Update Parsedown library to version 1.7.1v2.4.2

This commit updates the Parsedown library to the latest version 1.7.1. The patch to prevent that tab indentations in code blocks are being converted to spaces (see 78c5974cd34559d0130d8be509935e2c992cd9ca) is already applied here. In addition, the patch file itself is now shipped within the same directory where the Parsedown.php resides.

2 files changed, 195 insertions, 24 deletions

diff --git a/core/namespace/Parsedown.patch b/core/namespace/Parsedown.patch
new file mode 100644
index 0000000..1a81781
--- /dev/null
+++ b/core/namespace/Parsedown.patch
@@ -0,0 +1,40 @@
+160,176d159
+<             if (strpos($line, "\t") !== false)
+<             {
+<                 $parts = explode("\t", $line);
+< 
+<                 $line = $parts[0];
+< 
+<                 unset($parts[0]);
+< 
+<                 foreach ($parts as $part)
+<                 {
+<                     $shortage = 4 - mb_strlen($line, 'utf-8') % 4;
+< 
+<                     $line .= str_repeat(' ', $shortage);
+<                     $line .= $part;
+<                 }
+<             }
+< 
+327c310,313
+<         if ($Line['indent'] >= 4)
+---
+>         $conditionA = $Line['indent'] >= 4;
+>         $conditionB = substr($Line['body'], 0, 1) === "\t";
+> 
+>         if (($conditionA and $remove = 4) or ($conditionB and $remove = 1))
+329c315
+<             $text = substr($Line['body'], 4);
+---
+>             $text = substr($Line['body'], $remove);
+348c334,337
+<         if ($Line['indent'] >= 4)
+---
+>         $conditionA = $Line['indent'] >= 4;
+>         $conditionB = substr($Line['body'], 0, 1) === "\t";
+> 
+>         if (($conditionA and $remove = 4) or ($conditionB and $remove = 1))
+359c348
+<             $text = substr($Line['body'], 4);
+---
+>             $text = substr($Line['body'], $remove);
diff --git a/core/namespace/Parsedown.php b/core/namespace/Parsedown.php
index ec7bdde..e101bc5 100644
--- a/core/namespace/Parsedown.php
+++ b/core/namespace/Parsedown.php
@@ -17,7 +17,7 @@ class Parsedown
 {
     # ~
 
-    const version = '1.6.0';
+    const version = '1.7.1';
 
     # ~
 
@@ -75,6 +75,32 @@ class Parsedown
 
     protected $urlsLinked = true;
 
+    function setSafeMode($safeMode)
+    {
+        $this->safeMode = (bool) $safeMode;
+
+        return $this;
+    }
+
+    protected $safeMode;
+
+    protected $safeLinksWhitelist = array(
+        'http://',
+        'https://',
+        'ftp://',
+        'ftps://',
+        'mailto:',
+        'data:image/png;base64,',
+        'data:image/gif;base64,',
+        'data:image/jpeg;base64,',
+        'irc:',
+        'ircs:',
+        'git:',
+        'ssh:',
+        'news:',
+        'steam:',
+    );
+
     #
     # Lines
     #
@@ -331,8 +357,6 @@ class Parsedown
     {
         $text = $Block['element']['text']['text'];
 
-        $text = htmlspecialchars($text, ENT_NOQUOTES, 'UTF-8');
-
         $Block['element']['text']['text'] = $text;
 
         return $Block;
@@ -343,7 +367,7 @@ class Parsedown
 
     protected function blockComment($Line)
     {
-        if ($this->markupEscaped)
+        if ($this->markupEscaped or $this->safeMode)
         {
             return;
         }
@@ -385,7 +409,7 @@ class Parsedown
 
     protected function blockFencedCode($Line)
     {
-        if (preg_match('/^['.$Line['text'][0].']{3,}[ ]*([\w-]+)?[ ]*$/', $Line['text'], $matches))
+        if (preg_match('/^['.$Line['text'][0].']{3,}[ ]*([^`]+)?[ ]*$/', $Line['text'], $matches))
         {
             $Element = array(
                 'name' => 'code',
@@ -446,8 +470,6 @@ class Parsedown
     {
         $text = $Block['element']['text']['text'];
 
-        $text = htmlspecialchars($text, ENT_NOQUOTES, 'UTF-8');
-
         $Block['element']['text']['text'] = $text;
 
         return $Block;
@@ -504,10 +526,10 @@ class Parsedown
                 ),
             );
 
