Issue 5870 - Implement the new ElemHideEmulation filter type

compiled/filter/ElemHideBase.cpp

 /*
  * 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 69 matching lines @@
       case u'"':
       case u'!':
         return Type::UNKNOWN;
       case u' ':
         seenSpaces = true;
         break;
     }
   }
 
   seenSpaces |= scanner.skip(u' ');
+  bool emulation = false;
   bool exception = scanner.skipOne(u'@');
   if (exception)
     seenSpaces |= scanner.skip(u' ');
+  else
+    emulation = scanner.skipOne(u'?');
 
   String::value_type next = scanner.next();
   if (next != u'#')
     return Type::UNKNOWN;
 
   // Selector part
 
   // Selector shouldn't be empty
   seenSpaces |= scanner.skip(u' ');
   if (scanner.done())
@@ skipping 11 matching lines @@
   }
 
   // We are done validating, now we can normalize whitespace and the domain part
   if (seenSpaces)
     NormalizeWhitespace(text, data.mDomainsEnd, data.mSelectorStart);
   DependentString(text, 0, data.mDomainsEnd).toLower();
 
   if (exception)
     return Type::ELEMHIDEEXCEPTION;
 
-  if (text.find(u"[-abp-properties="_str, data.mSelectorStart) != text.npos)
+  if (emulation)
     return Type::ELEMHIDEEMULATION;
 
   return Type::ELEMHIDE;
 }
 
 OwnedString ElemHideBase::GetSelectorDomain() const
 {
   /* TODO this is inefficient */
   OwnedString result;
   if (mDomains)
   {
     for (const auto& item : *mDomains)
     {
       if (item.second && !item.first.empty())
       {
         if (!result.empty())
           result.append(u',');
         result.append(item.first);
       }
     }
   }
   return result;
 }