Remove Blackfriday markdown engine

It has been deprecated for a long time, its v1 version is not maintained anymore, and there are many known issues. Goldmark should be
a mature replacement by now.

Closes #9934

10 files changed, 44 insertions, 685 deletions

diff --git a/markup/blackfriday/anchors.go b/markup/blackfriday/anchors.go
new file mode 100644
index 000000000..90f65a64c
--- /dev/null
+++ b/markup/blackfriday/anchors.go
@@ -0,0 +1,39 @@
+// Copyright 2022 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package blackfriday holds some copmpability functions for the old Blackfriday v1 Markdown engine.
+package blackfriday
+
+import "unicode"
+
+// SanitizedAnchorName is how Blackfriday sanitizes anchor names.
+// Implementation borrowed from https://github.com/russross/blackfriday/blob/a477dd1646916742841ed20379f941cfa6c5bb6f/block.go#L1464
+// Note that Hugo removed its Blackfriday support in v0.100.0, but you can still use this strategy for
+// auto ID generation.
+func SanitizedAnchorName(text string) string {
+	var anchorName []rune
+	futureDash := false
+	for _, r := range text {
+		switch {
+		case unicode.IsLetter(r) || unicode.IsNumber(r):
+			if futureDash && len(anchorName) > 0 {
+				anchorName = append(anchorName, '-')
+			}
+			futureDash = false
+			anchorName = append(anchorName, unicode.ToLower(r))
+		default:
+			futureDash = true
+		}
+	}
+	return string(anchorName)
+}
diff --git a/markup/blackfriday/blackfriday_config/config.go b/markup/blackfriday/blackfriday_config/config.go
deleted file mode 100644
index 8c276c9f6..000000000
--- a/markup/blackfriday/blackfriday_config/config.go
+++ /dev/null
@@ -1,71 +0,0 @@
-// Copyright 2019 The Hugo Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package helpers implements general utility functions that work with
-// and on content.  The helper functions defined here lay down the
-// foundation of how Hugo works with files and filepaths, and perform
-// string operations on content.
-
-package blackfriday_config
-
-import (
-	"fmt"
-
-	"github.com/mitchellh/mapstructure"
-)
-
-// Default holds the default BlackFriday config.
-// Do not change!
-var Default = Config{
-	Smartypants:           true,
-	AngledQuotes:          false,
-	SmartypantsQuotesNBSP: false,
-	Fractions:             true,
-	HrefTargetBlank:       false,
-	NofollowLinks:         false,
-	NoreferrerLinks:       false,
-	SmartDashes:           true,
-	LatexDashes:           true,
-	PlainIDAnchors:        true,
-	TaskLists:             true,
-	SkipHTML:              false,
-}
-
-// Config holds configuration values for BlackFriday rendering.
-// It is kept here because it's used in several packages.
-type Config struct {
-	Smartypants           bool
-	SmartypantsQuotesNBSP bool
-	AngledQuotes          bool
-	Fractions             bool
-	HrefTargetBlank       bool
-	NofollowLinks         bool
-	NoreferrerLinks       bool
-	SmartDashes           bool
-	LatexDashes           bool
-	TaskLists             bool
-	PlainIDAnchors        bool
-	Extensions            []string
-	ExtensionsMask        []string
-	SkipHTML              bool
-
-	FootnoteAnchorPrefix       string
-	FootnoteReturnLinkContents string
-}
-
-func UpdateConfig(b Config, m map[string]any) (Config, error) {
