules/markup/markdown/markdown.go
@@ -0,0 +1,303 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+	"html/template"
+	"io"
+	"strings"
+	"sync"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/markup/common"
+	"code.gitea.io/gitea/modules/markup/markdown/callout"
+	"code.gitea.io/gitea/modules/markup/markdown/math"
+	"code.gitea.io/gitea/modules/setting"
+	giteautil "code.gitea.io/gitea/modules/util"
+
+	chromahtml "github.com/alecthomas/chroma/v2/formatters/html"
+	"github.com/yuin/goldmark"
+	highlighting "github.com/yuin/goldmark-highlighting/v2"
+	"github.com/yuin/goldmark/extension"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/util"
+)
+
+var (
+	specMarkdown     goldmark.Markdown
+	specMarkdownOnce sync.Once
+)
+
+var (
+	renderContextKey = parser.NewContextKey()
+	renderConfigKey  = parser.NewContextKey()
+)
+
+type limitWriter struct {
+	w     io.Writer
+	sum   int64
+	limit int64
+}
+
+// Write implements the standard Write interface:
+func (l *limitWriter) Write(data []byte) (int, error) {
+	leftToWrite := l.limit - l.sum
+	if leftToWrite < int64(len(data)) {
+		n, err := l.w.Write(data[:leftToWrite])
+		l.sum += int64(n)
+		if err != nil {
+			return n, err
+		}
+		return n, fmt.Errorf("rendered content too large - truncating render")
+	}
+	n, err := l.w.Write(data)
+	l.sum += int64(n)
+	return n, err
+}
+
+// newParserContext creates a parser.Context with the render context set
+func newParserContext(ctx *markup.RenderContext) parser.Context {
+	pc := parser.NewContext(parser.WithIDs(newPrefixedIDs()))
+	pc.Set(renderContextKey, ctx)
+	return pc
+}
+
+// SpecializedMarkdown sets up the Gitea specific markdown extensions
+func SpecializedMarkdown() goldmark.Markdown {
+	specMarkdownOnce.Do(func() {
+		specMarkdown = goldmark.New(
+			goldmark.WithExtensions(
+				extension.NewTable(
+					extension.WithTableCellAlignMethod(extension.TableCellAlignAttribute)),
+				extension.Strikethrough,
+				extension.TaskList,
+				extension.DefinitionList,
+				common.FootnoteExtension,
+				highlighting.NewHighlighting(
+					highlighting.WithFormatOptions(
+						chromahtml.WithClasses(true),
+						chromahtml.PreventSurroundingPre(true),
+					),
+					highlighting.WithWrapperRenderer(func(w util.BufWriter, c highlighting.CodeBlockContext, entering bool) {
+						if entering {
+							language, _ := c.Language()
+							if language == nil {
+								language = []byte("text")
+							}
+
+							languageStr := string(language)
+
+							preClasses := []string{"code-block"}
+							if languageStr == "mermaid" || languageStr == "math" {
+								preClasses = append(preClasses, "is-loading")
+							}
+
+							_, err := w.WriteString(`<pre class="` + strings.Join(preClasses, " ") + `">`)
+							if err != nil {
+								return
+							}
+
+							// include language-x class as part of commonmark spec
+							// the "display" class is used by "js/markup/math.js" to render the code element as a block
+							_, err = w.WriteString(`<code class="chroma language-` + string(language) + ` display">`)
+							if err != nil {
+								return
+							}
+						} else {
+							_, err := w.WriteString("</code></pre>")
+							if err != nil {
+								return
+							}
+						}
+					}),
+				),
+				math.NewExtension(
+					math.Enabled(setting.Markdown.EnableMath),
+				),
+			),
+			goldmark.WithParserOptions(
+				parser.WithAttribute(),
+				parser.WithAutoHeadingID(),
+				parser.WithASTTransformers(
+					util.Prioritized(&callout.GitHubLegacyCalloutTransformer{}, 8000),
+					util.Prioritized(&callout.GitHubCalloutTransformer{}, 9000),
+					util.Prioritized(&ASTTransformer{}, 10000),
+				),
+			),
+			goldmark.WithRendererOptions(
+				html.WithUnsafe(),
+			),
+		)
+
+		// Override the original Tasklist renderer!
+		specMarkdown.Renderer().AddOptions(
+			renderer.WithNodeRenderers(
+				util.Prioritized(callout.NewGitHubCalloutHTMLRenderer(), 10),
+				util.Prioritized(NewHTMLRenderer(), 10),
+			),
+		)
+	})
+	return specMarkdown
+}
+
+// actualRender renders Markdown to HTML without handling special links.
+func actualRender(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
+	converter := SpecializedMarkdown()
+	lw := &limitWriter{
+		w:     output,
+		limit: setting.UI.MaxDisplayFileSize * 3,
+	}
+
+	// FIXME: should we include a timeout to abort the renderer if it takes too long?
+	defer func() {
+		err := recover()
+		if err == nil {
+			return
+		}
+
+		log.Warn("Unable to render markdown due to panic in goldmark: %v", err)
+		if log.IsDebug() {
+			log.Debug("Panic in markdown: %v\n%s", err, log.Stack(2))
+		}
+	}()
+
+	// FIXME: Don't read all to memory, but goldmark doesn't support
+	pc := newParserContext(ctx)
+	buf, err := io.ReadAll(input)
+	if err != nil {
+		log.Error("Unable to ReadAll: %v", err)
+		return err
+	}
+	buf = giteautil.NormalizeEOL(buf)
+
+	// Preserve original length.
+	bufWithMetadataLength := len(buf)
+
+	rc := &RenderConfig{
+		Meta: markup.RenderMetaAsDetails,
+		Icon: "table",
+		Lang: "",
+	}
+	buf, _ = ExtractMetadataBytes(buf, rc)
+
+	metaLength := bufWithMetadataLength - len(buf)
+	if metaLength < 0 {
+		metaLength = 0
+	}
+	rc.metaLength = metaLength
+
+	pc.Set(renderConfigKey, rc)
+
+	if err := converter.Convert(buf, lw, parser.WithContext(pc)); err != nil {
+		log.Error("Unable to render: %v", err)
+		return err
+	}
+
+	return nil
+}
+
+// Note: The output of this method must get sanitized.
+func render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
+	defer func() {
+		err := recover()
+		if err == nil {
+			return
+		}
+
+		log.Warn("Unable to render markdown due to panic in goldmark - will return raw bytes")
+		if log.IsDebug() {
+			log.Debug("Panic in markdown: %v\n%s", err, log.Stack(2))
+		}
+		_, err = io.Copy(output, input)
+		if err != nil {
+			log.Error("io.Copy failed: %v", err)
+		}
+	}()
+	return actualRender(ctx, input, output)
+}
+
+// MarkupName describes markup's name
+var MarkupName = "markdown"
+
+func init() {
+	markup.RegisterRenderer(Renderer{})
+}
+
+// Renderer implements markup.Renderer
+type Renderer struct{}
+
+var _ markup.PostProcessRenderer = (*Renderer)(nil)
+
+// Name implements markup.Renderer
+func (Renderer) Name() string {
+	return MarkupName
+}
+
+// NeedPostProcess implements markup.PostProcessRenderer
+func (Renderer) NeedPostProcess() bool { return true }
+
+// Extensions implements markup.Renderer
+func (Renderer) Extensions() []string {
+	return setting.Markdown.FileExtensions
+}
+
+// SanitizerRules implements markup.Renderer
+func (Renderer) SanitizerRules() []setting.MarkupSanitizerRule {
+	return []setting.MarkupSanitizerRule{}
+}
+
+// Render implements markup.Renderer
+func (Renderer) Render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
+	return render(ctx, input, output)
+}
+
+// Render renders Markdown to HTML with all specific handling stuff.
+func Render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
+	if ctx.Type == "" {
+		ctx.Type = MarkupName
+	}
+	return markup.Render(ctx, input, output)
+}
+
+// RenderString renders Markdown string to HTML with all specific handling stuff and return string
+func RenderString(ctx *markup.RenderContext, content string) (template.HTML, error) {
+	var buf strings.Builder
+	if err := Render(ctx, strings.NewReader(content), &buf); err != nil {
+		return "", err
+	}
+	return template.HTML(buf.String()), nil
+}
+
+// RenderRaw renders Markdown to HTML without handling special links.
+func RenderRaw(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
+	rd, wr := io.Pipe()
+	defer func() {
+		_ = rd.Close()
+		_ = wr.Close()
+	}()
+
+	go func() {
+		if err := render(ctx, input, wr); err != nil {
+			_ = wr.CloseWithError(err)
+			return
+		}
+		_ = wr.Close()
+	}()
+
+	return markup.SanitizeReader(rd, "", output)
+}
+
+// RenderRawString renders Markdown to HTML without handling special links and return string
+func RenderRawString(ctx *markup.RenderContext, content string) (string, error) {
+	var buf strings.Builder
+	if err := RenderRaw(ctx, strings.NewReader(content), &buf); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
diff --git a/modules/markup/markdown/markdown_test.go b/modules/markup/markdown/markdown_test.go
new file mode 100644
index 0000000..cc2beca
--- /dev/null
+++ b/modules/markup/markdown/markdown_test.go
@@ -0,0 +1,1365 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown_test
+
+import (
+	"context"
+	"html/template"
+	"os"
+	"strings"
+	"testing"
+
+	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/markup/markdown"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/test"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const (
+	AppURL  = "http://localhost:3000/"
+	FullURL = AppURL + "gogits/gogs/"
+)
+
+// these values should match the const above
+var localMetas = map[string]string{
+	"user":     "gogits",
+	"repo":     "gogs",
+	"repoPath": "../../../tests/gitea-repositories-meta/user13/repo11.git/",
+}
+
+func TestMain(m *testing.M) {
+	unittest.InitSettings()
+	if err := git.InitSimple(context.Background()); err != nil {
+		log.Fatal("git init failed, err: %v", err)
+	}
+	markup.Init(&markup.ProcessorHelper{
+		IsUsernameMentionable: func(ctx context.Context, username string) bool {
+			return username == "r-lyeh"
+		},
+	})
+	os.Exit(m.Run())
+}
+
+func TestRender_StandardLinks(t *testing.T) {
