modules/markup: move common functions to markup.go

6 files changed, 663 insertions, 557 deletions

diff --git a/modules/markup/markdown.go b/modules/markup/markdown.go
index e59ae9a6..c325f19f 100644
--- a/modules/markup/markdown.go
+++ b/modules/markup/markdown.go
@@ -7,34 +7,18 @@ package markup
 import (
 	"bytes"
 	"fmt"
-	"io"
 	"path"
 	"path/filepath"
 	"regexp"
 	"strings"
 
-	"github.com/Unknwon/com"
 	"github.com/russross/blackfriday"
-	"golang.org/x/net/html"
 
 	"github.com/gogits/gogs/modules/base"
 	"github.com/gogits/gogs/modules/setting"
 )
 
-const (
-	ISSUE_NAME_STYLE_NUMERIC      = "numeric"
-	ISSUE_NAME_STYLE_ALPHANUMERIC = "alphanumeric"
-)
-
-var validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://|^mailto:`)
-
-// isLink reports whether link fits valid format.
-func isLink(link []byte) bool {
-	return validLinksPattern.Match(link)
-}
-
-// IsMarkdownFile reports whether name looks like a Markdown file
-// based on its extension.
+// IsMarkdownFile reports whether name looks like a Markdown file based on its extension.
 func IsMarkdownFile(name string) bool {
 	extension := strings.ToLower(filepath.Ext(name))
 	for _, ext := range setting.Markdown.FileExtensions {
@@ -45,61 +29,21 @@ func IsMarkdownFile(name string) bool {
 	return false
 }
 
-// IsReadmeFile reports whether name looks like a README file
-// based on its extension.
-func IsReadmeFile(name string) bool {
-	name = strings.ToLower(name)
-	if len(name) < 6 {
-		return false
-	} else if len(name) == 6 {
-		return name == "readme"
-	}
-	return name[:7] == "readme."
+// MarkdownRenderer is a extended version of underlying Markdown render object.
+type MarkdownRenderer struct {
+	blackfriday.Renderer
+	urlPrefix string
 }
 
-var (
-	// MentionPattern matches string that mentions someone, e.g. @Unknwon
-	MentionPattern = regexp.MustCompile(`(\s|^|\W)@[0-9a-zA-Z-_\.]+`)
-
-	// CommitPattern matches link to certain commit with or without trailing hash,
-	// e.g. https://try.gogs.io/gogs/gogs/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2
-	CommitPattern = regexp.MustCompile(`(\s|^)https?.*commit/[0-9a-zA-Z]+(#+[0-9a-zA-Z-]*)?`)
-
-	// IssueFullPattern matches link to an issue with or without trailing hash,
-	// e.g. https://try.gogs.io/gogs/gogs/issues/4#issue-685
-	IssueFullPattern = regexp.MustCompile(`(\s|^)https?.*issues/[0-9]+(#+[0-9a-zA-Z-]*)?`)
-	// IssueNumericPattern matches string that references to a numeric issue, e.g. #1287
-	IssueNumericPattern = regexp.MustCompile(`( |^|\()#[0-9]+\b`)
-	// IssueAlphanumericPattern matches string that references to an alphanumeric issue, e.g. ABC-1234
-	IssueAlphanumericPattern = regexp.MustCompile(`( |^|\()[A-Z]{1,10}-[1-9][0-9]*\b`)
-	// CrossReferenceIssueNumericPattern matches string that references a numeric issue in a difference repository
-	// e.g. gogits/gogs#12345
-	CrossReferenceIssueNumericPattern = regexp.MustCompile(`( |^)[0-9a-zA-Z-_\.]+/[0-9a-zA-Z-_\.]+#[0-9]+\b`)
-
-	// Sha1CurrentPattern matches string that represents a commit SHA, e.g. d8a994ef243349f321568f9e36d5c3f444b99cae
-	// FIXME: this pattern matches pure numbers as well, right now we do a hack to check in RenderSha1CurrentPattern
-	// by converting string to a number.
-	Sha1CurrentPattern = regexp.MustCompile(`\b[0-9a-f]{40}\b`)
-)
-
-// FindAllMentions matches mention patterns in given content
-// and returns a list of found user names without @ prefix.
-func FindAllMentions(content string) []string {
-	mentions := MentionPattern.FindAllString(content, -1)
-	for i := range mentions {
-		mentions[i] = mentions[i][strings.Index(mentions[i], "@")+1:] // Strip @ character
-	}
-	return mentions
-}
+var validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://|^mailto:`)
 
-// Renderer is a extended version of underlying render object.
-type Renderer struct {
-	blackfriday.Renderer
-	urlPrefix string
+// isLink reports whether link fits valid format.
+func isLink(link []byte) bool {
+	return validLinksPattern.Match(link)
 }
 
 // Link defines how formal links should be processed to produce corresponding HTML elements.
-func (r *Renderer) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
+func (r *MarkdownRenderer) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
 	if len(link) > 0 && !isLink(link) {
 		if link[0] != '#' {
 			link = []byte(path.Join(r.urlPrefix, string(link)))
@@ -111,7 +55,7 @@ func (r *Renderer) Link(out *bytes.Buffer, link []byte, title []byte, content []
 
 // AutoLink defines how auto-detected links should be processed to produce corresponding HTML elements.
 // Reference for kind: https://github.com/russross/blackfriday/blob/master/markdown.go#L69-L76
-func (r *Renderer) AutoLink(out *bytes.Buffer, link []byte, kind int) {
+func (r *MarkdownRenderer) AutoLink(out *bytes.Buffer, link []byte, kind int) {
 	if kind != blackfriday.LINK_TYPE_NORMAL {
 		r.Renderer.AutoLink(out, link, kind)
 		return
@@ -161,7 +105,7 @@ func (r *Renderer) AutoLink(out *bytes.Buffer, link []byte, kind int) {
 }
 
 // ListItem defines how list items should be processed to produce corresponding HTML elements.
-func (options *Renderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
+func (options *MarkdownRenderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
 	// Detect procedures to draw checkboxes.
 	switch {
 	case bytes.HasPrefix(text, []byte("[ ] ")):
@@ -172,108 +116,8 @@ func (options *Renderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
 	options.Renderer.ListItem(out, text, flags)
 }
 
