Index: src/org/openstreetmap/josm/data/conflict/ConflictCollection.java
===================================================================
--- src/org/openstreetmap/josm/data/conflict/ConflictCollection.java	(revision 17462)
+++ src/org/openstreetmap/josm/data/conflict/ConflictCollection.java	(working copy)
@@ -3,7 +3,6 @@
 
 import static org.openstreetmap.josm.tools.I18n.tr;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
@@ -38,7 +37,7 @@
  * </ul>
  */
 public class ConflictCollection implements Iterable<Conflict<? extends OsmPrimitive>> {
-    private final List<Conflict<? extends OsmPrimitive>> conflicts;
+    private final CopyOnWriteArrayList<Conflict<? extends OsmPrimitive>> conflicts;
     private final CopyOnWriteArrayList<IConflictListener> listeners;
 
     /**
@@ -45,7 +44,7 @@
      * Constructs a new {@code ConflictCollection}.
      */
     public ConflictCollection() {
-        conflicts = new ArrayList<>();
+        conflicts = new CopyOnWriteArrayList<>();
         listeners = new CopyOnWriteArrayList<>();
     }
 
@@ -326,8 +325,8 @@
     }
 
     /**
-     * Returns the list of conflicts involving nodes.
-     * @return The list of conflicts involving nodes.
+     * Returns the list of conflicts involving ways.
+     * @return The list of conflicts involving ways.
      * @since 6555
      */
     public final Collection<Conflict<? extends OsmPrimitive>> getWayConflicts() {
@@ -335,8 +334,8 @@
     }
 
     /**
-     * Returns the list of conflicts involving nodes.
-     * @return The list of conflicts involving nodes.
+     * Returns the list of conflicts involving relations.
+     * @return The list of conflicts involving relations.
      * @since 6555
      */
     public final Collection<Conflict<? extends OsmPrimitive>> getRelationConflicts() {
Index: src/org/openstreetmap/josm/gui/dialogs/ConflictDialog.java
===================================================================
--- src/org/openstreetmap/josm/gui/dialogs/ConflictDialog.java	(revision 17462)
+++ src/org/openstreetmap/josm/gui/dialogs/ConflictDialog.java	(working copy)
@@ -223,9 +223,7 @@
      */
     public void refreshView() {
         DataSet editDs = MainApplication.getLayerManager().getEditDataSet();
-        synchronized (this) {
-            conflicts = editDs == null ? new ConflictCollection() : editDs.getConflicts();
-        }
+        conflicts = editDs == null ? new ConflictCollection() : editDs.getConflicts();
         GuiHelper.runInEDT(() -> {
             model.fireContentChanged();
             updateTitle();