Index: trunk/src/org/openstreetmap/josm/command/ChangeMembersCommand.java
===================================================================
--- trunk/src/org/openstreetmap/josm/command/ChangeMembersCommand.java	(revision 17199)
+++ trunk/src/org/openstreetmap/josm/command/ChangeMembersCommand.java	(revision 17199)
@@ -0,0 +1,87 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.command;
+
+import static org.openstreetmap.josm.tools.I18n.tr;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+
+import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.DefaultNameFormatter;
+import org.openstreetmap.josm.data.osm.OsmPrimitive;
+import org.openstreetmap.josm.data.osm.Relation;
+import org.openstreetmap.josm.data.osm.RelationMember;
+
+/**
+ * Command that changes the members of a relation.
+ * The same can be done with ChangeCommand, but this is more efficient.
+ * @author Gerd Petermann
+ * @since xxx
+ *
+ */
+public class ChangeMembersCommand extends Command {
+
+    private final Relation relation;
+    private final List<RelationMember> cmdMembers;
+
+    /**
+     * Constructs a new {@code ChangeMembersCommand} in the context of a given data set.
+     * @param data the data set. Must not be null.
+     * @param relation the relation
+     * @param newMembers the new member list, must not be empty
+     */
+    public ChangeMembersCommand(DataSet data, Relation relation, List<RelationMember> newMembers) {
+        super(data);
+        this.relation = Objects.requireNonNull(relation, "relation");
+        this.cmdMembers = Objects.requireNonNull(newMembers, "newMembers");
+        if (cmdMembers.isEmpty()) {
+            throw new IllegalArgumentException("Members collection is empty");
+        }
+    }
+
+    /**
+     * Constructs a new {@code ChangeMembersCommand}  in the context of {@code r} data set.
+     * @param relation the relation. It must belong to a data set
+     * @param newMembers the new member list, must not be empty
+     */
+    public ChangeMembersCommand(Relation relation, List<RelationMember> newMembers) {
+        this(relation.getDataSet(), relation, newMembers);
+    }
+
+    @Override
+    public boolean executeCommand() {
+        super.executeCommand();
+        relation.setMembers(cmdMembers);
+        relation.setModified(true);
+        return true;
+
+    }
+
+    @Override
+    public String getDescriptionText() {
+        return tr("Change members of {0}", relation.getDisplayName(DefaultNameFormatter.getInstance()));
+    }
+
+    @Override
+    public void fillModifiedData(Collection<OsmPrimitive> modified, Collection<OsmPrimitive> deleted,
+            Collection<OsmPrimitive> added) {
+        modified.add(relation);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), relation, cmdMembers);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (obj == null || getClass() != obj.getClass()) return false;
+        if (!super.equals(obj)) return false;
+        ChangeMembersCommand that = (ChangeMembersCommand) obj;
+        return Objects.equals(relation, that.relation) &&
+               Objects.equals(cmdMembers, that.cmdMembers);
+    }
+
+}