System V.2 Curses (kind of) Bug #6

[Mike Laman]

Scrolling a window with the current position of the window's cursor on the the
top line of that window puts the cursor at an "invalid" value.  This is more a
change in the code to better handle an "undefined" action than anything else.
This just might help protect the user from himself/herself.

In "_tscroll()" (screen/_tscroll.c) change:

	win->_cury--;

to

	if(win->_cury-- <= 0)
		win->_cury = 0;

This is similar to the one I posted for 4.2 BSD curses.

		Mike Laman, NCR @ Torrey Pines
		UUCP: {ucbvax,philabs,sdcsla}!sdcsvax!laman