-	if err := mapstructure.Decode(m, &b); err != nil {
-		return b, fmt.Errorf("failed to decode rendering config: %w", err)
-	}
-	return b, nil
-}
diff --git a/markup/blackfriday/convert.go b/markup/blackfriday/convert.go
deleted file mode 100644
index b786e29de..000000000
--- a/markup/blackfriday/convert.go
+++ /dev/null
@@ -1,233 +0,0 @@
-// Copyright 2019 The Hugo Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package blackfriday converts Markdown to HTML using Blackfriday v1.
-package blackfriday
-
-import (
-	"unicode"
-
-	"github.com/gohugoio/hugo/identity"
-	"github.com/gohugoio/hugo/markup/blackfriday/blackfriday_config"
-	"github.com/gohugoio/hugo/markup/converter"
-	"github.com/russross/blackfriday"
-)
-
-// Provider is the package entry point.
-var Provider converter.ProviderProvider = provider{}
-
-type provider struct {
-}
-
-func (p provider) New(cfg converter.ProviderConfig) (converter.Provider, error) {
-	defaultExtensions := getMarkdownExtensions(cfg.MarkupConfig.BlackFriday)
-
-	return converter.NewProvider("blackfriday", func(ctx converter.DocumentContext) (converter.Converter, error) {
-		b := cfg.MarkupConfig.BlackFriday
-		extensions := defaultExtensions
-
-		if ctx.ConfigOverrides != nil {
-			var err error
-			b, err = blackfriday_config.UpdateConfig(b, ctx.ConfigOverrides)
-			if err != nil {
-				return nil, err
-			}
-			extensions = getMarkdownExtensions(b)
-		}
-
-		return &blackfridayConverter{
-			ctx:        ctx,
-			bf:         b,
-			extensions: extensions,
-			cfg:        cfg,
-		}, nil
-	}), nil
-}
-
-type blackfridayConverter struct {
-	ctx        converter.DocumentContext
-	bf         blackfriday_config.Config
-	extensions int
-	cfg        converter.ProviderConfig
-}
-
-func (c *blackfridayConverter) SanitizeAnchorName(s string) string {
-	return SanitizedAnchorName(s)
-}
-
-// SanitizedAnchorName is how Blackfriday sanitizes anchor names.
-// Implementation borrowed from https://github.com/russross/blackfriday/blob/a477dd1646916742841ed20379f941cfa6c5bb6f/block.go#L1464
-func SanitizedAnchorName(text string) string {
-	var anchorName []rune
-	futureDash := false
-	for _, r := range text {
-		switch {
-		case unicode.IsLetter(r) || unicode.IsNumber(r):
-			if futureDash && len(anchorName) > 0 {
-				anchorName = append(anchorName, '-')
-			}
-			futureDash = false
-			anchorName = append(anchorName, unicode.ToLower(r))
-		default:
-			futureDash = true
-		}
-	}
-	return string(anchorName)
-}
-
-func (c *blackfridayConverter) AnchorSuffix() string {
-	if c.bf.PlainIDAnchors {
-		return ""
-	}
-	return ":" + c.ctx.DocumentID
-}
-
-func (c *blackfridayConverter) Convert(ctx converter.RenderContext) (converter.Result, error) {
-	r := c.getHTMLRenderer(ctx.RenderTOC)
-
-	return converter.Bytes(blackfriday.Markdown(ctx.Src, r, c.extensions)), nil
-}
-
-func (c *blackfridayConverter) Supports(feature identity.Identity) bool {
-	return false
-}
-
-func (c *blackfridayConverter) getHTMLRenderer(renderTOC bool) blackfriday.Renderer {
-	flags := getFlags(renderTOC, c.bf)
-
-	documentID := c.ctx.DocumentID
-
-	renderParameters := blackfriday.HtmlRendererParameters{
-		FootnoteAnchorPrefix:       c.bf.FootnoteAnchorPrefix,
