Index: trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java	(revision 10204)
+++ trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java	(revision 10205)
@@ -11,4 +11,5 @@
 import java.awt.Composite;
 import java.awt.Graphics2D;
+import java.awt.GraphicsEnvironment;
 import java.awt.GridBagLayout;
 import java.awt.Point;
@@ -515,5 +516,5 @@
      *         May be <code>null</code>, which means nothing has been uploaded
      */
-    public void cleanupAfterUpload(final Collection<IPrimitive> processed) {
+    public void cleanupAfterUpload(final Collection<? extends IPrimitive> processed) {
         // return immediately if an upload attempt failed
         if (processed == null || processed.isEmpty())
@@ -973,4 +974,7 @@
             @Override
             public Integer call() {
+                if (GraphicsEnvironment.isHeadless()) {
+                    return 2;
+                }
                 ExtendedDialog dialog = new ExtendedDialog(
                         Main.parent,