In all games, rs_write_room_reference() stored -1 for a nonexistent
room, but rs_read_room_reference() did not check for out-of-bounds
values, leading to pointers to rooms[-1], which sometimes caused
crashes. rs_read_room_reference() has now been modified to use NULL
instead.
Some of the games required further changes to replace NULL with the
pointer to the actual room. Others are capable of handling NULL for
objects not in any room.
The save_file() function in save.c stored the savefile's device number,
inode number, creation time, and modification time in the file. The
restore() function read them back, and apparently used to compare them
to protect against cheaters.
Unfortunately, the types and sizes of these numbers differ from system
to system, which ruins the Roguelike Restoration Project's fine
portability work. So they have been removed from the savefile.
This BREAKS SAVEFILE COMPATIBILITY, but old files can be converted by
excising the chunk starting at offset 0x22 with length sizeof(ino_t) +
sizeof(dev_t) + 2 * sizeof(time_t). That's 0x14 on i686 and 0x20 on
x86_64, at least with current versions of Linux and glibc.