-		FootnoteReturnLinkContents: c.bf.FootnoteReturnLinkContents,
-	}
-
-	if documentID != "" && !c.bf.PlainIDAnchors {
-		renderParameters.FootnoteAnchorPrefix = documentID + ":" + renderParameters.FootnoteAnchorPrefix
-		renderParameters.HeaderIDSuffix = ":" + documentID
-	}
-
-	return &hugoHTMLRenderer{
-		c:        c,
-		Renderer: blackfriday.HtmlRendererWithParameters(flags, "", "", renderParameters),
-	}
-}
-
-func getFlags(renderTOC bool, cfg blackfriday_config.Config) int {
-	var flags int
-
-	if renderTOC {
-		flags = blackfriday.HTML_TOC
-	}
-
-	flags |= blackfriday.HTML_USE_XHTML
-	flags |= blackfriday.HTML_FOOTNOTE_RETURN_LINKS
-
-	if cfg.Smartypants {
-		flags |= blackfriday.HTML_USE_SMARTYPANTS
-	}
-
-	if cfg.SmartypantsQuotesNBSP {
-		flags |= blackfriday.HTML_SMARTYPANTS_QUOTES_NBSP
-	}
-
-	if cfg.AngledQuotes {
-		flags |= blackfriday.HTML_SMARTYPANTS_ANGLED_QUOTES
-	}
-
-	if cfg.Fractions {
-		flags |= blackfriday.HTML_SMARTYPANTS_FRACTIONS
-	}
-
-	if cfg.HrefTargetBlank {
-		flags |= blackfriday.HTML_HREF_TARGET_BLANK
-	}
-
-	if cfg.NofollowLinks {
-		flags |= blackfriday.HTML_NOFOLLOW_LINKS
-	}
-
-	if cfg.NoreferrerLinks {
-		flags |= blackfriday.HTML_NOREFERRER_LINKS
-	}
-
-	if cfg.SmartDashes {
-		flags |= blackfriday.HTML_SMARTYPANTS_DASHES
-	}
-
-	if cfg.LatexDashes {
-		flags |= blackfriday.HTML_SMARTYPANTS_LATEX_DASHES
-	}
-
-	if cfg.SkipHTML {
-		flags |= blackfriday.HTML_SKIP_HTML
-	}
-
-	return flags
-}
-
-func getMarkdownExtensions(cfg blackfriday_config.Config) int {
-	// Default Blackfriday common extensions
-	commonExtensions := 0 |
-		blackfriday.EXTENSION_NO_INTRA_EMPHASIS |
-		blackfriday.EXTENSION_TABLES |
-		blackfriday.EXTENSION_FENCED_CODE |
-		blackfriday.EXTENSION_AUTOLINK |
-		blackfriday.EXTENSION_STRIKETHROUGH |
-		blackfriday.EXTENSION_SPACE_HEADERS |
-		blackfriday.EXTENSION_HEADER_IDS |
-		blackfriday.EXTENSION_BACKSLASH_LINE_BREAK |
-		blackfriday.EXTENSION_DEFINITION_LISTS
-
-	// Extra Blackfriday extensions that Hugo enables by default
-	flags := commonExtensions |
-		blackfriday.EXTENSION_AUTO_HEADER_IDS |
-		blackfriday.EXTENSION_FOOTNOTES
-
-	for _, extension := range cfg.Extensions {
-		if flag, ok := blackfridayExtensionMap[extension]; ok {
-			flags |= flag
-		}
-	}
-	for _, extension := range cfg.ExtensionsMask {
-		if flag, ok := blackfridayExtensionMap[extension]; ok {
-			flags &= ^flag
-		}
-	}
-	return flags
-}
-
-var blackfridayExtensionMap = map[string]int{
-	"noIntraEmphasis":        blackfriday.EXTENSION_NO_INTRA_EMPHASIS,
-	"tables":                 blackfriday.EXTENSION_TABLES,
-	"fencedCode":             blackfriday.EXTENSION_FENCED_CODE,
-	"autolink":               blackfriday.EXTENSION_AUTOLINK,
-	"strikethrough":          blackfriday.EXTENSION_STRIKETHROUGH,
-	"laxHtmlBlocks":          blackfriday.EXTENSION_LAX_HTML_BLOCKS,
-	"spaceHeaders":           blackfriday.EXTENSION_SPACE_HEADERS,
-	"hardLineBreak":          blackfriday.EXTENSION_HARD_LINE_BREAK,
-	"tabSizeEight":           blackfriday.EXTENSION_TAB_SIZE_EIGHT,
-	"footnotes":              blackfriday.EXTENSION_FOOTNOTES,
-	"noEmptyLineBeforeBlock": blackfriday.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK,