+	setting.AppURL = AppURL
+
+	test := func(input, expected, expectedWiki string) {
+		buffer, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: FullURL,
+			},
+		}, input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(buffer)))
+
+		buffer, err = markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: FullURL,
+			},
+			IsWiki: true,
+		}, input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expectedWiki), strings.TrimSpace(string(buffer)))
+	}
+
+	googleRendered := `<p><a href="https://google.com/" rel="nofollow">https://google.com/</a></p>`
+	test("<https://google.com/>", googleRendered, googleRendered)
+
+	lnk := util.URLJoin(FullURL, "WikiPage")
+	lnkWiki := util.URLJoin(FullURL, "wiki", "WikiPage")
+	test("[WikiPage](WikiPage)",
+		`<p><a href="`+lnk+`" rel="nofollow">WikiPage</a></p>`,
+		`<p><a href="`+lnkWiki+`" rel="nofollow">WikiPage</a></p>`)
+}
+
+func TestRender_Images(t *testing.T) {
+	setting.AppURL = AppURL
+
+	test := func(input, expected string) {
+		buffer, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: FullURL,
+			},
+		}, input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(buffer)))
+	}
+
+	url := "../../.images/src/02/train.jpg"
+	title := "Train"
+	href := "https://gitea.io"
+	result := util.URLJoin(FullURL, url)
+	// hint: With Markdown v2.5.2, there is a new syntax: [link](URL){:target="_blank"} , but we do not support it now
+
+	test(
+		"!["+title+"]("+url+")",
+		`<p><a href="`+result+`" target="_blank" rel="nofollow noopener"><img src="`+result+`" alt="`+title+`"/></a></p>`)
+
+	test(
+		"[["+title+"|"+url+"]]",
+		`<p><a href="`+result+`" rel="nofollow"><img src="`+result+`" title="`+title+`" alt="`+title+`"/></a></p>`)
+	test(
+		"[!["+title+"]("+url+")]("+href+")",
+		`<p><a href="`+href+`" rel="nofollow"><img src="`+result+`" alt="`+title+`"/></a></p>`)
+
+	test(
+		"!["+title+"]("+url+")",
+		`<p><a href="`+result+`" target="_blank" rel="nofollow noopener"><img src="`+result+`" alt="`+title+`"/></a></p>`)
+
+	test(
+		"[["+title+"|"+url+"]]",
+		`<p><a href="`+result+`" rel="nofollow"><img src="`+result+`" title="`+title+`" alt="`+title+`"/></a></p>`)
+	test(
+		"[!["+title+"]("+url+")]("+href+")",
+		`<p><a href="`+href+`" rel="nofollow"><img src="`+result+`" alt="`+title+`"/></a></p>`)
+}
+
+func testAnswers(baseURLContent, baseURLImages string) []string {
+	return []string{
+		`<p>Wiki! Enjoy :)</p>
+<ul>
+<li><a href="` + baseURLContent + `/Links" rel="nofollow">Links, Language bindings, Engine bindings</a></li>
+<li><a href="` + baseURLContent + `/Tips" rel="nofollow">Tips</a></li>
+</ul>
+<p>See commit <a href="/gogits/gogs/commit/65f1bf27bc" rel="nofollow"><code>65f1bf27bc</code></a></p>
+<p>Ideas and codes</p>
+<ul>
+<li>Bezier widget (by <a href="/r-lyeh" rel="nofollow">@r-lyeh</a>) <a href="http://localhost:3000/ocornut/imgui/issues/786" class="ref-issue" rel="nofollow">ocornut/imgui#786</a></li>
+<li>Bezier widget (by <a href="/r-lyeh" rel="nofollow">@r-lyeh</a>) <a href="http://localhost:3000/gogits/gogs/issues/786" class="ref-issue" rel="nofollow">#786</a></li>
+<li>Node graph editors <a href="https://github.com/ocornut/imgui/issues/306" rel="nofollow">https://github.com/ocornut/imgui/issues/306</a></li>
+<li><a href="` + baseURLContent + `/memory_editor_example" rel="nofollow">Memory Editor</a></li>
+<li><a href="` + baseURLContent + `/plot_var_example" rel="nofollow">Plot var helper</a></li>
+</ul>
+`,
+		`<h2 id="user-content-what-is-wine-staging">What is Wine Staging?</h2>
+<p><strong>Wine Staging</strong> on website <a href="http://wine-staging.com" rel="nofollow">wine-staging.com</a>.</p>
+<h2 id="user-content-quick-links">Quick Links</h2>
+<p>Here are some links to the most important topics. You can find the full list of pages at the sidebar.</p>
+<table>
+<thead>
+<tr>
+<th><a href="` + baseURLImages + `/images/icon-install.png" rel="nofollow"><img src="` + baseURLImages + `/images/icon-install.png" title="icon-install.png" alt="images/icon-install.png"/></a></th>
+<th><a href="` + baseURLContent + `/Installation" rel="nofollow">Installation</a></th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td><a href="` + baseURLImages + `/images/icon-usage.png" rel="nofollow"><img src="` + baseURLImages + `/images/icon-usage.png" title="icon-usage.png" alt="images/icon-usage.png"/></a></td>
+<td><a href="` + baseURLContent + `/Usage" rel="nofollow">Usage</a></td>
+</tr>
+</tbody>
+</table>
+`,
+		`<p><a href="http://www.excelsiorjet.com/" rel="nofollow">Excelsior JET</a> allows you to create native executables for Windows, Linux and Mac OS X.</p>
+<ol>
+<li><a href="https://github.com/libgdx/libgdx/wiki/Gradle-on-the-Commandline#packaging-for-the-desktop" rel="nofollow">Package your libGDX application</a><br/>
+<a href="` + baseURLImages + `/images/1.png" rel="nofollow"><img src="` + baseURLImages + `/images/1.png" title="1.png" alt="images/1.png"/></a></li>
+<li>Perform a test run by hitting the Run! button.<br/>
+<a href="` + baseURLImages + `/images/2.png" rel="nofollow"><img src="` + baseURLImages + `/images/2.png" title="2.png" alt="images/2.png"/></a></li>
+</ol>
+<h2 id="user-content-custom-id">More tests</h2>
+<p>(from <a href="https://www.markdownguide.org/extended-syntax/" rel="nofollow">https://www.markdownguide.org/extended-syntax/</a>)</p>
+<h3 id="user-content-checkboxes">Checkboxes</h3>
+<ul>
+<li class="task-list-item"><input type="checkbox" disabled="" data-source-position="434"/>unchecked</li>
+<li class="task-list-item"><input type="checkbox" disabled="" data-source-position="450" checked=""/>checked</li>
+<li class="task-list-item"><input type="checkbox" disabled="" data-source-position="464"/>still unchecked</li>
+</ul>
+<h3 id="user-content-definition-list">Definition list</h3>
+<dl>
+<dt>First Term</dt>
+<dd>This is the definition of the first term.</dd>
+<dt>Second Term</dt>
+<dd>This is one definition of the second term.</dd>
+<dd>This is another definition of the second term.</dd>
+</dl>
+<h3 id="user-content-footnotes">Footnotes</h3>
+<p>Here is a simple footnote,<sup id="fnref:user-content-1"><a href="#fn:user-content-1" rel="nofollow">1</a></sup> and here is a longer one.<sup id="fnref:user-content-bignote"><a href="#fn:user-content-bignote" rel="nofollow">2</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-1">
+<p>This is the first footnote. <a href="#fnref:user-content-1" rel="nofollow">↩︎</a></p>
+</li>
+<li id="fn:user-content-bignote">
+<p>Here is one with multiple paragraphs and code.</p>
+<p>Indent paragraphs to include them in the footnote.</p>
+<p><code>{ my code }</code></p>
+<p>Add as many paragraphs as you like. <a href="#fnref:user-content-bignote" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`, `<ul>
+<li class="task-list-item"><input type="checkbox" disabled="" data-source-position="3"/> If you want to rebase/retry this PR, click this checkbox.</li>
+</ul>
+<hr/>
+<p>This PR has been generated by <a href="https://github.com/renovatebot/renovate" rel="nofollow">Renovate Bot</a>.</p>
+`,
+	}
+}
+
+// Test cases without ambiguous links
+var sameCases = []string{
+	// dear imgui wiki markdown extract: special wiki syntax
+	`Wiki! Enjoy :)
+- [[Links, Language bindings, Engine bindings|Links]]
+- [[Tips]]
+
+See commit 65f1bf27bc
+
+Ideas and codes
+
+- Bezier widget (by @r-lyeh) ` + AppURL + `ocornut/imgui/issues/786
+- Bezier widget (by @r-lyeh) ` + AppURL + `gogits/gogs/issues/786
+- Node graph editors https://github.com/ocornut/imgui/issues/306
+- [[Memory Editor|memory_editor_example]]
+- [[Plot var helper|plot_var_example]]`,
+	// wine-staging wiki home extract: tables, special wiki syntax, images
+	`## What is Wine Staging?
+**Wine Staging** on website [wine-staging.com](http://wine-staging.com).
+
+## Quick Links
+Here are some links to the most important topics. You can find the full list of pages at the sidebar.
+
+| [[images/icon-install.png]]    | [[Installation]]                                         |
+|--------------------------------|----------------------------------------------------------|
+| [[images/icon-usage.png]]      | [[Usage]]                                                |
+`,
+	// libgdx wiki page: inline images with special syntax
+	`[Excelsior JET](http://www.excelsiorjet.com/) allows you to create native executables for Windows, Linux and Mac OS X.
+
+1. [Package your libGDX application](https://github.com/libgdx/libgdx/wiki/Gradle-on-the-Commandline#packaging-for-the-desktop)
+[[images/1.png]]
+2. Perform a test run by hitting the Run! button.
+[[images/2.png]]
+
+## More tests {#custom-id}
+
+(from https://www.markdownguide.org/extended-syntax/)
+
+### Checkboxes
+
+- [ ] unchecked
+- [x] checked
+- [ ] still unchecked
+
+### Definition list
+
+First Term
+: This is the definition of the first term.
+
+Second Term
+: This is one definition of the second term.
+: This is another definition of the second term.
+
+### Footnotes
+
+Here is a simple footnote,[^1] and here is a longer one.[^bignote]
+
+[^1]: This is the first footnote.
+
+[^bignote]: Here is one with multiple paragraphs and code.
+
+    Indent paragraphs to include them in the footnote.
+
+    ` + "`{ my code }`" + `
+
+    Add as many paragraphs as you like.
+`,
+	`
+- [ ] <!-- rebase-check --> If you want to rebase/retry this PR, click this checkbox.
