Ticket #7241: 7241.diff

wp-admin/includes/widgets.php

@@ -64 +64 @@
                                 if ( 'all' == $show && $is_multi ) {
                                         // it's a multi-widget.  We only need to show it in the list once.
                                         $already_shown[] = $widget['callback'];
-                                        $num = (int) array_pop( explode( '-', $widget['id'] ) );
+                                        $num = (int) array_pop( $ids = explode( '-', $widget['id'] ) );
                                         $id_base = $wp_registered_widget_controls[$widget['id']]['id_base'];
                                         // so that we always add a new one when clicking "add"
                                         while ( isset($wp_registered_widgets["$id_base-$num"]) )