For those of you with event systems and oprogs

[Jeremy Hill]

You may run up against crashes with object programs.  I recently added a 'put'
trigger type that will segmentation fault unless the code takes into
consideration that the object may be in a container.  In many of the do_opXXX
commands you'll see:

    if ( ( victim = get_char_room( NULL,
obj->in_room?obj->in_room:obj->carried_by->in_room, arg ) ) == NULL )

If you have delayed prog parsing and a character shoves the triggering object
into his pack, or have implemented a 'put' trigger of your own, the MUD will
crash.  A recommendation is to allow the container that the object is in to act
as a "host" for the object:

void do_opechoat( OBJ_DATA *obj, char *argument )
...
    OBJ_DATA *host;
    host = find_container_or_obj(obj);
...
    if ( ( victim = get_char_room( NULL,
host->in_room?host->in_room:host->carried_by->in_room, arg ) ) == NULL )
        return;

    act( argument, host->carried_by?host->carried_by:host->in_room->people, obj,
victim, TO_VICT );

---------
You'll have to go through all the do_opXXX functions and change certain calls to
"host" instead of "obj", but it is a trivial modification which takes
approximately 20 minutes.

Three new functions to find an object's container: (not entirely necessary):

//JH: Only find an object's container.  If it's not in anything, return NULL.
OBJ_DATA *find_container(OBJ_DATA *obj)
{

    OBJ_DATA *in_obj;

    for (in_obj = obj; in_obj->in_obj != NULL; in_obj = in_obj->in_obj);

    if (in_obj == obj)
        return NULL;
    else
        return in_obj;
}

//JH: Find what container obj is ultimately in.  If it's not in anything, it'll
just return itself.
OBJ_DATA *find_container_or_obj(OBJ_DATA *obj)
{

    OBJ_DATA *in_obj;

    for (in_obj = obj; in_obj->in_obj != NULL; in_obj = in_obj->in_obj);

        return in_obj;
}

//JH: Find the owner of the container which obj is ultimately in.  Returns NULL
if not on anyone.
CHAR_DATA *find_container_owner(OBJ_DATA *obj)
{

    OBJ_DATA *in_obj;

    for (in_obj = obj; in_obj->in_obj != NULL; in_obj = in_obj->in_obj);

    return in_obj->carried_by;
}