-// Note: this section is for purpose of increase performance and
-// reduce memory allocation at runtime since they are constant literals.
-var (
-	pound        = []byte("#")
-	space        = " "
-	spaceEncoded = "%20"
-)
-
-// cutoutVerbosePrefix cutouts URL prefix including sub-path to
-// return a clean unified string of request URL path.
-func cutoutVerbosePrefix(prefix string) string {
-	if len(prefix) == 0 || prefix[0] != '/' {
-		return prefix
-	}
-	count := 0
-	for i := 0; i < len(prefix); i++ {
-		if prefix[i] == '/' {
-			count++
-		}
-		if count >= 3+setting.AppSubUrlDepth {
-			return prefix[:i]
-		}
-	}
-	return prefix
-}
-
-// RenderIssueIndexPattern renders issue indexes to corresponding links.
-func RenderIssueIndexPattern(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
-	urlPrefix = cutoutVerbosePrefix(urlPrefix)
-
-	pattern := IssueNumericPattern
-	if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
-		pattern = IssueAlphanumericPattern
-	}
-
-	ms := pattern.FindAll(rawBytes, -1)
-	for _, m := range ms {
-		if m[0] == ' ' || m[0] == '(' {
-			m = m[1:] // ignore leading space or opening parentheses
-		}
-		var link string
-		if metas == nil {
-			link = fmt.Sprintf(`<a href="%s/issues/%s">%s</a>`, urlPrefix, m[1:], m)
-		} else {
-			// Support for external issue tracker
-			if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
-				metas["index"] = string(m)
-			} else {
-				metas["index"] = string(m[1:])
-			}
-			link = fmt.Sprintf(`<a href="%s">%s</a>`, com.Expand(metas["format"], metas), m)
-		}
-		rawBytes = bytes.Replace(rawBytes, m, []byte(link), 1)
-	}
-	return rawBytes
-}
-
-// RenderCrossReferenceIssueIndexPattern renders issue indexes from other repositories to corresponding links.
-func RenderCrossReferenceIssueIndexPattern(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
-	ms := CrossReferenceIssueNumericPattern.FindAll(rawBytes, -1)
-	for _, m := range ms {
-		if m[0] == ' ' || m[0] == '(' {
-			m = m[1:] // ignore leading space or opening parentheses
-		}
-
-		delimIdx := bytes.Index(m, pound)
-		repo := string(m[:delimIdx])
-		index := string(m[delimIdx+1:])
-
-		link := fmt.Sprintf(`<a href="%s%s/issues/%s">%s</a>`, setting.AppUrl, repo, index, m)
-		rawBytes = bytes.Replace(rawBytes, m, []byte(link), 1)
-	}
-	return rawBytes
-}
-
-// RenderSha1CurrentPattern renders SHA1 strings to corresponding links that assumes in the same repository.
-func RenderSha1CurrentPattern(rawBytes []byte, urlPrefix string) []byte {
-	return []byte(Sha1CurrentPattern.ReplaceAllStringFunc(string(rawBytes[:]), func(m string) string {
-		if com.StrTo(m).MustInt() > 0 {
-			return m
-		}
-		return fmt.Sprintf(`<a href="%s/commit/%s"><code>%s</code></a>`, urlPrefix, m, base.ShortSha(string(m)))
-	}))
-}
-
-// RenderSpecialLink renders mentions, indexes and SHA1 strings to corresponding links.
-func RenderSpecialLink(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
-	ms := MentionPattern.FindAll(rawBytes, -1)
-	for _, m := range ms {
-		m = m[bytes.Index(m, []byte("@")):]
-		rawBytes = bytes.Replace(rawBytes, m,
-			[]byte(fmt.Sprintf(`<a href="%s/%s">%s</a>`, setting.AppSubUrl, m[1:], m)), -1)
-	}
-
-	rawBytes = RenderIssueIndexPattern(rawBytes, urlPrefix, metas)
-	rawBytes = RenderCrossReferenceIssueIndexPattern(rawBytes, urlPrefix, metas)
-	rawBytes = RenderSha1CurrentPattern(rawBytes, urlPrefix)
-	return rawBytes
-}
-
-// RenderRaw renders Markdown to HTML without handling special links.
-func RenderRaw(body []byte, urlPrefix string) []byte {
+// RawMarkdown renders Markdown to HTML without handling special links.
+func RawMarkdown(body []byte, urlPrefix string) []byte {
 	htmlFlags := 0
 	htmlFlags |= blackfriday.HTML_SKIP_STYLE
 	htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
@@ -294,7 +138,7 @@ func RenderRaw(body []byte, urlPrefix string) []byte {
 		}
 	}
 
-	renderer := &Renderer{
+	renderer := &MarkdownRenderer{
 		Renderer:  blackfriday.HtmlRenderer(htmlFlags, "", ""),
 		urlPrefix: urlPrefix,
 	}
@@ -317,162 +161,7 @@ func RenderRaw(body []byte, urlPrefix string) []byte {
 	return body
 }
 
