Ticket #24498: 24498.patch

src/wp-admin/includes/template.php

@@ -677 +677 @@
          * @param int $limit Number of custom fields to retrieve. Default 30.
          */
         $limit = apply_filters( 'postmeta_form_limit', 30 );
-        $sql = "SELECT meta_key
+        $sql = "SELECT DISTINCT meta_key
                 FROM $wpdb->postmeta
-                GROUP BY meta_key
+                WHERE meta_key NOT BETWEEN '_' AND '_z'
                 HAVING meta_key NOT LIKE %s
                 ORDER BY meta_key
                 LIMIT %d";