Ticket #38948: 38948_1.diff

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

@@ -1045 +1045 @@
                                         }
                                 } );
 
-                                if ( 'resolved' !== section.deferred.initSortables.state() ) {
-                                        wpNavMenu.initSortables(); // Depends on menu-to-edit ID being set above.
-                                        section.deferred.initSortables.resolve( wpNavMenu.menuList ); // Now MenuControl can extend the sortable.
+                                // Make sure Sortables is initialized after the section has been expanded to prevent `offset` issues.
+                                api.state( 'expandedSection' ).bind( $.proxy( function( newSection ) {
+                                        var section = this;
 
-                                        // @todo Note that wp.customize.reflowPaneContents() is debounced, so this immediate change will show a slight flicker while priorities get updated.
-                                        api.control( 'nav_menu[' + String( section.params.menu_id ) + ']' ).reflowMenuItems();
-                                }
+                                        if ( ! newSection || newSection.id !== section.id ) {
+                                                return false;
+                                        }
+                                        if ( 'resolved' !== section.deferred.initSortables.state() ) {
+                                                wpNavMenu.initSortables(); // Depends on menu-to-edit ID being set above.
+                                                section.deferred.initSortables.resolve( wpNavMenu.menuList ); // Now MenuControl can extend the sortable.
+
+                                                // @todo Note that wp.customize.reflowPaneContents() is debounced, so this immediate change will show a slight flicker while priorities get updated.
+                                                api.control( 'nav_menu[' + String( section.params.menu_id ) + ']' ).reflowMenuItems();
+                                        }
+                                }, section ) );
                         }
                         api.Section.prototype.onChangeExpanded.call( section, expanded, args );
                 }