fix: reserve '*' and '_' when detecting escape char '\' (close: #544).

Author: ulivz

lib/util/parseHeaders.js

@@ -16,8 +16,9 @@ const removeMarkdownToken = str => String(str)
   .replace(/`(.*)`/, '$1')  // ``
   .replace(/\[(.*)\]\(.*\)/, '$1')  // []()
   .replace(/\*\*(.*)\*\*/, '$1')  // **
-  .replace(/\*(.*)\*/, '$1')  // *
-  .replace(/_(.*)_/, '$1')  // _
+  .replace(/\*(.*[^\\])\*/, '$1')  // *
+  .replace(/_(.*[^\\])_/g, '$1')  // _ _
+  .replace(/(\\)(\*|_)/g, '$2') // remove escaped char '\'
 
 exports.removeTailHtml = (str) => {
   return String(str).replace(/<.*>\s*$/g, '')