Issue 4593 - Support regular expressions for CSS property matching

lib/filterClasses.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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 1024 matching lines @@
    * @type String
    */
   get regexpString()
   {
     // Despite this property being cached, the getter is called
     // several times on Safari, due to WebKit bug 132872
     let prop = Object.getOwnPropertyDescriptor(this, "regexpString");
     if (prop)
       return prop.value;
 
-    let regexp = Filter.toRegExp(this.regexpSource);
+    let regexp;
+    if (this.regexpSource.length >= 2 && this.regexpSource[0] == "/" &&
+        this.regexpSource[this.regexpSource.length - 1] == "/")

[Wladimir Palant, 2016/11/08 17:41:34]

Well, accessing this.regexpSource four times is obviously not perfect either but
whatever - I guess that by the time this code path becomes relevant
performance-wise we'll have it replaced by C++ anyway.

+      regexp = this.regexpSource.slice(1, -1);
+    else
+      regexp = Filter.toRegExp(this.regexpSource);
     Object.defineProperty(this, "regexpString", {value: regexp});
     return regexp;
   }
 });