Index: /trunk/src/org/openstreetmap/josm/actions/HistoryInfoAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/HistoryInfoAction.java	(revision 6448)
+++ /trunk/src/org/openstreetmap/josm/actions/HistoryInfoAction.java	(revision 6449)
@@ -1,3 +1,3 @@
-//License: GPL. For details, see LICENSE file.
+// License: GPL. For details, see LICENSE file.
 package org.openstreetmap.josm.actions;
 
@@ -14,6 +14,13 @@
 import static org.openstreetmap.josm.gui.help.HelpUtil.ht;
 
+/**
+ * Display history information about OSM ways, nodes, or relations.
+ * @since 968
+ */
 public class HistoryInfoAction extends JosmAction {
 
+    /**
+     * Constructs a new {@code HistoryInfoAction}.
+     */
     public HistoryInfoAction() {
         super(tr("History"), "about",
@@ -40,6 +47,13 @@
     }
 
+    /**
+     * Dialog allowing to choose object id if no one is selected.
+     * @since 6448
+     */
     public static class HistoryObjectIDDialog extends OsmIdSelectionDialog {
 
+        /**
+         * Constructs a new {@code HistoryObjectIDDialog}.
+         */
         public HistoryObjectIDDialog() {
             super(Main.parent, tr("Show history"), new String[]{tr("Show history"), tr("Cancel")});
@@ -48,4 +62,3 @@
         }
     }
-
 }
Index: /trunk/src/org/openstreetmap/josm/data/osm/history/HistoryDataSet.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/history/HistoryDataSet.java	(revision 6448)
+++ /trunk/src/org/openstreetmap/josm/data/osm/history/HistoryDataSet.java	(revision 6449)
@@ -13,4 +13,5 @@
 import org.openstreetmap.josm.Main;
 import org.openstreetmap.josm.data.osm.Changeset;
+import org.openstreetmap.josm.data.osm.IPrimitive;
 import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
 import org.openstreetmap.josm.data.osm.PrimitiveId;
@@ -20,10 +21,8 @@
 import org.openstreetmap.josm.gui.layer.Layer;
 import org.openstreetmap.josm.tools.CheckParameterUtil;
-import org.openstreetmap.josm.tools.Utils;
 
 /**
  * A data set holding histories of OSM primitives.
- *
- *
+ * @since 1670
  */
 public class HistoryDataSet implements LayerChangeListener{
@@ -163,4 +162,7 @@
         CheckParameterUtil.ensureParameterNotNull(pid, "pid");
         List<HistoryOsmPrimitive> versions = data.get(pid);
+        if (versions == null && pid instanceof IPrimitive) {
+            versions = data.get(((IPrimitive) pid).getPrimitiveId());
+        }
         if (versions == null)
             return null;