/* Sequential list data type implemented by a binary tree.

   Copyright (C) 2006, 2009-2026 Free Software Foundation, Inc.

   Written by Bruno Haible <bruno@clisp.org>, 2006.

   This file is free software: you can redistribute it and/or modify

   it under the terms of the GNU Lesser General Public License as

   published by the Free Software Foundation; either version 2.1 of the

   License, or (at your option) any later version.

   This file is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License

   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Common code of gl_avltree_list.c, gl_rbtree_list.c,

                  gl_avltreehash_list.c, gl_rbtreehash_list.c.  */

/* An item on the stack used for iterating across the elements.  */

typedef struct

{

  gl_list_node_t node;

  size_t rightp;

} iterstack_item_t;

/* A stack used for iterating across the elements.  */

typedef iterstack_item_t iterstack_t[MAXHEIGHT];

/* Frees a non-empty subtree recursively.

   This function is recursive and therefore not very fast.  */

static void

free_subtree (gl_list_node_t node)

{

  if (node->left != NULL)

    free_subtree (node->left);

  if (node->right != NULL)

    free_subtree (node->right);

  free (node);

}