Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/GenericRelationEditor.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/GenericRelationEditor.java	(revision 19013)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/GenericRelationEditor.java	(revision 19014)
@@ -56,5 +56,4 @@
 import org.openstreetmap.josm.data.UndoRedoHandler.CommandQueueListener;
 import org.openstreetmap.josm.data.osm.DefaultNameFormatter;
-import org.openstreetmap.josm.data.osm.IRelation;
 import org.openstreetmap.josm.data.osm.OsmPrimitive;
 import org.openstreetmap.josm.data.osm.Relation;
@@ -406,4 +405,5 @@
      * builds the panel with the OK and the Cancel button
      * @param okAction OK action
+     * @param deleteAction  Delete action
      * @param cancelAction Cancel action
      *
@@ -422,5 +422,5 @@
         // Keep users from saving invalid relations -- a relation MUST have at least a tag with the key "type"
         // AND must contain at least one other OSM object.
-        final TableModelListener listener = l -> updateOkPanel(this.actionAccess.getChangedRelation(), okButton, deleteButton);
+        final TableModelListener listener = l -> updateOkPanel(okButton, deleteButton);
         listener.tableChanged(null);
         this.memberTableModel.addTableModelListener(listener);
@@ -430,13 +430,13 @@
 
     /**
-     * Update the OK panel area
-     * @param newRelation What the new relation would "look" like if it were to be saved now
+     * Update the OK panel area with a temporary relation that looks if it were to be saved now.
      * @param okButton The OK button
      * @param deleteButton The delete button
      */
-    private void updateOkPanel(IRelation<?> newRelation, JButton okButton, JButton deleteButton) {
-        okButton.setVisible(newRelation.isUseful() || this.getRelationSnapshot() == null);
-        deleteButton.setVisible(!newRelation.isUseful() && this.getRelationSnapshot() != null);
-        if (this.getRelationSnapshot() == null && !newRelation.isUseful()) {
+    private void updateOkPanel(JButton okButton, JButton deleteButton) {
+        boolean useful = this.actionAccess.wouldRelationBeUseful();
+        okButton.setVisible(useful || this.getRelationSnapshot() == null);
+        deleteButton.setVisible(!useful && this.getRelationSnapshot() != null);
+        if (this.getRelationSnapshot() == null && !useful) {
             okButton.setText(tr("Delete"));
         } else {
Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/ApplyAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/ApplyAction.java	(revision 19013)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/ApplyAction.java	(revision 19014)
@@ -36,5 +36,5 @@
     @Override
     public void updateEnabledState() {
-        setEnabled(this.editorAccess.getChangedRelation().isUseful() && isEditorDirty());
+        setEnabled(this.editorAccess.wouldRelationBeUseful() && isEditorDirty());
     }
 }
Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/CancelAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/CancelAction.java	(revision 19013)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/CancelAction.java	(revision 19014)
@@ -9,5 +9,4 @@
 import javax.swing.RootPaneContainer;
 
-import org.openstreetmap.josm.data.osm.IRelation;
 import org.openstreetmap.josm.data.osm.Relation;
 import org.openstreetmap.josm.gui.HelpAwareOptionPane;
@@ -49,5 +48,5 @@
          && !(snapshot == null && getTagModel().getTags().isEmpty())) {
             //give the user a chance to save the changes
-            int ret = confirmClosingByCancel(this.editorAccess.getChangedRelation());
+            int ret = confirmClosingByCancel(this.editorAccess.wouldRelationBeUseful());
             if (ret == 0) { //Yes, save the changes
                 //copied from OKAction.run()
@@ -62,5 +61,5 @@
     }
 
-    protected int confirmClosingByCancel(final IRelation<?> newRelation) {
+    protected int confirmClosingByCancel(boolean isUseful) {
         ButtonSpec[] options = {
                 new ButtonSpec(
@@ -86,5 +85,5 @@
         // Keep users from saving invalid relations -- a relation MUST have at least a tag with the key "type"
         // AND must contain at least one other OSM object.
-        options[0].setEnabled(newRelation.isUseful());
+        options[0].setEnabled(isUseful);
 
         return HelpAwareOptionPane.showOptionDialog(
Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/IRelationEditorActionAccess.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/IRelationEditorActionAccess.java	(revision 19013)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/relation/actions/IRelationEditorActionAccess.java	(revision 19014)
@@ -72,5 +72,7 @@
     /**
      * Get the changed relation
-     * @return The changed relation (note: will not be part of a dataset). This should never be {@code null}.
+     * @return The changed relation (note: will not be part of a dataset) or the
+     * value returned by {@code getEditor().getRelation()}. This should never be {@code null}.
+     * If called for a temporary use of the relation instance, make sure to cleanup a copy to avoid memory leaks, see #23527
      * @since 18413
      */
@@ -98,4 +100,13 @@
 
     /**
+     * Check if the changed relation would be useful.
+     * @return true if the saved relation has at least one tag and one member
+     * @since 19014
+     */
+    default boolean wouldRelationBeUseful() {
+        return (getTagModel().getRowCount() > 0 && getMemberTableModel().getRowCount() > 0);
+    }
+
+    /**
      * Get the text field that is used to edit the role.
      * @return The role text field.
Index: /trunk/test/unit/org/openstreetmap/josm/gui/dialogs/relation/actions/RelationEditorActionsTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/gui/dialogs/relation/actions/RelationEditorActionsTest.java	(revision 19013)
+++ /trunk/test/unit/org/openstreetmap/josm/gui/dialogs/relation/actions/RelationEditorActionsTest.java	(revision 19014)
@@ -17,4 +17,5 @@
 import org.openstreetmap.josm.data.coor.LatLon;
 import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.IRelation;
 import org.openstreetmap.josm.data.osm.Node;
 import org.openstreetmap.josm.data.osm.Relation;
@@ -169,5 +170,10 @@
         relationEditorAccess.getTagModel().initFromPrimitive(relation);
         relationEditorAccess.getEditor().reloadDataFromRelation();
-        assertDoesNotThrow(relationEditorAccess::getChangedRelation);
+
+        assertDoesNotThrow(() -> {
+            IRelation<?> tempRelation = relationEditorAccess.getChangedRelation();
+            if (tempRelation.getDataSet() == null)
+                tempRelation.setMembers(null); // see #19885
+        });
     }
 }