From 2574208a529ec9fe2f1af0ab2596369e3d449453 Mon Sep 17 00:00:00 2001
From: Thomas Leitner <t_leitner@gmx.at>
Date: Wed, 1 Jul 2015 09:28:23 +0200
Subject: [PATCH] Fixed regexp backtracking problem in footnote definitions and
 codeblocks

Fixes #256
---
 lib/kramdown/parser/kramdown/blank_line.rb    |  2 +-
 .../span/04_footnote/regexp_problem.html      | 14 +++++
 .../span/04_footnote/regexp_problem.text      | 52 +++++++++++++++++++
 3 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 test/testcases/span/04_footnote/regexp_problem.html
 create mode 100644 test/testcases/span/04_footnote/regexp_problem.text

diff --git a/lib/kramdown/parser/kramdown/blank_line.rb b/lib/kramdown/parser/kramdown/blank_line.rb
index 538d1169..148ce523 100644
--- a/lib/kramdown/parser/kramdown/blank_line.rb
+++ b/lib/kramdown/parser/kramdown/blank_line.rb
@@ -11,7 +11,7 @@ module Kramdown
   module Parser
     class Kramdown
 
-      BLANK_LINE = /(?:^\s*\n)+/
+      BLANK_LINE = /(?>^\s*\n)+/
 
       # Parse the blank line at the current postition.
       def parse_blank_line
diff --git a/test/testcases/span/04_footnote/regexp_problem.html b/test/testcases/span/04_footnote/regexp_problem.html
new file mode 100644
index 00000000..8ea102b7
--- /dev/null
+++ b/test/testcases/span/04_footnote/regexp_problem.html
@@ -0,0 +1,14 @@
+<h1>Something</h1>
+<p>something<sup id="fnref:note1"><a href="#fn:note1" class="footnote">1</a></sup>.</p>
+
+<h1>Footnotes</h1>
+
+<h1>Test</h1>
+<div class="footnotes">
+  <ol>
+    <li id="fn:note1">
+
+      <p>A note <a href="#fnref:note1" class="reversefootnote">&#8617;</a></p>
+    </li>
+  </ol>
+</div>
diff --git a/test/testcases/span/04_footnote/regexp_problem.text b/test/testcases/span/04_footnote/regexp_problem.text
new file mode 100644
index 00000000..6a60c612
--- /dev/null
+++ b/test/testcases/span/04_footnote/regexp_problem.text
@@ -0,0 +1,52 @@
+# Something
+something[^note1].
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+# Footnotes
+[^note1]:
+    A note
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+# Test