-	"headerIds":              blackfriday.EXTENSION_HEADER_IDS,
-	"titleblock":             blackfriday.EXTENSION_TITLEBLOCK,
-	"autoHeaderIds":          blackfriday.EXTENSION_AUTO_HEADER_IDS,
-	"backslashLineBreak":     blackfriday.EXTENSION_BACKSLASH_LINE_BREAK,
-	"definitionLists":        blackfriday.EXTENSION_DEFINITION_LISTS,
-	"joinLines":              blackfriday.EXTENSION_JOIN_LINES,
-}
-
-var (
-	_ converter.DocumentInfo        = (*blackfridayConverter)(nil)
-	_ converter.AnchorNameSanitizer = (*blackfridayConverter)(nil)
-)
diff --git a/markup/blackfriday/convert_test.go b/markup/blackfriday/convert_test.go
deleted file mode 100644
index 0d691f646..000000000
--- a/markup/blackfriday/convert_test.go
+++ /dev/null
@@ -1,223 +0,0 @@
-// Copyright 2019 The Hugo Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package blackfriday
-
-import (
-	"testing"
-
-	"github.com/gohugoio/hugo/config"
-
-	"github.com/gohugoio/hugo/markup/converter"
-
-	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/markup/blackfriday/blackfriday_config"
-	"github.com/russross/blackfriday"
-)
-
-func TestGetMarkdownExtensionsMasksAreRemovedFromExtensions(t *testing.T) {
-	b := blackfriday_config.Default
-	b.Extensions = []string{"headerId"}
-	b.ExtensionsMask = []string{"noIntraEmphasis"}
-
-	actualFlags := getMarkdownExtensions(b)
-	if actualFlags&blackfriday.EXTENSION_NO_INTRA_EMPHASIS == blackfriday.EXTENSION_NO_INTRA_EMPHASIS {
-		t.Errorf("Masked out flag {%v} found amongst returned extensions.", blackfriday.EXTENSION_NO_INTRA_EMPHASIS)
-	}
-}
-
-func TestGetMarkdownExtensionsByDefaultAllExtensionsAreEnabled(t *testing.T) {
-	type data struct {
-		testFlag int
-	}
-
-	b := blackfriday_config.Default
-
-	b.Extensions = []string{""}
-	b.ExtensionsMask = []string{""}
-	allExtensions := []data{
-		{blackfriday.EXTENSION_NO_INTRA_EMPHASIS},
-		{blackfriday.EXTENSION_TABLES},
-		{blackfriday.EXTENSION_FENCED_CODE},
-		{blackfriday.EXTENSION_AUTOLINK},
-		{blackfriday.EXTENSION_STRIKETHROUGH},
-		// {blackfriday.EXTENSION_LAX_HTML_BLOCKS},
-		{blackfriday.EXTENSION_SPACE_HEADERS},
-		// {blackfriday.EXTENSION_HARD_LINE_BREAK},
-		// {blackfriday.EXTENSION_TAB_SIZE_EIGHT},
-		{blackfriday.EXTENSION_FOOTNOTES},
-		// {blackfriday.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK},
-		{blackfriday.EXTENSION_HEADER_IDS},
-		// {blackfriday.EXTENSION_TITLEBLOCK},
-		{blackfriday.EXTENSION_AUTO_HEADER_IDS},
-		{blackfriday.EXTENSION_BACKSLASH_LINE_BREAK},
-		{blackfriday.EXTENSION_DEFINITION_LISTS},
-	}
-
-	actualFlags := getMarkdownExtensions(b)
-	for _, e := range allExtensions {
-		if actualFlags&e.testFlag != e.testFlag {
-			t.Errorf("Flag %v was not found in the list of extensions.", e)
-		}
-	}
-}
-
-func TestGetMarkdownExtensionsAddingFlagsThroughRenderingContext(t *testing.T) {
-	b := blackfriday_config.Default
-
-	b.Extensions = []string{"definitionLists"}
-	b.ExtensionsMask = []string{""}
-
-	actualFlags := getMarkdownExtensions(b)
-	if actualFlags&blackfriday.EXTENSION_DEFINITION_LISTS != blackfriday.EXTENSION_DEFINITION_LISTS {
-		t.Errorf("Masked out flag {%v} found amongst returned extensions.", blackfriday.EXTENSION_DEFINITION_LISTS)
-	}
-}
-
-func TestGetFlags(t *testing.T) {
-	b := blackfriday_config.Default
