Base version of ncurses-5.7 library
diff --git a/ncurses/base/lib_scroll.c b/ncurses/base/lib_scroll.c
new file mode 100644
index 0000000..ac85bd5
--- /dev/null
+++ b/ncurses/base/lib_scroll.c
@@ -0,0 +1,150 @@
+/****************************************************************************
+ * Copyright (c) 1998-2004,2006 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 *
+ * "Software"), to deal in the Software without restriction, including *
+ * without limitation the rights to use, copy, modify, merge, publish, *
+ * distribute, distribute with modifications, sublicense, and/or sell *
+ * copies of the Software, and to permit persons to whom the Software is *
+ * furnished to do so, subject to the following conditions: *
+ * *
+ * The above copyright notice and this permission notice shall be included *
+ * in all copies or substantial portions of the Software. *
+ * *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
+ * *
+ * Except as contained in this notice, the name(s) of the above copyright *
+ * holders shall not be used in advertising or otherwise to promote the *
+ * sale, use or other dealings in this Software without prior written *
+ * authorization. *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Author: Thomas E. Dickey 1996-2003 *
+ * and: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
+ * and: Eric S. Raymond <esr@snark.thyrsus.com> *
+ ****************************************************************************/
+
+/*
+** lib_scroll.c
+**
+** The routine wscrl(win, n).
+** positive n scroll the window up (ie. move lines down)
+** negative n scroll the window down (ie. move lines up)
+**
+*/
+
+#include <curses.priv.h>
+
+MODULE_ID("$Id: lib_scroll.c,v 1.26 2006/10/14 20:46:08 tom Exp $")
+
+NCURSES_EXPORT(void)
+_nc_scroll_window(WINDOW *win,
+ int const n,
+ NCURSES_SIZE_T const top,
+ NCURSES_SIZE_T const bottom,
+ NCURSES_CH_T blank)
+{
+ int limit;
+ int line;
+ int j;
+ size_t to_copy = (size_t) (sizeof(NCURSES_CH_T) * (win->_maxx + 1));
+
+ TR(TRACE_MOVE, ("_nc_scroll_window(%p, %d, %ld, %ld)",
+ win, n, (long) top, (long) bottom));
+
+ if (top < 0
+ || bottom < top
+ || bottom > win->_maxy) {
+ TR(TRACE_MOVE, ("nothing to scroll"));
+ return;
+ }
+
+ /*
+ * This used to do a line-text pointer-shuffle instead of text copies.
+ * That (a) doesn't work when the window is derived and doesn't have
+ * its own storage, (b) doesn't save you a lot on modern machines
+ * anyway. Your typical memcpy implementations are coded in
+ * assembler using a tight BLT loop; for the size of copies we're
+ * talking here, the total execution time is dominated by the one-time
+ * setup cost. So there is no point in trying to be excessively
+ * clever -- esr.
+ */
+
+ /* shift n lines downwards */
+ if (n < 0) {
+ limit = top - n;
+ for (line = bottom; line >= limit && line >= 0; line--) {
+ TR(TRACE_MOVE, ("...copying %d to %d", line + n, 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 = top; line < limit && line <= win->_maxy; line++) {
+ TR(TRACE_MOVE, ("...filling %d", line));
+ for (j = 0; j <= win->_maxx; j++)
+ win->_line[line].text[j] = blank;
+ if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX);
+ }
+ }
+
+ /* shift n lines upwards */
+ if (n > 0) {
+ limit = bottom - n;
+ for (line = top; line <= limit && line <= win->_maxy; 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 (j = 0; j <= win->_maxx; j++)
+ win->_line[line].text[j] = blank;
+ if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX);
+ }
+ }
+ touchline(win, top, bottom - top + 1);
+
+ if_WIDEC({
+ if (WINDOW_EXT(win, addch_used) != 0) {
+ int next = WINDOW_EXT(win, addch_y) + n;
+ if (next < 0 || next > win->_maxy) {
+ TR(TRACE_VIRTPUT,
+ ("Alert discarded multibyte on scroll"));
+ WINDOW_EXT(win, addch_y) = 0;
+ } else {
+ TR(TRACE_VIRTPUT, ("scrolled working position to %d,%d",
+ WINDOW_EXT(win, addch_y),
+ WINDOW_EXT(win, addch_x)));
+ WINDOW_EXT(win, addch_y) = next;
+ }
+ }
+ })
+}
+
+NCURSES_EXPORT(int)
+wscrl(WINDOW *win, int n)
+{
+ T((T_CALLED("wscrl(%p,%d)"), win, n));
+
+ if (!win || !win->_scroll) {
+ TR(TRACE_MOVE, ("...scrollok is false"));
+ returnCode(ERR);
+ }
+
+ if (n != 0) {
+ _nc_scroll_window(win, n, win->_regtop, win->_regbottom, win->_nc_bkgd);
+ _nc_synchook(win);
+ }
+ returnCode(OK);
+}