Base version of ncurses-5.7 library
diff --git a/ncurses/tty/lib_mvcur.c b/ncurses/tty/lib_mvcur.c
new file mode 100644
index 0000000..8e66fa3
--- /dev/null
+++ b/ncurses/tty/lib_mvcur.c
@@ -0,0 +1,1249 @@
+/****************************************************************************
+ * Copyright (c) 1998-2007,2008 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: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
+ *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
+ *     and: Thomas E. Dickey                        1996-on                 *
+ ****************************************************************************/
+
+/*
+**	lib_mvcur.c
+**
+**	The routines for moving the physical cursor and scrolling:
+**
+**		void _nc_mvcur_init(void)
+**
+**		void _nc_mvcur_resume(void)
+**
+**		int mvcur(int old_y, int old_x, int new_y, int new_x)
+**
+**		void _nc_mvcur_wrap(void)
+**
+** Comparisons with older movement optimizers:
+**    SVr3 curses mvcur() can't use cursor_to_ll or auto_left_margin.
+**    4.4BSD curses can't use cuu/cud/cuf/cub/hpa/vpa/tab/cbt for local
+** motions.  It doesn't use tactics based on auto_left_margin.  Weirdly
+** enough, it doesn't use its own hardware-scrolling routine to scroll up
+** destination lines for out-of-bounds addresses!
+**    old ncurses optimizer: less accurate cost computations (in fact,
+** it was broken and had to be commented out!).
+**
+** Compile with -DMAIN to build an interactive tester/timer for the movement
+** optimizer.  You can use it to investigate the optimizer's behavior.
+** You can also use it for tuning the formulas used to determine whether
+** or not full optimization is attempted.
+**
+** This code has a nasty tendency to find bugs in terminfo entries, because it
+** exercises the non-cup movement capabilities heavily.  If you think you've
+** found a bug, try deleting subsets of the following capabilities (arranged
+** in decreasing order of suspiciousness): it, tab, cbt, hpa, vpa, cuu, cud,
+** cuf, cub, cuu1, cud1, cuf1, cub1.  It may be that one or more are wrong.
+**
+** Note: you should expect this code to look like a resource hog in a profile.
+** That's because it does a lot of I/O, through the tputs() calls.  The I/O
+** cost swamps the computation overhead (and as machines get faster, this
+** will become even more true).  Comments in the test exerciser at the end
+** go into detail about tuning and how you can gauge the optimizer's
+** effectiveness.
+**/
+
+/****************************************************************************
+ *
+ * Constants and macros for optimizer tuning.
+ *
+ ****************************************************************************/
+
+/*
+ * The average overhead of a full optimization computation in character
+ * transmission times.  If it's too high, the algorithm will be a bit
+ * over-biased toward using cup rather than local motions; if it's too
+ * low, the algorithm may spend more time than is strictly optimal
+ * looking for non-cup motions.  Profile the optimizer using the `t'
+ * command of the exerciser (see below), and round to the nearest integer.
+ *
+ * Yes, I (esr) thought about computing expected overhead dynamically, say
+ * by derivation from a running average of optimizer times.  But the
+ * whole point of this optimization is to *decrease* the frequency of
+ * system calls. :-)
+ */
+#define COMPUTE_OVERHEAD	1	/* I use a 90MHz Pentium @ 9.6Kbps */
+
+/*
+ * LONG_DIST is the distance we consider to be just as costly to move over as a
+ * cup sequence is to emit.  In other words, it's the length of a cup sequence
+ * adjusted for average computation overhead.  The magic number is the length
+ * of "\033[yy;xxH", the typical cup sequence these days.
+ */
+#define LONG_DIST		(8 - COMPUTE_OVERHEAD)
+
+/*
+ * Tell whether a motion is optimizable by local motions.  Needs to be cheap to
+ * compute. In general, all the fast moves go to either the right or left edge
+ * of the screen.  So any motion to a location that is (a) further away than
+ * LONG_DIST and (b) further inward from the right or left edge than LONG_DIST,
+ * we'll consider nonlocal.
