Patch blackfriday's fix for issue 122 in

To be more inline with black friday I removed from CommonMark-isms
(fenced code blocks at the end of the file). Updated the tests
and manual patched stuff in.

block.go

@@ -5,7 +5,6 @@ package mmark
 import (
 	"bytes"
 	"strconv"
-	"strings"
 	"unicode"
 )
 
@@ -1042,44 +1041,32 @@ func (p *parser) isFencedCode(data []byte, syntax **string, oldmarker string) (s
 
 	c := data[i]
 
-	// the whole line must be the same char per CommonMark whitespace is not allowed
+	// the whole line must be the same char or whitespace
 	for i < len(data) && data[i] == c {
 		size++
 		i++
 	}
 	if i >= len(data) {
 		return
 	}
-	// if we find spaces and them some more markers, this is not a fenced code block
-	j := i
-	for j < len(data) && data[j] == ' ' {
-		j++
-	}
-	if j >= len(data) {
-		return
-	}
-	if data[j] == c {
-		return
-	}
 
 	// the marker char must occur at least 3 times
 	if size < 3 {
 		return
 	}
+
 	marker = string(data[i-size : i])
 
-	// if this is the end marker, it must be at least as long as the
-	// original marker we have
-	if oldmarker != "" && !strings.HasPrefix(marker, oldmarker) {
+	// if this is the end marker, it must match the beginning marker
+	if oldmarker != "" && marker != oldmarker {
 		return
 	}
 
 	if syntax != nil {
 		syn := 0
 
-		for i < len(data) && data[i] == ' ' {
-			i++
-		}
+		i = skipChar(data, i, ' ')
+
 		if i >= len(data) {
 			return
 		}
@@ -1122,9 +1109,9 @@ func (p *parser) isFencedCode(data []byte, syntax **string, oldmarker string) (s
 		*syntax = &language
 	}
 
-	// CommonMark: skip garbage until end of line
-	for i < len(data) && data[i] != '\n' {
-		i++
+	i = skipChar(data, i, ' ')
+	if i >= len(data) || data[i] != '\n' {
+		return
 	}
 
 	skip = i + 1
@@ -1156,7 +1143,7 @@ func (p *parser) isTOMLBlockBlock(data []byte) int {
 func (p *parser) fencedCode(out *bytes.Buffer, data []byte, doRender bool) int {
 	var lang *string
 	beg, marker := p.isFencedCode(data, &lang, "")
-	if beg == 0 {
+	if beg == 0 || beg >= len(data) {
 		return 0
 	}
 
@@ -1166,18 +1153,6 @@ func (p *parser) fencedCode(out *bytes.Buffer, data []byte, doRender bool) int {
 		co = p.ial.Value("callout")
 	}
 
-	if beg >= len(data) {
-		// only the marker and end of doc. CommonMark dictates this is valid
-
-		p.r.SetInlineAttr(p.ial)
-		p.ial = nil
-
-		// Data here?
-		p.r.BlockCode(out, nil, "", nil, p.insideFigure, false)
-
-		return len(data)
-	}
-
 	// CommonMark: if indented strip this many leading spaces from code block
 	indent := 0
 	for indent < beg && data[indent] == ' ' {
@@ -1204,11 +1179,8 @@ func (p *parser) fencedCode(out *bytes.Buffer, data []byte, doRender bool) int {
 		end++
 
 		// did we reach the end of the buffer without a closing marker?
-		// CommonMark: end of buffer closes fencec code block
 		if end >= len(data) {
-			work.Write(data[beg:])
-			beg = end
-			break
+			return 0
 		}
 
 		// CommmonMark, strip beginning spaces

block_test.go

@@ -836,25 +836,25 @@ func TestFencedCodeBlock(t *testing.T) {
 		"<pre><code class=\"language-python\">extra\n</code></pre>\n",
 
 		"~~~ perl\nthree to start, four to end\n~~~~\n",
-		"<pre><code class=\"language-perl\">three to start, four to end\n</code></pre>\n",
+		"<p>~~~ perl\nthree to start, four to end\n~~~~</p>\n",
 
 		"~~~~ perl\nfour to start, three to end\n~~~\n",
-		"<pre><code class=\"language-perl\">four to start, three to end\n~~~\n</code></pre>\n",
+		"<p>~~~~ perl\nfour to start, three to end\n~~~</p>\n",
 