-var (
-	leftAngleBracket  = []byte("</")
-	rightAngleBracket = []byte(">")
-)
-
-var noEndTags = []string{"input", "br", "hr", "img"}
-
-// wrapImgWithLink warps link to standalone <img> tags.
-func wrapImgWithLink(urlPrefix string, buf *bytes.Buffer, token html.Token) {
-	var src, alt string
-	// Extract "src" and "alt" attributes
-	for i := range token.Attr {
-		switch token.Attr[i].Key {
-		case "src":
-			src = token.Attr[i].Val
-		case "alt":
-			alt = token.Attr[i].Val
-		}
-	}
-
-	// Skip in case the "src" is empty
-	if len(src) == 0 {
-		buf.WriteString(token.String())
-		return
-	}
-
-	// Prepend repository base URL for internal links
-	needPrepend := !isLink([]byte(src))
-	if needPrepend {
-		urlPrefix = strings.Replace(urlPrefix, "/src/", "/raw/", 1)
-		if src[0] != '/' {
-			urlPrefix += "/"
-		}
-	}
-
-	buf.WriteString(`<a href="`)
-	if needPrepend {
-		buf.WriteString(urlPrefix)
-		buf.WriteString(src)
-	} else {
-		buf.WriteString(src)
-	}
-	buf.WriteString(`">`)
-
-	if needPrepend {
-		src = strings.Replace(urlPrefix+string(src), " ", "%20", -1)
-		buf.WriteString(`<img src="`)
-		buf.WriteString(src)
-		buf.WriteString(`"`)
-
-		if len(alt) > 0 {
-			buf.WriteString(` alt="`)
-			buf.WriteString(alt)
-			buf.WriteString(`"`)
-		}
-
-		buf.WriteString(`>`)
-
-	} else {
-		buf.WriteString(token.String())
-	}
-
-	buf.WriteString(`</a>`)
-}
-
-// PostProcess treats different types of HTML differently,
-// and only renders special links for plain text blocks.
-func PostProcess(rawHTML []byte, urlPrefix string, metas map[string]string) []byte {
-	startTags := make([]string, 0, 5)
-	buf := bytes.NewBuffer(nil)
-	tokenizer := html.NewTokenizer(bytes.NewReader(rawHTML))
-
-OUTER_LOOP:
-	for html.ErrorToken != tokenizer.Next() {
-		token := tokenizer.Token()
-		switch token.Type {
-		case html.TextToken:
-			buf.Write(RenderSpecialLink([]byte(token.String()), urlPrefix, metas))
-
-		case html.StartTagToken:
-			tagName := token.Data
-
-			if tagName == "img" {
-				wrapImgWithLink(urlPrefix, buf, token)
-				continue OUTER_LOOP
-			}
-
-			buf.WriteString(token.String())
-			// If this is an excluded tag, we skip processing all output until a close tag is encountered.
-			if strings.EqualFold("a", tagName) || strings.EqualFold("code", tagName) || strings.EqualFold("pre", tagName) {
-				stackNum := 1
-				for html.ErrorToken != tokenizer.Next() {
-					token = tokenizer.Token()
-
-					// Copy the token to the output verbatim
-					buf.WriteString(token.String())
-
-					// Stack number doesn't increate for tags without end tags.
-					if token.Type == html.StartTagToken && !com.IsSliceContainsStr(noEndTags, token.Data) {
-						stackNum++
-					}
-
-					// If this is the close tag to the outer-most, we are done
-					if token.Type == html.EndTagToken {
-						stackNum--
-						if stackNum <= 0 && strings.EqualFold(tagName, token.Data) {
-							break
-						}
-					}
-				}
-				continue OUTER_LOOP
-			}
-
-			if !com.IsSliceContainsStr(noEndTags, tagName) {
-				startTags = append(startTags, tagName)
-			}
-
-		case html.EndTagToken:
-			if len(startTags) == 0 {
-				buf.WriteString(token.String())
-				break
-			}
-
-			buf.Write(leftAngleBracket)
-			buf.WriteString(startTags[len(startTags)-1])
-			buf.Write(rightAngleBracket)
-			startTags = startTags[:len(startTags)-1]
-		default:
-			buf.WriteString(token.String())
-		}
-	}
-
-	if io.EOF == tokenizer.Err() {
-		return buf.Bytes()
-	}
-
-	// If we are not at the end of the input, then some other parsing error has occurred,
-	// so return the input verbatim.
-	return rawHTML
-}
-
 // Markdown takes a string or []byte and renders to HTML in Markdown syntax with special links.
 func Markdown(input interface{}, urlPrefix string, metas map[string]string) []byte {
-	var rawBytes []byte
-	switch v := input.(type) {
-	case []byte:
-		rawBytes = v
-	case string:
-		rawBytes = []byte(v)
-	default:
-		panic(fmt.Sprintf("unexpected input content type: %T", input))
-	}
-
-	urlPrefix = strings.Replace(urlPrefix, space, spaceEncoded, -1)
-	result := RenderRaw(rawBytes, urlPrefix)
-	result = PostProcess(result, urlPrefix, metas)
-	result = SanitizeBytes(result)
-	return result
+	return Render(MARKDOWN, input, urlPrefix, metas)
 }
diff --git a/modules/markup/markdown_test.go b/modules/markup/markdown_test.go
index cbf75312..8f048df8 100644
--- a/modules/markup/markdown_test.go
+++ b/modules/markup/markdown_test.go
@@ -1,7 +1,12 @@
+// Copyright 2016 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
 package markup_test
 
 import (
 	"bytes"
+	"strings"
 	"testing"
 
 	"github.com/russross/blackfriday"
@@ -11,238 +16,35 @@ import (
 	"github.com/gogits/gogs/modules/setting"
 )
 