-	flags := getFlags(false, b)
-	if flags&blackfriday.HTML_USE_XHTML != blackfriday.HTML_USE_XHTML {
-		t.Errorf("Test flag: %d was not found amongs set flags:%d; Result: %d", blackfriday.HTML_USE_XHTML, flags, flags&blackfriday.HTML_USE_XHTML)
-	}
-}
-
-func TestGetAllFlags(t *testing.T) {
-	c := qt.New(t)
-
-	b := blackfriday_config.Default
-
-	type data struct {
-		testFlag int
-	}
-
-	allFlags := []data{
-		{blackfriday.HTML_USE_XHTML},
-		{blackfriday.HTML_FOOTNOTE_RETURN_LINKS},
-		{blackfriday.HTML_USE_SMARTYPANTS},
-		{blackfriday.HTML_SMARTYPANTS_QUOTES_NBSP},
-		{blackfriday.HTML_SMARTYPANTS_ANGLED_QUOTES},
-		{blackfriday.HTML_SMARTYPANTS_FRACTIONS},
-		{blackfriday.HTML_HREF_TARGET_BLANK},
-		{blackfriday.HTML_NOFOLLOW_LINKS},
-		{blackfriday.HTML_NOREFERRER_LINKS},
-		{blackfriday.HTML_SMARTYPANTS_DASHES},
-		{blackfriday.HTML_SMARTYPANTS_LATEX_DASHES},
-	}
-
-	b.AngledQuotes = true
-	b.Fractions = true
-	b.HrefTargetBlank = true
-	b.NofollowLinks = true
-	b.NoreferrerLinks = true
-	b.LatexDashes = true
-	b.PlainIDAnchors = true
-	b.SmartDashes = true
-	b.Smartypants = true
-	b.SmartypantsQuotesNBSP = true
-
-	actualFlags := getFlags(false, b)
-
-	var expectedFlags int
-	// OR-ing flags together...
-	for _, d := range allFlags {
-		expectedFlags |= d.testFlag
-	}
-
-	c.Assert(actualFlags, qt.Equals, expectedFlags)
-}
-
-func TestConvert(t *testing.T) {
-	c := qt.New(t)
-	p, err := Provider.New(converter.ProviderConfig{
-		Cfg: config.New(),
-	})
-	c.Assert(err, qt.IsNil)
-	conv, err := p.New(converter.DocumentContext{})
-	c.Assert(err, qt.IsNil)
-	b, err := conv.Convert(converter.RenderContext{Src: []byte("testContent")})
-	c.Assert(err, qt.IsNil)
-	c.Assert(string(b.Bytes()), qt.Equals, "<p>testContent</p>\n")
-}
-
-func TestGetHTMLRendererAnchors(t *testing.T) {
-	c := qt.New(t)
-	p, err := Provider.New(converter.ProviderConfig{
-		Cfg: config.New(),
-	})
-	c.Assert(err, qt.IsNil)
-	conv, err := p.New(converter.DocumentContext{
-		DocumentID: "testid",
-		ConfigOverrides: map[string]any{
-			"plainIDAnchors": false,
-			"footnotes":      true,
-		},
-	})
-	c.Assert(err, qt.IsNil)
-	b, err := conv.Convert(converter.RenderContext{Src: []byte(`# Header
-
-This is a footnote.[^1] And then some.
-
-
-[^1]: Footnote text.
-
-`)})
-
-	c.Assert(err, qt.IsNil)
-	s := string(b.Bytes())
-	c.Assert(s, qt.Contains, "<h1 id=\"header:testid\">Header</h1>")
-	c.Assert(s, qt.Contains, "This is a footnote.<sup class=\"footnote-ref\" id=\"fnref:testid:1\"><a href=\"#fn:testid:1\">1</a></sup>")
-	c.Assert(s, qt.Contains, "<a class=\"footnote-return\" href=\"#fnref:testid:1\"><sup>[return]</sup></a>")
-}
-
-// Tests borrowed from https://github.com/russross/blackfriday/blob/a925a152c144ea7de0f451eaf2f7db9e52fa005a/block_test.go#L1817
-func TestSanitizedAnchorName(t *testing.T) {
-	tests := []struct {
-		text string
-		want string
-	}{
-		{
-			text: "This is a header",
-			want: "this-is-a-header",
-		},
-		{
-			text: "This is also          a header",
-			want: "this-is-also-a-header",
-		},
-		{
-			text: "main.go",
-			want: "main-go",
-		},
-		{
-			text: "Article 123",
-			want: "article-123",
-		},
-		{
-			text: "<- Let's try this, shall we?",
-			want: "let-s-try-this-shall-we",