+
+---
+
+This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
+
+<!-- test-comment -->`,
+}
+
+func TestTotal_RenderWiki(t *testing.T) {
+	setting.AppURL = AppURL
+
+	answers := testAnswers(util.URLJoin(FullURL, "wiki"), util.URLJoin(FullURL, "wiki", "raw"))
+
+	for i := 0; i < len(sameCases); i++ {
+		line, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: FullURL,
+			},
+			Metas:  localMetas,
+			IsWiki: true,
+		}, sameCases[i])
+		require.NoError(t, err)
+		assert.Equal(t, template.HTML(answers[i]), line)
+	}
+
+	testCases := []string{
+		// Guard wiki sidebar: special syntax
+		`[[Guardfile-DSL / Configuring-Guard|Guardfile-DSL---Configuring-Guard]]`,
+		// rendered
+		`<p><a href="` + FullURL + `wiki/Guardfile-DSL---Configuring-Guard" rel="nofollow">Guardfile-DSL / Configuring-Guard</a></p>
+`,
+		// special syntax
+		`[[Name|Link]]`,
+		// rendered
+		`<p><a href="` + FullURL + `wiki/Link" rel="nofollow">Name</a></p>
+`,
+	}
+
+	for i := 0; i < len(testCases); i += 2 {
+		line, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: FullURL,
+			},
+			IsWiki: true,
+		}, testCases[i])
+		require.NoError(t, err)
+		assert.Equal(t, template.HTML(testCases[i+1]), line)
+	}
+}
+
+func TestTotal_RenderString(t *testing.T) {
+	setting.AppURL = AppURL
+
+	answers := testAnswers(util.URLJoin(FullURL, "src", "master"), util.URLJoin(FullURL, "media", "master"))
+
+	for i := 0; i < len(sameCases); i++ {
+		line, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base:       FullURL,
+				BranchPath: "master",
+			},
+			Metas: localMetas,
+		}, sameCases[i])
+		require.NoError(t, err)
+		assert.Equal(t, template.HTML(answers[i]), line)
+	}
+
+	testCases := []string{}
+
+	for i := 0; i < len(testCases); i += 2 {
+		line, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base: FullURL,
+			},
+		}, testCases[i])
+		require.NoError(t, err)
+		assert.Equal(t, template.HTML(testCases[i+1]), line)
+	}
+}
+
+func TestRender_RenderParagraphs(t *testing.T) {
+	test := func(t *testing.T, str string, cnt int) {
+		res, err := markdown.RenderRawString(&markup.RenderContext{Ctx: git.DefaultContext}, str)
+		require.NoError(t, err)
+		assert.Equal(t, cnt, strings.Count(res, "<p"), "Rendered result for unix should have %d paragraph(s) but has %d:\n%s\n", cnt, strings.Count(res, "<p"), res)
+
+		mac := strings.ReplaceAll(str, "\n", "\r")
+		res, err = markdown.RenderRawString(&markup.RenderContext{Ctx: git.DefaultContext}, mac)
+		require.NoError(t, err)
+		assert.Equal(t, cnt, strings.Count(res, "<p"), "Rendered result for mac should have %d paragraph(s) but has %d:\n%s\n", cnt, strings.Count(res, "<p"), res)
+
+		dos := strings.ReplaceAll(str, "\n", "\r\n")
+		res, err = markdown.RenderRawString(&markup.RenderContext{Ctx: git.DefaultContext}, dos)
+		require.NoError(t, err)
+		assert.Equal(t, cnt, strings.Count(res, "<p"), "Rendered result for windows should have %d paragraph(s) but has %d:\n%s\n", cnt, strings.Count(res, "<p"), res)
+	}
+
+	test(t, "\nOne\nTwo\nThree", 1)
+	test(t, "\n\nOne\nTwo\nThree", 1)
+	test(t, "\n\nOne\nTwo\nThree\n\n\n", 1)
+	test(t, "A\n\nB\nC\n", 2)
+	test(t, "A\n\n\nB\nC\n", 2)
+}
+
+func TestMarkdownRenderRaw(t *testing.T) {
+	testcases := [][]byte{
+		{ // clusterfuzz_testcase_minimized_fuzz_markdown_render_raw_6267570554535936
+			0x2a, 0x20, 0x2d, 0x0a, 0x09, 0x20, 0x60, 0x5b, 0x0a, 0x09, 0x20, 0x60,
+			0x5b,
+		},
+		{ // clusterfuzz_testcase_minimized_fuzz_markdown_render_raw_6278827345051648
+			0x2d, 0x20, 0x2d, 0x0d, 0x09, 0x60, 0x0d, 0x09, 0x60,
+		},
+		{ // clusterfuzz_testcase_minimized_fuzz_markdown_render_raw_6016973788020736[] = {
+			0x7b, 0x63, 0x6c, 0x61, 0x73, 0x73, 0x3d, 0x35, 0x7d, 0x0a, 0x3d,
+		},
+	}
+
+	for _, testcase := range testcases {
+		log.Info("Test markdown render error with fuzzy data: %x, the following errors can be recovered", testcase)
+		_, err := markdown.RenderRawString(&markup.RenderContext{Ctx: git.DefaultContext}, string(testcase))
+		require.NoError(t, err)
+	}
+}
+
+func TestRenderSiblingImages_Issue12925(t *testing.T) {
+	testcase := `![image1](/image1)
+![image2](/image2)
+`
+	expected := `<p><a href="/image1" target="_blank" rel="nofollow noopener"><img src="/image1" alt="image1"></a><br>
+<a href="/image2" target="_blank" rel="nofollow noopener"><img src="/image2" alt="image2"></a></p>
+`
+	res, err := markdown.RenderRawString(&markup.RenderContext{Ctx: git.DefaultContext}, testcase)
+	require.NoError(t, err)
+	assert.Equal(t, expected, res)
+}
+
+func TestRenderEmojiInLinks_Issue12331(t *testing.T) {
+	testcase := `[Link with emoji :moon: in text](https://gitea.io)`
+	expected := `<p><a href="https://gitea.io" rel="nofollow">Link with emoji <span class="emoji" aria-label="waxing gibbous moon">🌔</span> in text</a></p>
+`
+	res, err := markdown.RenderString(&markup.RenderContext{Ctx: git.DefaultContext}, testcase)
+	require.NoError(t, err)
+	assert.Equal(t, template.HTML(expected), res)
+}
+
+func TestColorPreview(t *testing.T) {
+	const nl = "\n"
+	positiveTests := []struct {
+		testcase string
+		expected string
+	}{
+		{ // hex
+			"`#FF0000`",
+			`<p><code>#FF0000<span class="color-preview" style="background-color: #FF0000"></span></code></p>` + nl,
+		},
+		{ // rgb
+			"`rgb(16, 32, 64)`",
+			`<p><code>rgb(16, 32, 64)<span class="color-preview" style="background-color: rgb(16, 32, 64)"></span></code></p>` + nl,
+		},
+		{ // short hex
+			"This is the color white `#000`",
+			`<p>This is the color white <code>#000<span class="color-preview" style="background-color: #000"></span></code></p>` + nl,
+		},
+		{ // hsl
+			"HSL stands for hue, saturation, and lightness. An example: `hsl(0, 100%, 50%)`.",
+			`<p>HSL stands for hue, saturation, and lightness. An example: <code>hsl(0, 100%, 50%)<span class="color-preview" style="background-color: hsl(0, 100%, 50%)"></span></code>.</p>` + nl,
+		},
+		{ // uppercase hsl
+			"HSL stands for hue, saturation, and lightness. An example: `HSL(0, 100%, 50%)`.",
+			`<p>HSL stands for hue, saturation, and lightness. An example: <code>HSL(0, 100%, 50%)<span class="color-preview" style="background-color: HSL(0, 100%, 50%)"></span></code>.</p>` + nl,
+		},
+	}
+
+	for _, test := range positiveTests {
+		res, err := markdown.RenderString(&markup.RenderContext{Ctx: git.DefaultContext}, test.testcase)
+		require.NoError(t, err, "Unexpected error in testcase: %q", test.testcase)
+		assert.Equal(t, template.HTML(test.expected), res, "Unexpected result in testcase %q", test.testcase)
+	}
+
+	negativeTests := []string{
+		// not a color code
+		"`FF0000`",
+		// inside a code block
+		"```javascript" + nl + `const red = "#FF0000";` + nl + "```",
+		// no backticks
+		"rgb(166, 32, 64)",
+		// typo
+		"`hsI(0, 100%, 50%)`", // codespell-ignore
+		// looks like a color but not really
+		"`hsl(40, 60, 80)`",
+	}
+
+	for _, test := range negativeTests {
+		res, err := markdown.RenderString(&markup.RenderContext{Ctx: git.DefaultContext}, test)
+		require.NoError(t, err, "Unexpected error in testcase: %q", test)
+		assert.NotContains(t, res, `<span class="color-preview" style="background-color: `, "Unexpected result in testcase %q", test)
+	}
+}
+
+func TestMathBlock(t *testing.T) {
+	const nl = "\n"
+	testcases := []struct {
+		testcase string
+		expected string
+	}{
+		{
+			"$a$",
+			`<p><code class="language-math is-loading">a</code></p>` + nl,
+		},
+		{
+			"$ a $",
+			`<p><code class="language-math is-loading">a</code></p>` + nl,
+		},
+		{
+			"$a$ $b$",
+			`<p><code class="language-math is-loading">a</code> <code class="language-math is-loading">b</code></p>` + nl,
+		},
+		{
+			`\(a\) \(b\)`,
+			`<p><code class="language-math is-loading">a</code> <code class="language-math is-loading">b</code></p>` + nl,
+		},
+		{
+			`$a$.`,
+			`<p><code class="language-math is-loading">a</code>.</p>` + nl,
+		},
+		{
+			`.$a$`,
+			`<p>.$a$</p>` + nl,
+		},
+		{
+			`$a a$b b$`,
+			`<p>$a a$b b$</p>` + nl,
+		},
+		{
+			`a a$b b`,
+			`<p>a a$b b</p>` + nl,
+		},
+		{
+			`a$b $a a$b b$`,
+			`<p>a$b $a a$b b$</p>` + nl,
+		},
+		{
+			"a$x$",
+			`<p>a$x$</p>` + nl,
+		},
+		{
+			"$x$a",
+			`<p>$x$a</p>` + nl,
+		},
+		{
+			"$$a$$",
+			`<pre class="code-block is-loading"><code class="chroma language-math display">a</code></pre>` + nl,
+		},
+		{
+			`\[a b\]`,
+			`<pre class="code-block is-loading"><code class="chroma language-math display">a b</code></pre>` + nl,
+		},
+		{
+			`\[a b]`,
+			`<p>[a b]</p>` + nl,
+		},
+		{
+			`$$a`,
+			`<p>$$a</p>` + nl,
+		},
+		{
+			"$a$ ($b$) [$c$] {$d$}",
+			`<p><code class="language-math is-loading">a</code> (<code class="language-math is-loading">b</code>) [$c$] {$d$}</p>` + nl,
+		},
+		{
+			"$$a$$ test",
+			`<p><code class="language-math display is-loading">a</code> test</p>` + nl,
+		},
+		{
+			"test $$a$$",
+			`<p>test <code class="language-math display is-loading">a</code></p>` + nl,
+		},
+	}
+
+	for _, test := range testcases {
+		res, err := markdown.RenderString(&markup.RenderContext{Ctx: git.DefaultContext}, test.testcase)
+		require.NoError(t, err, "Unexpected error in testcase: %q", test.testcase)
+		assert.Equal(t, template.HTML(test.expected), res, "Unexpected result in testcase %q", test.testcase)
+	}
+}
+
+func TestFootnote(t *testing.T) {
+	testcases := []struct {
+		testcase string
+		expected string
+	}{
+		{
+			`Citation needed[^0].
+[^0]: Source`,
+			`<p>Citation needed<sup id="fnref:user-content-0"><a href="#fn:user-content-0" rel="nofollow">1</a></sup>.</p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-0">
+<p>Source <a href="#fnref:user-content-0" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Citation needed[^0]`,
+			`<p>Citation needed[^0]</p>
+`,
+		},
+		{
+			`Citation needed[^1], Citation needed twice[^3]
+[^3]: Source`,
+			`<p>Citation needed[^1], Citation needed twice<sup id="fnref:user-content-3"><a href="#fn:user-content-3" rel="nofollow">1</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-3">
+<p>Source <a href="#fnref:user-content-3" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Citation needed[^0]
+[^1]: Source`,
+			`<p>Citation needed[^0]</p>
+`,
+		},
+		{
+			`Citation needed[^0]
+[^0]: Source 1
+[^0]: Source 2`,
+			`<p>Citation needed<sup id="fnref:user-content-0"><a href="#fn:user-content-0" rel="nofollow">1</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-0">
+<p>Source 1 <a href="#fnref:user-content-0" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Citation needed![^0]
+[^0]: Source`,
+			`<p>Citation needed<sup id="fnref:user-content-0"><a href="#fn:user-content-0" rel="nofollow">1</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-0">
+<p>Source <a href="#fnref:user-content-0" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Trigger [^`,
+			`<p>Trigger [^</p>
+`,
+		},
+		{
+			`Trigger 2 [^0`,
+			`<p>Trigger 2 [^0</p>
+`,
+		},
+		{
+			`Citation needed[^0]
+[^0]: Source with citation needed[^1]
+[^1]: Source`,
+			`<p>Citation needed<sup id="fnref:user-content-0"><a href="#fn:user-content-0" rel="nofollow">1</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-0">
+<p>Source with citation needed<sup id="fnref:user-content-1"><a href="#fn:user-content-1" rel="nofollow">2</a></sup> <a href="#fnref:user-content-0" rel="nofollow">↩︎</a></p>
+</li>
+<li id="fn:user-content-1">
+<p>Source <a href="#fnref:user-content-1" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Citation needed[^#]
+[^#]: Source`,
+			`<p>Citation needed<sup id="fnref:user-content-1"><a href="#fn:user-content-1" rel="nofollow">1</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-1">
+<p>Source <a href="#fnref:user-content-1" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Citation needed[^0]
+    [^0]: Source`,
+			`<p>Citation needed[^0]<br/>
+[^0]: Source</p>
+`,
+		},
+		{
+			`[^0]: Source
+
+Citation needed[^0].`,
+			`<p>Citation needed<sup id="fnref:user-content-0"><a href="#fn:user-content-0" rel="nofollow">1</a></sup>.</p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-0">
+<p>Source <a href="#fnref:user-content-0" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Citation needed[^]
+[^]: Source`,
+			`<p>Citation needed[^]<br/>
+[^]: Source</p>
+`,
+		},
+		{
+			`Citation needed[^0]
+[^0] Source`,
+			`<p>Citation needed[^0]<br/>
+[^0] Source</p>
+`,
+		},
+		{
+			`Citation needed[^0]
+[^0 Source`,
+			`<p>Citation needed[^0]<br/>
+[^0 Source</p>
+`,
+		},
+		{
+			`Citation needed[^0] [^0]: Source`,
+			`<p>Citation needed[^0] [^0]: Source</p>
+`,
+		},
+		{
+			`Citation needed[^Source here 0 # 9-3]
+[^Source here 0 # 9-3]: Source`,
+			`<p>Citation needed<sup id="fnref:user-content-source-here-0-9-3"><a href="#fn:user-content-source-here-0-9-3" rel="nofollow">1</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-source-here-0-9-3">
+<p>Source <a href="#fnref:user-content-source-here-0-9-3" rel="nofollow">↩︎</a></p>
+</li>
+</ol>
+</div>
+`,
+		},
+		{
+			`Citation needed[^0]
+[^0]:`,
+			`<p>Citation needed<sup id="fnref:user-content-0"><a href="#fn:user-content-0" rel="nofollow">1</a></sup></p>
+<div>
+<hr/>
+<ol>
+<li id="fn:user-content-0">
+ <a href="#fnref:user-content-0" rel="nofollow">↩︎</a></li>
+</ol>
+</div>
+`,
+		},
+	}
+	for _, test := range testcases {
+		res, err := markdown.RenderString(&markup.RenderContext{Ctx: git.DefaultContext}, test.testcase)
+		require.NoError(t, err, "Unexpected error in testcase: %q", test.testcase)
+		assert.Equal(t, test.expected, string(res), "Unexpected result in testcase %q", test.testcase)
+	}
+}
+
+func TestTaskList(t *testing.T) {
+	testcases := []struct {
+		testcase string
+		expected string
+	}{
+		{
+			// data-source-position should take into account YAML frontmatter.
