Index: applications/editors/josm/plugins/opendata/src/org/openstreetmap/josm/plugins/opendata/core/io/geographic/ShpReader.java
===================================================================
--- applications/editors/josm/plugins/opendata/src/org/openstreetmap/josm/plugins/opendata/core/io/geographic/ShpReader.java	(revision 34996)
+++ applications/editors/josm/plugins/opendata/src/org/openstreetmap/josm/plugins/opendata/core/io/geographic/ShpReader.java	(revision 34997)
@@ -155,4 +155,5 @@
                 Geometry g = gc.getGeometryN(i);
                 if (g instanceof Polygon) {
+                    // TODO: Split this section between Polygon and MultiPolygon.
                     Relation r = (Relation) op;
                     Polygon p = (Polygon) g;
@@ -170,4 +171,5 @@
                         }
                     }
+                    op = r != null ? r : w;
                 } else if (g instanceof LineString) {
                     op = createOrGetWay((LineString) g);
Index: applications/editors/josm/plugins/opendata/test/data/regress/17529/west_webmerc.prj
===================================================================
--- applications/editors/josm/plugins/opendata/test/data/regress/17529/west_webmerc.prj	(revision 34997)
+++ applications/editors/josm/plugins/opendata/test/data/regress/17529/west_webmerc.prj	(revision 34997)
@@ -0,0 +1,1 @@
+PROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator_Auxiliary_Sphere"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",0.0],PARAMETER["Standard_Parallel_1",0.0],PARAMETER["Auxiliary_Sphere_Type",0.0],UNIT["Meter",1.0]]
Index: applications/editors/josm/plugins/opendata/test/unit/org/openstreetmap/josm/plugins/opendata/core/io/geographic/ShpReaderTest.java
===================================================================
--- applications/editors/josm/plugins/opendata/test/unit/org/openstreetmap/josm/plugins/opendata/core/io/geographic/ShpReaderTest.java	(revision 34996)
+++ applications/editors/josm/plugins/opendata/test/unit/org/openstreetmap/josm/plugins/opendata/core/io/geographic/ShpReaderTest.java	(revision 34997)
@@ -104,3 +104,19 @@
         }
     }
+
+    /**
+     * Non-regression test for ticket <a href="https://josm.openstreetmap.de/ticket/17529">#17529</a>
+     * @throws Exception if an error occurs during reading
+     */
+    @Test
+    public void testTicket17529() throws Exception {
+        // There is only 1 feature in this data set.
+        File file = new File(TestUtils.getRegressionDataFile(17529, "west_webmerc.shp"));
+        try (InputStream is = new FileInputStream(file)) {
+            Collection<Way> ways = ShpReader.parseDataSet(is, file, null, null).getWays();
+            assertFalse(ways.isEmpty());
+            Way way = ways.iterator().next();
+            assertEquals("Westminster city", way.get("NAMELSAD"));
+        }
+    }
 }