Index: trunk/src/org/openstreetmap/josm/gui/MapView.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/MapView.java	(revision 10668)
+++ trunk/src/org/openstreetmap/josm/gui/MapView.java	(revision 10669)
@@ -30,4 +30,5 @@
 import java.util.List;
 import java.util.Set;
+import java.util.TreeSet;
 import java.util.concurrent.CopyOnWriteArrayList;
 
@@ -1286,15 +1287,15 @@
      */
     public String getLayerInformationForSourceTag() {
-        final Collection<String> layerInfo = new ArrayList<>();
-        if (!getLayersOfType(GpxLayer.class).isEmpty()) {
+        final Set<String> layerInfo = new TreeSet<>();
+        if (!layerManager.getLayersOfType(GpxLayer.class).isEmpty()) {
             // no i18n for international values
             layerInfo.add("survey");
         }
-        for (final GeoImageLayer i : getLayersOfType(GeoImageLayer.class)) {
+        for (final GeoImageLayer i : layerManager.getLayersOfType(GeoImageLayer.class)) {
             if (i.isVisible()) {
                 layerInfo.add(i.getName());
             }
         }
-        for (final ImageryLayer i : getLayersOfType(ImageryLayer.class)) {
+        for (final ImageryLayer i : layerManager.getLayersOfType(ImageryLayer.class)) {
             if (i.isVisible()) {
                 layerInfo.add(ImageryInfo.ImageryType.BING.equals(i.getInfo().getImageryType()) ? "Bing" : i.getName());