Rewrite markdown rendering to blackfriday v2 and rewrite orgmode rendering to go-org (#8560)

* Rewrite markdown rendering to blackfriday v2.0

* Fix style

* Fix go mod with golang 1.13

* Fix blackfriday v2 import

* Inital orgmode renderer migration to go-org

* Vendor go-org dependency

* Ignore errors :/

* Update go-org to latest version

* Update test

* Fix go-org test

* Remove unneeded code

* Fix comments

* Fix markdown test

* Fix blackfriday regression rendering HTML block

2 files changed, 84 insertions, 26 deletions

diff --git a/modules/markup/orgmode/orgmode.go b/modules/markup/orgmode/orgmode.go
index f63155201e..54188d2734 100644
--- a/modules/markup/orgmode/orgmode.go
+++ b/modules/markup/orgmode/orgmode.go
@@ -5,12 +5,16 @@
 package markup
 
 import (
+	"bytes"
+	"fmt"
+	"html"
+	"strings"
+
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/markup"
-	"code.gitea.io/gitea/modules/markup/markdown"
+	"code.gitea.io/gitea/modules/util"
 
-	"github.com/chaseadamsio/goorgeous"
-	"github.com/russross/blackfriday"
+	"github.com/niklasfasching/go-org/org"
 )
 
 func init() {
@@ -32,23 +36,23 @@ func (Parser) Extensions() []string {
 }
 
 // Render renders orgmode rawbytes to HTML
-func Render(rawBytes []byte, urlPrefix string, metas map[string]string, isWiki bool) (result []byte) {
-	defer func() {
-		if err := recover(); err != nil {
-			log.Error("Panic in orgmode.Render: %v Just returning the rawBytes", err)
-			result = rawBytes
-		}
-	}()
-	htmlFlags := blackfriday.HTML_USE_XHTML
-	htmlFlags |= blackfriday.HTML_SKIP_STYLE
-	htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
-	renderer := &markdown.Renderer{
-		Renderer:  blackfriday.HtmlRenderer(htmlFlags, "", ""),
-		URLPrefix: urlPrefix,
-		IsWiki:    isWiki,
+func Render(rawBytes []byte, urlPrefix string, metas map[string]string, isWiki bool) []byte {
+	htmlWriter := org.NewHTMLWriter()
+
+	renderer := &Renderer{
+		HTMLWriter: htmlWriter,
+		URLPrefix:  urlPrefix,
+		IsWiki:     isWiki,
+	}
+
+	htmlWriter.ExtendingWriter = renderer
+
+	res, err := org.New().Silent().Parse(bytes.NewReader(rawBytes), "").Write(renderer)
+	if err != nil {
+		log.Error("Panic in orgmode.Render: %v Just returning the rawBytes", err)
+		return rawBytes
 	}
-	result = goorgeous.Org(rawBytes, renderer)
-	return
+	return []byte(res)
 }
 
 // RenderString reners orgmode string to HTML string
@@ -56,7 +60,63 @@ func RenderString(rawContent string, urlPrefix string, metas map[string]string,
 	return string(Render([]byte(rawContent), urlPrefix, metas, isWiki))
 }
 
-// Render implements markup.Parser
+// Render reners orgmode string to HTML string
 func (Parser) Render(rawBytes []byte, urlPrefix string, metas map[string]string, isWiki bool) []byte {
 	return Render(rawBytes, urlPrefix, metas, isWiki)
 }
+
+// Renderer implements org.Writer
+type Renderer struct {
+	*org.HTMLWriter
+	URLPrefix string
+	IsWiki    bool
+}
+
+var byteMailto = []byte("mailto:")
+
+// WriteRegularLink renders images, links or videos
+func (r *Renderer) WriteRegularLink(l org.RegularLink) {
+	link := []byte(html.EscapeString(l.URL))
+	if l.Protocol == "file" {
+		link = link[len("file:"):]
+	}
+	if len(link) > 0 && !markup.IsLink(link) &&
+		link[0] != '#' && !bytes.HasPrefix(link, byteMailto) {
+		lnk := string(link)
+		if r.IsWiki {
+			lnk = util.URLJoin("wiki", lnk)
+		}
+		link = []byte(util.URLJoin(r.URLPrefix, lnk))
+	}
+
+	description := string(link)
+	if l.Description != nil {
+		description = r.nodesAsString(l.Description...)
+	}
+	switch l.Kind() {
+	case "image":
+		r.WriteString(fmt.Sprintf(`<img src="%s" alt="%s" title="%s" />`, link, description, description))
+	case "video":
+		r.WriteString(fmt.Sprintf(`<video src="%s" title="%s">%s</video>`, link, description, description))
+	default:
+		r.WriteString(fmt.Sprintf(`<a href="%s" title="%s">%s</a>`, link, description, description))
+	}
+}
+
+func (r *Renderer) emptyClone() *Renderer {
+	wcopy := *(r.HTMLWriter)
+	wcopy.Builder = strings.Builder{}
+
+	rcopy := *r
+	rcopy.HTMLWriter = &wcopy
+
+	wcopy.ExtendingWriter = &rcopy
+
+	return &rcopy
+}
+
+func (r *Renderer) nodesAsString(nodes ...org.Node) string {
+	tmp := r.emptyClone()
+	org.WriteNodes(tmp, nodes...)
+	return tmp.String()
+}
diff --git a/modules/markup/orgmode/orgmode_test.go b/modules/markup/orgmode/orgmode_test.go
index 3846922c25..40323912b4 100644
--- a/modules/markup/orgmode/orgmode_test.go
+++ b/modules/markup/orgmode/orgmode_test.go
@@ -27,12 +27,12 @@ func TestRender_StandardLinks(t *testing.T) {
 		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(buffer))
 	}
 
-	googleRendered := `<p><a href="https://google.com/" title="https://google.com/">https://google.com/</a></p>`
+	googleRendered := "<p>\n<a href=\"https://google.com/\" title=\"https://google.com/\">https://google.com/</a>\n</p>"
 	test("[[https://google.com/]]", googleRendered)
 
 	lnk := util.URLJoin(AppSubURL, "WikiPage")
 	test("[[WikiPage][WikiPage]]",
-		`<p><a href="`+lnk+`" title="WikiPage">WikiPage</a></p>`)
+		"<p>\n<a href=\""+lnk+"\" title=\"WikiPage\">WikiPage</a>\n</p>")
 }
 
 func TestRender_Images(t *testing.T) {
@@ -45,10 +45,8 @@ func TestRender_Images(t *testing.T) {
 	}
 
 	url := "../../.images/src/02/train.jpg"
-	title := "Train"
 	result := util.URLJoin(AppSubURL, url)
 
-	test(
-		"[[file:"+url+"]["+title+"]]",
-		`<p><a href="`+result+`"><img src="`+result+`" alt="`+title+`" title="`+title+`" /></a></p>`)
+	test("[[file:"+url+"]]",
+		"<p>\n<img src=\""+result+"\" alt=\""+result+"\" title=\""+result+"\" />\n</p>")
 }