Index: trunk/src/org/openstreetmap/josm/data/validation/tests/SharpAngles.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/validation/tests/SharpAngles.java	(revision 18618)
+++ trunk/src/org/openstreetmap/josm/data/validation/tests/SharpAngles.java	(revision 18619)
@@ -92,5 +92,9 @@
 
     private void checkAngle(Node node1, Node node2, Node node3, int i, Way way, boolean last) {
-        if (node1 == null || node2 == null || node3 == null) return;
+        if (node1 == null || !node1.isLatLonKnown()
+            || node2 == null || !node2.isLatLonKnown()
+            || node3 == null || !node3.isLatLonKnown()) {
+            return;
+        }
         EastNorth n1 = node1.getEastNorth();
         EastNorth n2 = node2.getEastNorth();