message: change toBool
diff: @@ -68,7 +68,7 @@ private:
  auto result = filterExp_->eval(*expCtx_);
  // NULL is always false
  auto ret = result.toBool();
  - if (ret.second && ret.first) {
  + if (ret.isBool() && ret.getBool()) {
  return true;
  }
  return false;
  