-func TestMarkdown(t *testing.T) {
-	Convey("Rendering an issue mention", t, func() {
-		var (
-			urlPrefix                   = "/prefix"
-			metas     map[string]string = nil
-		)
-		setting.AppSubUrlDepth = 0
-
-		Convey("To the internal issue tracker", func() {
-			Convey("It should not render anything when there are no mentions", func() {
-				testCases := []string{
-					"",
-					"this is a test",
-					"test 123 123 1234",
-					"#",
-					"# # #",
-					"# 123",
-					"#abcd",
-					"##1234",
-					"test#1234",
-					"#1234test",
-					" test #1234test",
-				}
-
-				for i := 0; i < len(testCases); i++ {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
-				}
-			})
-			Convey("It should render freestanding mentions", func() {
-				testCases := []string{
-					"#1234 test", "<a href=\"/prefix/issues/1234\">#1234</a> test",
-					"test #1234 issue", "test <a href=\"/prefix/issues/1234\">#1234</a> issue",
-					"test issue #1234", "test issue <a href=\"/prefix/issues/1234\">#1234</a>",
-					"#5 test", "<a href=\"/prefix/issues/5\">#5</a> test",
-					"test #5 issue", "test <a href=\"/prefix/issues/5\">#5</a> issue",
-					"test issue #5", "test issue <a href=\"/prefix/issues/5\">#5</a>",
-				}
-
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-			Convey("It should not render issue mention without leading space", func() {
-				input := []byte("test#54321 issue")
-				expected := "test#54321 issue"
-				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
-			})
-			Convey("It should not render issue mention without trailing space", func() {
-				input := []byte("test #54321issue")
-				expected := "test #54321issue"
-				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
-			})
-			Convey("It should render issue mention in parentheses", func() {
-				testCases := []string{
-					"(#54321 issue)", "(<a href=\"/prefix/issues/54321\">#54321</a> issue)",
-					"test (#54321) issue", "test (<a href=\"/prefix/issues/54321\">#54321</a>) issue",
-					"test (#54321 extra) issue", "test (<a href=\"/prefix/issues/54321\">#54321</a> extra) issue",
-					"test (#54321 issue)", "test (<a href=\"/prefix/issues/54321\">#54321</a> issue)",
-					"test (#54321)", "test (<a href=\"/prefix/issues/54321\">#54321</a>)",
-				}
-
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-			Convey("It should render multiple issue mentions in the same line", func() {
-				testCases := []string{
-					"#54321 #1243", "<a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>",
-					"test #54321 #1243", "test <a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>",
-					"(#54321 #1243)", "(<a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>)",
-					"(#54321)(#1243)", "(<a href=\"/prefix/issues/54321\">#54321</a>)(<a href=\"/prefix/issues/1243\">#1243</a>)",
-					"text #54321 test #1243 issue", "text <a href=\"/prefix/issues/54321\">#54321</a> test <a href=\"/prefix/issues/1243\">#1243</a> issue",
-					"#1 (#4321) test", "<a href=\"/prefix/issues/1\">#1</a> (<a href=\"/prefix/issues/4321\">#4321</a>) test",
-				}
-
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-		})
-		Convey("To an external issue tracker with numeric style", func() {
-			metas = make(map[string]string)
-			metas["format"] = "https://someurl.com/{user}/{repo}/{index}"
-			metas["user"] = "someuser"
-			metas["repo"] = "somerepo"
-			metas["style"] = ISSUE_NAME_STYLE_NUMERIC
-
-			Convey("should not render anything when there are no mentions", func() {
-				testCases := []string{
-					"this is a test",
-					"test 123 123 1234",
-					"#",
-					"# # #",
-					"# 123",
-					"#abcd",
-				}
-
-				for i := 0; i < len(testCases); i++ {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
-				}
-			})
-			Convey("It should render freestanding issue mentions", func() {
-				testCases := []string{
-					"#1234 test", "<a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a> test",
-					"test #1234 issue", "test <a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a> issue",
-					"test issue #1234", "test issue <a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a>",
-					"#5 test", "<a href=\"https://someurl.com/someuser/somerepo/5\">#5</a> test",
-					"test #5 issue", "test <a href=\"https://someurl.com/someuser/somerepo/5\">#5</a> issue",
-					"test issue #5", "test issue <a href=\"https://someurl.com/someuser/somerepo/5\">#5</a>",
-				}
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-			Convey("It should not render issue mention without leading space", func() {
-				input := []byte("test#54321 issue")
-				expected := "test#54321 issue"
-				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
-			})
-			Convey("It should not render issue mention without trailing space", func() {
-				input := []byte("test #54321issue")
-				expected := "test #54321issue"
-				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
-			})
-			Convey("It should render issue mention in parentheses", func() {
-				testCases := []string{
-					"(#54321 issue)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> issue)",
-					"test (#54321) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>) issue",
-					"test (#54321 extra) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> extra) issue",
-					"test (#54321 issue)", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> issue)",
-					"test (#54321)", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>)",
-				}
-
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-			Convey("It should render multiple issue mentions in the same line", func() {
-				testCases := []string{
-					"#54321 #1243", "<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>",
-					"test #54321 #1243", "test <a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>",
-					"(#54321 #1243)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>)",
-					"(#54321)(#1243)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>)(<a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>)",
-					"text #54321 test #1243 issue", "text <a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> test <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a> issue",
-					"#1 (#4321) test", "<a href=\"https://someurl.com/someuser/somerepo/1\">#1</a> (<a href=\"https://someurl.com/someuser/somerepo/4321\">#4321</a>) test",
-				}
-
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-		})
-		Convey("To an external issue tracker with alphanumeric style", func() {
-			metas = make(map[string]string)
-			metas["format"] = "https://someurl.com/{user}/{repo}/?b={index}"
-			metas["user"] = "someuser"
-			metas["repo"] = "somerepo"
-			metas["style"] = ISSUE_NAME_STYLE_ALPHANUMERIC
-			Convey("It should not render anything when there are no mentions", func() {
-				testCases := []string{
-					"",
-					"this is a test",
-					"test 123 123 1234",
-					"#",
-					"##1234",
-					"# 123",
-					"#abcd",
-					"test #123",
-					"abc-1234",         // issue prefix must be capital
-					"ABc-1234",         // issue prefix must be _all_ capital
-					"ABCDEFGHIJK-1234", // the limit is 10 characters in the prefix
-					"ABC1234",          // dash is required
-					"test ABC- test",   // number is required
-					"test -1234 test",  // prefix is required
-					"testABC-123 test", // leading space is required
-					"test ABC-123test", // trailing space is required
-					"ABC-0123",         // no leading zero
-				}
-
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
-				}
-			})
-			Convey("It should render freestanding issue mention", func() {
-				testCases := []string{
-					"OTT-1234 test", "<a href=\"https://someurl.com/someuser/somerepo/?b=OTT-1234\">OTT-1234</a> test",
-					"test T-12 issue", "test <a href=\"https://someurl.com/someuser/somerepo/?b=T-12\">T-12</a> issue",
-					"test issue ABCDEFGHIJ-1234567890", "test issue <a href=\"https://someurl.com/someuser/somerepo/?b=ABCDEFGHIJ-1234567890\">ABCDEFGHIJ-1234567890</a>",
-					"A-1 test", "<a href=\"https://someurl.com/someuser/somerepo/?b=A-1\">A-1</a> test",
-					"test ZED-1 issue", "test <a href=\"https://someurl.com/someuser/somerepo/?b=ZED-1\">ZED-1</a> issue",
-					"test issue DEED-7154", "test issue <a href=\"https://someurl.com/someuser/somerepo/?b=DEED-7154\">DEED-7154</a>",
-				}
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-			Convey("It should render issue mention in parentheses", func() {
-				testCases := []string{
-					"(ABG-124 issue)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> issue)",
-					"test (ABG-124) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>) issue",
-					"test (ABG-124 extra) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> extra) issue",
-					"test (ABG-124 issue)", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> issue)",
-					"test (ABG-124)", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>)",
-				}
-
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-			Convey("It should render multiple issue mentions in the same line", func() {
-				testCases := []string{
-					"ABG-124 OTT-4321", "<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>",
-					"test ABG-124 OTT-4321", "test <a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>",
-					"(ABG-124 OTT-4321)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>)",
-					"(ABG-124)(OTT-4321)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>)(<a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>)",
-					"text ABG-124 test OTT-4321 issue", "text <a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> test <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a> issue",
-					"A-1 (RRE-345) test", "<a href=\"https://someurl.com/someuser/somerepo/?b=A-1\">A-1</a> (<a href=\"https://someurl.com/someuser/somerepo/?b=RRE-345\">RRE-345</a>) test",
-				}
+func Test_IsMarkdownFile(t *testing.T) {
+	setting.Markdown.FileExtensions = strings.Split(".md,.markdown,.mdown,.mkd", ",")
+	Convey("Detect Markdown file extension", t, func() {
+		testCases := []struct {
+			ext   string
+			match bool
+		}{
+			{".md", true},
+			{".markdown", true},
+			{".mdown", true},
+			{".mkd", true},
+			{".org", false},
+			{".rst", false},
+			{".asciidoc", false},
+		}
 
-				for i := 0; i < len(testCases); i += 2 {
-					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
-				}
-			})
-		})
+		for _, tc := range testCases {
+			So(IsMarkdownFile(tc.ext), ShouldEqual, tc.match)
+		}
 	})
+}
 
