Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java	(revision 10105)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java	(revision 10106)
@@ -230,12 +230,15 @@
 
     private final transient TaggingPresetHandler presetHandler = new TaggingPresetHandler() {
-        @Override public void updateTags(List<Tag> tags) {
+        @Override
+        public void updateTags(List<Tag> tags) {
             Command command = TaggingPreset.createCommand(getSelection(), tags);
-            if (command != null) Main.main.undoRedo.add(command);
-        }
-
-        @Override public Collection<OsmPrimitive> getSelection() {
-            if (Main.main == null) return null;
-            return Main.main.getInProgressSelection();
+            if (command != null) {
+                Main.main.undoRedo.add(command);
+            }
+        }
+
+        @Override
+        public Collection<OsmPrimitive> getSelection() {
+            return Main.main == null ? Collections.<OsmPrimitive>emptyList() : Main.main.getInProgressSelection();
         }
     };
Index: /trunk/src/org/openstreetmap/josm/gui/history/HistoryLoadTask.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/history/HistoryLoadTask.java	(revision 10105)
+++ /trunk/src/org/openstreetmap/josm/gui/history/HistoryLoadTask.java	(revision 10106)
@@ -193,18 +193,19 @@
     protected static HistoryDataSet loadHistory(OsmServerHistoryReader reader, ProgressMonitor progressMonitor) throws OsmTransferException {
         HistoryDataSet ds = reader.parseHistory(progressMonitor.createSubTaskMonitor(1, false));
-        // load corresponding changesets (mostly for changeset comment)
-        OsmServerChangesetReader changesetReader = new OsmServerChangesetReader();
-        List<Long> changesetIds = new ArrayList<>(ds.getChangesetIds());
-
-        // query changesets 100 by 100 (OSM API limit)
-        int n = ChangesetQuery.MAX_CHANGESETS_NUMBER;
-        for (int i = 0; i < changesetIds.size(); i += n) {
-            for (Changeset c : changesetReader.queryChangesets(
-                    new ChangesetQuery().forChangesetIds(changesetIds.subList(i, Math.min(i + n, changesetIds.size()))),
-                    progressMonitor.createSubTaskMonitor(1, false))) {
-                ds.putChangeset(c);
+        if (ds != null) {
+            // load corresponding changesets (mostly for changeset comment)
+            OsmServerChangesetReader changesetReader = new OsmServerChangesetReader();
+            List<Long> changesetIds = new ArrayList<>(ds.getChangesetIds());
+
+            // query changesets 100 by 100 (OSM API limit)
+            int n = ChangesetQuery.MAX_CHANGESETS_NUMBER;
+            for (int i = 0; i < changesetIds.size(); i += n) {
+                for (Changeset c : changesetReader.queryChangesets(
+                        new ChangesetQuery().forChangesetIds(changesetIds.subList(i, Math.min(i + n, changesetIds.size()))),
+                        progressMonitor.createSubTaskMonitor(1, false))) {
+                    ds.putChangeset(c);
+                }
             }
         }
-
         return ds;
     }