+ */
+#define NOT_LOCAL(fy, fx, ty, tx)	((tx > LONG_DIST) \
+ 		 && (tx < screen_columns - 1 - LONG_DIST) \
+		 && (abs(ty-fy) + abs(tx-fx) > LONG_DIST))
+
+/****************************************************************************
+ *
+ * External interfaces
+ *
+ ****************************************************************************/
+
+/*
+ * For this code to work OK, the following components must live in the
+ * screen structure:
+ *
+ *	int		_char_padding;	// cost of character put
+ *	int		_cr_cost;	// cost of (carriage_return)
+ *	int		_cup_cost;	// cost of (cursor_address)
+ *	int		_home_cost;	// cost of (cursor_home)
+ *	int		_ll_cost;	// cost of (cursor_to_ll)
+ *#if USE_HARD_TABS
+ *	int		_ht_cost;	// cost of (tab)
+ *	int		_cbt_cost;	// cost of (back_tab)
+ *#endif USE_HARD_TABS
+ *	int		_cub1_cost;	// cost of (cursor_left)
+ *	int		_cuf1_cost;	// cost of (cursor_right)
+ *	int		_cud1_cost;	// cost of (cursor_down)
+ *	int		_cuu1_cost;	// cost of (cursor_up)
+ *	int		_cub_cost;	// cost of (parm_cursor_left)
+ *	int		_cuf_cost;	// cost of (parm_cursor_right)
+ *	int		_cud_cost;	// cost of (parm_cursor_down)
+ *	int		_cuu_cost;	// cost of (parm_cursor_up)
+ *	int		_hpa_cost;	// cost of (column_address)
+ *	int		_vpa_cost;	// cost of (row_address)
+ *	int		_ech_cost;	// cost of (erase_chars)
+ *	int		_rep_cost;	// cost of (repeat_char)
+ *
+ * The USE_HARD_TABS switch controls whether it is reliable to use tab/backtabs
+ * for local motions.  On many systems, it's not, due to uncertainties about
+ * tab delays and whether or not tabs will be expanded in raw mode.  If you
+ * have parm_right_cursor, tab motions don't win you a lot anyhow.
+ */
+
+#include <curses.priv.h>
+#include <term.h>
+#include <ctype.h>
+
+MODULE_ID("$Id: lib_mvcur.c,v 1.113 2008/08/16 19:30:58 tom Exp $")
+
+#define WANT_CHAR(y, x)	SP->_newscr->_line[y].text[x]	/* desired state */
+#define BAUDRATE	cur_term->_baudrate	/* bits per second */
+
+#if defined(MAIN) || defined(NCURSES_TEST)
+#include <sys/time.h>
+
+static bool profiling = FALSE;
+static float diff;
+#endif /* MAIN */
+
+#define OPT_SIZE 512
+
+static int normalized_cost(const char *const cap, int affcnt);
+
+/****************************************************************************
+ *
+ * Initialization/wrapup (including cost pre-computation)
+ *
+ ****************************************************************************/
+
+#ifdef TRACE
+static int
+trace_cost_of(const char *capname, const char *cap, int affcnt)
+{
+    int result = _nc_msec_cost(cap, affcnt);
+    TR(TRACE_CHARPUT | TRACE_MOVE,
+       ("CostOf %s %d %s", capname, result, _nc_visbuf(cap)));
+    return result;
+}
+#define CostOf(cap,affcnt) trace_cost_of(#cap,cap,affcnt);
+
+static int
+trace_normalized_cost(const char *capname, const char *cap, int affcnt)
+{
+    int result = normalized_cost(cap, affcnt);
+    TR(TRACE_CHARPUT | TRACE_MOVE,
+       ("NormalizedCost %s %d %s", capname, result, _nc_visbuf(cap)));
+    return result;
+}
+#define NormalizedCost(cap,affcnt) trace_normalized_cost(#cap,cap,affcnt);
+
+#else
+
+#define CostOf(cap,affcnt) _nc_msec_cost(cap,affcnt);
+#define NormalizedCost(cap,affcnt) normalized_cost(cap,affcnt);
+
+#endif
+
+NCURSES_EXPORT(int)
+_nc_msec_cost(const char *const cap, int affcnt)
+/* compute the cost of a given operation */
+{
+    if (cap == 0)
+	return (INFINITY);
+    else {
+	const char *cp;
+	float cum_cost = 0.0;
+
+	for (cp = cap; *cp; cp++) {
+	    /* extract padding, either mandatory or required */
