From 58cca54cb6efe13b24a565f69700d2a74b06c09d Mon Sep 17 00:00:00 2001
From: Robin Dupret <robin.dupret@gmail.com>
Date: Sat, 28 Jan 2017 12:54:53 +0100
Subject: [PATCH] Automatically enable the `fenced_code_blocks` option for
 HTML_TOC

Since some languages rely on the sharp to comment code, the output
may be unexpected as titles begin with a sharp in Markdown.

Refs #451.
---
 CHANGELOG.md                 |  4 ++++
 ext/redcarpet/rc_markdown.c  | 10 ++++++++++
 ext/redcarpet/rc_render.c    |  2 +-
 test/html_toc_render_test.rb | 15 +++++++++++++++
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 401a06c8..0811b004 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+* Automatically enable the `fenced_code_blocks` option passing a
+  `HTML_TOC` object to the `Markdown` object's constructor since
+  some languages rely on the sharp to comment code.
+
 * Allow passing `Range` objects to the `nesting_level` option to have
   a higher level of customization for table of contents:
 
diff --git a/ext/redcarpet/rc_markdown.c b/ext/redcarpet/rc_markdown.c
index 8a3df1d7..b69e951d 100644
--- a/ext/redcarpet/rc_markdown.c
+++ b/ext/redcarpet/rc_markdown.c
@@ -24,6 +24,7 @@
 
 VALUE rb_mRedcarpet;
 VALUE rb_cMarkdown;
+VALUE rb_cRenderHTML_TOC;
 
 extern VALUE rb_cRenderBase;
 
@@ -101,6 +102,15 @@ static VALUE rb_redcarpet_md__new(int argc, VALUE *argv, VALUE klass)
 	if (!rb_obj_is_kind_of(rb_rndr, rb_cRenderBase))
 		rb_raise(rb_eTypeError, "Invalid Renderer instance given");
 
+	/**
+	 * Automatically enable the `fenced_code_blocks` option if
+	 * given a kind of `HTML_TOC` object since many languages
+	 * like Ruby use the sharp to comment code so these comments
+	 * would be processed as titles.
+	 */
+	if (rb_obj_is_kind_of(rb_rndr, rb_cRenderHTML_TOC))
+		extensions |= MKDEXT_FENCED_CODE;
+
 	Data_Get_Struct(rb_rndr, struct rb_redcarpet_rndr, rndr);
 
 	/* Merge the current options in the @options hash */
diff --git a/ext/redcarpet/rc_render.c b/ext/redcarpet/rc_render.c
index 09756472..297f7531 100644
--- a/ext/redcarpet/rc_render.c
+++ b/ext/redcarpet/rc_render.c
@@ -40,10 +40,10 @@
 }
 
 extern VALUE rb_mRedcarpet;
+extern VALUE rb_cRenderHTML_TOC;
 VALUE rb_mRender;
 VALUE rb_cRenderBase;
 VALUE rb_cRenderHTML;
-VALUE rb_cRenderHTML_TOC;
 VALUE rb_mSmartyPants;
 
 #define buf2str(t) ((t) ? rb_enc_str_new((const char*)(t)->data, (t)->size, opt->active_enc) : Qnil)
diff --git a/test/html_toc_render_test.rb b/test/html_toc_render_test.rb
index f06b1836..6dc5ad8b 100644
--- a/test/html_toc_render_test.rb
+++ b/test/html_toc_render_test.rb
@@ -93,4 +93,19 @@ def test_inline_markup_escaping
     assert_match "&lt;strong&gt;", output
     assert_no_match %r{<strong>}, output
   end
+
+  def test_ignoring_fenced_code_blocks_comments
+    markdown = <<-Markdown.strip_heredoc
+    # Hello world !
+
+    ~~~ruby
+    # This is a comment
+    ~~~
+    Markdown
+
+    output = render(markdown)
+
+    assert output.match("Hello world")
+    refute output.match("This is a comment")
+  end
 end