Hi Marko,

thanks for the feedback. Did you use r2888 or later together with the patch?
I think the warning is produced long before it comes to the point
where mkgmap decides if the polygon is big enough.
I am not very familiar with the SeaGenerator algo, but I think
this message is produced when incomplete data is processed and
mkgmap once decided that way 242824968 encloses sea
and later detects that it must be an island.
A bigger problem would be the other case (island changed to sea)

Gerd

> Date: Wed, 18 Dec 2013 17:17:46 +0200
> From: marko.makela@iki.fi
> To: mkgmap-dev@lists.mkgmap.org.uk
> Subject: [mkgmap-dev] Bogus anti-island warnings for tiny natural=coastline polygons
>
> On Tue, Dec 17, 2013 at 12:18:23PM -0800, GerdP wrote:
> >@Marko: Please check if the "converting anti-island" messages are gone
> >now.
>
> There are 20 of them for Finland after applying my filter. There could
> also be valid warnings, because I have been ignoring these errors and
> not adding them to my filter either.
>
> I checked one example:
>
> 2013/12/18 16:28:01 WARNING (SeaGenerator): 63240002.osm.pbf: Converting
> anti-island starting at
> http://www.openstreetmap.org/?mlat=60.20405&mlon=25.49942&zoom=17 into
> an island as it is surrounded by water
>
> It looks like this is referring to the 1.5m wide islet or rock
>
> http://www.openstreetmap.org/way/242824968
>
> which is a closed polygon, with land on the left. I think that the
> proper action would be to shrink this to a single point and then discard
> it, because it would be a polygon with zero area.
>
> Best regards,
>
> Marko
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