supress errors for incomplete rings

geom/geom.go

@@ -25,6 +25,7 @@ func NewGeomError(message string, level int) *GeomError {
 
 var (
 	ErrorOneNodeWay = NewGeomError("need at least two separate nodes for way", 0)
+	ErrorNoRing     = NewGeomError("linestrings do not form ring", 0)
 )
 
 func PointWKB(g *geos.GEOS, node element.Node) (*element.Geometry, error) {

geom/multipolygon.go

@@ -59,9 +59,7 @@ func BuildRings(rel *element.Relation) ([]*Ring, error) {
 	// create geometries for merged rings
 	for _, ring := range mergedRings {
 		if !ring.IsClosed() {
-			return nil, errors.New(
-				fmt.Sprintf("linestrings from relation %d do not form a ring", rel.Id),
-			)
+			return nil, ErrorNoRing
 		}
 		ring.geom, err = Polygon(g, ring.nodes)
 		if err != nil {

goposm.go

@@ -310,7 +310,12 @@ func main() {
 
 			err = geom.BuildRelation(r)
 			if err != nil {
-				fmt.Println(err)
+				if err, ok := err.(ErrorLevel); ok {
+					if err.Level() <= 0 {
+						continue
+					}
+				}
+				log.Println(err)
 				continue
 			}
 			if matches := polygons.Match(r.OSMElem); len(matches) > 0 {