Fix hashes in code blocks rendered as hashtags

Previously, our hashtag parser would indiscriminately replace
hashtag-like text with hashtag HTML -- including in places it shouldn't
have, like inside code blocks. Along with the v1.7.0 changes to
writeas/saturday, this fixes that and closes #6.

As a bonus, strings of #spaceless#hashtags#in#a#row are now rendered
correctly.

app.go

@@ -142,7 +142,7 @@ func handleTemplatedPage(app *app, w http.ResponseWriter, r *http.Request, t *te
 		if err != nil {
 			return err
 		}
-		p.Content = template.HTML(applyMarkdown([]byte(c)))
+		p.Content = template.HTML(applyMarkdown([]byte(c), ""))
 		p.PlainContent = shortPostDescription(stripmd.Strip(c))
 		if updated != nil {
 			p.Updated = updated.Format("January 2, 2006")

feed.go

@@ -93,7 +93,7 @@ func ViewFeed(app *app, w http.ResponseWriter, req *http.Request) error {
 			Title:       title,
 			Link:        &Link{Href: permalink},
 			Description: "<![CDATA[" + stripmd.Strip(p.Content) + "]]>",
-			Content:     applyMarkdown([]byte(p.Content)),
+			Content:     applyMarkdown([]byte(p.Content), ""),
 			Author:      &Author{author, ""},
 			Created:     p.Created,
 			Updated:     p.Updated,

postrender.go

@@ -11,7 +11,6 @@
 package writefreely
 
 import (
-	"bytes"
 	"fmt"
 	"github.com/microcosm-cc/bluemonday"
 	stripmd "github.com/writeas/go-strip-markdown"
@@ -31,7 +30,7 @@ var (
 	endBlockReg     = regexp.MustCompile("</([a-z]+)>\n</(ul|ol|blockquote)>")
 	youtubeReg      = regexp.MustCompile("(https?://www.youtube.com/embed/[a-zA-Z0-9\\-_]+)(\\?[^\t\n\f\r \"']+)?")
 	titleElementReg = regexp.MustCompile("</?h[1-6]>")
-	hashtagReg      = regexp.MustCompile(`(?m)(^| )#([\p{L}\p{M}\d]+)`)
+	hashtagReg      = regexp.MustCompile(`{{\[\[\|\|([^|]+)\|\|\]\]}}`)
 	markeddownReg   = regexp.MustCompile("<p>(.+)</p>")
 )
 
@@ -40,22 +39,10 @@ func (p *Post) formatContent(c *Collection, isOwner bool) {
 	if !isSingleUser {
 		baseURL = "/" + c.Alias + "/"
 	}
-	newCon := hashtagReg.ReplaceAllFunc([]byte(p.Content), func(b []byte) []byte {
-		// Ensure we only replace "hashtags" that have already been extracted.
-		// `hashtagReg` catches everything, including any hash on the end of a
-		// URL, so we rely on p.Tags as the final word on whether or not to link
-		// a tag.
-		for _, t := range p.Tags {
-			if strings.TrimSpace(string(b)) == "#"+t {
-				return bytes.Replace(b, []byte("#"+t), []byte("<a href=\""+baseURL+"tag:"+t+"\" class=\"hashtag\"><span>#</span><span class=\"p-category\">"+t+"</span></a>"), -1)
-			}
-		}
-		return b
-	})
 	p.HTMLTitle = template.HTML(applyBasicMarkdown([]byte(p.Title.String)))
-	p.HTMLContent = template.HTML(applyMarkdown([]byte(newCon)))
-	if exc := strings.Index(string(newCon), "<!--more-->"); exc > -1 {
-		p.HTMLExcerpt = template.HTML(applyMarkdown([]byte(newCon[:exc])))
+	p.HTMLContent = template.HTML(applyMarkdown([]byte(p.Content), baseURL))
+	if exc := strings.Index(string(p.Content), "<!--more-->"); exc > -1 {
+		p.HTMLExcerpt = template.HTML(applyMarkdown([]byte(p.Content[:exc]), baseURL))
 	}
 }
 
@@ -63,11 +50,11 @@ func (p *PublicPost) formatContent(isOwner bool) {
 	p.Post.formatContent(&p.Collection.Collection, isOwner)
 }
 
-func applyMarkdown(data []byte) string {
-	return applyMarkdownSpecial(data, false)
+func applyMarkdown(data []byte, baseURL string) string {
+	return applyMarkdownSpecial(data, false, baseURL)
 }
 
-func applyMarkdownSpecial(data []byte, skipNoFollow bool) string {
+func applyMarkdownSpecial(data []byte, skipNoFollow bool, baseURL string) string {
 	mdExtensions := 0 |
 		blackfriday.EXTENSION_TABLES |
 		blackfriday.EXTENSION_FENCED_CODE |
@@ -79,8 +66,16 @@ func applyMarkdownSpecial(data []byte, skipNoFollow bool) string {
 		blackfriday.HTML_USE_SMARTYPANTS |
 		blackfriday.HTML_SMARTYPANTS_DASHES
 
+	if baseURL != "" {
+		htmlFlags |= blackfriday.HTML_HASHTAGS
+	}
+
 	// Generate Markdown
 	md := blackfriday.Markdown([]byte(data), blackfriday.HtmlRenderer(htmlFlags, "", ""), mdExtensions)
+	if baseURL != "" {
+		// Replace special text generated by Markdown parser
+		md = []byte(hashtagReg.ReplaceAll(md, []byte("<a href=\""+baseURL+"tag:$1\" class=\"hashtag\"><span>#</span><span class=\"p-category\">$1</span></a>")))
+	}
 	// Strip out bad HTML
 	policy := getSanitizationPolicy()
 	policy.RequireNoFollowOnLinks(!skipNoFollow)

posts.go

@@ -368,7 +368,7 @@ func handleViewPost(app *app, w http.ResponseWriter, r *http.Request) error {
 			Direction:   d,
 		}
 		if !isRaw {
-			post.HTMLContent = template.HTML(applyMarkdown([]byte(content)))
+			post.HTMLContent = template.HTML(applyMarkdown([]byte(content), ""))
 		}
 	}
 

read.go

@@ -95,7 +95,7 @@ func (db *datastore) FetchPublicPosts() (interface{}, error) {
 		}
 
 		p.extractData()
-		p.HTMLContent = template.HTML(applyMarkdown([]byte(p.Content)))
+		p.HTMLContent = template.HTML(applyMarkdown([]byte(p.Content), ""))
 		fp := p.processPost()
 		if isCollectionPost {
 			fp.Collection = &CollectionObj{Collection: *c}
@@ -283,7 +283,7 @@ func viewLocalTimelineFeed(app *app, w http.ResponseWriter, req *http.Request) e
 			Title:       title,
 			Link:        &Link{Href: permalink},
 			Description: "<![CDATA[" + stripmd.Strip(p.Content) + "]]>",
-			Content:     applyMarkdown([]byte(p.Content)),
+			Content:     applyMarkdown([]byte(p.Content), ""),
 			Author:      &Author{author, ""},
 			Created:     p.Created,
 			Updated:     p.Updated,