Index: /applications/editors/josm/plugins/simplifyarea/src/sk/zdila/josm/plugin/simplify/SimplifyAreaAction.java
===================================================================
--- /applications/editors/josm/plugins/simplifyarea/src/sk/zdila/josm/plugin/simplify/SimplifyAreaAction.java	(revision 26996)
+++ /applications/editors/josm/plugins/simplifyarea/src/sk/zdila/josm/plugin/simplify/SimplifyAreaAction.java	(revision 26997)
@@ -230,6 +230,11 @@
                 Node node2 = null;
 
+                final int len = nodes.size();
+                if (len == 0) {
+                    break;
+                }
+
                 // find smallest distance
-                for (int i = 0, len = nodes.size(); i <= len; i++) {
+                for (int i = 0; i <= len; i++) {
                     final Node n1 = nodes.get(i % len);
                     final Node n2 = nodes.get((i + 1) % len);
@@ -354,4 +359,8 @@
             final int size2 = nodes.size();
 
+            if (size2 == 0) {
+                break;
+            }
+
             for (int i = 0, len = size2 + (closed ? 2 : 1); i < len; i++) {
                 final int index = i % size2;