setscrreg behavior

[Dan Gookin]

Greetings, all. Doing more tests here...

In my tests of the setscrreg() function I've found some weird behavior
that I haven't seen documented anywhere.

When I try to put text below a scrolling region in the middle of a
window the \n appears in the scrolling region and not below it. This
code demonstrates:

#include <curses.h>

int main()
{
        initscr();

        scrollok(stdscr,TRUE);
        setscrreg(0,3);

        addstr("Hello.");
        refresh();
        getchar();

        mvaddstr(4,0,"Obligatory text.\n");
        refresh();
        getchar();

        endwin();
        return(0);
}

The effect of the mvaddstr() function is to display its text on line
4, but the \n from that string somehow appears on line 3 in the
scrolling region. Visually this scrolls up line 0 with "Hello" into
oblivion.

Displaying the new line anwhere else behaves as expected. E.g., if the
scrolling region omits lines at the top of a window, then the \n
displays fine on those lines. It's only the lines below the scrolling
region that have this issue.

This was tested on xterm in Mac OS X using NCurses 5.4 as well as
FreeBSD with a more ancient version of NCurses.

Thanks for any insight you can offer.
DAN