lib/55434: Bug in hline() in libcurses

[jnaman806%gmail.com@localhost]

>Number:         55434
>Category:       lib
>Synopsis:       Bug in hline() in libcurses
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 30 10:20:00 +0000 2020
>Originator:     Naman Jain
>Release:        NetBSD 9.0
>Organization:
IIT Kanpur
>Environment:
NetBSD localhost 9.0 NetBSD 9.0 (GENERIC) #0: Fri Feb 14 00:06:28 UTC 2020  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
hline() do not advance the cursor position. But with the following commands,i.e. when the line moves past the right-hand side of stdscr, the cursor moves to the next line.
 
>How-To-Repeat:
In tests/libcurses, the following test

include start
call OK mvhline 3 75 `\000A` 10
call OK refresh

gives [cup4;76XAAAAAcup5;76X] as the output. (COLS = 80 for testframe psuedo-terminal)

Equivalent C program,

#include <curses.h>
int main() {
    initscr();
    mvhline(3,COLS-5,'A', 10);
    refresh();
    getch();
    endwin();
    return 0;
}




>Fix: