Hi WanMil,
This has two advantages: 1. The artefacts on the cut lines in Mapsource are reduced because there are less cut lines. 2. The performance of the mp code for large multipolygons is very much dependend on how many cuts must be performed.
A third advantage: the image file might be slightly smaller. I found something strange in my test: Error at line 2341764, col 41 Bad file format: 63240004.osm.gz Exception in thread "main" java.lang.NullPointerException at uk.me.parabola.mkgmap.combiners.FileInfo.getFileInfo(FileInfo.java:136) at uk.me.parabola.mkgmap.main.Main.endOptions(Main.java:369) at uk.me.parabola.mkgmap.CommandArgsReader.readArgs(CommandArgsReader.java:124) at uk.me.parabola.mkgmap.main.Main.main(Main.java:122) This would be the 'outer' in the following line: <relation id='302404'> <member type='way' ref='31755158' role='outer'/> I will retest without the patch, and also test the patch with yesterday's dump. Marko