[mkgmap-dev] multipolygon support?

I have a large lake with a relation connecting all ways together. It seems mkgmap creates a polygon for each of the ways by connecting start and end together. Do we have support for multipolygons. In this case 2 arms of the lake cross the tile boundary. the 2 arms are rendered correct in the next tile but the main part of the lake is a complete mess. it looks like the relation is completely ignored. can create a small osm file if this is an unknown problem.