+func Test_Markdown(t *testing.T) {
 	Convey("Rendering an issue URL", t, func() {
 		setting.AppUrl = "http://localhost:3000/"
 		htmlFlags := 0
 		htmlFlags |= blackfriday.HTML_SKIP_STYLE
 		htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
-		renderer := &Renderer{
+		renderer := &MarkdownRenderer{
 			Renderer: blackfriday.HtmlRenderer(htmlFlags, "", ""),
 		}
 		buffer := new(bytes.Buffer)
@@ -284,7 +86,7 @@ func TestMarkdown(t *testing.T) {
 		htmlFlags := 0
 		htmlFlags |= blackfriday.HTML_SKIP_STYLE
 		htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
-		renderer := &Renderer{
+		renderer := &MarkdownRenderer{
 			Renderer: blackfriday.HtmlRenderer(htmlFlags, "", ""),
 		}
 		buffer := new(bytes.Buffer)
diff --git a/modules/markup/markup.go b/modules/markup/markup.go
new file mode 100644
index 00000000..a1c862a9
--- /dev/null
+++ b/modules/markup/markup.go
@@ -0,0 +1,335 @@
+// Copyright 2017 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+
+	"github.com/Unknwon/com"
+	"golang.org/x/net/html"
+
+	"github.com/gogits/gogs/modules/base"
+	"github.com/gogits/gogs/modules/setting"
+)
+
+// IsReadmeFile reports whether name looks like a README file based on its extension.
+func IsReadmeFile(name string) bool {
+	return strings.HasPrefix(strings.ToLower(name), "readme")
+}
+
+const (
+	ISSUE_NAME_STYLE_NUMERIC      = "numeric"
+	ISSUE_NAME_STYLE_ALPHANUMERIC = "alphanumeric"
+)
+
+var (
+	// MentionPattern matches string that mentions someone, e.g. @Unknwon
+	MentionPattern = regexp.MustCompile(`(\s|^|\W)@[0-9a-zA-Z-_\.]+`)
+
+	// CommitPattern matches link to certain commit with or without trailing hash,
+	// e.g. https://try.gogs.io/gogs/gogs/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2
+	CommitPattern = regexp.MustCompile(`(\s|^)https?.*commit/[0-9a-zA-Z]+(#+[0-9a-zA-Z-]*)?`)
+
+	// IssueFullPattern matches link to an issue with or without trailing hash,
+	// e.g. https://try.gogs.io/gogs/gogs/issues/4#issue-685
+	IssueFullPattern = regexp.MustCompile(`(\s|^)https?.*issues/[0-9]+(#+[0-9a-zA-Z-]*)?`)
+	// IssueNumericPattern matches string that references to a numeric issue, e.g. #1287
+	IssueNumericPattern = regexp.MustCompile(`( |^|\()#[0-9]+\b`)
+	// IssueAlphanumericPattern matches string that references to an alphanumeric issue, e.g. ABC-1234
+	IssueAlphanumericPattern = regexp.MustCompile(`( |^|\()[A-Z]{1,10}-[1-9][0-9]*\b`)
+	// CrossReferenceIssueNumericPattern matches string that references a numeric issue in a difference repository
+	// e.g. gogits/gogs#12345
+	CrossReferenceIssueNumericPattern = regexp.MustCompile(`( |^)[0-9a-zA-Z-_\.]+/[0-9a-zA-Z-_\.]+#[0-9]+\b`)
+
+	// Sha1CurrentPattern matches string that represents a commit SHA, e.g. d8a994ef243349f321568f9e36d5c3f444b99cae
+	// FIXME: this pattern matches pure numbers as well, right now we do a hack to check in RenderSha1CurrentPattern
+	// by converting string to a number.
+	Sha1CurrentPattern = regexp.MustCompile(`\b[0-9a-f]{40}\b`)
+)
+
+// FindAllMentions matches mention patterns in given content
+// and returns a list of found user names without @ prefix.
+func FindAllMentions(content string) []string {
+	mentions := MentionPattern.FindAllString(content, -1)
+	for i := range mentions {
+		mentions[i] = mentions[i][strings.Index(mentions[i], "@")+1:] // Strip @ character
+	}
+	return mentions
+}
+
+// cutoutVerbosePrefix cutouts URL prefix including sub-path to
+// return a clean unified string of request URL path.
+func cutoutVerbosePrefix(prefix string) string {
+	if len(prefix) == 0 || prefix[0] != '/' {
+		return prefix
+	}
+	count := 0
+	for i := 0; i < len(prefix); i++ {
+		if prefix[i] == '/' {
+			count++
+		}
+		if count >= 3+setting.AppSubUrlDepth {
+			return prefix[:i]
+		}
+	}
+	return prefix
+}
+
+// RenderIssueIndexPattern renders issue indexes to corresponding links.
+func RenderIssueIndexPattern(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
+	urlPrefix = cutoutVerbosePrefix(urlPrefix)
+
+	pattern := IssueNumericPattern
+	if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
+		pattern = IssueAlphanumericPattern
+	}
+
+	ms := pattern.FindAll(rawBytes, -1)
+	for _, m := range ms {
+		if m[0] == ' ' || m[0] == '(' {
+			m = m[1:] // ignore leading space or opening parentheses
+		}
+		var link string
+		if metas == nil {
+			link = fmt.Sprintf(`<a href="%s/issues/%s">%s</a>`, urlPrefix, m[1:], m)
+		} else {
+			// Support for external issue tracker
+			if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
+				metas["index"] = string(m)
+			} else {
+				metas["index"] = string(m[1:])
+			}
+			link = fmt.Sprintf(`<a href="%s">%s</a>`, com.Expand(metas["format"], metas), m)
+		}
+		rawBytes = bytes.Replace(rawBytes, m, []byte(link), 1)
+	}
+	return rawBytes
+}
+
+// Note: this section is for purpose of increase performance and
+// reduce memory allocation at runtime since they are constant literals.
+var pound = []byte("#")
+
+// RenderCrossReferenceIssueIndexPattern renders issue indexes from other repositories to corresponding links.
+func RenderCrossReferenceIssueIndexPattern(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
+	ms := CrossReferenceIssueNumericPattern.FindAll(rawBytes, -1)
+	for _, m := range ms {
+		if m[0] == ' ' || m[0] == '(' {
+			m = m[1:] // ignore leading space or opening parentheses
+		}
+
+		delimIdx := bytes.Index(m, pound)
+		repo := string(m[:delimIdx])
+		index := string(m[delimIdx+1:])
+
+		link := fmt.Sprintf(`<a href="%s%s/issues/%s">%s</a>`, setting.AppUrl, repo, index, m)
+		rawBytes = bytes.Replace(rawBytes, m, []byte(link), 1)
+	}
+	return rawBytes
+}
+
+// RenderSha1CurrentPattern renders SHA1 strings to corresponding links that assumes in the same repository.
+func RenderSha1CurrentPattern(rawBytes []byte, urlPrefix string) []byte {
+	return []byte(Sha1CurrentPattern.ReplaceAllStringFunc(string(rawBytes[:]), func(m string) string {
+		if com.StrTo(m).MustInt() > 0 {
+			return m
+		}
+		return fmt.Sprintf(`<a href="%s/commit/%s"><code>%s</code></a>`, urlPrefix, m, base.ShortSha(string(m)))
+	}))
+}
+
+// RenderSpecialLink renders mentions, indexes and SHA1 strings to corresponding links.
+func RenderSpecialLink(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
+	ms := MentionPattern.FindAll(rawBytes, -1)
+	for _, m := range ms {
+		m = m[bytes.Index(m, []byte("@")):]
+		rawBytes = bytes.Replace(rawBytes, m,
+			[]byte(fmt.Sprintf(`<a href="%s/%s">%s</a>`, setting.AppSubUrl, m[1:], m)), -1)
+	}
+
+	rawBytes = RenderIssueIndexPattern(rawBytes, urlPrefix, metas)
+	rawBytes = RenderCrossReferenceIssueIndexPattern(rawBytes, urlPrefix, metas)
+	rawBytes = RenderSha1CurrentPattern(rawBytes, urlPrefix)
+	return rawBytes
+}
+
+var (
+	leftAngleBracket  = []byte("</")
+	rightAngleBracket = []byte(">")
+)
+
+var noEndTags = []string{"input", "br", "hr", "img"}
+
+// wrapImgWithLink warps link to standalone <img> tags.
+func wrapImgWithLink(urlPrefix string, buf *bytes.Buffer, token html.Token) {
+	// Extract "src" and "alt" attributes
+	var src, alt string
+	for i := range token.Attr {
+		switch token.Attr[i].Key {
+		case "src":
+			src = token.Attr[i].Val
+		case "alt":
+			alt = token.Attr[i].Val
+		}
+	}
+
+	// Skip in case the "src" is empty
+	if len(src) == 0 {
+		buf.WriteString(token.String())
+		return
+	}
+
+	// Prepend repository base URL for internal links
+	needPrepend := !isLink([]byte(src))
+	if needPrepend {
+		urlPrefix = strings.Replace(urlPrefix, "/src/", "/raw/", 1)
+		if src[0] != '/' {
+			urlPrefix += "/"
+		}
+	}
+
+	buf.WriteString(`<a href="`)
+	if needPrepend {