-		},
-		{
-			text: "        ",
-			want: "",
-		},
-		{
-			text: "Hello, 世界",
-			want: "hello-世界",
-		},
-	}
-	for _, test := range tests {
-		if got := SanitizedAnchorName(test.text); got != test.want {
-			t.Errorf("SanitizedAnchorName(%q):\ngot %q\nwant %q", test.text, got, test.want)
-		}
-	}
-}
diff --git a/markup/blackfriday/renderer.go b/markup/blackfriday/renderer.go
deleted file mode 100644
index 5d4cab048..000000000
--- a/markup/blackfriday/renderer.go
+++ /dev/null
@@ -1,84 +0,0 @@
-// Copyright 2019 The Hugo Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package blackfriday
-
-import (
-	"bytes"
-	"strings"
-
-	"github.com/russross/blackfriday"
-)
-
-// hugoHTMLRenderer wraps a blackfriday.Renderer, typically a blackfriday.Html
-// adding some custom behaviour.
-type hugoHTMLRenderer struct {
-	c *blackfridayConverter
-	blackfriday.Renderer
-}
-
-// BlockCode renders a given text as a block of code.
-// Chroma is used if it is setup to handle code fences.
-func (r *hugoHTMLRenderer) BlockCode(out *bytes.Buffer, text []byte, lang string) {
-	if r.c.cfg.MarkupConfig.Highlight.CodeFences {
-		str := strings.Trim(string(text), "\n\r")
-		highlighted, _ := r.c.cfg.Highlight(str, lang, "")
-		out.WriteString(highlighted)
-	} else {
-		r.Renderer.BlockCode(out, text, lang)
-	}
-}
-
-// ListItem adds task list support to the Blackfriday renderer.
-func (r *hugoHTMLRenderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
-	if !r.c.bf.TaskLists {
-		r.Renderer.ListItem(out, text, flags)
-		return
-	}
-
-	switch {
-	case bytes.HasPrefix(text, []byte("[ ] ")):
-		text = append([]byte(`<label><input type="checkbox" disabled class="task-list-item">`), text[3:]...)
-		text = append(text, []byte(`</label>`)...)
-
-	case bytes.HasPrefix(text, []byte("[x] ")) || bytes.HasPrefix(text, []byte("[X] ")):
-		text = append([]byte(`<label><input type="checkbox" checked disabled class="task-list-item">`), text[3:]...)
-		text = append(text, []byte(`</label>`)...)
-	}
-
-	r.Renderer.ListItem(out, text, flags)
-}
-
-// List adds task list support to the Blackfriday renderer.
-func (r *hugoHTMLRenderer) List(out *bytes.Buffer, text func() bool, flags int) {
-	if !r.c.bf.TaskLists {
-		r.Renderer.List(out, text, flags)
-		return
-	}
-	marker := out.Len()
-	r.Renderer.List(out, text, flags)
-	if out.Len() > marker {
-		list := out.Bytes()[marker:]
-		if bytes.Contains(list, []byte("task-list-item")) {
-			// Find the index of the first >, it might be 3 or 4 depending on whether
-			// there is a new line at the start, but this is safer than just hardcoding it.
-			closingBracketIndex := bytes.Index(list, []byte(">"))
-			// Rewrite the buffer from the marker
-			out.Truncate(marker)
-			// Safely assuming closingBracketIndex won't be -1 since there is a list
-			// May be either dl, ul or ol
-			list := append(list[:closingBracketIndex], append([]byte(` class="task-list"`), list[closingBracketIndex:]...)...)
-			out.Write(list)
-		}
-	}
-}
diff --git a/markup/converter/converter.go b/markup/converter/converter.go
index 1ea301aa6..c760381f4 100644
--- a/markup/converter/converter.go
+++ b/markup/converter/converter.go
@@ -119,11 +119,10 @@ func (b Bytes) Bytes() []byte {
 
