Index: trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java	(revision 17756)
+++ trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java	(revision 17757)
@@ -147,4 +147,7 @@
 public class OsmDataLayer extends AbstractOsmDataLayer implements Listener, DataSelectionListener, HighlightUpdateListener {
     private static final int HATCHED_SIZE = 15;
+    // U+2205 EMPTY SET
+    private static final String IS_EMPTY_SYMBOL = "\u2205";
+    private static final String IS_DIRTY_SYMBOL = "*";
     /** Property used to know if this layer has to be saved on disk */
     public static final String REQUIRES_SAVE_TO_DISK_PROP = OsmDataLayer.class.getName() + ".requiresSaveToDisk";
@@ -710,4 +713,6 @@
         addConditionalInformation(p, tr("Upload is discouraged"), isUploadDiscouraged());
         addConditionalInformation(p, tr("Upload is blocked"), data.getUploadPolicy() == UploadPolicy.BLOCKED);
+        addConditionalInformation(p, IS_EMPTY_SYMBOL + " " + tr("Empty layer"), this.getDataSet().isEmpty());
+        addConditionalInformation(p, IS_DIRTY_SYMBOL + " " + tr("Unsaved changes"), this.isDirty());
 
         return p;
@@ -1073,9 +1078,8 @@
         String label = super.getLabel();
         if (this.isDirty()) {
-            label += " *";
+            label += " " + IS_DIRTY_SYMBOL;
         }
         if (this.getDataSet().isEmpty()) {
-            // U+2205 EMPTY SET
-            label += " \u2205";
+            label += " " + IS_EMPTY_SYMBOL;
         }
         return label;
@@ -1214,7 +1218,7 @@
             new ExtendedDialog(
                     MainApplication.getMainFrame(),
-                    tr("Empty document"),
+                    tr("Empty layer"),
                     tr("Save anyway"), tr("Cancel"))
-                .setContent(tr("The document contains no data."))
+                .setContent(tr("The layer contains no data."))
                 .setButtonIcons("save", "cancel")
                 .showDialog().getValue()