+		buf.WriteString(urlPrefix)
+		buf.WriteString(src)
+	} else {
+		buf.WriteString(src)
+	}
+	buf.WriteString(`">`)
+
+	if needPrepend {
+		src = strings.Replace(urlPrefix+string(src), " ", "%20", -1)
+		buf.WriteString(`<img src="`)
+		buf.WriteString(src)
+		buf.WriteString(`"`)
+
+		if len(alt) > 0 {
+			buf.WriteString(` alt="`)
+			buf.WriteString(alt)
+			buf.WriteString(`"`)
+		}
+
+		buf.WriteString(`>`)
+
+	} else {
+		buf.WriteString(token.String())
+	}
+
+	buf.WriteString(`</a>`)
+}
+
+// postProcessHTML treats different types of HTML differently,
+// and only renders special links for plain text blocks.
+func postProcessHTML(rawHTML []byte, urlPrefix string, metas map[string]string) []byte {
+	startTags := make([]string, 0, 5)
+	buf := bytes.NewBuffer(nil)
+	tokenizer := html.NewTokenizer(bytes.NewReader(rawHTML))
+
+OUTER_LOOP:
+	for html.ErrorToken != tokenizer.Next() {
+		token := tokenizer.Token()
+		switch token.Type {
+		case html.TextToken:
+			buf.Write(RenderSpecialLink([]byte(token.String()), urlPrefix, metas))
+
+		case html.StartTagToken:
+			tagName := token.Data
+
+			if tagName == "img" {
+				wrapImgWithLink(urlPrefix, buf, token)
+				continue OUTER_LOOP
+			}
+
+			buf.WriteString(token.String())
+			// If this is an excluded tag, we skip processing all output until a close tag is encountered.
+			if strings.EqualFold("a", tagName) || strings.EqualFold("code", tagName) || strings.EqualFold("pre", tagName) {
+				stackNum := 1
+				for html.ErrorToken != tokenizer.Next() {
+					token = tokenizer.Token()
+
+					// Copy the token to the output verbatim
+					buf.WriteString(token.String())
+
+					// Stack number doesn't increate for tags without end tags.
+					if token.Type == html.StartTagToken && !com.IsSliceContainsStr(noEndTags, token.Data) {
+						stackNum++
+					}
+
+					// If this is the close tag to the outer-most, we are done
+					if token.Type == html.EndTagToken {
+						stackNum--
+						if stackNum <= 0 && strings.EqualFold(tagName, token.Data) {
+							break
+						}
+					}
+				}
+				continue OUTER_LOOP
+			}
+
+			if !com.IsSliceContainsStr(noEndTags, tagName) {
+				startTags = append(startTags, tagName)
+			}
+
+		case html.EndTagToken:
+			if len(startTags) == 0 {
+				buf.WriteString(token.String())
+				break
+			}
+
+			buf.Write(leftAngleBracket)
+			buf.WriteString(startTags[len(startTags)-1])
+			buf.Write(rightAngleBracket)
+			startTags = startTags[:len(startTags)-1]
+		default:
+			buf.WriteString(token.String())
+		}
+	}
+
+	if io.EOF == tokenizer.Err() {
+		return buf.Bytes()
+	}
+
+	// If we are not at the end of the input, then some other parsing error has occurred,
+	// so return the input verbatim.
+	return rawHTML
+}
+
+type Type string
+
+const (
+	UNRECOGNIZED Type = "unrecognized"
+	MARKDOWN     Type = "markdown"
+	ORG_MODE     Type = "orgmode"
+)
+
+// Render takes a string or []byte and renders to HTML in given type of syntax with special links.
+func Render(typ Type, input interface{}, urlPrefix string, metas map[string]string) []byte {
+	var rawBytes []byte
+	switch v := input.(type) {
+	case []byte:
+		rawBytes = v
+	case string:
+		rawBytes = []byte(v)
+	default:
+		panic(fmt.Sprintf("unrecognized input content type: %T", input))
+	}
+
+	urlPrefix = strings.Replace(urlPrefix, " ", "%20", -1)
+	var rawHTML []byte
+	switch typ {
+	case MARKDOWN:
+		rawHTML = RawMarkdown(rawBytes, urlPrefix)
+	case ORG_MODE:
+	default:
+		return rawBytes // Do nothing if syntax type is not recognized
+	}
+
+	rawHTML = postProcessHTML(rawHTML, urlPrefix, metas)
+	return SanitizeBytes(rawHTML)
+}
diff --git a/modules/markup/markup_test.go b/modules/markup/markup_test.go
new file mode 100644
index 00000000..8352911b
--- /dev/null
+++ b/modules/markup/markup_test.go
@@ -0,0 +1,284 @@
+// Copyright 2017 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package markup_test
+
+import (
+	"strings"
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+
+	. "github.com/gogits/gogs/modules/markup"
+	"github.com/gogits/gogs/modules/setting"
+)
+
+func Test_IsReadmeFile(t *testing.T) {
+	Convey("Detect README file extension", t, func() {
+		testCases := []struct {
+			ext   string
+			match bool
+		}{
+			{"readme", true},
+			{"README", true},
+			{"readme.md", true},
+			{"readme.markdown", true},
+			{"readme.mdown", true},
+			{"readme.mkd", true},
+			{"readme.org", true},
+			{"readme.rst", true},
+			{"readme.asciidoc", true},
+			{"readme_ZH", true},
+		}
+
+		for _, tc := range testCases {
+			So(IsReadmeFile(tc.ext), ShouldEqual, tc.match)
+		}
+	})
+}
+
+func Test_FindAllMentions(t *testing.T) {
+	Convey("Find all mention patterns", t, func() {
+		testCases := []struct {
+			content string
+			matches string
+		}{
+			{"@Unknwon, what do you think?", "Unknwon"},
+			{"@Unknwon what do you think?", "Unknwon"},
+			{"Hi @Unknwon, sounds good to me", "Unknwon"},
+			{"cc/ @Unknwon @User", "Unknwon,User"},
+		}
+
+		for _, tc := range testCases {
+			So(strings.Join(FindAllMentions(tc.content), ","), ShouldEqual, tc.matches)
+		}
+	})
+}
+
+func Test_RenderIssueIndexPattern(t *testing.T) {
+	Convey("Rendering an issue reference", t, func() {
+		var (
+			urlPrefix                   = "/prefix"
+			metas     map[string]string = nil
+		)
+		setting.AppSubUrlDepth = 0
+
+		Convey("To the internal issue tracker", func() {
+			Convey("It should not render anything when there are no mentions", func() {
+				testCases := []string{
+					"",
+					"this is a test",
+					"test 123 123 1234",
+					"#",
+					"# # #",
+					"# 123",
+					"#abcd",
+					"##1234",
+					"test#1234",
+					"#1234test",
+					" test #1234test",
+				}
+
+				for i := 0; i < len(testCases); i++ {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
+				}
+			})
+			Convey("It should render freestanding mentions", func() {
+				testCases := []string{
+					"#1234 test", "<a href=\"/prefix/issues/1234\">#1234</a> test",
+					"test #1234 issue", "test <a href=\"/prefix/issues/1234\">#1234</a> issue",
+					"test issue #1234", "test issue <a href=\"/prefix/issues/1234\">#1234</a>",
+					"#5 test", "<a href=\"/prefix/issues/5\">#5</a> test",
+					"test #5 issue", "test <a href=\"/prefix/issues/5\">#5</a> issue",
+					"test issue #5", "test issue <a href=\"/prefix/issues/5\">#5</a>",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should not render issue mention without leading space", func() {
+				input := []byte("test#54321 issue")
+				expected := "test#54321 issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should not render issue mention without trailing space", func() {
+				input := []byte("test #54321issue")
+				expected := "test #54321issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should render issue mention in parentheses", func() {
+				testCases := []string{
+					"(#54321 issue)", "(<a href=\"/prefix/issues/54321\">#54321</a> issue)",
+					"test (#54321) issue", "test (<a href=\"/prefix/issues/54321\">#54321</a>) issue",
+					"test (#54321 extra) issue", "test (<a href=\"/prefix/issues/54321\">#54321</a> extra) issue",
+					"test (#54321 issue)", "test (<a href=\"/prefix/issues/54321\">#54321</a> issue)",
+					"test (#54321)", "test (<a href=\"/prefix/issues/54321\">#54321</a>)",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render multiple issue mentions in the same line", func() {
+				testCases := []string{
+					"#54321 #1243", "<a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>",
+					"test #54321 #1243", "test <a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>",