+	    if (cp[0] == '$' && cp[1] == '<' && strchr(cp, '>')) {
+		float number = 0.0;
+
+		for (cp += 2; *cp != '>'; cp++) {
+		    if (isdigit(UChar(*cp)))
+			number = number * 10 + (*cp - '0');
+		    else if (*cp == '*')
+			number *= affcnt;
+		    else if (*cp == '.' && (*++cp != '>') && isdigit(UChar(*cp)))
+			number += (*cp - '0') / 10.0;
+		}
+
+#if NCURSES_NO_PADDING
+		if (!GetNoPadding(SP))
+#endif
+		    cum_cost += number * 10;
+	    } else
+		cum_cost += SP->_char_padding;
+	}
+
+	return ((int) cum_cost);
+    }
+}
+
+static int
+normalized_cost(const char *const cap, int affcnt)
+/* compute the effective character-count for an operation (round up) */
+{
+    int cost = _nc_msec_cost(cap, affcnt);
+    if (cost != INFINITY)
+	cost = (cost + SP->_char_padding - 1) / SP->_char_padding;
+    return cost;
+}
+
+static void
+reset_scroll_region(void)
+/* Set the scroll-region to a known state (the default) */
+{
+    if (change_scroll_region) {
+	TPUTS_TRACE("change_scroll_region");
+	putp(TPARM_2(change_scroll_region, 0, screen_lines - 1));
+    }
+}
+
+NCURSES_EXPORT(void)
+_nc_mvcur_resume(void)
+/* what to do at initialization time and after each shellout */
+{
+    /* initialize screen for cursor access */
+    if (enter_ca_mode) {
+	TPUTS_TRACE("enter_ca_mode");
+	putp(enter_ca_mode);
+    }
+
+    /*
+     * Doing this here rather than in _nc_mvcur_wrap() ensures that
+     * ncurses programs will see a reset scroll region even if a
+     * program that messed with it died ungracefully.
+     *
+     * This also undoes the effects of terminal init strings that assume
+     * they know the screen size.  This is useful when you're running
+     * a vt100 emulation through xterm.
+     */
+    reset_scroll_region();
+    SP->_cursrow = SP->_curscol = -1;
+
+    /* restore cursor shape */
+    if (SP->_cursor != -1) {
+	int cursor = SP->_cursor;
+	SP->_cursor = -1;
+	curs_set(cursor);
+    }
+}
+
+NCURSES_EXPORT(void)
+_nc_mvcur_init(void)
+/* initialize the cost structure */
+{
+    if (isatty(fileno(SP->_ofp)))
+	SP->_char_padding = ((BAUDBYTE * 1000 * 10)
+			     / (BAUDRATE > 0 ? BAUDRATE : 9600));
+    else
+	SP->_char_padding = 1;	/* must be nonzero */
+    if (SP->_char_padding <= 0)
+	SP->_char_padding = 1;	/* must be nonzero */
+    TR(TRACE_CHARPUT | TRACE_MOVE, ("char_padding %d msecs", SP->_char_padding));
+
+    /* non-parameterized local-motion strings */
+    SP->_cr_cost = CostOf(carriage_return, 0);
+    SP->_home_cost = CostOf(cursor_home, 0);
+    SP->_ll_cost = CostOf(cursor_to_ll, 0);
+#if USE_HARD_TABS
+    if (getenv("NCURSES_NO_HARD_TABS") == 0) {
+	SP->_ht_cost = CostOf(tab, 0);
+	SP->_cbt_cost = CostOf(back_tab, 0);
+    } else {
+	SP->_ht_cost = INFINITY;
+	SP->_cbt_cost = INFINITY;
+    }
+#endif /* USE_HARD_TABS */
+    SP->_cub1_cost = CostOf(cursor_left, 0);
+    SP->_cuf1_cost = CostOf(cursor_right, 0);
+    SP->_cud1_cost = CostOf(cursor_down, 0);
+    SP->_cuu1_cost = CostOf(cursor_up, 0);
+
+    SP->_smir_cost = CostOf(enter_insert_mode, 0);
+    SP->_rmir_cost = CostOf(exit_insert_mode, 0);
+    SP->_ip_cost = 0;
+    if (insert_padding) {
+	SP->_ip_cost = CostOf(insert_padding, 0);
+    }
+
+    /*
+     * Assumption: if the terminal has memory_relative addressing, the
+     * initialization strings or smcup will set single-page mode so we
+     * can treat it like absolute screen addressing.  This seems to be true
+     * for all cursor_mem_address terminal types in the terminfo database.