-            if($name === 'ol') 
+            if($name === 'ol')
             {
                 $listStart = stristr($matches[0], '.', true);
-                
+
                 if($listStart !== '1')
                 {
                     $Block['element']['attributes'] = array('start' => $listStart);
@@ -536,6 +558,8 @@ class Parsedown
             {
                 $Block['li']['text'] []= '';
 
+                $Block['loose'] = true;
+
                 unset($Block['interrupted']);
             }
 
@@ -584,6 +608,22 @@ class Parsedown
         }
     }
 
+    protected function blockListComplete(array $Block)
+    {
+        if (isset($Block['loose']))
+        {
+            foreach ($Block['element']['text'] as &$li)
+            {
+                if (end($li['text']) !== '')
+                {
+                    $li['text'] []= '';
+                }
+            }
+        }
+
+        return $Block;
+    }
+
     #
     # Quote
 
@@ -667,12 +707,12 @@ class Parsedown
 
     protected function blockMarkup($Line)
     {
-        if ($this->markupEscaped)
+        if ($this->markupEscaped or $this->safeMode)
         {
             return;
         }
 
-        if (preg_match('/^<(\w*)(?:[ ]*'.$this->regexHtmlAttribute.')*[ ]*(\/)?>/', $Line['text'], $matches))
+        if (preg_match('/^<(\w[\w-]*)(?:[ ]*'.$this->regexHtmlAttribute.')*[ ]*(\/)?>/', $Line['text'], $matches))
         {
             $element = strtolower($matches[1]);
 
@@ -986,7 +1026,7 @@ class Parsedown
     # ~
     #
 
-    public function line($text)
+    public function line($text, $nonNestables=array())
     {
         $markup = '';
 
@@ -1002,6 +1042,13 @@ class Parsedown
 
             foreach ($this->InlineTypes[$marker] as $inlineType)
             {
+                # check to see if the current inline type is nestable in the current context
+
+                if ( ! empty($nonNestables) and in_array($inlineType, $nonNestables))
+                {
+                    continue;
+                }
+
                 $Inline = $this->{'inline'.$inlineType}($Excerpt);
 
                 if ( ! isset($Inline))
@@ -1023,6 +1070,13 @@ class Parsedown
                     $Inline['position'] = $markerPosition;
                 }
 
+                # cause the new element to 'inherit' our non nestables
+
+                foreach ($nonNestables as $non_nestable)
+                {
+                    $Inline['element']['nonNestables'][] = $non_nestable;
+                }
+
                 # the text that comes before the inline
                 $unmarkedText = substr($text, 0, $Inline['position']);
 
@@ -1063,7 +1117,6 @@ class Parsedown
         if (preg_match('/^('.$marker.'+)[ ]*(.+?)[ ]*(?<!'.$marker.')\1(?!'.$marker.')/s', $Excerpt['text'], $matches))
         {
             $text = $matches[2];
-            $text = htmlspecialchars($text, ENT_NOQUOTES, 'UTF-8');
             $text = preg_replace("/[ ]*\n/", ' ', $text);
 
             return array(
@@ -1182,6 +1235,7 @@ class Parsedown
         $Element = array(
             'name' => 'a',
             'handler' => 'line',
+            'nonNestables' => array('Url', 'Link'),
             'text' => null,
             'attributes' => array(
                 'href' => null,
@@ -1242,8 +1296,6 @@ class Parsedown
             $Element['attributes']['title'] = $Definition['title'];
         }
 
-        $Element['attributes']['href'] = str_replace(array('&', '<'), array('&amp;', '&lt;'), $Element['attributes']['href']);
-
         return array(
             'extent' => $extent,
             'element' => $Element,
@@ -1252,12 +1304,12 @@ class Parsedown
 
     protected function inlineMarkup($Excerpt)
     {
-        if ($this->markupEscaped or strpos($Excerpt['text'], '>') === false)
+        if ($this->markupEscaped or $this->safeMode or strpos($Excerpt['text'], '>') === false)
         {
             return;
         }
 
-        if ($Excerpt['text'][1] === '/' and preg_match('/^<\/\w*[ ]*>/s', $Excerpt['text'], $matches))
+        if ($Excerpt['text'][1] === '/' and preg_match('/^<\/\w[\w-]*[ ]*>/s', $Excerpt['text'], $matches))
         {
             return array(
                 'markup' => $matches[0],
@@ -1273,7 +1325,7 @@ class Parsedown
             );
         }
 
