From b2b6af24d69193e0a1e18e32267c8d5b1873cab6 Mon Sep 17 00:00:00 2001
From: Martin Zimmermann <info@posativ.org>
Date: Sun, 6 Jul 2014 18:34:06 +0200
Subject: [PATCH] fix clode block generation

added fenced code blocks to default extension list
---
 isso/core.py            |  2 +-
 isso/tests/test_html.py | 32 ++++++++++++++++++++++++++++++++
 isso/utils/html.py      | 24 ++++++++++++++++++++----
 3 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/isso/core.py b/isso/core.py
index 4e30f49..3cdadf5 100644
--- a/isso/core.py
+++ b/isso/core.py
@@ -113,7 +113,7 @@ class Config:
         "direct-reply = 3",
         "reply-to-self = false",
         "[markup]",
-        "options = strikethrough, autolink",
+        "options = strikethrough, autolink, fenced_code",
         "allowed-elements = ",
         "allowed-attributes = "
     ]
diff --git a/isso/tests/test_html.py b/isso/tests/test_html.py
index f03d4c2..65d6056 100644
--- a/isso/tests/test_html.py
+++ b/isso/tests/test_html.py
@@ -4,6 +4,7 @@ try:
 except ImportError:
     import unittest
 
+import textwrap
 
 from isso.core import Config
 from isso.utils import html
@@ -30,6 +31,37 @@ class TestHTML(unittest.TestCase):
         for (input, expected) in examples:
             self.assertEqual(convert(input), expected)
 
+    def test_github_flavoured_markdown(self):
+        convert = html.Markdown(extensions=("fenced_code", ))
+
+        # without lang
+        _in = textwrap.dedent("""\
+            Hello, World
+
+            ```
+            #!/usr/bin/env python
+            print("Hello, World")""")
+        _out = textwrap.dedent("""\
+            <p>Hello, World</p>
+            <pre><code>#!/usr/bin/env python
+            print("Hello, World")
+            </code></pre>""")
+
+        self.assertEqual(convert(_in), _out)
+
+        # w/ lang
+        _in = textwrap.dedent("""\
+            Hello, World
+
+            ```python
+            #!/usr/bin/env python
+            print("Hello, World")""")
+        _out = textwrap.dedent("""\
+            <p>Hello, World</p>
+            <pre><code class="python">#!/usr/bin/env python
+            print("Hello, World")
+            </code></pre>""")
+
     @unittest.skipIf(html.html5lib_version == "0.95", "backport")
     def test_sanitizer(self):
         sanitizer = html.Sanitizer(elements=[], attributes=[])
diff --git a/isso/utils/html.py b/isso/utils/html.py
index 212875d..4c8013a 100644
--- a/isso/utils/html.py
+++ b/isso/utils/html.py
@@ -1,5 +1,7 @@
 # -*- encoding: utf-8 -*-
 
+from __future__ import unicode_literals
+
 import pkg_resources
 import operator
 
@@ -54,16 +56,30 @@ def Markdown(extensions=("strikethrough", "superscript", "autolink")):
 
     flags = reduce(operator.xor, map(
         lambda ext: getattr(misaka, 'EXT_' + ext.upper()), extensions), 0)
+    md = misaka.Markdown(Unofficial(), extensions=flags)
 
     def inner(text):
-        rv = misaka.html(text, extensions=flags).rstrip("\n")
-        if not rv.endswith("<p>") and not rv.endswith("</p>"):
-            return "<p>" + rv + "</p>"
-        return rv
+        rv = md.render(text).rstrip("\n")
+        if rv.startswith("<p>") or rv.endswith("</p>"):
+            return rv
+        return "<p>" + rv + "</p>"
 
     return inner
 
 
+class Unofficial(misaka.HtmlRenderer):
+    """A few modifications to process "common" Markdown.
+
+    For instance, fenced code blocks (~~~ or ```) are just wrapped in <code>
+    which does not preserve line breaks. If a language is given, it is added
+    to <code class="$lang">, compatible with Highlight.js.
+    """
+
+    def block_code(self, text, lang):
+        lang = ' class="{0}"'.format(lang) if lang else ''
+        return "<pre><code{1}>{0}</code></pre>\n".format(text, lang)
+
+
 class Markup(object):
 
     def __init__(self, conf):