[mkgmap-dev] Problem with nested apply

Mon Jan 4 21:26:39 GMT 2010

On Mon, Jan 04, 2010 at 05:09:43PM +0200, Marko Mäkelä wrote:
> I figured out that mkgmap does already support nested relations, but it
> is not working for me.  The attached patch attempts to copy the route name
> to the members of member relations.  This is the relation in question:
> 
>   <relation id='155054' timestamp='2010-01-03T22:13:56Z' uid='93285' user='skela' visible='true' version='3' changeset='3533281'>
>     <member type='relation' ref='375952' role='stop' />
>     <member type='way' ref='2735495' role='' />
>     <member type='relation' ref='375951' role='stop' />
> 
> The route name is successfully applied to relation 375952 (and its members)
> and way 2735495, but according to an echo action that I added, not even
> the outer apply is executed on relation 375951.  What am I doing wrong?
> I could not see any obvious bug in the code.

The bug apparently is in the relation parser, in the way how
uk.me.parabola.mkgmap.reader.osm.Relation.addElement() is invoked.

In the source file, <relation id='375952'> occurs after the super-relation,
while relation 375951 is defined before the super-relation.  It seems that
there should be a Relation.addRelation(String role, long id) and the
subrelation id resolution would be deferred until all relation definitions
have been parsed.  Currently, the id resolution is attempted too early.
It works for node and way members, because they always occur before
relations in the input file.  It is broken for relation members.

Another bug in Relation.addElement() is that it allows members to occur in
at most one role.  Route relations can legitimately contain members multiple
times in different roles.

	Marko