+			`---
+foo: bar
+---
+- [ ] task 1`,
+			`<details><summary><i class="icon table"></i></summary><table>
+<thead>
+<tr>
+<th>foo</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>bar</td>
+</tr>
+</tbody>
+</table>
+</details><ul>
+<li class="task-list-item"><input type="checkbox" disabled="" data-source-position="19"/>task 1</li>
+</ul>
+`,
+		},
+	}
+
+	for _, test := range testcases {
+		res, err := markdown.RenderString(&markup.RenderContext{Ctx: git.DefaultContext}, test.testcase)
+		require.NoError(t, err, "Unexpected error in testcase: %q", test.testcase)
+		assert.Equal(t, template.HTML(test.expected), res, "Unexpected result in testcase %q", test.testcase)
+	}
+}
+
+func TestRenderLinks(t *testing.T) {
+	input := `  space @mention-user${SPACE}${SPACE}
+/just/a/path.bin
+https://example.com/file.bin
+[local link](file.bin)
+[remote link](https://example.com)
+[[local link|file.bin]]
+[[remote link|https://example.com]]
+![local image](image.jpg)
+![local image](path/file)
+![local image](/path/file)
+![remote image](https://example.com/image.jpg)
+[[local image|image.jpg]]
+[[remote link|https://example.com/image.jpg]]
+https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare
+https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit
+:+1:
+mail@domain.com
+@mention-user test
+#123
+  space${SPACE}${SPACE}
+`
+	input = strings.ReplaceAll(input, "${SPACE}", " ") // replace ${SPACE} with " ", to avoid some editor's auto-trimming
+	cases := []struct {
+		Links    markup.Links
+		IsWiki   bool
+		Expected string
+	}{
+		{ // 0
+			Links:  markup.Links{},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/src/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/image.jpg" target="_blank" rel="nofollow noopener"><img src="/image.jpg" alt="local image"/></a><br/>
+<a href="/path/file" target="_blank" rel="nofollow noopener"><img src="/path/file" alt="local image"/></a><br/>
+<a href="/path/file" target="_blank" rel="nofollow noopener"><img src="/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/image.jpg" rel="nofollow"><img src="/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 1
+			Links:  markup.Links{},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/wiki/raw/image.jpg" rel="nofollow"><img src="/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 2
+			Links: markup.Links{
+				Base: "https://gitea.io/",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="https://gitea.io/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/src/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/image.jpg" alt="local image"/></a><br/>
+<a href="https://gitea.io/path/file" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/path/file" alt="local image"/></a><br/>
+<a href="https://gitea.io/path/file" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="https://gitea.io/image.jpg" rel="nofollow"><img src="https://gitea.io/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 3
+			Links: markup.Links{
+				Base: "https://gitea.io/",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="https://gitea.io/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="https://gitea.io/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="https://gitea.io/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="https://gitea.io/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="https://gitea.io/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="https://gitea.io/wiki/raw/image.jpg" rel="nofollow"><img src="https://gitea.io/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 4
+			Links: markup.Links{
+				Base: "/relative/path",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/src/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/image.jpg" alt="local image"/></a><br/>
+<a href="/relative/path/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/path/file" alt="local image"/></a><br/>
+<a href="/relative/path/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/image.jpg" rel="nofollow"><img src="/relative/path/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 5
+			Links: markup.Links{
+				Base: "/relative/path",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 6
+			Links: markup.Links{
+				Base:       "/user/repo",
+				BranchPath: "branch/main",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/user/repo/src/branch/main/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/src/branch/main/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/media/branch/main/image.jpg" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/image.jpg" alt="local image"/></a><br/>
+<a href="/user/repo/media/branch/main/path/file" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/path/file" alt="local image"/></a><br/>
+<a href="/user/repo/media/branch/main/path/file" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/user/repo/media/branch/main/image.jpg" rel="nofollow"><img src="/user/repo/media/branch/main/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 7
+			Links: markup.Links{
+				Base:       "/relative/path",
+				BranchPath: "branch/main",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 8
+			Links: markup.Links{
+				Base:     "/user/repo",
+				TreePath: "sub/folder",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/user/repo/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/src/sub/folder/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/image.jpg" target="_blank" rel="nofollow noopener"><img src="/user/repo/image.jpg" alt="local image"/></a><br/>
+<a href="/user/repo/path/file" target="_blank" rel="nofollow noopener"><img src="/user/repo/path/file" alt="local image"/></a><br/>
+<a href="/user/repo/path/file" target="_blank" rel="nofollow noopener"><img src="/user/repo/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/user/repo/image.jpg" rel="nofollow"><img src="/user/repo/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 9
+			Links: markup.Links{
+				Base:     "/relative/path",
+				TreePath: "sub/folder",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 10
+			Links: markup.Links{
+				Base:       "/user/repo",
+				BranchPath: "branch/main",
+				TreePath:   "sub/folder",
+			},
+			IsWiki: false,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/user/repo/src/branch/main/sub/folder/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/src/branch/main/sub/folder/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/user/repo/media/branch/main/sub/folder/image.jpg" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/sub/folder/image.jpg" alt="local image"/></a><br/>
+<a href="/user/repo/media/branch/main/sub/folder/path/file" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/sub/folder/path/file" alt="local image"/></a><br/>
+<a href="/user/repo/media/branch/main/sub/folder/path/file" target="_blank" rel="nofollow noopener"><img src="/user/repo/media/branch/main/sub/folder/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/user/repo/media/branch/main/sub/folder/image.jpg" rel="nofollow"><img src="/user/repo/media/branch/main/sub/folder/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+		{ // 11
+			Links: markup.Links{
+				Base:       "/relative/path",
+				BranchPath: "branch/main",
+				TreePath:   "sub/folder",
+			},
+			IsWiki: true,
+			Expected: `<p>space @mention-user<br/>
+/just/a/path.bin<br/>
+<a href="https://example.com/file.bin" rel="nofollow">https://example.com/file.bin</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/file.bin" rel="nofollow">local link</a><br/>
+<a href="https://example.com" rel="nofollow">remote link</a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/image.jpg" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="/relative/path/wiki/raw/path/file" target="_blank" rel="nofollow noopener"><img src="/relative/path/wiki/raw/path/file" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" target="_blank" rel="nofollow noopener"><img src="https://example.com/image.jpg" alt="remote image"/></a><br/>
+<a href="/relative/path/wiki/raw/image.jpg" rel="nofollow"><img src="/relative/path/wiki/raw/image.jpg" title="local image" alt="local image"/></a><br/>
+<a href="https://example.com/image.jpg" rel="nofollow"><img src="https://example.com/image.jpg" title="remote link" alt="remote link"/></a><br/>
+<a href="https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash" rel="nofollow">https://example.com/user/repo/compare/88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb#hash</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb...12fc37a3c0a4dda553bdcfc80c178a58247f42fb pare<br/>
+<a href="https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb" rel="nofollow">https://example.com/user/repo/commit/88fc37a3c0a4dda553bdcfc80c178a58247f42fb</a><br/>
+com 88fc37a3c0a4dda553bdcfc80c178a58247f42fb mit<br/>
+<span class="emoji" aria-label="thumbs up">👍</span><br/>
+<a href="mailto:mail@domain.com" rel="nofollow">mail@domain.com</a><br/>
+@mention-user test<br/>
+#123<br/>
+space</p>
+`,
+		},
+	}
+
+	for i, c := range cases {
+		result, err := markdown.RenderString(&markup.RenderContext{Ctx: context.Background(), Links: c.Links, IsWiki: c.IsWiki}, input)
+		require.NoError(t, err, "Unexpected error in testcase: %v", i)
+		assert.Equal(t, template.HTML(c.Expected), result, "Unexpected result in testcase %v", i)
+	}
+}
+
+func TestCustomMarkdownURL(t *testing.T) {
+	defer test.MockVariableValue(&setting.Markdown.CustomURLSchemes, []string{"abp"})()
+	setting.AppURL = AppURL
+
+	test := func(input, expected string) {
+		buffer, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+			Links: markup.Links{
+				Base:       FullURL,
+				BranchPath: "branch/main",
+			},
+		}, input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(buffer)))
+	}
+
+	test("[test](abp:subscribe?location=https://codeberg.org/filters.txt&amp;title=joy)",
+		`<p><a href="abp:subscribe?location=https://codeberg.org/filters.txt&amp;title=joy" rel="nofollow">test</a></p>`)
+
+	// Ensure that the schema itself without `:` is still made absolute.
