resolve #248

Parsedown.php

@@ -1410,13 +1410,13 @@ class Parsedown
     );
 
     protected $StrongRegex = array(
-        '*' => '/^[*]{2}((?:[^*]|[*][^*]*[*])+?)[*]{2}(?![*])/s',
-        '_' => '/^__((?:[^_]|_[^_]*_)+?)__(?!_)/us',
+        '*' => '/^[*]{2}((?:\\\\\*|[^*]|[*][^*]*[*])+?)[*]{2}(?![*])/s',
+        '_' => '/^__((?:\\\\_|[^_]|_[^_]*_)+?)__(?!_)/us',
     );
 
     protected $EmRegex = array(
-        '*' => '/^[*]((?:[^*]|[*][*][^*]+?[*][*])+?)[*](?![*])/s',
-        '_' => '/^_((?:[^_]|__[^_]*__)+?)_(?!_)\b/us',
+        '*' => '/^[*]((?:\\\\\*|[^*]|[*][*][^*]+?[*][*])+?)[*](?![*])/s',
+        '_' => '/^_((?:\\\\_|[^_]|__[^_]*__)+?)_(?!_)\b/us',
     );
 
     protected $voidElements = array(

test/data/escaping.html

@@ -1,4 +1,6 @@
 <p>escaped *emphasis*.</p>
 <p><code>escaped \*emphasis\* in a code span</code></p>
 <pre><code>escaped \*emphasis\* in a code block</code></pre>
-<p>\ ` * _ { } [ ] ( ) > # + - . !</p>
+<p>\ ` * _ { } [ ] ( ) > # + - . !</p>
+<p><em>one_two</em> <strong>one_two</strong></p>
+<p><em>one*two</em> <strong>one*two</strong></p>

test/data/escaping.md

@@ -4,4 +4,8 @@ escaped \*emphasis\*.
 
     escaped \*emphasis\* in a code block
 
-\\ \` \* \_ \{ \} \[ \] \( \) \> \# \+ \- \. \!
+\\ \` \* \_ \{ \} \[ \] \( \) \> \# \+ \- \. \!
+
+_one\_two_ __one\_two__
+
+*one\*two* **one\*two**