+     */
+    SP->_address_cursor = cursor_address ? cursor_address : cursor_mem_address;
+
+    /*
+     * Parametrized local-motion strings.  This static cost computation
+     * depends on the following assumptions:
+     *
+     * (1) They never have * padding.  In the entire master terminfo database
+     *     as of March 1995, only the obsolete Zenith Z-100 pc violates this.
+     *     (Proportional padding is found mainly in insert, delete and scroll
+     *     capabilities).
+     *
+     * (2) The average case of cup has two two-digit parameters.  Strictly,
+     *     the average case for a 24 * 80 screen has ((10*10*(1 + 1)) +
+     *     (14*10*(1 + 2)) + (10*70*(2 + 1)) + (14*70*4)) / (24*80) = 3.458
+     *     digits of parameters.  On a 25x80 screen the average is 3.6197.
+     *     On larger screens the value gets much closer to 4.
+     *
+     * (3) The average case of cub/cuf/hpa/ech/rep has 2 digits of parameters
+     *     (strictly, (((10 * 1) + (70 * 2)) / 80) = 1.8750).
+     *
+     * (4) The average case of cud/cuu/vpa has 2 digits of parameters
+     *     (strictly, (((10 * 1) + (14 * 2)) / 24) = 1.5833).
+     *
+     * All these averages depend on the assumption that all parameter values
+     * are equally probable.
+     */
+    SP->_cup_cost = CostOf(TPARM_2(SP->_address_cursor, 23, 23), 1);
+    SP->_cub_cost = CostOf(TPARM_1(parm_left_cursor, 23), 1);
+    SP->_cuf_cost = CostOf(TPARM_1(parm_right_cursor, 23), 1);
+    SP->_cud_cost = CostOf(TPARM_1(parm_down_cursor, 23), 1);
+    SP->_cuu_cost = CostOf(TPARM_1(parm_up_cursor, 23), 1);
+    SP->_hpa_cost = CostOf(TPARM_1(column_address, 23), 1);
+    SP->_vpa_cost = CostOf(TPARM_1(row_address, 23), 1);
+
+    /* non-parameterized screen-update strings */
+    SP->_ed_cost = NormalizedCost(clr_eos, 1);
+    SP->_el_cost = NormalizedCost(clr_eol, 1);
+    SP->_el1_cost = NormalizedCost(clr_bol, 1);
+    SP->_dch1_cost = NormalizedCost(delete_character, 1);
+    SP->_ich1_cost = NormalizedCost(insert_character, 1);
+
+    /*
+     * If this is a bce-terminal, we want to bias the choice so we use clr_eol
+     * rather than spaces at the end of a line.
+     */
+    if (back_color_erase)
+	SP->_el_cost = 0;
+
+    /* parameterized screen-update strings */
+    SP->_dch_cost = NormalizedCost(TPARM_1(parm_dch, 23), 1);
+    SP->_ich_cost = NormalizedCost(TPARM_1(parm_ich, 23), 1);
+    SP->_ech_cost = NormalizedCost(TPARM_1(erase_chars, 23), 1);
+    SP->_rep_cost = NormalizedCost(TPARM_2(repeat_char, ' ', 23), 1);
+
+    SP->_cup_ch_cost = NormalizedCost(TPARM_2(SP->_address_cursor, 23, 23), 1);
+    SP->_hpa_ch_cost = NormalizedCost(TPARM_1(column_address, 23), 1);
+    SP->_cuf_ch_cost = NormalizedCost(TPARM_1(parm_right_cursor, 23), 1);
+    SP->_inline_cost = min(SP->_cup_ch_cost,
+			   min(SP->_hpa_ch_cost,
+			       SP->_cuf_ch_cost));
+
+    /*
+     * If save_cursor is used within enter_ca_mode, we should not use it for
+     * scrolling optimization, since the corresponding restore_cursor is not
+     * nested on the various terminals (vt100, xterm, etc.) which use this
+     * feature.
+     */
+    if (save_cursor != 0
+	&& enter_ca_mode != 0
+	&& strstr(enter_ca_mode, save_cursor) != 0) {
+	T(("...suppressed sc/rc capability due to conflict with smcup/rmcup"));
+	save_cursor = 0;
+	restore_cursor = 0;
+    }
+
+    /*
+     * A different, possibly better way to arrange this would be to set
+     * SP->_endwin = TRUE at window initialization time and let this be
+     * called by doupdate's return-from-shellout code.
