Version mkgmap-r4590 was committed by gerd on Wed, 30 Dec 2020 Fix invalid overview map if options --overview-dem-dist and --dem and --order-by-decreasing-area are combined. Disable --order-by-decreasing-area for overview map in this situation. Further changes might be needed regarding option handling. http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4590