 // DocumentContext holds contextual information about the document to convert.
 type DocumentContext struct {
-	Document        any // May be nil. Usually a page.Page
-	DocumentID      string
-	DocumentName    string
-	Filename        string
-	ConfigOverrides map[string]any
+	Document     any // May be nil. Usually a page.Page
+	DocumentID   string
+	DocumentName string
+	Filename     string
 }
 
 // RenderContext holds contextual information about the content to render.
diff --git a/markup/markup.go b/markup/markup.go
index 13e5f3042..f5e46ad90 100644
--- a/markup/markup.go
+++ b/markup/markup.go
@@ -25,7 +25,6 @@ import (
 	"github.com/gohugoio/hugo/markup/org"
 
 	"github.com/gohugoio/hugo/markup/asciidocext"
-	"github.com/gohugoio/hugo/markup/blackfriday"
 	"github.com/gohugoio/hugo/markup/converter"
 	"github.com/gohugoio/hugo/markup/pandoc"
 	"github.com/gohugoio/hugo/markup/rst"
@@ -66,9 +65,6 @@ func NewConverterProvider(cfg converter.ProviderConfig) (ConverterProvider, erro
 	if err := add(goldmark.Provider); err != nil {
 		return nil, err
 	}
-	if err := add(blackfriday.Provider); err != nil {
-		return nil, err
-	}
 	if err := add(asciidocext.Provider, "ad", "adoc"); err != nil {
 		return nil, err
 	}
@@ -96,7 +92,7 @@ type ConverterProvider interface {
 }
 
 type converterRegistry struct {
-	// Maps name (md, markdown, blackfriday etc.) to a converter provider.
+	// Maps name (md, markdown, goldmark etc.) to a converter provider.
 	// Note that this is also used for aliasing, so the same converter
 	// may be registered multiple times.
 	// All names are lower case.
diff --git a/markup/markup_config/config.go b/markup/markup_config/config.go
index ddcba8c3a..e254ba7a0 100644
--- a/markup/markup_config/config.go
+++ b/markup/markup_config/config.go
@@ -18,7 +18,6 @@ import (
 	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/docshelper"
 	"github.com/gohugoio/hugo/markup/asciidocext/asciidocext_config"
-	"github.com/gohugoio/hugo/markup/blackfriday/blackfriday_config"
 	"github.com/gohugoio/hugo/markup/goldmark/goldmark_config"
 	"github.com/gohugoio/hugo/markup/highlight"
 	"github.com/gohugoio/hugo/markup/tableofcontents"
@@ -37,8 +36,6 @@ type Config struct {
 
 	// Content renderers
 	Goldmark    goldmark_config.Config
-	BlackFriday blackfriday_config.Config
-
 	AsciidocExt asciidocext_config.Config
 }
 
@@ -56,10 +53,6 @@ func Decode(cfg config.Provider) (conf Config, err error) {
 		return
 	}
 
-	if err = applyLegacyConfig(cfg, &conf); err != nil {
-		return
-	}
-
 	if err = highlight.ApplyLegacyConfig(cfg, &conf.Highlight); err != nil {
 		return
 	}
@@ -83,26 +76,6 @@ func normalizeConfig(m map[string]any) {
 	}
 }
 
