Index: /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/MergeOverlapAction.java
===================================================================
--- /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/MergeOverlapAction.java	(revision 33153)
+++ /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/MergeOverlapAction.java	(revision 33154)
@@ -52,4 +52,9 @@
 public class MergeOverlapAction extends JosmAction {
 
+    Map<Way, List<Relation>> relations = new HashMap<>();
+    Map<Way, Way> oldWays = new HashMap<>();
+    Map<Relation, Relation> newRelations = new HashMap<>();
+    Set<Way> deletes = new HashSet<>();
+
     /**
      * Constructs a new {@code MergeOverlapAction}.
@@ -61,9 +66,4 @@
                 Shortcut.ALT_CTRL), true);
     }
-
-    Map<Way, List<Relation>> relations = new HashMap<>();
-    Map<Way, Way> oldWays = new HashMap<>();
-    Map<Relation, Relation> newRelations = new HashMap<>();
-    Set<Way> deletes = new HashSet<>();
 
     /**
Index: /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/hack/MyCombinePrimitiveResolverDialog.java
===================================================================
--- /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/hack/MyCombinePrimitiveResolverDialog.java	(revision 33153)
+++ /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/hack/MyCombinePrimitiveResolverDialog.java	(revision 33154)
@@ -54,4 +54,12 @@
 
     /**
+     * Constructs a new {@code MyCombinePrimitiveResolverDialog}.
+     * @param parent The parent component in which this dialog will be displayed.
+     */
+    public MyCombinePrimitiveResolverDialog(Component parent) {
+        super(parent);
+    }
+
+    /**
      * Replies the unique instance of the dialog
      *
@@ -60,9 +68,5 @@
     public static MyCombinePrimitiveResolverDialog getInstance() {
         if (instance == null) {
-            GuiHelper.runInEDTAndWait(new Runnable() {
-                @Override public void run() {
-                    instance = new MyCombinePrimitiveResolverDialog(Main.parent);
-                }
-            });
+            GuiHelper.runInEDTAndWait(() -> instance = new MyCombinePrimitiveResolverDialog(Main.parent));
         }
         return instance;
@@ -86,12 +90,4 @@
             }
         };
-    }
-
-    /**
-     * Constructs a new {@code MyCombinePrimitiveResolverDialog}.
-     * @param parent The parent component in which this dialog will be displayed.
-     */
-    public MyCombinePrimitiveResolverDialog(Component parent) {
-        super(parent);
     }
 
Index: /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/hack/MyRelationMemberConflictResolverModel.java
===================================================================
--- /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/hack/MyRelationMemberConflictResolverModel.java	(revision 33153)
+++ /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/hack/MyRelationMemberConflictResolverModel.java	(revision 33154)
@@ -67,6 +67,6 @@
     public void populate(Collection<Relation> relations, Collection<Way> memberWays, Map<Way, Way> oldWays) {
         decisions.clear();
-        relations = relations == null ? new LinkedList<Relation>() : relations;
-        memberWays = memberWays == null ? new LinkedList<Way>() : memberWays;
+        relations = relations == null ? new LinkedList<>() : relations;
+        memberWays = memberWays == null ? new LinkedList<>() : memberWays;
         for (Relation r : relations) {
             for (Way w : memberWays) {