Index: trunk/src/org/openstreetmap/josm/gui/MainApplication.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/MainApplication.java	(revision 16223)
+++ trunk/src/org/openstreetmap/josm/gui/MainApplication.java	(revision 16225)
@@ -412,5 +412,7 @@
      */
     public static List<String> getCommandLineArgs() {
-        return Collections.unmodifiableList(commandLineArgs);
+        return commandLineArgs == null
+                ? Collections.emptyList()
+                : Collections.unmodifiableList(commandLineArgs);
     }