-func applyLegacyConfig(cfg config.Provider, conf *Config) error {
-	if bm := cfg.GetStringMap("blackfriday"); bm != nil {
-		// Legacy top level blackfriday config.
-		err := mapstructure.WeakDecode(bm, &conf.BlackFriday)
-		if err != nil {
-			return err
-		}
-	}
-
-	if conf.BlackFriday.FootnoteAnchorPrefix == "" {
-		conf.BlackFriday.FootnoteAnchorPrefix = cfg.GetString("footnoteAnchorPrefix")
-	}
-
-	if conf.BlackFriday.FootnoteReturnLinkContents == "" {
-		conf.BlackFriday.FootnoteReturnLinkContents = cfg.GetString("footnoteReturnLinkContents")
-	}
-
-	return nil
-}
-
 var Default = Config{
 	DefaultMarkdownHandler: "goldmark",
 
@@ -110,8 +83,6 @@ var Default = Config{
 	Highlight:       highlight.DefaultConfig,
 
 	Goldmark:    goldmark_config.Default,
-	BlackFriday: blackfriday_config.Default,
-
 	AsciidocExt: asciidocext_config.Default,
 }
 
diff --git a/markup/markup_config/config_test.go b/markup/markup_config/config_test.go
index 06bd0b11c..a320e6912 100644
--- a/markup/markup_config/config_test.go
+++ b/markup/markup_config/config_test.go
@@ -45,7 +45,6 @@ func TestConfig(t *testing.T) {
 
 		c.Assert(err, qt.IsNil)
 		c.Assert(conf.Goldmark.Renderer.Unsafe, qt.Equals, true)
-		c.Assert(conf.BlackFriday.Fractions, qt.Equals, true)
 		c.Assert(conf.Goldmark.Parser.Attribute.Title, qt.Equals, true)
 		c.Assert(conf.Goldmark.Parser.Attribute.Block, qt.Equals, false)
 
@@ -53,37 +52,4 @@ func TestConfig(t *testing.T) {
 		c.Assert(conf.AsciidocExt.Extensions[0], qt.Equals, "asciidoctor-html5s")
 	})
 
-	c.Run("legacy", func(c *qt.C) {
-		c.Parallel()
-		v := config.New()
-
-		v.Set("blackfriday", map[string]any{
-			"angledQuotes": true,
-		})
-
-		v.Set("footnoteAnchorPrefix", "myprefix")
-		v.Set("footnoteReturnLinkContents", "myreturn")
-		v.Set("pygmentsStyle", "hugo")
-		v.Set("pygmentsCodefencesGuessSyntax", true)
-
-		v.Set("markup", map[string]any{
-			"goldmark": map[string]any{
-				"parser": map[string]any{
-					"attribute": false, // Was changed to a struct in 0.81.0
-				},
-			},
-		})
-		conf, err := Decode(v)
-
-		c.Assert(err, qt.IsNil)
-		c.Assert(conf.BlackFriday.AngledQuotes, qt.Equals, true)
-		c.Assert(conf.BlackFriday.FootnoteAnchorPrefix, qt.Equals, "myprefix")
-		c.Assert(conf.BlackFriday.FootnoteReturnLinkContents, qt.Equals, "myreturn")
-		c.Assert(conf.Highlight.Style, qt.Equals, "hugo")
-		c.Assert(conf.Highlight.CodeFences, qt.Equals, true)
-		c.Assert(conf.Highlight.GuessSyntax, qt.Equals, true)
-		c.Assert(conf.Goldmark.Parser.Attribute.Title, qt.Equals, false)
-		c.Assert(conf.Goldmark.Parser.Attribute.Block, qt.Equals, false)
-
-	})
 }
diff --git a/markup/markup_test.go b/markup/markup_test.go
index c0cc5ba8b..5ec27c45c 100644
--- a/markup/markup_test.go
+++ b/markup/markup_test.go
@@ -43,5 +43,4 @@ func TestConverterRegistry(t *testing.T) {
 	checkName("rst")
 	checkName("pandoc")
 	checkName("org")
-	checkName("blackfriday")
 }