+	test("[test](abp)",
+		`<p><a href="http://localhost:3000/gogits/gogs/src/branch/main/abp" rel="nofollow">test</a></p>`)
+}
+
+func TestYAMLMeta(t *testing.T) {
+	setting.AppURL = AppURL
+
+	test := func(input, expected string) {
+		buffer, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+		}, input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(buffer)))
+	}
+
+	test(`---
+include_toc: true
+---
+## Header`,
+		`<details><summary><i class="icon table"></i></summary><table>
+<thead>
+<tr>
+<th>include_toc</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>true</td>
+</tr>
+</tbody>
+</table>
+</details><details><summary>toc</summary><ul>
+<li>
+<a href="#user-content-header" rel="nofollow">Header</a></li>
+</ul>
+</details><h2 id="user-content-header">Header</h2>`)
+
+	test(`---
+key: value
+---`,
+		`<details><summary><i class="icon table"></i></summary><table>
+<thead>
+<tr>
+<th>key</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>value</td>
+</tr>
+</tbody>
+</table>
+</details>`)
+
+	test("---\n---\n",
+		`<hr/>
+<hr/>`)
+
+	test(`---
+gitea:
+  details_icon: smiley
+  include_toc: true
+---
+# Another header`,
+		`<details><summary><i class="icon smiley"></i></summary><table>
+<thead>
+<tr>
+<th>gitea</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td><table>
+<thead>
+<tr>
+<th>details_icon</th>
+<th>include_toc</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>smiley</td>
+<td>true</td>
+</tr>
+</tbody>
+</table>
+</td>
+</tr>
+</tbody>
+</table>
+</details><details><summary>toc</summary><ul>
+<li>
+<a href="#user-content-another-header" rel="nofollow">Another header</a></li>
+</ul>
+</details><h1 id="user-content-another-header">Another header</h1>`)
+
+	test(`---
+gitea:
+  meta: table
+key: value
+---`, `<table>
+<thead>
+<tr>
+<th>gitea</th>
+<th>key</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td><table>
+<thead>
+<tr>
+<th>meta</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>table</td>
+</tr>
+</tbody>
+</table>
+</td>
+<td>value</td>
+</tr>
+</tbody>
+</table>`)
+}
+
+func TestCallout(t *testing.T) {
+	setting.AppURL = AppURL
+
+	test := func(input, expected string) {
+		buffer, err := markdown.RenderString(&markup.RenderContext{
+			Ctx: git.DefaultContext,
+		}, input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(buffer)))
+	}
+
+	test(">\n0", "<blockquote>\n</blockquote>\n<p>0</p>")
+	test("> **Warning**\n> Bad stuff is brewing here", `<blockquote class="attention-header attention-warning"><p class="attention-title"><strong class="attention-warning">Warning</strong></p>
+<p>Bad stuff is brewing here</p>
+</blockquote>`)
+	test("> [!WARNING]\n> Bad stuff is brewing here", `<blockquote class="attention-header attention-warning"><p class="attention-title"><strong class="attention-warning">Warning</strong></p>
+<p>Bad stuff is brewing here</p>
+</blockquote>`)
+}
diff --git a/modules/markup/markdown/math/block_node.go b/modules/markup/markdown/math/block_node.go
new file mode 100644
index 0000000..10d17ff
--- /dev/null
+++ b/modules/markup/markdown/math/block_node.go
@@ -0,0 +1,41 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import "github.com/yuin/goldmark/ast"
+
+// Block represents a display math block e.g. $$...$$ or \[...\]
+type Block struct {
+	ast.BaseBlock
+	Dollars bool
+	Indent  int
+	Closed  bool
+}
+
+// KindBlock is the node kind for math blocks
+var KindBlock = ast.NewNodeKind("MathBlock")
+
+// NewBlock creates a new math Block
+func NewBlock(dollars bool, indent int) *Block {
+	return &Block{
+		Dollars: dollars,
+		Indent:  indent,
+	}
+}
+
+// Dump dumps the block to a string
+func (n *Block) Dump(source []byte, level int) {
+	m := map[string]string{}
+	ast.DumpHelper(n, source, level, m, nil)
+}
+
+// Kind returns KindBlock for math Blocks
+func (n *Block) Kind() ast.NodeKind {
+	return KindBlock
+}
+
+// IsRaw returns true as this block should not be processed further
+func (n *Block) IsRaw() bool {
+	return true
+}
diff --git a/modules/markup/markdown/math/block_parser.go b/modules/markup/markdown/math/block_parser.go
new file mode 100644
index 0000000..527df84
--- /dev/null
+++ b/modules/markup/markdown/math/block_parser.go
@@ -0,0 +1,125 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import (
+	"bytes"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+type blockParser struct {
+	parseDollars bool
+}
+
+// NewBlockParser creates a new math BlockParser
+func NewBlockParser(parseDollarBlocks bool) parser.BlockParser {
+	return &blockParser{
+		parseDollars: parseDollarBlocks,
+	}
+}
+
+// Open parses the current line and returns a result of parsing.
+func (b *blockParser) Open(parent ast.Node, reader text.Reader, pc parser.Context) (ast.Node, parser.State) {
+	line, segment := reader.PeekLine()
+	pos := pc.BlockOffset()
+	if pos == -1 || len(line[pos:]) < 2 {
+		return nil, parser.NoChildren
+	}
+
+	dollars := false
+	if b.parseDollars && line[pos] == '$' && line[pos+1] == '$' {
+		dollars = true
+	} else if line[pos] != '\\' || line[pos+1] != '[' {
+		return nil, parser.NoChildren
+	}
+
+	node := NewBlock(dollars, pos)
+
+	// Now we need to check if the ending block is on the segment...
+	endBytes := []byte{'\\', ']'}
+	if dollars {
+		endBytes = []byte{'$', '$'}
+	}
+	idx := bytes.Index(line[pos+2:], endBytes)
+	if idx >= 0 {
+		// for case $$ ... $$ any other text
+		for i := pos + idx + 4; i < len(line); i++ {
+			if line[i] != ' ' && line[i] != '\n' {
+				return nil, parser.NoChildren
+			}
+		}
+		segment.Stop = segment.Start + idx + 2
+		reader.Advance(segment.Len() - 1)
+		segment.Start += 2
+		node.Lines().Append(segment)
+		node.Closed = true
+		return node, parser.Close | parser.NoChildren
+	}
+
+	return nil, parser.NoChildren
+}
+
+// Continue parses the current line and returns a result of parsing.
+func (b *blockParser) Continue(node ast.Node, reader text.Reader, pc parser.Context) parser.State {
+	block := node.(*Block)
+	if block.Closed {
+		return parser.Close
+	}
+
+	line, segment := reader.PeekLine()
+	w, pos := util.IndentWidth(line, 0)
+	if w < 4 {
+		if block.Dollars {
+			i := pos
+			for ; i < len(line) && line[i] == '$'; i++ {
+			}
+			length := i - pos
+			if length >= 2 && util.IsBlank(line[i:]) {
+				reader.Advance(segment.Stop - segment.Start - segment.Padding)
+				block.Closed = true
+				return parser.Close
+			}
+		} else if len(line[pos:]) > 1 && line[pos] == '\\' && line[pos+1] == ']' && util.IsBlank(line[pos+2:]) {
+			reader.Advance(segment.Stop - segment.Start - segment.Padding)
+			block.Closed = true
+			return parser.Close
+		}
+	}
+
+	pos, padding := util.IndentPosition(line, 0, block.Indent)
+	seg := text.NewSegmentPadding(segment.Start+pos, segment.Stop, padding)
+	node.Lines().Append(seg)
+	reader.AdvanceAndSetPadding(segment.Stop-segment.Start-pos-1, padding)
+	return parser.Continue | parser.NoChildren
+}
+
+// Close will be called when the parser returns Close.
+func (b *blockParser) Close(node ast.Node, reader text.Reader, pc parser.Context) {
+	// noop
+}
+
+// CanInterruptParagraph returns true if the parser can interrupt paragraphs,
+// otherwise false.
+func (b *blockParser) CanInterruptParagraph() bool {
+	return true
+}
+
+// CanAcceptIndentedLine returns true if the parser can open new node when
+// the given line is being indented more than 3 spaces.
+func (b *blockParser) CanAcceptIndentedLine() bool {
+	return false
+}
+
+// Trigger returns a list of characters that triggers Parse method of
+// this parser.
+// If Trigger returns a nil, Open will be called with any lines.
+//
+// We leave this as nil as our parse method is quick enough
+func (b *blockParser) Trigger() []byte {
+	return nil
+}
diff --git a/modules/markup/markdown/math/block_renderer.go b/modules/markup/markdown/math/block_renderer.go
new file mode 100644
index 0000000..84817ef
--- /dev/null
+++ b/modules/markup/markdown/math/block_renderer.go
@@ -0,0 +1,42 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import (
+	gast "github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/util"
+)
+
+// BlockRenderer represents a renderer for math Blocks
+type BlockRenderer struct{}
+
+// NewBlockRenderer creates a new renderer for math Blocks
+func NewBlockRenderer() renderer.NodeRenderer {
+	return &BlockRenderer{}
+}
+
+// RegisterFuncs registers the renderer for math Blocks
+func (r *BlockRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(KindBlock, r.renderBlock)
+}
+
+func (r *BlockRenderer) writeLines(w util.BufWriter, source []byte, n gast.Node) {
+	l := n.Lines().Len()
+	for i := 0; i < l; i++ {
+		line := n.Lines().At(i)
+		_, _ = w.Write(util.EscapeHTML(line.Value(source)))
+	}
+}
+
+func (r *BlockRenderer) renderBlock(w util.BufWriter, source []byte, node gast.Node, entering bool) (gast.WalkStatus, error) {
+	n := node.(*Block)
+	if entering {
+		_, _ = w.WriteString(`<pre class="code-block is-loading"><code class="chroma language-math display">`)
+		r.writeLines(w, source, n)
+	} else {
+		_, _ = w.WriteString(`</code></pre>` + "\n")
+	}
+	return gast.WalkContinue, nil
+}
diff --git a/modules/markup/markdown/math/inline_block_node.go b/modules/markup/markdown/math/inline_block_node.go
new file mode 100644
index 0000000..c92d0c8
--- /dev/null
+++ b/modules/markup/markdown/math/inline_block_node.go
@@ -0,0 +1,31 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import (
+	"github.com/yuin/goldmark/ast"
+)
+
+// InlineBlock represents inline math e.g. $$...$$
+type InlineBlock struct {
+	Inline
+}
+
+// InlineBlock implements InlineBlock.
+func (n *InlineBlock) InlineBlock() {}
+
+// KindInlineBlock is the kind for math inline block
+var KindInlineBlock = ast.NewNodeKind("MathInlineBlock")
+
+// Kind returns KindInlineBlock
+func (n *InlineBlock) Kind() ast.NodeKind {
+	return KindInlineBlock
+}
+
+// NewInlineBlock creates a new ast math inline block node
+func NewInlineBlock() *InlineBlock {
+	return &InlineBlock{
+		Inline{},
+	}
+}
diff --git a/modules/markup/markdown/math/inline_node.go b/modules/markup/markdown/math/inline_node.go
new file mode 100644
index 0000000..2221a25
--- /dev/null
+++ b/modules/markup/markdown/math/inline_node.go
@@ -0,0 +1,48 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import (
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/util"
+)
+
+// Inline represents inline math e.g. $...$ or \(...\)
+type Inline struct {
+	ast.BaseInline
+}
+
+// Inline implements Inline.Inline.
+func (n *Inline) Inline() {}
+
+// IsBlank returns if this inline node is empty
+func (n *Inline) IsBlank(source []byte) bool {
+	for c := n.FirstChild(); c != nil; c = c.NextSibling() {
+		text := c.(*ast.Text).Segment
+		if !util.IsBlank(text.Value(source)) {
+			return false
+		}
+	}
+	return true
+}
+
+// Dump renders this inline math as debug
+func (n *Inline) Dump(source []byte, level int) {
+	ast.DumpHelper(n, source, level, nil, nil)
+}
+
+// KindInline is the kind for math inline
+var KindInline = ast.NewNodeKind("MathInline")
+
+// Kind returns KindInline
+func (n *Inline) Kind() ast.NodeKind {
+	return KindInline
+}
+
+// NewInline creates a new ast math inline node
+func NewInline() *Inline {
+	return &Inline{
+		BaseInline: ast.BaseInline{},
+	}
+}
diff --git a/modules/markup/markdown/math/inline_parser.go b/modules/markup/markdown/math/inline_parser.go
new file mode 100644
index 0000000..b11195d
--- /dev/null
+++ b/modules/markup/markdown/math/inline_parser.go
@@ -0,0 +1,153 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import (
+	"bytes"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/text"
+)
+
+type inlineParser struct {
+	start []byte
+	end   []byte
+}
+
+var defaultInlineDollarParser = &inlineParser{
+	start: []byte{'$'},
+	end:   []byte{'$'},
+}
+
+var defaultDualDollarParser = &inlineParser{
+	start: []byte{'$', '$'},
+	end:   []byte{'$', '$'},
+}
+
+// NewInlineDollarParser returns a new inline parser
+func NewInlineDollarParser() parser.InlineParser {
+	return defaultInlineDollarParser
+}
+
+func NewInlineDualDollarParser() parser.InlineParser {
+	return defaultDualDollarParser
+}
+
+var defaultInlineBracketParser = &inlineParser{
+	start: []byte{'\\', '('},
+	end:   []byte{'\\', ')'},
+}
+
+// NewInlineDollarParser returns a new inline parser
+func NewInlineBracketParser() parser.InlineParser {
+	return defaultInlineBracketParser
+}
+
+// Trigger triggers this parser on $ or \
+func (parser *inlineParser) Trigger() []byte {
+	return parser.start
+}
+
+func isPunctuation(b byte) bool {
+	return b == '.' || b == '!' || b == '?' || b == ',' || b == ';' || b == ':'
+}
+
+func isBracket(b byte) bool {
+	return b == ')'
+}
+
+func isAlphanumeric(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || (b >= '0' && b <= '9')
+}
+
+// Parse parses the current line and returns a result of parsing.
