UltraRogue: clear the next_obj field when removing items from the floor. The next_obj field is a pointer which the top item in a stack uses to keep a list of the other items. When removing an item from the stack, rem_obj() failed to set next_obj to NULL, which can cause items in monster inventory to point to items earlier in the inventory list. That causes infinite co-recursion when saving or restoring.

/*
 * Super-Rogue
 * Copyright (C) 1984 Robert D. Kindelberger
 * All rights reserved.
 *
 * See the file LICENSE.TXT for full copyright and licensing information.
 */

#include	<sgtty.h>
typedef	struct sgttyb	SGTTY;
static SGTTY _tty, _res_flg;