+					"(#54321 #1243)", "(<a href=\"/prefix/issues/54321\">#54321</a> <a href=\"/prefix/issues/1243\">#1243</a>)",
+					"(#54321)(#1243)", "(<a href=\"/prefix/issues/54321\">#54321</a>)(<a href=\"/prefix/issues/1243\">#1243</a>)",
+					"text #54321 test #1243 issue", "text <a href=\"/prefix/issues/54321\">#54321</a> test <a href=\"/prefix/issues/1243\">#1243</a> issue",
+					"#1 (#4321) test", "<a href=\"/prefix/issues/1\">#1</a> (<a href=\"/prefix/issues/4321\">#4321</a>) test",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+		Convey("To an external issue tracker with numeric style", func() {
+			metas = make(map[string]string)
+			metas["format"] = "https://someurl.com/{user}/{repo}/{index}"
+			metas["user"] = "someuser"
+			metas["repo"] = "somerepo"
+			metas["style"] = ISSUE_NAME_STYLE_NUMERIC
+
+			Convey("should not render anything when there are no mentions", func() {
+				testCases := []string{
+					"this is a test",
+					"test 123 123 1234",
+					"#",
+					"# # #",
+					"# 123",
+					"#abcd",
+				}
+
+				for i := 0; i < len(testCases); i++ {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
+				}
+			})
+			Convey("It should render freestanding issue mentions", func() {
+				testCases := []string{
+					"#1234 test", "<a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a> test",
+					"test #1234 issue", "test <a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a> issue",
+					"test issue #1234", "test issue <a href=\"https://someurl.com/someuser/somerepo/1234\">#1234</a>",
+					"#5 test", "<a href=\"https://someurl.com/someuser/somerepo/5\">#5</a> test",
+					"test #5 issue", "test <a href=\"https://someurl.com/someuser/somerepo/5\">#5</a> issue",
+					"test issue #5", "test issue <a href=\"https://someurl.com/someuser/somerepo/5\">#5</a>",
+				}
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should not render issue mention without leading space", func() {
+				input := []byte("test#54321 issue")
+				expected := "test#54321 issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should not render issue mention without trailing space", func() {
+				input := []byte("test #54321issue")
+				expected := "test #54321issue"
+				So(string(RenderIssueIndexPattern(input, urlPrefix, metas)), ShouldEqual, expected)
+			})
+			Convey("It should render issue mention in parentheses", func() {
+				testCases := []string{
+					"(#54321 issue)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> issue)",
+					"test (#54321) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>) issue",
+					"test (#54321 extra) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> extra) issue",
+					"test (#54321 issue)", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> issue)",
+					"test (#54321)", "test (<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>)",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render multiple issue mentions in the same line", func() {
+				testCases := []string{
+					"#54321 #1243", "<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>",
+					"test #54321 #1243", "test <a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>",
+					"(#54321 #1243)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>)",
+					"(#54321)(#1243)", "(<a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a>)(<a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a>)",
+					"text #54321 test #1243 issue", "text <a href=\"https://someurl.com/someuser/somerepo/54321\">#54321</a> test <a href=\"https://someurl.com/someuser/somerepo/1243\">#1243</a> issue",
+					"#1 (#4321) test", "<a href=\"https://someurl.com/someuser/somerepo/1\">#1</a> (<a href=\"https://someurl.com/someuser/somerepo/4321\">#4321</a>) test",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+		Convey("To an external issue tracker with alphanumeric style", func() {
+			metas = make(map[string]string)
+			metas["format"] = "https://someurl.com/{user}/{repo}/?b={index}"
+			metas["user"] = "someuser"
+			metas["repo"] = "somerepo"
+			metas["style"] = ISSUE_NAME_STYLE_ALPHANUMERIC
+			Convey("It should not render anything when there are no mentions", func() {
+				testCases := []string{
+					"",
+					"this is a test",
+					"test 123 123 1234",
+					"#",
+					"##1234",
+					"# 123",
+					"#abcd",
+					"test #123",
+					"abc-1234",         // issue prefix must be capital
+					"ABc-1234",         // issue prefix must be _all_ capital
+					"ABCDEFGHIJK-1234", // the limit is 10 characters in the prefix
+					"ABC1234",          // dash is required
+					"test ABC- test",   // number is required
+					"test -1234 test",  // prefix is required
+					"testABC-123 test", // leading space is required
+					"test ABC-123test", // trailing space is required
+					"ABC-0123",         // no leading zero
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i])
+				}
+			})
+			Convey("It should render freestanding issue mention", func() {
+				testCases := []string{
+					"OTT-1234 test", "<a href=\"https://someurl.com/someuser/somerepo/?b=OTT-1234\">OTT-1234</a> test",
+					"test T-12 issue", "test <a href=\"https://someurl.com/someuser/somerepo/?b=T-12\">T-12</a> issue",
+					"test issue ABCDEFGHIJ-1234567890", "test issue <a href=\"https://someurl.com/someuser/somerepo/?b=ABCDEFGHIJ-1234567890\">ABCDEFGHIJ-1234567890</a>",
+					"A-1 test", "<a href=\"https://someurl.com/someuser/somerepo/?b=A-1\">A-1</a> test",
+					"test ZED-1 issue", "test <a href=\"https://someurl.com/someuser/somerepo/?b=ZED-1\">ZED-1</a> issue",
+					"test issue DEED-7154", "test issue <a href=\"https://someurl.com/someuser/somerepo/?b=DEED-7154\">DEED-7154</a>",
+				}
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render issue mention in parentheses", func() {
+				testCases := []string{
+					"(ABG-124 issue)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> issue)",
+					"test (ABG-124) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>) issue",
+					"test (ABG-124 extra) issue", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> extra) issue",
+					"test (ABG-124 issue)", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> issue)",
+					"test (ABG-124)", "test (<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>)",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+			Convey("It should render multiple issue mentions in the same line", func() {
+				testCases := []string{
+					"ABG-124 OTT-4321", "<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>",
+					"test ABG-124 OTT-4321", "test <a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>",
+					"(ABG-124 OTT-4321)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>)",
+					"(ABG-124)(OTT-4321)", "(<a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a>)(<a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a>)",
+					"text ABG-124 test OTT-4321 issue", "text <a href=\"https://someurl.com/someuser/somerepo/?b=ABG-124\">ABG-124</a> test <a href=\"https://someurl.com/someuser/somerepo/?b=OTT-4321\">OTT-4321</a> issue",
+					"A-1 (RRE-345) test", "<a href=\"https://someurl.com/someuser/somerepo/?b=A-1\">A-1</a> (<a href=\"https://someurl.com/someuser/somerepo/?b=RRE-345\">RRE-345</a>) test",
+				}
+
+				for i := 0; i < len(testCases); i += 2 {
+					So(string(RenderIssueIndexPattern([]byte(testCases[i]), urlPrefix, metas)), ShouldEqual, testCases[i+1])
+				}
+			})
+		})
+	})
+}
diff --git a/modules/markup/sanitizer.go b/modules/markup/sanitizer.go
index f685657b..8a88f761 100644
--- a/modules/markup/sanitizer.go
+++ b/modules/markup/sanitizer.go
@@ -9,7 +9,6 @@ import (
 	"sync"
 