+func (parser *inlineParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
+	line, _ := block.PeekLine()
+
+	if !bytes.HasPrefix(line, parser.start) {
+		// We'll catch this one on the next time round
+		return nil
+	}
+
+	precedingCharacter := block.PrecendingCharacter()
+	if precedingCharacter < 256 && (isAlphanumeric(byte(precedingCharacter)) || isPunctuation(byte(precedingCharacter))) {
+		// need to exclude things like `a$` from being considered a start
+		return nil
+	}
+
+	// move the opener marker point at the start of the text
+	opener := len(parser.start)
+
+	// Now look for an ending line
+	ender := opener
+	for {
+		pos := bytes.Index(line[ender:], parser.end)
+		if pos < 0 {
+			return nil
+		}
+
+		ender += pos
+
+		// Now we want to check the character at the end of our parser section
+		// that is ender + len(parser.end) and check if char before ender is '\'
+		pos = ender + len(parser.end)
+		if len(line) <= pos {
+			break
+		}
+		suceedingCharacter := line[pos]
+		// check valid ending character
+		if !isPunctuation(suceedingCharacter) &&
+			!(suceedingCharacter == ' ') &&
+			!(suceedingCharacter == '\n') &&
+			!isBracket(suceedingCharacter) {
+			return nil
+		}
+		if line[ender-1] != '\\' {
+			break
+		}
+
+		// move the pointer onwards
+		ender += len(parser.end)
+	}
+
+	block.Advance(opener)
+	_, pos := block.Position()
+	var node ast.Node
+	if parser == defaultDualDollarParser {
+		node = NewInlineBlock()
+	} else {
+		node = NewInline()
+	}
+	segment := pos.WithStop(pos.Start + ender - opener)
+	node.AppendChild(node, ast.NewRawTextSegment(segment))
+	block.Advance(ender - opener + len(parser.end))
+
+	if parser == defaultDualDollarParser {
+		trimBlock(&(node.(*InlineBlock)).Inline, block)
+	} else {
+		trimBlock(node.(*Inline), block)
+	}
+	return node
+}
+
+func trimBlock(node *Inline, block text.Reader) {
+	if node.IsBlank(block.Source()) {
+		return
+	}
+
+	// trim first space and last space
+	first := node.FirstChild().(*ast.Text)
+	if !(!first.Segment.IsEmpty() && block.Source()[first.Segment.Start] == ' ') {
+		return
+	}
+
+	last := node.LastChild().(*ast.Text)
+	if !(!last.Segment.IsEmpty() && block.Source()[last.Segment.Stop-1] == ' ') {
+		return
+	}
+
+	first.Segment = first.Segment.WithStart(first.Segment.Start + 1)
+	last.Segment = last.Segment.WithStop(last.Segment.Stop - 1)
+}
diff --git a/modules/markup/markdown/math/inline_renderer.go b/modules/markup/markdown/math/inline_renderer.go
new file mode 100644
index 0000000..9684809
--- /dev/null
+++ b/modules/markup/markdown/math/inline_renderer.go
@@ -0,0 +1,51 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import (
+	"bytes"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/util"
+)
+
+// InlineRenderer is an inline renderer
+type InlineRenderer struct{}
+
+// NewInlineRenderer returns a new renderer for inline math
+func NewInlineRenderer() renderer.NodeRenderer {
+	return &InlineRenderer{}
+}
+
+func (r *InlineRenderer) renderInline(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+	if entering {
+		extraClass := ""
+		if _, ok := n.(*InlineBlock); ok {
+			extraClass = "display "
+		}
+		_, _ = w.WriteString(`<code class="language-math ` + extraClass + `is-loading">`)
+		for c := n.FirstChild(); c != nil; c = c.NextSibling() {
+			segment := c.(*ast.Text).Segment
+			value := util.EscapeHTML(segment.Value(source))
+			if bytes.HasSuffix(value, []byte("\n")) {
+				_, _ = w.Write(value[:len(value)-1])
+				if c != n.LastChild() {
+					_, _ = w.Write([]byte(" "))
+				}
+			} else {
+				_, _ = w.Write(value)
+			}
+		}
+		return ast.WalkSkipChildren, nil
+	}
+	_, _ = w.WriteString(`</code>`)
+	return ast.WalkContinue, nil
+}
+
+// RegisterFuncs registers the renderer for inline math nodes
+func (r *InlineRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(KindInline, r.renderInline)
+	reg.Register(KindInlineBlock, r.renderInline)
+}
diff --git a/modules/markup/markdown/math/math.go b/modules/markup/markdown/math/math.go
new file mode 100644
index 0000000..3d9f376
--- /dev/null
+++ b/modules/markup/markdown/math/math.go
@@ -0,0 +1,108 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package math
+
+import (
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/util"
+)
+
+// Extension is a math extension
+type Extension struct {
+	enabled           bool
+	parseDollarInline bool
+	parseDollarBlock  bool
+}
+
+// Option is the interface Options should implement
+type Option interface {
+	SetOption(e *Extension)
+}
+
+type extensionFunc func(e *Extension)
+
+func (fn extensionFunc) SetOption(e *Extension) {
+	fn(e)
+}
+
+// Enabled enables or disables this extension
+func Enabled(enable ...bool) Option {
+	value := true
+	if len(enable) > 0 {
+		value = enable[0]
+	}
+	return extensionFunc(func(e *Extension) {
+		e.enabled = value
+	})
+}
+
+// WithInlineDollarParser enables or disables the parsing of $...$
+func WithInlineDollarParser(enable ...bool) Option {
+	value := true
+	if len(enable) > 0 {
+		value = enable[0]
+	}
+	return extensionFunc(func(e *Extension) {
+		e.parseDollarInline = value
+	})
+}
+
+// WithBlockDollarParser enables or disables the parsing of $$...$$
+func WithBlockDollarParser(enable ...bool) Option {
+	value := true
+	if len(enable) > 0 {
+		value = enable[0]
+	}
+	return extensionFunc(func(e *Extension) {
+		e.parseDollarBlock = value
+	})
+}
+
+// Math represents a math extension with default rendered delimiters
+var Math = &Extension{
+	enabled:           true,
+	parseDollarBlock:  true,
+	parseDollarInline: true,
+}
+
+// NewExtension creates a new math extension with the provided options
+func NewExtension(opts ...Option) *Extension {
+	r := &Extension{
+		enabled:           true,
+		parseDollarBlock:  true,
+		parseDollarInline: true,
+	}
+
+	for _, o := range opts {
+		o.SetOption(r)
+	}
+	return r
+}
+
+// Extend extends goldmark with our parsers and renderers
+func (e *Extension) Extend(m goldmark.Markdown) {
+	if !e.enabled {
+		return
+	}
+
+	m.Parser().AddOptions(parser.WithBlockParsers(
+		util.Prioritized(NewBlockParser(e.parseDollarBlock), 701),
+	))
+
+	inlines := []util.PrioritizedValue{
+		util.Prioritized(NewInlineBracketParser(), 501),
+	}
+	if e.parseDollarInline {
+		inlines = append(inlines, util.Prioritized(NewInlineDollarParser(), 503),
+			util.Prioritized(NewInlineDualDollarParser(), 502))
+	}
+	m.Parser().AddOptions(parser.WithInlineParsers(inlines...))
+
+	m.Renderer().AddOptions(renderer.WithNodeRenderers(
+		util.Prioritized(NewBlockRenderer(), 501),
+		util.Prioritized(NewInlineRenderer(), 502),
+	))
+}
diff --git a/modules/markup/markdown/meta.go b/modules/markup/markdown/meta.go
new file mode 100644
index 0000000..e76b253
--- /dev/null
+++ b/modules/markup/markdown/meta.go
@@ -0,0 +1,103 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"bytes"
+	"errors"
+	"unicode"
+	"unicode/utf8"
+
+	"gopkg.in/yaml.v3"
+)
+
+func isYAMLSeparator(line []byte) bool {
+	idx := 0
+	for ; idx < len(line); idx++ {
+		if line[idx] >= utf8.RuneSelf {
+			r, sz := utf8.DecodeRune(line[idx:])
+			if !unicode.IsSpace(r) {
+				return false
+			}
+			idx += sz
+			continue
+		}
+		if line[idx] != ' ' {
+			break
+		}
+	}
+	dashCount := 0
+	for ; idx < len(line); idx++ {
+		if line[idx] != '-' {
+			break
+		}
+		dashCount++
+	}
+	if dashCount < 3 {
+		return false
+	}
+	for ; idx < len(line); idx++ {
+		if line[idx] >= utf8.RuneSelf {
+			r, sz := utf8.DecodeRune(line[idx:])
+			if !unicode.IsSpace(r) {
+				return false
+			}
+			idx += sz
+			continue
+		}
+		if line[idx] != ' ' {
+			return false
+		}
+	}
+	return true
+}
+
+// ExtractMetadata consumes a markdown file, parses YAML frontmatter,
+// and returns the frontmatter metadata separated from the markdown content
+func ExtractMetadata(contents string, out any) (string, error) {
+	body, err := ExtractMetadataBytes([]byte(contents), out)
+	return string(body), err
+}
+
+// ExtractMetadata consumes a markdown file, parses YAML frontmatter,
+// and returns the frontmatter metadata separated from the markdown content
+func ExtractMetadataBytes(contents []byte, out any) ([]byte, error) {
+	var front, body []byte
+
+	start, end := 0, len(contents)
+	idx := bytes.IndexByte(contents[start:], '\n')
+	if idx >= 0 {
+		end = start + idx
+	}
+	line := contents[start:end]
+
+	if !isYAMLSeparator(line) {
+		return contents, errors.New("frontmatter must start with a separator line")
+	}
+	frontMatterStart := end + 1
+	for start = frontMatterStart; start < len(contents); start = end + 1 {
+		end = len(contents)
+		idx := bytes.IndexByte(contents[start:], '\n')
+		if idx >= 0 {
+			end = start + idx
+		}
+		line := contents[start:end]
+		if isYAMLSeparator(line) {
+			front = contents[frontMatterStart:start]
+			if end+1 < len(contents) {
+				body = contents[end+1:]
+			}
+			break
+		}
+	}
+
+	if len(front) == 0 {
+		return contents, errors.New("could not determine metadata")
+	}
+
+	if err := yaml.Unmarshal(front, out); err != nil {
+		return contents, err
+	}
+	return body, nil
+}
diff --git a/modules/markup/markdown/meta_test.go b/modules/markup/markdown/meta_test.go
new file mode 100644
index 0000000..d341ae4
--- /dev/null
+++ b/modules/markup/markdown/meta_test.go
@@ -0,0 +1,110 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+/*
+IssueTemplate is a legacy to keep the unit tests working.
+Copied from structs.IssueTemplate, the original type has been changed a lot to support yaml template.
