Index: /trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitiveComparator.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitiveComparator.java	(revision 13223)
+++ /trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitiveComparator.java	(revision 13224)
@@ -25,5 +25,5 @@
      */
     public static Comparator<OsmPrimitive> comparingNames() {
-        final Comparator<String> digitsLast = comparing(str -> Character.isDigit(str.charAt(0)) ? 1 : 0);
+        final Comparator<String> digitsLast = comparing(str -> !str.isEmpty() && Character.isDigit(str.charAt(0)) ? 1 : 0);
         return comparing(memoize(DefaultNameFormatter.getInstance()::format),
                 digitsLast.thenComparing(AlphanumComparator.getInstance()));