Issue 1282 - Let user-defined filters override filter lists

lib/elemHide.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 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 164 matching lines @@
    * Checks whether an exception rule is registered for a filter on a particular
    * domain.
    */
   getException: function(/**Filter*/ filter, /**String*/ docDomain) /**ElemHideException*/
   {
     if (!(filter.selector in exceptions))
       return null;
 
     let list = exceptions[filter.selector];
     for (let i = list.length - 1; i >= 0; i--)
-      if (list[i].isActiveOnDomain(docDomain))
-        return list[i];
+    {
+      let exception = list[i];
+      if (exception.isActiveOnDomain(docDomain) && (!filter.isUserDefined || exception.isUserDefined))
+        return exception;
+    }
 
     return null;
   },
 
   /**
    * Will be set to true if apply() is running (reentrance protection).
    * @type Boolean
    */
   _applying: false,
 
@@ skipping 186 matching lines @@
       let filter = filterByKey[key];
       if (specificOnly && (!filter.domains || filter.domains[""]))
         continue;
 
       if (filter.isActiveOnDomain(domain) && !this.getException(filter, domain))
         result.push(filter.selector);
     }
     return result;
   }
 };