Undefined property with uid handler and not enough fields

When using the uid field with "Link to this field to its user" checked, if severity, type, timestamp, message, and variables aren't all set then you'll get

Notice: Undefined property: stdClass::$watchdog_[missing field] in better_watchdog_ui_handler_field_watchdog_uid->render_link() (line 27 of better_watchdog_ui/views/handlers/better_watchdog_ui_handler_field_watchdog_uid.inc).

These fields aren't all necessarily going to be available.