 		"~~~ bash\ntildes\n~~~\n",
 		"<pre><code class=\"language-bash\">tildes\n</code></pre>\n",
 
 		"``` lisp\nno ending\n",
-		"<pre><code class=\"language-lisp\">no ending\n</code></pre>\n",
+		"<p>``` lisp\nno ending</p>\n",
 
 		"~~~ lisp\nend with language\n~~~ lisp\n",
-		"<pre><code class=\"language-lisp\">end with language\n</code></pre>\n",
+		"<p>~~~ lisp\nend with language\n~~~ lisp</p>\n",
 
 		"```\nmismatched begin and end\n~~~\n",
-		"<pre><code>mismatched begin and end\n~~~\n</code></pre>\n",
+		"<p>```\nmismatched begin and end\n~~~</p>\n",
 
 		"~~~\nmismatched begin and end\n```\n",
-		"<pre><code>mismatched begin and end\n```\n</code></pre>\n",
+		"<p>~~~\nmismatched begin and end\n```</p>\n",
 
 		"   ``` oz\nleading spaces\n```\n",
 		"<pre><code class=\"language-oz\">leading spaces\n</code></pre>\n",
@@ -1221,25 +1221,25 @@ func TestFencedCodeBlock_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
 		"<pre><code class=\"language-python\">extra\n</code></pre>\n",
 
 		"~~~ perl\nthree to start, four to end\n~~~~\n",
-		"<pre><code class=\"language-perl\">three to start, four to end\n</code></pre>\n",
+		"<p>~~~ perl\nthree to start, four to end\n~~~~</p>\n",
 
 		"~~~~ perl\nfour to start, three to end\n~~~\n",
-		"<pre><code class=\"language-perl\">four to start, three to end\n~~~\n</code></pre>\n",
+		"<p>~~~~ perl\nfour to start, three to end\n~~~</p>\n",
 
 		"~~~ bash\ntildes\n~~~\n",
 		"<pre><code class=\"language-bash\">tildes\n</code></pre>\n",
 
 		"``` lisp\nno ending\n",
-		"<pre><code class=\"language-lisp\">no ending\n</code></pre>\n",
+		"<p>``` lisp\nno ending</p>\n",
 
 		"~~~ lisp\nend with language\n~~~ lisp\n",
-		"<pre><code class=\"language-lisp\">end with language\n</code></pre>\n",
+		"<p>~~~ lisp\nend with language\n~~~ lisp</p>\n",
 
 		"```\nmismatched begin and end\n~~~\n",
-		"<pre><code>mismatched begin and end\n~~~\n</code></pre>\n",
+		"<p>```\nmismatched begin and end\n~~~</p>\n",
 
 		"~~~\nmismatched begin and end\n```\n",
-		"<pre><code>mismatched begin and end\n```\n</code></pre>\n",
+		"<p>~~~\nmismatched begin and end\n```</p>\n",
 
 		"   ``` oz\nleading spaces\n```\n",
 		"<pre><code class=\"language-oz\">leading spaces\n</code></pre>\n",

cm_test.go

@@ -78,8 +78,10 @@ func TestFencedCodeBlockCommonMark_81(t *testing.T) {
 		"```\n bbb\nbbb\n```\n",
 		"<pre><code> bbb\nbbb\n</code></pre>\n",
 
+		// disabled this behavior, using blackfriday's standard now.
 		"```\nbbb\nbbb\n",
-		"<pre><code>bbb\nbbb\n</code></pre>\n",
+		//"<pre><code>bbb\nbbb\n</code></pre>\n",
+		"<p>```\nbbb\nbbb</p>\n",
 
 		"~~~~    ruby\ndef foo(x)\n return 3\nend\n~~~~\n",
 		"<pre><code class=\"language-ruby\">def foo(x)\n return 3\nend\n</code></pre>\n",

html.go

@@ -1184,6 +1184,14 @@ func skipSpace(tag []byte, i int) int {
 	return i
 }
 
+func skipChar(data []byte, start int, char byte) int {
+	i := start
+	for i < len(data) && data[i] == char {
+		i++
+	}
+	return i
+}
+
 func doubleSpace(out *bytes.Buffer) {
 	if out.Len() > 0 {
 		out.WriteByte('\n')