From 700b5ddbffa2ac6ce78f28b6646773a818d32f5b Mon Sep 17 00:00:00 2001
From: Won-Kyu Park <wkpark@gmail.com>
Date: Thu, 27 Feb 2014 23:47:00 +0900
Subject: [PATCH] match balanced parens in URLs to resolve #126

* match balanced parens using recursive pattern
* match quoted title correctly
---
 Parsedown.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Parsedown.php b/Parsedown.php
index d2501a0..8cd6733 100755
--- a/Parsedown.php
+++ b/Parsedown.php
@@ -1020,13 +1020,13 @@ class Parsedown
 
                         $remainingText = substr($text, $offset);
 
-                        if ($remainingText[0] === '(' and preg_match('/\([ ]*(.*?)(?:[ ]+[\'"](.+?)[\'"])?[ ]*\)/', $remainingText, $matches))
+                        if ($remainingText[0] === '(' and preg_match('/^\([ ]*((?:[^()\s]+|(\((?:[^()\s]+|(?2))*\)))+)(?:[ ]+([\'"])(.+?)\\3)?[ ]*\)/', $remainingText, $matches))
                         {
                             $element['link'] = $matches[1];
 
-                            if (isset($matches[2]))
+                            if (isset($matches[4]))
                             {
-                                $element['title'] = $matches[2];
+                                $element['title'] = $matches[4];
                             }
 
                             $offset += strlen($matches[0]);