message: Final tweaks after
  This cleans up xml_attribute::set_value to be uniform wrt
  xml_node::set_value and xml_text::set_value - for now we duplicate the
  body since the logic is trivial and this keeps debug performance
  excellent.
diff: @@ -5381,7 +5381,9 @@ namespace pugi
  PUGI__FN bool xml_attribute::set_value(const char_t* rhs)
  {
  - return set_value(rhs, impl::strlength(rhs));
  + if (!_attr) return false;
  +
  + return impl::strcpy_insitu(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs));
  }
  PUGI__FN bool xml_attribute::set_value(int rhs)
  