Ticket #45089: 45089.patch

src/wp-admin/includes/class-wp-list-table.php

@@ -1126 +1126 @@
                                         $class[] = 'sorted';
                                         $class[] = $current_order;
                                 } else {
-                                        $order   = $desc_first ? 'desc' : 'asc';
+                                        if( in_array( strtolower($desc_first), array('desc', 'asc'), true ) )
+                                                $order = strtolower( $desc_first );
+                                        else
+                                                        $order = $desc_first ? 'desc' : 'asc';
                                         $class[] = 'sortable';
-                                        $class[] = $desc_first ? 'asc' : 'desc';
+                                        $class[] = $order === 'desc' ? 'asc' : 'desc';
                                 }
 
                                 $column_display_name = '<a href="' . esc_url( add_query_arg( compact( 'orderby', 'order' ), $current_url ) ) . '"><span>' . $column_display_name . '</span><span class="sorting-indicator"></span></a>';