Issue 5175 - Reject element hiding filter with empty domain names

compiled/filter/ElemHideBase.cpp

Index: compiled/filter/ElemHideBase.cpp
===================================================================
--- a/compiled/filter/ElemHideBase.cpp
+++ b/compiled/filter/ElemHideBase.cpp
@@ -61,24 +61,26 @@
 
   static constexpr String::value_type OLD_PROPS_SELECTOR[] = u"[-abp-properties=";
   static constexpr String::size_type OLD_PROPS_SELECTOR_LEN = str_length_of(OLD_PROPS_SELECTOR);
 
   static constexpr String::value_type PROPS_SELECTOR[] = u":-abp-properties(";
   static constexpr String::size_type PROPS_SELECTOR_LEN = str_length_of(PROPS_SELECTOR);
 }
 
-ElemHideBase::ElemHideBase(Type type, const String& text, const ElemHideData& data)
+ElemHideBase::ElemHideBase(Type type, const String& text, const ElemHideData& data, const ParsedDomains& parsedDomains)
     : ActiveFilter(type, text, false), mData(data)
 {
   if (mData.HasDomains())
-    ParseDomains(mData.GetDomainsSource(mText), u',');
+    FillDomains(mData.GetDomainsSource(mText), parsedDomains);
 }
 
-Filter::Type ElemHideBase::Parse(DependentString& text, ElemHideData& data, bool& needConversion)
+Filter::Type ElemHideBase::Parse(DependentString& text, DependentString& error,
+                                 ElemHideData& data, bool& needConversion,
+                                 ParsedDomains& parsedDomains)
 {
   needConversion = false;
 
   StringScanner scanner(text);
 
   // Domains part
   bool seenSpaces = false;
   while (!scanner.done())
@@ -126,16 +128,23 @@
 
   data.mSelectorStart = scanner.position() + 1;
 
   // 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();
 
+  parsedDomains =
+    ParseDomainsInternal(data.GetDomainsSource(text), u',', false);
+  if (parsedDomains.hasEmpty)
+  {
+    error = u"filter_invalid_domain"_str;
+    return Type::INVALID;
+  }
   // We still need to check the old syntax. It will be converted when
   // we instantiate the filter.
   if (!emulation &&
       text.find(OLD_PROPS_SELECTOR, data.mSelectorStart, OLD_PROPS_SELECTOR_LEN) != text.npos)
   {
     needConversion = true;
     emulation = !exception;
   }