Index: trunk/src/org/openstreetmap/josm/gui/widgets/HistoryComboBox.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/widgets/HistoryComboBox.java	(revision 18127)
+++ trunk/src/org/openstreetmap/josm/gui/widgets/HistoryComboBox.java	(revision 18128)
@@ -6,5 +6,4 @@
 import javax.swing.text.JTextComponent;
 
-import org.openstreetmap.josm.data.tagging.ac.AutoCompletionItem;
 import org.openstreetmap.josm.gui.tagging.ac.AutoCompletingComboBox;
 import org.openstreetmap.josm.spi.preferences.Config;
@@ -56,12 +55,5 @@
      */
     public void addCurrentItemToHistory() {
-        Object item = getEditor().getItem();
-        if (item instanceof String) {
-            model.addElement((String) item);
-        } else if (item instanceof AutoCompletionItem) {
-            model.addElement((AutoCompletionItem) item);
-        } else {
-            throw new IllegalArgumentException(item.getClass().getSimpleName() + " is not supported in addCurrentItemToHistory");
-        }
+        model.addElement(getEditor().getItem().toString());
     }