Fix for issue russross/blackfriday#239 (#372)

Issue russross/blackfriday#239 codeblock inside list.

block.go

@@ -1258,6 +1258,7 @@ func (p *Markdown) listItem(data []byte, flags *ListType) int {
 	// process the following lines
 	containsBlankLine := false
 	sublist := 0
+	codeBlockMarker := ""
 
 gatherlines:
 	for line < len(data) {
@@ -1291,6 +1292,27 @@ gatherlines:
 
 		chunk := data[line+indentIndex : i]
 
+		if p.extensions&FencedCode != 0 {
+		// determine if in or out of codeblock
+		// if in codeblock, ignore normal list processing
+			_, marker := isFenceLine(chunk, nil, codeBlockMarker)
+			if marker != "" {
+				if codeBlockMarker == "" {
+					// start of codeblock
+					codeBlockMarker = marker
+				} else {
+					// end of codeblock.
+					codeBlockMarker = ""
+				}
+			}
+			// we are in a codeblock, write line, and continue
+			if codeBlockMarker != "" || marker != "" {
+				raw.Write(data[line+indentIndex : i])
+				line = i
+				continue gatherlines
+			}
+		}
+
 		// evaluate how this line fits in
 		switch {
 		// is this a nested list item?

block_test.go

@@ -1475,6 +1475,44 @@ func TestFencedCodeBlock_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
 	doTestsBlock(t, tests, FencedCode|NoEmptyLineBeforeBlock)
 }
 
+func TestListWithFencedCodeBlock(t *testing.T) {
+	var tests = []string{
+		"1. one\n\n    ```\n    code\n    ```\n\n2. two\n",
+		"<ol>\n<li><p>one</p>\n\n<pre><code>code\n</code></pre></li>\n\n<li><p>two</p></li>\n</ol>\n",
+		// https://github.com/russross/blackfriday/issues/239
+		"1. one\n\n    ```\n    - code\n    ```\n\n2. two\n",
+		"<ol>\n<li><p>one</p>\n\n<pre><code>- code\n</code></pre></li>\n\n<li><p>two</p></li>\n</ol>\n",
+	}
+	doTestsBlock(t, tests, FencedCode)
+}
+
+func TestListWithMalformedFencedCodeBlock(t *testing.T) {
+	// Ensure that in the case of an unclosed fenced code block in a list,
+	// no source gets ommitted (even if it is malformed).
+	// See russross/blackfriday#372 for context.
+	var tests = []string{
+		"1. one\n\n    ```\n    code\n\n2. two\n",
+		"<ol>\n<li>one\n```\ncode\n2. two</li>\n</ol>\n",
+
+		"1. one\n\n    ```\n    - code\n\n2. two\n",
+		"<ol>\n<li>one\n```\n- code\n2. two</li>\n</ol>\n",
+	}
+	doTestsBlock(t, tests, FencedCode)
+}
+
+func TestListWithFencedCodeBlockNoExtensions(t *testing.T) {
+	// If there is a fenced code block in a list, and FencedCode is not set,
+	// lists should be processed normally.
+	var tests = []string{
+		"1. one\n\n    ```\n    code\n    ```\n\n2. two\n",
+		"<ol>\n<li><p>one</p>\n\n<p><code>\ncode\n</code></p></li>\n\n<li><p>two</p></li>\n</ol>\n",
+
+		"1. one\n\n    ```\n    - code\n    ```\n\n2. two\n",
+		"<ol>\n<li><p>one</p>\n\n<p>```</p>\n\n<ul>\n<li>code\n```</li>\n</ul></li>\n\n<li><p>two</p></li>\n</ol>\n",
+	}
+	doTestsBlock(t, tests, 0)
+}
+
 func TestTitleBlock_EXTENSION_TITLEBLOCK(t *testing.T) {
 	var tests = []string{
 		"% Some title\n" +