-        if ($Excerpt['text'][1] !== ' ' and preg_match('/^<\w*(?:[ ]*'.$this->regexHtmlAttribute.')*[ ]*\/?>/s', $Excerpt['text'], $matches))
+        if ($Excerpt['text'][1] !== ' ' and preg_match('/^<\w[\w-]*(?:[ ]*'.$this->regexHtmlAttribute.')*[ ]*\/?>/s', $Excerpt['text'], $matches))
         {
             return array(
                 'markup' => $matches[0],
@@ -1332,14 +1384,16 @@ class Parsedown
 
         if (preg_match('/\bhttps?:[\/]{2}[^\s<]+\b\/*/ui', $Excerpt['context'], $matches, PREG_OFFSET_CAPTURE))
         {
+            $url = $matches[0][0];
+
             $Inline = array(
                 'extent' => strlen($matches[0][0]),
                 'position' => $matches[0][1],
                 'element' => array(
                     'name' => 'a',
-                    'text' => $matches[0][0],
+                    'text' => $url,
                     'attributes' => array(
-                        'href' => $matches[0][0],
+                        'href' => $url,
                     ),
                 ),
             );
@@ -1352,7 +1406,7 @@ class Parsedown
     {
         if (strpos($Excerpt['text'], '>') !== false and preg_match('/^<(\w+:\/{2}[^ >]+)>/i', $Excerpt['text'], $matches))
         {
-            $url = str_replace(array('&', '<'), array('&amp;', '&lt;'), $matches[1]);
+            $url = $matches[1];
 
             return array(
                 'extent' => strlen($matches[0]),
@@ -1390,6 +1444,11 @@ class Parsedown
 
     protected function element(array $Element)
     {
+        if ($this->safeMode)
+        {
+            $Element = $this->sanitiseElement($Element);
+        }
+
         $markup = '<'.$Element['name'];
 
         if (isset($Element['attributes']))
@@ -1401,7 +1460,7 @@ class Parsedown
                     continue;
                 }
 
-                $markup .= ' '.$name.'="'.$value.'"';
+                $markup .= ' '.$name.'="'.self::escape($value).'"';
             }
         }
 
@@ -1409,13 +1468,18 @@ class Parsedown
         {
             $markup .= '>';
 
+            if (!isset($Element['nonNestables'])) 
+            {
+                $Element['nonNestables'] = array();
+            }
+
             if (isset($Element['handler']))
             {
-                $markup .= $this->{$Element['handler']}($Element['text']);
+                $markup .= $this->{$Element['handler']}($Element['text'], $Element['nonNestables']);
             }
             else
             {
-                $markup .= $Element['text'];
+                $markup .= self::escape($Element['text'], true);
             }
 
             $markup .= '</'.$Element['name'].'>';
@@ -1474,10 +1538,77 @@ class Parsedown
         return $markup;
     }
 
+    protected function sanitiseElement(array $Element)
+    {
+        static $goodAttribute = '/^[a-zA-Z0-9][a-zA-Z0-9-_]*+$/';
+        static $safeUrlNameToAtt  = array(
+            'a'   => 'href',
+            'img' => 'src',
+        );
+
+        if (isset($safeUrlNameToAtt[$Element['name']]))
+        {
+            $Element = $this->filterUnsafeUrlInAttribute($Element, $safeUrlNameToAtt[$Element['name']]);
+        }
+
+        if ( ! empty($Element['attributes']))
+        {
+            foreach ($Element['attributes'] as $att => $val)
+            {
+                # filter out badly parsed attribute
+                if ( ! preg_match($goodAttribute, $att))
+                {
+                    unset($Element['attributes'][$att]);
+                }
+                # dump onevent attribute
+                elseif (self::striAtStart($att, 'on'))
+                {
+                    unset($Element['attributes'][$att]);
+                }
+            }
+        }
+
+        return $Element;
+    }
+
+    protected function filterUnsafeUrlInAttribute(array $Element, $attribute)
+    {
+        foreach ($this->safeLinksWhitelist as $scheme)
+        {
+            if (self::striAtStart($Element['attributes'][$attribute], $scheme))
+            {
+                return $Element;
+            }
+        }
+
+        $Element['attributes'][$attribute] = str_replace(':', '%3A', $Element['attributes'][$attribute]);
+
+        return $Element;
+    }
+
     #
     # Static Methods
     #
 
+    protected static function escape($text, $allowQuotes = false)
+    {
+        return htmlspecialchars($text, $allowQuotes ? ENT_NOQUOTES : ENT_QUOTES, 'UTF-8');
+    }
+
+    protected static function striAtStart($string, $needle)
+    {
+        $len = strlen($needle);
+
+        if ($len > strlen($string))
+        {
+            return false;
+        }
+        else
+        {
+            return strtolower(substr($string, 0, $len)) === strtolower($needle);
+        }
+    }
+
     static function instance($name = 'default')
     {
         if (isset(self::$instances[$name]))