+     */
+    _nc_mvcur_resume();
+}
+
+NCURSES_EXPORT(void)
+_nc_mvcur_wrap(void)
+/* wrap up cursor-addressing mode */
+{
+    /* leave cursor at screen bottom */
+    mvcur(-1, -1, screen_lines - 1, 0);
+
+    /* set cursor to normal mode */
+    if (SP->_cursor != -1) {
+	int cursor = SP->_cursor;
+	curs_set(1);
+	SP->_cursor = cursor;
+    }
+
+    if (exit_ca_mode) {
+	TPUTS_TRACE("exit_ca_mode");
+	putp(exit_ca_mode);
+    }
+    /*
+     * Reset terminal's tab counter.  There's a long-time bug that
+     * if you exit a "curses" program such as vi or more, tab
+     * forward, and then backspace, the cursor doesn't go to the
+     * right place.  The problem is that the kernel counts the
+     * escape sequences that reset things as column positions.
+     * Utter a \r to reset this invisibly.
+     */
+    _nc_outch('\r');
+}
+
+/****************************************************************************
+ *
+ * Optimized cursor movement
+ *
+ ****************************************************************************/
+
+/*
+ * Perform repeated-append, returning cost
+ */
+static NCURSES_INLINE int
+repeated_append(string_desc * target, int total, int num, int repeat, const char *src)
+{
+    size_t need = repeat * strlen(src);
+
+    if (need < target->s_size) {
+	while (repeat-- > 0) {
+	    if (_nc_safe_strcat(target, src)) {
+		total += num;
+	    } else {
+		total = INFINITY;
+		break;
+	    }
+	}
+    } else {
+	total = INFINITY;
+    }
+    return total;
+}
+
+#ifndef NO_OPTIMIZE
+#define NEXTTAB(fr)	(fr + init_tabs - (fr % init_tabs))
+
+/*
+ * Assume back_tab (CBT) does not wrap backwards at the left margin, return
+ * a negative value at that point to simplify the loop.
+ */
+#define LASTTAB(fr)	((fr > 0) ? ((fr - 1) / init_tabs) * init_tabs : -1)
+
+static int
+relative_move(string_desc * target, int from_y, int from_x, int to_y, int
+	      to_x, bool ovw)
+/* move via local motions (cuu/cuu1/cud/cud1/cub1/cub/cuf1/cuf/vpa/hpa) */
+{
+    string_desc save;
+    int n, vcost = 0, hcost = 0;
+
+    (void) _nc_str_copy(&save, target);
+
+    if (to_y != from_y) {
+	vcost = INFINITY;
+
+	if (row_address != 0
+	    && _nc_safe_strcat(target, TPARM_1(row_address, to_y))) {
+	    vcost = SP->_vpa_cost;
+	}
+
+	if (to_y > from_y) {
+	    n = (to_y - from_y);
+
+	    if (parm_down_cursor
+		&& SP->_cud_cost < vcost
+		&& _nc_safe_strcat(_nc_str_copy(target, &save),
+				   TPARM_1(parm_down_cursor, n))) {
+		vcost = SP->_cud_cost;
+	    }
+
+	    if (cursor_down
+		&& (*cursor_down != '\n' || SP->_nl)
+		&& (n * SP->_cud1_cost < vcost)) {
+		vcost = repeated_append(_nc_str_copy(target, &save), 0,
+					SP->_cud1_cost, n, cursor_down);
+	    }
+	} else {		/* (to_y < from_y) */
+	    n = (from_y - to_y);
+
+	    if (parm_up_cursor
+		&& SP->_cuu_cost < vcost
+		&& _nc_safe_strcat(_nc_str_copy(target, &save),
+				   TPARM_1(parm_up_cursor, n))) {
+		vcost = SP->_cuu_cost;
+	    }
+
+	    if (cursor_up && (n * SP->_cuu1_cost < vcost)) {
+		vcost = repeated_append(_nc_str_copy(target, &save), 0,
+					SP->_cuu1_cost, n, cursor_up);
+	    }
+	}
+
+	if (vcost == INFINITY)
+	    return (INFINITY);
+    }
+
+    save = *target;
+
+    if (to_x != from_x) {
+	char str[OPT_SIZE];
+	string_desc check;
+
+	hcost = INFINITY;
+
+	if (column_address
+	    && _nc_safe_strcat(_nc_str_copy(target, &save),
+			       TPARM_1(column_address, to_x))) {
+	    hcost = SP->_hpa_cost;
+	}
+
+	if (to_x > from_x) {
+	    n = to_x - from_x;
+
+	    if (parm_right_cursor
+		&& SP->_cuf_cost < hcost
+		&& _nc_safe_strcat(_nc_str_copy(target, &save),
+				   TPARM_1(parm_right_cursor, n))) {
+		hcost = SP->_cuf_cost;