 	"github.com/microcosm-cc/bluemonday"
-	log "gopkg.in/clog.v1"
 
 	"github.com/gogits/gogs/modules/setting"
 )
@@ -27,7 +26,6 @@ var sanitizer = &Sanitizer{}
 // Multiple calls to this function will only create one instance of Sanitizer during
 // entire application lifecycle.
 func NewSanitizer() {
-	log.Trace("Markup: sanitizer initialization requested")
 	sanitizer.init.Do(func() {
 		sanitizer.policy = bluemonday.UGCPolicy()
 		// We only want to allow HighlightJS specific classes for code blocks
@@ -39,8 +37,6 @@ func NewSanitizer() {
 
 		// Custom URL-Schemes
 		sanitizer.policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
-
-		log.Trace("Markup: sanitizer initialized")
 	})
 }
 
diff --git a/modules/markup/sanitizer_test.go b/modules/markup/sanitizer_test.go
index a8f41fbf..2bd7d537 100644
--- a/modules/markup/sanitizer_test.go
+++ b/modules/markup/sanitizer_test.go
@@ -13,7 +13,7 @@ import (
 )
 
 func Test_Sanitizer(t *testing.T) {
-	BuildSanitizer()
+	NewSanitizer()
 	Convey("Sanitize HTML string and bytes", t, func() {
 		testCases := []string{
 			// Regular