lib/57605: curses cursor does not move as expected

[rhialto%falu.nl@localhost]

>Number:         57605
>Category:       lib
>Synopsis:       curses cursor does not move as expected
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Sep 05 16:45:00 +0000 2023
>Originator:     Rhialto
>Release:        NetBSD 9.3
>Organization:
	
>Environment:
System: NetBSD murthe.falu.nl 9.3 NetBSD 9.3 (MAXLWP8192) #0: Sat Aug 6 22:25:06 CEST 2022 rhialto%murthe.falu.nl@localhost:/mnt/scratch/scratch/NetBSD/NetBSD-9.3/source/sets/x/usr/src/sys/arch/amd64/compile/MAXLWP8192 amd64
Architecture: x86_64
Machine: amd64
>Description:
	The cursor is not always on the screen where it is expected.  In
	particular, in the package games/nethack-tty, the cursor remains
	in the same location all the time. With ncurses, the cursor
	moves around as expected.

	Unfortunately I didn't succeed (yet?) in making a small
	reproducer.  I have attached my attempt at the end, to
	illustrate that the issue is likely to be more subtle than I
	could think of.

>How-To-Repeat:

	Let's build a curses and an ncurses version of the nethack package.

	Go to games/nethack-lib. In patches/patch-sys_unix_Makefile.src there
	are 2 lines ":+#CFLAGS += -ggdb". Remove the '#' and do make mps.
	Go to games/nethack-tty and add "INSTALL_UNSTRIPPED=     yes" to the
	Makefile. make package. Rename the package to include "ncurses" in the
	name.

	Now edit games/nethack-lib/Makefile.common and comment out
	"PREFER.curses=pkgsrc". make clean && make package. Rename the
	package to include "curses" in the name.

	Create a file ~/.nethackrc with just "OPTIONS=windowtype:curses"
	in it.

	Install the ncurses package variant.

	Run "nethack" in an xterm of at least 80x25. A dark (black)
	background seems to work better.
	You get some prompts; answer "y" to all of them.
	Part of the screen will show a map, with something like this in it:

                                                   +---------+
                                                   |·········|
                                                   +@········|
                                                   |·d········
                                                   +---------+
	(looking a bit nicer because of curses)

	The cursor (I made mine red so I can see easily where it is) should be
	on the @ symbol, which represents you, the hero.

	Move around a bit with the hjkl keys like in vi. The cursor
	should move with you.

	Type a semicolon ";", this is a command which prompts you to
	select a position on the map. It prompts "Pick an object.". Move
	again with hjkl.  The curor should move away from @, according
	to your hjkl commands. End with Escape.

	Quit with "#q<return>". Really quit? [yn] (n) -> y. You can
	answer "n" to all following prompts. Hit return to the ">>"
	prompt and the following "pop up window".

	With NetBSD's builtin curses I see that the cursor either
	remains in the home position, or even in some random location,
	and doesn't move.

	/usr/pkg/share/doc/nethack/Guidebook is a very extensive
	explanation of how to play NetHack.

	All the curses related source code in nethack should be in the
	directory NetHack-3.6.7/win/curses.

	The test program below does NOT exhibit the problem.

####
#
# Test program for curses vs ncurses.
#

all: curstest ncurstest

curstest: curstest.c
	cc curstest.c -lcurses -o curstest

ncurstest: curstest.c
	cc -I /usr/pkg/include -DN curstest.c -L /usr/pkg/lib -Wl,-R,/usr/pkg/lib -lncurses -o ncurstest


#include <unistd.h>
#ifdef N
# include <ncurses/curses.h>
#else
# include <curses.h>
#endif

WINDOW *
curses_create_window(int width, int height)
{
    WINDOW *win;
    static int startx = 10, starty = 10 ;

    startx += 5;
    starty += 5;

    win = newwin(height, width, starty, startx);
    box(win, 0, 0);
    return win;
}

int orig_cursor;

int
main(int argc, char **argv)
{
    WINDOW *mainwindow = initscr();

    noecho();
    raw();
    nonl();
    meta(stdscr, TRUE);
    keypad(stdscr, TRUE);

    border(0,0,0,0,0,0,0,0);
    sleep(1); refresh();

    move(10, 10);
    sleep(1); refresh();
    addch('@');
    sleep(1); refresh();
    move(10, 10);
    sleep(1); refresh();

    WINDOW *dummywind = curses_create_window(5, 5);
    sleep(1); wrefresh(dummywind);

    WINDOW *mapwind = curses_create_window(20, 20);
    sleep(1); wrefresh(mapwind);

    wmove(mapwind, 10, 10);
    sleep(1); wrefresh(mapwind);
    waddch(mapwind, '@');
    sleep(1); wrefresh(mapwind);
    wmove(mapwind, 10, 10);
    sleep(1); wrefresh(mapwind);

    sleep(5);
    noraw();
    echo();
    nl();

    return 0;
}
>Fix:
	unknown to me