markup should preserve empty lines

Ignore html comments as well with markupEscape option.

Parsedown.php

@@ -359,6 +359,11 @@ class Parsedown
 
     protected function identifyComment($Line)
     {
+        if ($this->markupEscaped)
+        {
+            return;
+        }
+
         if (isset($Line['text'][3]) and $Line['text'][3] === '-' and $Line['text'][2] === '-' and $Line['text'][1] === '!')
         {
             $Block = array(
@@ -644,7 +649,7 @@ class Parsedown
                 'element' => $Line['body'],
             );
 
-            if ($matches[2] or $matches[1] === 'hr' or preg_match('/<\/'.$matches[1].'>[ ]*$/', $Line['text']))
+            if ($matches[2] or in_array($matches[1], $this->voidElements) or preg_match('/<\/'.$matches[1].'>[ ]*$/', $Line['text']))
             {
                 $Block['closed'] = true;
             }
@@ -682,6 +687,13 @@ class Parsedown
             }
         }
 
+        if (isset($Block['interrupted']))
+        {
+            $Block['element'] .= "\n";
+
+            unset($Block['interrupted']);
+        }
+
         $Block['element'] .= "\n".$Line['body'];
 
         return $Block;
@@ -1407,6 +1419,10 @@ class Parsedown
         '_' => '/^_((?:[^_]|__[^_]*__)+?)_(?!_)\b/us',
     );
 
+    protected $voidElements = array(
+        'area', 'base', 'br', 'col', 'command', 'embed', 'hr', 'img', 'input', 'link', 'meta', 'param', 'source',
+    );
+
     protected $textLevelElements = array(
         'a', 'br', 'bdo', 'abbr', 'blink', 'nextid', 'acronym', 'basefont',
         'b', 'em', 'big', 'cite', 'small', 'spacer', 'listing',

README.md

@@ -1,6 +1,6 @@
 ## Parsedown
 
-Better [Markdown](http://en.wikipedia.org/wiki/Markdown) parser for PHP.
+Better Markdown Parser in PHP
 
 [[ demo ]](http://parsedown.org/demo)
 
@@ -8,7 +8,7 @@ Better [Markdown](http://en.wikipedia.org/wiki/Markdown) parser for PHP.
 
 * [Fast](http://parsedown.org/speed)
 * [Consistent](http://parsedown.org/consistency)
-* [GitHub Flavored](https://help.github.com/articles/github-flavored-markdown)
+* [GitHub flavored](https://help.github.com/articles/github-flavored-markdown)
 * [Tested](http://parsedown.org/tests/) in PHP 5.2, 5.3, 5.4, 5.5, 5.6 and [hhvm](http://www.hhvm.com/)
 * Extensible
 * [Markdown Extra extension](https://github.com/erusev/parsedown-extra) <sup>new</sup>

test/ParsedownTest.php

@@ -109,6 +109,10 @@ paragraph
         color: red;
     }
 </style>
+
+comment
+
+<!-- html comment -->
 MARKDOWN_WITH_MARKUP;
 
         $expectedHtml = <<<EXPECTED_HTML
@@ -125,6 +129,8 @@ MARKDOWN_WITH_MARKUP;
     color: red;
 }</code></pre>
 <p>&lt;/style></p>
+<p>comment</p>
+<p>&lt;!-- html comment --></p>
 EXPECTED_HTML;
         $parsedownWithNoMarkup = new Parsedown();
         $parsedownWithNoMarkup->setMarkupEscaped(true);

test/data/sparse_html.html

@@ -0,0 +1,8 @@
+<div>
+line 1
+
+line 2
+line 3
+
+line 4
+</div>

test/data/sparse_html.md

@@ -0,0 +1,8 @@
+<div>
+line 1
+
+line 2
+line 3
+
+line 4
+</div>