make road_class parser more resilient

Author: karussell

core/src/main/java/com/graphhopper/routing/util/parsers/OSMRoadClassParser.java

@@ -48,6 +48,8 @@ public IntsRef handleWayTags(IntsRef edgeFlags, ReaderWay readerWay, EncodingMan
             return edgeFlags;
 
         String roadClassTag = readerWay.getTag("highway");
+        if (roadClassTag == null)
+            return edgeFlags;
         RoadClass roadClass = RoadClass.find(roadClassTag);
         if (roadClass == OTHER && roadClassTag.endsWith("_link"))
             roadClass = RoadClass.find(roadClassTag.substring(0, roadClassTag.length() - 5));

core/src/test/java/com/graphhopper/routing/util/parsers/OSMRoadClassParserTest.java

@@ -52,4 +52,12 @@ public void testIgnore() {
         parser.handleWayTags(intsRef, readerWay, FERRY, 0);
         assertEquals(RoadClass.OTHER, rcEnc.getEnum(false, intsRef));
     }
+
+    @Test
+    public void testNoNPE() {
+        ReaderWay readerWay = new ReaderWay(1);
+        IntsRef intsRef = em.createEdgeFlags();
+        parser.handleWayTags(intsRef, readerWay, WAY, 0);
+        assertEquals(RoadClass.OTHER, rcEnc.getEnum(false, intsRef));
+    }
 }