+	    }
+
+	    if (cursor_right) {
+		int lhcost = 0;
+
+		(void) _nc_str_init(&check, str, sizeof(str));
+
+#if USE_HARD_TABS
+		/* use hard tabs, if we have them, to do as much as possible */
+		if (init_tabs > 0 && tab) {
+		    int nxt, fr;
+
+		    for (fr = from_x; (nxt = NEXTTAB(fr)) <= to_x; fr = nxt) {
+			lhcost = repeated_append(&check, lhcost,
+						 SP->_ht_cost, 1, tab);
+			if (lhcost == INFINITY)
+			    break;
+		    }
+
+		    n = to_x - fr;
+		    from_x = fr;
+		}
+#endif /* USE_HARD_TABS */
+
+		if (n <= 0 || n >= (int) check.s_size)
+		    ovw = FALSE;
+#if BSD_TPUTS
+		/*
+		 * If we're allowing BSD-style padding in tputs, don't generate
+		 * a string with a leading digit.  Otherwise, that will be
+		 * interpreted as a padding value rather than sent to the
+		 * screen.
+		 */
+		if (ovw
+		    && n > 0
+		    && n < (int) check.s_size
+		    && vcost == 0
+		    && str[0] == '\0') {
+		    int wanted = CharOf(WANT_CHAR(to_y, from_x));
+		    if (is8bits(wanted) && isdigit(wanted))
+			ovw = FALSE;
+		}
+#endif
+		/*
+		 * If we have no attribute changes, overwrite is cheaper.
+		 * Note: must suppress this by passing in ovw = FALSE whenever
+		 * WANT_CHAR would return invalid data.  In particular, this
+		 * is true between the time a hardware scroll has been done
+		 * and the time the structure WANT_CHAR would access has been
+		 * updated.
+		 */
+		if (ovw) {
+		    int i;
+
+		    for (i = 0; i < n; i++) {
+			NCURSES_CH_T ch = WANT_CHAR(to_y, from_x + i);
+			if (!SameAttrOf(ch, SCREEN_ATTRS(SP))
+#if USE_WIDEC_SUPPORT
+			    || !Charable(ch)
+#endif
+			    ) {
+			    ovw = FALSE;
+			    break;
+			}
+		    }
+		}
+		if (ovw) {
+		    int i;
+
+		    for (i = 0; i < n; i++)
+			*check.s_tail++ = (char) CharOf(WANT_CHAR(to_y,
+								  from_x + i));
+		    *check.s_tail = '\0';
+		    check.s_size -= n;
+		    lhcost += n * SP->_char_padding;
+		} else {
+		    lhcost = repeated_append(&check, lhcost, SP->_cuf1_cost,
+					     n, cursor_right);
+		}
+
+		if (lhcost < hcost
+		    && _nc_safe_strcat(_nc_str_copy(target, &save), str)) {
+		    hcost = lhcost;
+		}
+	    }
+	} else {		/* (to_x < from_x) */
+	    n = from_x - to_x;
+
+	    if (parm_left_cursor
+		&& SP->_cub_cost < hcost
+		&& _nc_safe_strcat(_nc_str_copy(target, &save),
+				   TPARM_1(parm_left_cursor, n))) {
+		hcost = SP->_cub_cost;
+	    }
+
+	    if (cursor_left) {
+		int lhcost = 0;
+
+		(void) _nc_str_init(&check, str, sizeof(str));
+
+#if USE_HARD_TABS
+		if (init_tabs > 0 && back_tab) {
+		    int nxt, fr;
+
+		    for (fr = from_x; (nxt = LASTTAB(fr)) >= to_x; fr = nxt) {
+			lhcost = repeated_append(&check, lhcost,
+						 SP->_cbt_cost, 1, back_tab);
+			if (lhcost == INFINITY)
+			    break;
+		    }
+
+		    n = fr - to_x;
+		}
+#endif /* USE_HARD_TABS */
+
+		lhcost = repeated_append(&check, lhcost, SP->_cub1_cost, n, cursor_left);
+
+		if (lhcost < hcost
+		    && _nc_safe_strcat(_nc_str_copy(target, &save), str)) {
+		    hcost = lhcost;
+		}
+	    }
+	}
+
+	if (hcost == INFINITY)
+	    return (INFINITY);
+    }
+
+    return (vcost + hcost);
+}
+#endif /* !NO_OPTIMIZE */
+
+/*
+ * With the machinery set up above, it's conceivable that
+ * onscreen_mvcur could be modified into a recursive function that does
+ * an alpha-beta search of motion space, as though it were a chess
+ * move tree, with the weight function being boolean and the search
+ * depth equated to length of string.  However, this would jack up the
+ * computation cost a lot, especially on terminals without a cup
+ * capability constraining the search tree depth.  So we settle for
+ * the simpler method below.
