Ticket #32810: 32810.diff

src/wp-admin/js/customize-nav-menus.js

@@ -314 +314 @@
                         request.done(function( data ) {
                                 var items, typeInner;
                                 items = data.items;
+                                typeInner = $( '#available-menu-items-' + type + ' .accordion-section-content' );
                                 if ( 0 === items.length ) {
                                         self.pages[ type ] = -1;
+                                        typeInner.append( noItemTemplate() );
                                         return;
                                 }
                                 items = new api.Menus.AvailableItemCollection( items ); // @todo Why is this collection created and then thrown away?
-                                self.collection.add( items.models );
-                                typeInner = $( '#available-menu-items-' + type + ' .accordion-section-content' );
+                                self.collection.add( items.models );                            
                                 items.each(function( menu_item ) {
                                         typeInner.append( itemTemplate( menu_item.attributes ) );
                                 });

src/wp-includes/class-wp-customize-nav-menus.php

@@ -589 +589 @@
                         </div>
                 </script>
 
+                <script type="text/html" id="tmpl-not-available-menu-item">                     
+                        <span class="item-title"><?php _e( 'No items' ) ?></span>
+                </script>
+
                 <script type="text/html" id="tmpl-available-menu-item-type">
                         <div id="available-menu-items-{{ data.type }}" class="accordion-section">
                                 <h4 class="accordion-section-title">{{ data.type_label }}</h4>