[mkgmap-dev] mkgmap dropping ways on multipolygon boundary "outer"

Sun Dec 27 21:53:30 GMT 2009

On 27.12.2009 22:33, Mark Burton wrote:
> Festive greetings Felix,
>
>    
>> Have a look here, wherever the boundaries use the same way as the ways,
>> the ways get dropped, even if not rendering the boundaries at all
>> (removing any reference to boundary from the style-file).
>>
>> Is this maybe a geofabrik error, or some error in mkgmap multipolygon
>> handling? I have noticed many (all that I checked) mkgmap maps suffer
>> from missing roads in this example. (anyhow I don't render boundaries
>>   >admin_level=6)
>>
>> http://www.openstreetmap.org/?lat=48.03113&lon=16.88459&zoom=16&layers=B000FTF
>>
>> Seems to be a bug in the Multipolygon Code.
>>      
> Perhaps it's the same issue as I mentioned yesterday (outer ways in
> multipolygons are trashed by the process of generating the polygon). I
> suggested that we should duplicate() the outer ways to preserve their
> original use. As it stands, if a way is referenced in some multipolygon
> its tags are wiped out so it will not work as the original author of
> the way intended.
>
> Cheers,
>
> Mark
>
> diff --git a/src/uk/me/parabola/mkgmap/reader/osm/xml/Osm5XmlHandler.java b/src/uk/me/parabola/mkgmap/reader/osm/xml/Osm5XmlHandler.java
> index acc5cf9..fbb1d57 100644
> --- a/src/uk/me/parabola/mkgmap/reader/osm/xml/Osm5XmlHandler.java
> +++ b/src/uk/me/parabola/mkgmap/reader/osm/xml/Osm5XmlHandler.java
> @@ -266,10 +266,12 @@ class Osm5XmlHandler extends DefaultHandler {
>          private void startInRelation(String qName, Attributes attributes) {
>                  if (qName.equals("member")) {
>                          long id = idVal(attributes.getValue("ref"));
> -                       Element el;
> +                       Element el = null;
>                          String type = attributes.getValue("type");
> -                       if ("way".equals(type)){
> -                               el = wayMap.get(id);
> +                       if ("way".equals(type)) {
> +                               Way way = wayMap.get(id);
> +                               if(way != null)
> +                                       el = way.duplicate();
>                          } else if ("node".equals(type)) {
>                                  el = nodeMap.get(id);
>                                  if(el == null) {
>
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>    
Thanks for that patch... It does remove the bug, but all relations seem 
to get dropped by using this patch too. So not an ideal solution -:)

BTW before using this patch, relations like cycleroutes would even show 
up when all ways were dropped due to multipolygon outer...