+*/
+type IssueTemplate struct {
+	Name   string   `json:"name" yaml:"name"`
+	Title  string   `json:"title" yaml:"title"`
+	About  string   `json:"about" yaml:"about"`
+	Labels []string `json:"labels" yaml:"labels"`
+	Ref    string   `json:"ref" yaml:"ref"`
+}
+
+func (it *IssueTemplate) Valid() bool {
+	return strings.TrimSpace(it.Name) != "" && strings.TrimSpace(it.About) != ""
+}
+
+func TestExtractMetadata(t *testing.T) {
+	t.Run("ValidFrontAndBody", func(t *testing.T) {
+		var meta IssueTemplate
+		body, err := ExtractMetadata(fmt.Sprintf("%s\n%s\n%s\n%s", sepTest, frontTest, sepTest, bodyTest), &meta)
+		require.NoError(t, err)
+		assert.Equal(t, bodyTest, body)
+		assert.Equal(t, metaTest, meta)
+		assert.True(t, meta.Valid())
+	})
+
+	t.Run("NoFirstSeparator", func(t *testing.T) {
+		var meta IssueTemplate
+		_, err := ExtractMetadata(fmt.Sprintf("%s\n%s\n%s", frontTest, sepTest, bodyTest), &meta)
+		require.Error(t, err)
+	})
+
+	t.Run("NoLastSeparator", func(t *testing.T) {
+		var meta IssueTemplate
+		_, err := ExtractMetadata(fmt.Sprintf("%s\n%s\n%s", sepTest, frontTest, bodyTest), &meta)
+		require.Error(t, err)
+	})
+
+	t.Run("NoBody", func(t *testing.T) {
+		var meta IssueTemplate
+		body, err := ExtractMetadata(fmt.Sprintf("%s\n%s\n%s", sepTest, frontTest, sepTest), &meta)
+		require.NoError(t, err)
+		assert.Equal(t, "", body)
+		assert.Equal(t, metaTest, meta)
+		assert.True(t, meta.Valid())
+	})
+}
+
+func TestExtractMetadataBytes(t *testing.T) {
+	t.Run("ValidFrontAndBody", func(t *testing.T) {
+		var meta IssueTemplate
+		body, err := ExtractMetadataBytes([]byte(fmt.Sprintf("%s\n%s\n%s\n%s", sepTest, frontTest, sepTest, bodyTest)), &meta)
+		require.NoError(t, err)
+		assert.Equal(t, bodyTest, string(body))
+		assert.Equal(t, metaTest, meta)
+		assert.True(t, meta.Valid())
+	})
+
+	t.Run("NoFirstSeparator", func(t *testing.T) {
+		var meta IssueTemplate
+		_, err := ExtractMetadataBytes([]byte(fmt.Sprintf("%s\n%s\n%s", frontTest, sepTest, bodyTest)), &meta)
+		require.Error(t, err)
+	})
+
+	t.Run("NoLastSeparator", func(t *testing.T) {
+		var meta IssueTemplate
+		_, err := ExtractMetadataBytes([]byte(fmt.Sprintf("%s\n%s\n%s", sepTest, frontTest, bodyTest)), &meta)
+		require.Error(t, err)
+	})
+
+	t.Run("NoBody", func(t *testing.T) {
+		var meta IssueTemplate
+		body, err := ExtractMetadataBytes([]byte(fmt.Sprintf("%s\n%s\n%s", sepTest, frontTest, sepTest)), &meta)
+		require.NoError(t, err)
+		assert.Equal(t, "", string(body))
+		assert.Equal(t, metaTest, meta)
+		assert.True(t, meta.Valid())
+	})
+}
+
+var (
+	sepTest   = "-----"
+	frontTest = `name: Test
+about: "A Test"
+title: "Test Title"
+labels:
+  - bug
+  - "test label"`
+	bodyTest = "This is the body"
+	metaTest = IssueTemplate{
+		Name:   "Test",
+		About:  "A Test",
+		Title:  "Test Title",
+		Labels: []string{"bug", "test label"},
+	}
+)
diff --git a/modules/markup/markdown/prefixed_id.go b/modules/markup/markdown/prefixed_id.go
new file mode 100644
index 0000000..63d7fad
--- /dev/null
+++ b/modules/markup/markdown/prefixed_id.go
@@ -0,0 +1,59 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"bytes"
+	"fmt"
+
+	"code.gitea.io/gitea/modules/container"
+	"code.gitea.io/gitea/modules/markup/common"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/yuin/goldmark/ast"
+)
+
+type prefixedIDs struct {
+	values container.Set[string]
+}
+
+// Generate generates a new element id.
+func (p *prefixedIDs) Generate(value []byte, kind ast.NodeKind) []byte {
+	dft := []byte("id")
+	if kind == ast.KindHeading {
+		dft = []byte("heading")
+	}
+	return p.GenerateWithDefault(value, dft)
+}
+
+// GenerateWithDefault generates a new element id.
+func (p *prefixedIDs) GenerateWithDefault(value, dft []byte) []byte {
+	result := common.CleanValue(value)
+	if len(result) == 0 {
+		result = dft
+	}
+	if !bytes.HasPrefix(result, []byte("user-content-")) {
+		result = append([]byte("user-content-"), result...)
+	}
+	if p.values.Add(util.UnsafeBytesToString(result)) {
+		return result
+	}
+	for i := 1; ; i++ {
+		newResult := fmt.Sprintf("%s-%d", result, i)
+		if p.values.Add(newResult) {
+			return []byte(newResult)
+		}
+	}
+}
+
+// Put puts a given element id to the used ids table.
+func (p *prefixedIDs) Put(value []byte) {
+	p.values.Add(util.UnsafeBytesToString(value))
+}
+
+func newPrefixedIDs() *prefixedIDs {
+	return &prefixedIDs{
+		values: make(container.Set[string]),
+	}
+}
diff --git a/modules/markup/markdown/renderconfig.go b/modules/markup/markdown/renderconfig.go
new file mode 100644
index 0000000..f4c48d1
--- /dev/null
+++ b/modules/markup/markdown/renderconfig.go
@@ -0,0 +1,126 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/modules/markup"
+
+	"github.com/yuin/goldmark/ast"
+	"gopkg.in/yaml.v3"
+)
+
+// RenderConfig represents rendering configuration for this file
+type RenderConfig struct {
+	Meta     markup.RenderMetaMode
+	Icon     string
+	TOC      string // "false": hide,  "side"/empty: in sidebar,  "main"/"true": in main view
+	Lang     string
+	yamlNode *yaml.Node
+
+	// Used internally.  Cannot be controlled by frontmatter.
+	metaLength int
+}
+
+func renderMetaModeFromString(s string) markup.RenderMetaMode {
+	switch strings.TrimSpace(strings.ToLower(s)) {
+	case "none":
+		return markup.RenderMetaAsNone
+	case "table":
+		return markup.RenderMetaAsTable
+	default: // "details"
+		return markup.RenderMetaAsDetails
+	}
+}
+
+// UnmarshalYAML implement yaml.v3 UnmarshalYAML
+func (rc *RenderConfig) UnmarshalYAML(value *yaml.Node) error {
+	if rc == nil {
+		return nil
+	}
+
+	rc.yamlNode = value
+
+	type commonRenderConfig struct {
+		TOC  string `yaml:"include_toc"`
+		Lang string `yaml:"lang"`
+	}
+	var basic commonRenderConfig
+	if err := value.Decode(&basic); err != nil {
+		return fmt.Errorf("unable to decode into commonRenderConfig %w", err)
+	}
+
+	if basic.Lang != "" {
+		rc.Lang = basic.Lang
+	}
+
+	rc.TOC = basic.TOC
+
+	type controlStringRenderConfig struct {
+		Gitea string `yaml:"gitea"`
+	}
+
+	var stringBasic controlStringRenderConfig
+
+	if err := value.Decode(&stringBasic); err == nil {
+		if stringBasic.Gitea != "" {
+			rc.Meta = renderMetaModeFromString(stringBasic.Gitea)
+		}
+		return nil
+	}
+
+	type yamlRenderConfig struct {
+		Meta *string `yaml:"meta"`
+		Icon *string `yaml:"details_icon"`
+		TOC  *string `yaml:"include_toc"`
+		Lang *string `yaml:"lang"`
+	}
+
+	type yamlRenderConfigWrapper struct {
+		Gitea *yamlRenderConfig `yaml:"gitea"`
+	}
+
+	var cfg yamlRenderConfigWrapper
+	if err := value.Decode(&cfg); err != nil {
+		return fmt.Errorf("unable to decode into yamlRenderConfigWrapper %w", err)
+	}
+
+	if cfg.Gitea == nil {
+		return nil
+	}
+
+	if cfg.Gitea.Meta != nil {
+		rc.Meta = renderMetaModeFromString(*cfg.Gitea.Meta)
+	}
+
+	if cfg.Gitea.Icon != nil {
+		rc.Icon = strings.TrimSpace(strings.ToLower(*cfg.Gitea.Icon))
+	}
+
+	if cfg.Gitea.Lang != nil && *cfg.Gitea.Lang != "" {
+		rc.Lang = *cfg.Gitea.Lang
+	}
+
+	if cfg.Gitea.TOC != nil {
+		rc.TOC = *cfg.Gitea.TOC
+	}
+
+	return nil
+}
+
+func (rc *RenderConfig) toMetaNode() ast.Node {
+	if rc.yamlNode == nil {
+		return nil
+	}
+	switch rc.Meta {
+	case markup.RenderMetaAsTable:
+		return nodeToTable(rc.yamlNode)
+	case markup.RenderMetaAsDetails:
+		return nodeToDetails(rc.yamlNode, rc.Icon)
+	default:
+		return nil
+	}
+}
diff --git a/modules/markup/markdown/renderconfig_test.go b/modules/markup/markdown/renderconfig_test.go
new file mode 100644
index 0000000..c53acdc
--- /dev/null
+++ b/modules/markup/markdown/renderconfig_test.go
@@ -0,0 +1,162 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"strings"
+	"testing"
+
+	"gopkg.in/yaml.v3"
+)
+
+func TestRenderConfig_UnmarshalYAML(t *testing.T) {
+	tests := []struct {
+		name     string
+		expected *RenderConfig
+		args     string
+	}{
+		{
+			"empty", &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				Lang: "",
+			}, "",
+		},
+		{
+			"lang", &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				Lang: "test",
+			}, "lang: test",
+		},
+		{
+			"metatable", &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				Lang: "",
+			}, "gitea: table",
+		},
+		{
+			"metanone", &RenderConfig{
+				Meta: "none",
+				Icon: "table",
+				Lang: "",
+			}, "gitea: none",
+		},
+		{
+			"metadetails", &RenderConfig{
+				Meta: "details",
+				Icon: "table",
+				Lang: "",
+			}, "gitea: details",
+		},
+		{
+			"metawrong", &RenderConfig{
+				Meta: "details",
+				Icon: "table",
+				Lang: "",
+			}, "gitea: wrong",
+		},
+		{
+			"toc", &RenderConfig{
+				TOC:  "true",
+				Meta: "table",
+				Icon: "table",
+				Lang: "",
+			}, "include_toc: true",
+		},
+		{
+			"tocfalse", &RenderConfig{
+				TOC:  "false",
+				Meta: "table",
+				Icon: "table",
+				Lang: "",
+			}, "include_toc: false",
+		},
+		{
+			"toclang", &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				TOC:  "true",
+				Lang: "testlang",
+			}, `
+				include_toc: true
+				lang: testlang
+				`,
+		},
+		{
+			"complexlang", &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				Lang: "testlang",
+			}, `
+				gitea:
+					lang: testlang
+				`,
+		},
+		{
+			"complexlang2", &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				Lang: "testlang",
+			}, `
+	lang: notright
+	gitea:
+		lang: testlang
+`,
+		},
+		{
+			"complexlang", &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				Lang: "testlang",
+			}, `
+	gitea:
+		lang: testlang
+`,
+		},
+		{
+			"complex2", &RenderConfig{
+				Lang: "two",
+				Meta: "table",
+				TOC:  "true",
+				Icon: "smiley",
+			}, `
+	lang: one
+	include_toc: true
+	gitea:
+		details_icon: smiley
+		meta: table
+		include_toc: true
+		lang: two
+`,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := &RenderConfig{
+				Meta: "table",
+				Icon: "table",
+				Lang: "",
+			}
+			if err := yaml.Unmarshal([]byte(strings.ReplaceAll(tt.args, "\t", "    ")), got); err != nil {
+				t.Errorf("RenderConfig.UnmarshalYAML() error = %v\n%q", err, tt.args)
+				return
+			}
+
+			if got.Meta != tt.expected.Meta {
+				t.Errorf("Meta Expected %s Got %s", tt.expected.Meta, got.Meta)
+			}
+			if got.Icon != tt.expected.Icon {
+				t.Errorf("Icon Expected %s Got %s", tt.expected.Icon, got.Icon)
+			}
+			if got.Lang != tt.expected.Lang {
+				t.Errorf("Lang Expected %s Got %s", tt.expected.Lang, got.Lang)
+			}
+			if got.TOC != tt.expected.TOC {
+				t.Errorf("TOC Expected %q Got %q", tt.expected.TOC, got.TOC)
+			}
+		})
+	}
+}
diff --git a/modules/markup/markdown/toc.go b/modules/markup/markdown/toc.go
new file mode 100644
index 0000000..38f744a
--- /dev/null
+++ b/modules/markup/markdown/toc.go
@@ -0,0 +1,54 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+	"net/url"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/translation"
+
+	"github.com/yuin/goldmark/ast"
+)
+
+func createTOCNode(toc []markup.Header, lang string, detailsAttrs map[string]string) ast.Node {
+	details := NewDetails()
+	summary := NewSummary()
+
+	for k, v := range detailsAttrs {
+		details.SetAttributeString(k, []byte(v))
+	}
+
+	summary.AppendChild(summary, ast.NewString([]byte(translation.NewLocale(lang).TrString("toc"))))
+	details.AppendChild(details, summary)
+	ul := ast.NewList('-')
+	details.AppendChild(details, ul)
+	currentLevel := 6
+	for _, header := range toc {
+		if header.Level < currentLevel {
+			currentLevel = header.Level
+		}
+	}
+	for _, header := range toc {
+		for currentLevel > header.Level {
+			ul = ul.Parent().(*ast.List)
+			currentLevel--
+		}
+		for currentLevel < header.Level {
+			newL := ast.NewList('-')
+			ul.AppendChild(ul, newL)
+			currentLevel++
+			ul = newL
+		}
+		li := ast.NewListItem(currentLevel * 2)
+		a := ast.NewLink()
+		a.Destination = []byte(fmt.Sprintf("#%s", url.QueryEscape(header.ID)))
+		a.AppendChild(a, ast.NewString([]byte(header.Text)))
+		li.AppendChild(li, a)
+		ul.AppendChild(ul, li)
+	}
+
+	return details
+}
diff --git a/modules/markup/markdown/transform_codespan.go b/modules/markup/markdown/transform_codespan.go
new file mode 100644
index 0000000..a2cd4fb
--- /dev/null
+++ b/modules/markup/markdown/transform_codespan.go
@@ -0,0 +1,56 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/modules/markup"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+// renderCodeSpan renders CodeSpan elements (like goldmark upstream does) but also renders ColorPreview elements.
