Index: trunk/src/org/openstreetmap/josm/gui/dialogs/relation/sort/WayConnectionTypeCalculator.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/relation/sort/WayConnectionTypeCalculator.java	(revision 11885)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/relation/sort/WayConnectionTypeCalculator.java	(revision 11886)
@@ -135,8 +135,8 @@
     private int firstGroupIdx;
     private void makeLoopIfNeeded(final List<WayConnectionType> con, final int i) {
-        boolean loop;
+        boolean loop = false;
         if (i == firstGroupIdx) { //is primitive loop
             loop = determineDirection(i, FORWARD, i) == FORWARD;
-        } else {
+        } else if (i >= 0) {
             loop = determineDirection(i, con.get(i).direction, firstGroupIdx) == con.get(firstGroupIdx).direction;
         }