Noissue - Remove unnecessary references to undefined

lib/content/elemHideEmulation.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 169 matching lines @@
 
 /**
  * Make a regular expression from a text argument. If it can be parsed as a
  * regular expression, parse it and the flags.
  * @param {string} text the text argument.
  * @return {?RegExp} a RegExp object or null in case of error.
  */
 function makeRegExpParameter(text)
 {
   let [, pattern, flags] =
-      regexpRegexp.exec(text) || [undefined, textToRegExp(text)];
+      regexpRegexp.exec(text) || [null, textToRegExp(text)];
 
   try
   {
     return new RegExp(pattern, flags);
   }
   catch (e)
   {
   }
   return null;
 }
@@ skipping 664 matching lines @@
           characterData: shouldObserveCharacterData(this.patterns),
           subtree: true
         }
       );
       this.document.addEventListener("load", this.onLoad.bind(this), true);
     }
   }
 };
 
 exports.ElemHideEmulation = ElemHideEmulation;