+ */
+
+static NCURSES_INLINE int
+onscreen_mvcur(int yold, int xold, int ynew, int xnew, bool ovw)
+/* onscreen move from (yold, xold) to (ynew, xnew) */
+{
+    string_desc result;
+    char buffer[OPT_SIZE];
+    int tactic = 0, newcost, usecost = INFINITY;
+    int t5_cr_cost;
+
+#if defined(MAIN) || defined(NCURSES_TEST)
+    struct timeval before, after;
+
+    gettimeofday(&before, NULL);
+#endif /* MAIN */
+
+#define NullResult _nc_str_null(&result, sizeof(buffer))
+#define InitResult _nc_str_init(&result, buffer, sizeof(buffer))
+
+    /* tactic #0: use direct cursor addressing */
+    if (_nc_safe_strcpy(InitResult, TPARM_2(SP->_address_cursor, ynew, xnew))) {
+	tactic = 0;
+	usecost = SP->_cup_cost;
+
+#if defined(TRACE) || defined(NCURSES_TEST)
+	if (!(_nc_optimize_enable & OPTIMIZE_MVCUR))
+	    goto nonlocal;
+#endif /* TRACE */
+
+	/*
+	 * We may be able to tell in advance that the full optimization
+	 * will probably not be worth its overhead.  Also, don't try to
+	 * use local movement if the current attribute is anything but
+	 * A_NORMAL...there are just too many ways this can screw up
+	 * (like, say, local-movement \n getting mapped to some obscure
+	 * character because A_ALTCHARSET is on).
+	 */
+	if (yold == -1 || xold == -1 || NOT_LOCAL(yold, xold, ynew, xnew)) {
+#if defined(MAIN) || defined(NCURSES_TEST)
+	    if (!profiling) {
+		(void) fputs("nonlocal\n", stderr);
+		goto nonlocal;	/* always run the optimizer if profiling */
+	    }
+#else
+	    goto nonlocal;
+#endif /* MAIN */
+	}
+    }
+#ifndef NO_OPTIMIZE
+    /* tactic #1: use local movement */
+    if (yold != -1 && xold != -1
+	&& ((newcost = relative_move(NullResult, yold, xold, ynew, xnew,
+				     ovw)) != INFINITY)
+	&& newcost < usecost) {
+	tactic = 1;
+	usecost = newcost;
+    }
+
+    /* tactic #2: use carriage-return + local movement */
+    if (yold != -1 && carriage_return
+	&& ((newcost = relative_move(NullResult, yold, 0, ynew, xnew, ovw))
+	    != INFINITY)
+	&& SP->_cr_cost + newcost < usecost) {
+	tactic = 2;
+	usecost = SP->_cr_cost + newcost;
+    }
+
+    /* tactic #3: use home-cursor + local movement */
+    if (cursor_home
+	&& ((newcost = relative_move(NullResult, 0, 0, ynew, xnew, ovw)) != INFINITY)
+	&& SP->_home_cost + newcost < usecost) {
+	tactic = 3;
+	usecost = SP->_home_cost + newcost;
+    }
+
+    /* tactic #4: use home-down + local movement */
+    if (cursor_to_ll
+	&& ((newcost = relative_move(NullResult, screen_lines - 1, 0, ynew,
+				     xnew, ovw)) != INFINITY)
+	&& SP->_ll_cost + newcost < usecost) {
+	tactic = 4;
+	usecost = SP->_ll_cost + newcost;
+    }
+
+    /*
+     * tactic #5: use left margin for wrap to right-hand side,
+     * unless strange wrap behavior indicated by xenl might hose us.