+// See #21474 for reference
+func (r *HTMLRenderer) renderCodeSpan(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+	if entering {
+		if n.Attributes() != nil {
+			_, _ = w.WriteString("<code")
+			html.RenderAttributes(w, n, html.CodeAttributeFilter)
+			_ = w.WriteByte('>')
+		} else {
+			_, _ = w.WriteString("<code>")
+		}
+		for c := n.FirstChild(); c != nil; c = c.NextSibling() {
+			switch v := c.(type) {
+			case *ast.Text:
+				segment := v.Segment
+				value := segment.Value(source)
+				if bytes.HasSuffix(value, []byte("\n")) {
+					r.Writer.RawWrite(w, value[:len(value)-1])
+					r.Writer.RawWrite(w, []byte(" "))
+				} else {
+					r.Writer.RawWrite(w, value)
+				}
+			case *ColorPreview:
+				_, _ = w.WriteString(fmt.Sprintf(`<span class="color-preview" style="background-color: %v"></span>`, string(v.Color)))
+			}
+		}
+		return ast.WalkSkipChildren, nil
+	}
+	_, _ = w.WriteString("</code>")
+	return ast.WalkContinue, nil
+}
+
+func (g *ASTTransformer) transformCodeSpan(_ *markup.RenderContext, v *ast.CodeSpan, reader text.Reader) {
+	colorContent := v.Text(reader.Source())
+	if matchColor(strings.ToLower(string(colorContent))) {
+		v.AppendChild(v, NewColorPreview(colorContent))
+	}
+}
diff --git a/modules/markup/markdown/transform_heading.go b/modules/markup/markdown/transform_heading.go
new file mode 100644
index 0000000..6d48f34
--- /dev/null
+++ b/modules/markup/markdown/transform_heading.go
@@ -0,0 +1,32 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/text"
+)
+
+func (g *ASTTransformer) transformHeading(_ *markup.RenderContext, v *ast.Heading, reader text.Reader, tocList *[]markup.Header) {
+	for _, attr := range v.Attributes() {
+		if _, ok := attr.Value.([]byte); !ok {
+			v.SetAttribute(attr.Name, []byte(fmt.Sprintf("%v", attr.Value)))
+		}
+	}
+	txt := v.Text(reader.Source())
+	header := markup.Header{
+		Text:  util.UnsafeBytesToString(txt),
+		Level: v.Level,
+	}
+	if id, found := v.AttributeString("id"); found {
+		header.ID = util.UnsafeBytesToString(id.([]byte))
+	}
+	*tocList = append(*tocList, header)
+	g.applyElementDir(v)
+}
diff --git a/modules/markup/markdown/transform_image.go b/modules/markup/markdown/transform_image.go
new file mode 100644
index 0000000..b34a710
--- /dev/null
+++ b/modules/markup/markdown/transform_image.go
@@ -0,0 +1,65 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"strings"
+
+	"code.gitea.io/gitea/modules/markup"
+	giteautil "code.gitea.io/gitea/modules/util"
+
+	"github.com/yuin/goldmark/ast"
+)
+
+func (g *ASTTransformer) transformImage(ctx *markup.RenderContext, v *ast.Image) {
+	// Images need two things:
+	//
+	// 1. Their src needs to munged to be a real value
+	// 2. If they're not wrapped with a link they need a link wrapper
+
+	// Check if the destination is a real link
+	if len(v.Destination) > 0 && !markup.IsLink(v.Destination) {
+		v.Destination = []byte(giteautil.URLJoin(
+			ctx.Links.ResolveMediaLink(ctx.IsWiki),
+			strings.TrimLeft(string(v.Destination), "/"),
+		))
+	}
+
+	parent := v.Parent()
+	// Create a link around image only if parent is not already a link
+	if _, ok := parent.(*ast.Link); !ok && parent != nil {
+		next := v.NextSibling()
+
+		// Create a link wrapper
+		wrap := ast.NewLink()
+		wrap.Destination = v.Destination
+		wrap.Title = v.Title
+		wrap.SetAttributeString("target", []byte("_blank"))
+
+		// Duplicate the current image node
+		image := ast.NewImage(ast.NewLink())
+		image.Destination = v.Destination
+		image.Title = v.Title
+		for _, attr := range v.Attributes() {
+			image.SetAttribute(attr.Name, attr.Value)
+		}
+		for child := v.FirstChild(); child != nil; {
+			next := child.NextSibling()
+			image.AppendChild(image, child)
+			child = next
+		}
+
+		// Append our duplicate image to the wrapper link
+		wrap.AppendChild(wrap, image)
+
+		// Wire in the next sibling
+		wrap.SetNextSibling(next)
+
+		// Replace the current node with the wrapper link
+		parent.ReplaceChild(parent, v, wrap)
+
+		// But most importantly ensure the next sibling is still on the old image too
+		v.SetNextSibling(next)
+	}
+}
diff --git a/modules/markup/markdown/transform_link.go b/modules/markup/markdown/transform_link.go
new file mode 100644
index 0000000..e6f3836
--- /dev/null
+++ b/modules/markup/markdown/transform_link.go
@@ -0,0 +1,46 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"bytes"
+	"slices"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/setting"
+	giteautil "code.gitea.io/gitea/modules/util"
+
+	"github.com/yuin/goldmark/ast"
+)
+
+func (g *ASTTransformer) transformLink(ctx *markup.RenderContext, v *ast.Link) {
+	// Links need their href to munged to be a real value
+	link := v.Destination
+
+	// Do not process the link if it's not a link, starts with an hashtag
+	// (indicating it's an anchor link), starts with `mailto:` or any of the
+	// custom markdown URLs.
+	processLink := len(link) > 0 && !markup.IsLink(link) &&
+		link[0] != '#' && !bytes.HasPrefix(link, byteMailto) &&
+		!slices.ContainsFunc(setting.Markdown.CustomURLSchemes, func(s string) bool {
+			return bytes.HasPrefix(link, []byte(s+":"))
+		})
+
+	if processLink {
+		var base string
+		if ctx.IsWiki {
+			base = ctx.Links.WikiLink()
+		} else if ctx.Links.HasBranchInfo() {
+			base = ctx.Links.SrcLink()
+		} else {
+			base = ctx.Links.Base
+		}
+
+		link = []byte(giteautil.URLJoin(base, string(link)))
+	}
+	if len(link) > 0 && link[0] == '#' {
+		link = []byte("#user-content-" + string(link)[1:])
+	}
+	v.Destination = link
+}
diff --git a/modules/markup/markdown/transform_list.go b/modules/markup/markdown/transform_list.go
new file mode 100644
index 0000000..b982fd4
--- /dev/null
+++ b/modules/markup/markdown/transform_list.go
@@ -0,0 +1,85 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+
+	"code.gitea.io/gitea/modules/markup"
+
+	"github.com/yuin/goldmark/ast"
+	east "github.com/yuin/goldmark/extension/ast"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/util"
+)
+
+func (r *HTMLRenderer) renderTaskCheckBoxListItem(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*TaskCheckBoxListItem)
+	if entering {
+		if n.Attributes() != nil {
+			_, _ = w.WriteString("<li")
+			html.RenderAttributes(w, n, html.ListItemAttributeFilter)
+			_ = w.WriteByte('>')
+		} else {
+			_, _ = w.WriteString("<li>")
+		}
+		fmt.Fprintf(w, `<input type="checkbox" disabled="" data-source-position="%d"`, n.SourcePosition)
+		if n.IsChecked {
+			_, _ = w.WriteString(` checked=""`)
+		}
+		if r.XHTML {
+			_, _ = w.WriteString(` />`)
+		} else {
+			_ = w.WriteByte('>')
+		}
+		fc := n.FirstChild()
+		if fc != nil {
+			if _, ok := fc.(*ast.TextBlock); !ok {
+				_ = w.WriteByte('\n')
+			}
+		}
+	} else {
+		_, _ = w.WriteString("</li>\n")
+	}
+	return ast.WalkContinue, nil
+}
+
+func (r *HTMLRenderer) renderTaskCheckBox(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	return ast.WalkContinue, nil
+}
+
+func (g *ASTTransformer) transformList(_ *markup.RenderContext, v *ast.List, rc *RenderConfig) {
+	if v.HasChildren() {
+		children := make([]ast.Node, 0, v.ChildCount())
+		child := v.FirstChild()
+		for child != nil {
+			children = append(children, child)
+			child = child.NextSibling()
+		}
+		v.RemoveChildren(v)
+
+		for _, child := range children {
+			listItem := child.(*ast.ListItem)
+			if !child.HasChildren() || !child.FirstChild().HasChildren() {
+				v.AppendChild(v, child)
+				continue
+			}
+			taskCheckBox, ok := child.FirstChild().FirstChild().(*east.TaskCheckBox)
+			if !ok {
+				v.AppendChild(v, child)
+				continue
+			}
+			newChild := NewTaskCheckBoxListItem(listItem)
+			newChild.IsChecked = taskCheckBox.IsChecked
+			newChild.SetAttributeString("class", []byte("task-list-item"))
+			segments := newChild.FirstChild().Lines()
+			if segments.Len() > 0 {
+				segment := segments.At(0)
+				newChild.SourcePosition = rc.metaLength + segment.Start
+			}
+			v.AppendChild(v, newChild)
+		}
+	}
+	g.applyElementDir(v)
+}