[mkgmap-dev] boundary relations duplicated by splitter, not merged by mkgmap

Fri Dec 25 22:31:14 GMT 2009

I am not sure if this is a splitter or mkgmap bug.

In my map generated from Geofabrik's finland.osm.bz2, in the national border
between Finland and Sweden, the name Sverige (name:sv for Sweden) occurs
three times, apparently once per map tile.  In the *.osm.gz files output
by splitter, only the relation 52822 has name=Sweden, and that relation
does occur in every *.osm.gz tile file.

In the generated gmapsupp.img, the name occurs in two labels, like this:

SVERIGE/SVERIGE/SVERIGE/NORRA NORRLAND/NORRA NORRLAND/NORRA NORRLAND/NORRBOTTENS LÄN/NORRBOTTENS LÄN/NORRBOTTENS LÄN/SUOMI
SVERIGE/SVERIGE/NORRA NORRLAND/NORRA NORRLAND/NORRBOTTENS LÄN/NORRBOTTENS LÄN/SUOMI

For some reason, the second occurrence is apparently only using two of the
tiles.  The desired label would mention each area only once.  Would it be
possible for mkgmap to merge relations between input tiles, if each carries
the same id?

A quick-and-dirty solution might be a not-substring filter that would not
append the relation name to the mkgmap:boundary_name in the relations file
if it is already contained.  But I am wondering if the duplicate relations
could be causing other problems.

Best regards,

	Marko