boost::polygon::detail::resize creates invalid polygons on expansion

I have a regular polygon that is expanded via functions in boost::polygon / boost::polygon::polygon_set_data resize().

Expanding a polygon should result in a new outline (yellow) which nowhere touches the original polygon (green) and which nowhere comes closer to the original polygon outline than the expansion size:


Unfortunately this is not the result I get with boost::polygon. Here the new ouline cuts the original one:


In other words: the result is damaged and wrong even to its own specification. This happens with Boost 1.77.