diff options
Diffstat (limited to 'ncurses/base/lib_scroll.c')
| -rw-r--r-- | ncurses/base/lib_scroll.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/ncurses/base/lib_scroll.c b/ncurses/base/lib_scroll.c index 8684e25..ecc0ba5 100644 --- a/ncurses/base/lib_scroll.c +++ b/ncurses/base/lib_scroll.c @@ -1,5 +1,6 @@ /**************************************************************************** - * Copyright (c) 1998-2010,2011 Free Software Foundation, Inc. * + * Copyright 2019,2020 Thomas E. Dickey * + * Copyright 1998-2010,2011 Free Software Foundation, Inc. * * * * Permission is hereby granted, free of charge, to any person obtaining a * * copy of this software and associated documentation files (the * @@ -43,7 +44,7 @@ #include <curses.priv.h> -MODULE_ID("$Id: lib_scroll.c,v 1.29 2011/10/22 16:34:50 tom Exp $") +MODULE_ID("$Id: lib_scroll.c,v 1.32 2020/02/02 23:34:34 tom Exp $") NCURSES_EXPORT(void) _nc_scroll_window(WINDOW *win, @@ -77,11 +78,13 @@ _nc_scroll_window(WINDOW *win, * setup cost. So there is no point in trying to be excessively * clever -- esr. */ +#define BottomLimit(n) ((n) >= 0 && (n) >= top) +#define TopLimit(n) ((n) <= win->_maxy && (n) <= bottom) /* shift n lines downwards */ if (n < 0) { limit = top - n; - for (line = bottom; line >= limit && line >= 0; line--) { + for (line = bottom; line >= limit && BottomLimit(line); line--) { TR(TRACE_MOVE, ("...copying %d to %d", line + n, line)); memcpy(win->_line[line].text, win->_line[line + n].text, @@ -89,7 +92,7 @@ _nc_scroll_window(WINDOW *win, if_USE_SCROLL_HINTS(win->_line[line].oldindex = win->_line[line + n].oldindex); } - for (line = top; line < limit && line <= win->_maxy; line++) { + for (line = top; line < limit && TopLimit(line); line++) { TR(TRACE_MOVE, ("...filling %d", line)); for (j = 0; j <= win->_maxx; j++) win->_line[line].text[j] = blank; @@ -100,14 +103,14 @@ _nc_scroll_window(WINDOW *win, /* shift n lines upwards */ if (n > 0) { limit = bottom - n; - for (line = top; line <= limit && line <= win->_maxy; line++) { + for (line = top; line <= limit && TopLimit(line); line++) { memcpy(win->_line[line].text, win->_line[line + n].text, to_copy); if_USE_SCROLL_HINTS(win->_line[line].oldindex = win->_line[line + n].oldindex); } - for (line = bottom; line > limit && line >= 0; line--) { + for (line = bottom; line > limit && BottomLimit(line); line--) { for (j = 0; j <= win->_maxx; j++) win->_line[line].text[j] = blank; if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX); |