+     */
+    t5_cr_cost = (xold > 0 ? SP->_cr_cost : 0);
+    if (auto_left_margin && !eat_newline_glitch
+	&& yold > 0 && cursor_left
+	&& ((newcost = relative_move(NullResult, yold - 1, screen_columns -
+				     1, ynew, xnew, ovw)) != INFINITY)
+	&& t5_cr_cost + SP->_cub1_cost + newcost < usecost) {
+	tactic = 5;
+	usecost = t5_cr_cost + SP->_cub1_cost + newcost;
+    }
+
+    /*
+     * These cases are ordered by estimated relative frequency.
+     */
+    if (tactic)
+	InitResult;
+    switch (tactic) {
+    case 1:
+	(void) relative_move(&result, yold, xold, ynew, xnew, ovw);
+	break;
+    case 2:
+	(void) _nc_safe_strcpy(&result, carriage_return);
+	(void) relative_move(&result, yold, 0, ynew, xnew, ovw);
+	break;
+    case 3:
+	(void) _nc_safe_strcpy(&result, cursor_home);
+	(void) relative_move(&result, 0, 0, ynew, xnew, ovw);
+	break;
+    case 4:
+	(void) _nc_safe_strcpy(&result, cursor_to_ll);
+	(void) relative_move(&result, screen_lines - 1, 0, ynew, xnew, ovw);
+	break;
+    case 5:
+	if (xold > 0)
+	    (void) _nc_safe_strcat(&result, carriage_return);
+	(void) _nc_safe_strcat(&result, cursor_left);
+	(void) relative_move(&result, yold - 1, screen_columns - 1, ynew,
+			     xnew, ovw);
+	break;
+    }
+#endif /* !NO_OPTIMIZE */
+
+  nonlocal:
+#if defined(MAIN) || defined(NCURSES_TEST)
+    gettimeofday(&after, NULL);
+    diff = after.tv_usec - before.tv_usec
+	+ (after.tv_sec - before.tv_sec) * 1000000;
+    if (!profiling)
+	(void) fprintf(stderr,
+		       "onscreen: %d microsec, %f 28.8Kbps char-equivalents\n",
+		       (int) diff, diff / 288);
+#endif /* MAIN */
+
+    if (usecost != INFINITY) {
+	TPUTS_TRACE("mvcur");
+	tputs(buffer, 1, _nc_outch);
+	SP->_cursrow = ynew;
+	SP->_curscol = xnew;
+	return (OK);
+    } else
+	return (ERR);
+}
+
+NCURSES_EXPORT(int)
+mvcur(int yold, int xold, int ynew, int xnew)
+/* optimized cursor move from (yold, xold) to (ynew, xnew) */
+{
+    NCURSES_CH_T oldattr;
+    int code;
+
+    TR(TRACE_CALLS | TRACE_MOVE, (T_CALLED("mvcur(%d,%d,%d,%d)"),
+				  yold, xold, ynew, xnew));
+
+    if (SP == 0) {
+	code = ERR;
+    } else if (yold == ynew && xold == xnew) {
+	code = OK;
+    } else {
+
+	/*
+	 * Most work here is rounding for terminal boundaries getting the
+	 * column position implied by wraparound or the lack thereof and
+	 * rolling up the screen to get ynew on the screen.
+	 */
+	if (xnew >= screen_columns) {
+	    ynew += xnew / screen_columns;
+	    xnew %= screen_columns;
+	}
+
+	/*
+	 * Force restore even if msgr is on when we're in an alternate
+	 * character set -- these have a strong tendency to screw up the CR &
+	 * LF used for local character motions!
+	 */
+	oldattr = SCREEN_ATTRS(SP);
+	if ((AttrOf(oldattr) & A_ALTCHARSET)
+	    || (AttrOf(oldattr) && !move_standout_mode)) {
+	    TR(TRACE_CHARPUT, ("turning off (%#lx) %s before move",
+			       (unsigned long) AttrOf(oldattr),
+			       _traceattr(AttrOf(oldattr))));
+	    (void) VIDATTR(A_NORMAL, 0);
+	}
+
+	if (xold >= screen_columns) {
+	    int l;
+
+	    if (SP->_nl) {
+		l = (xold + 1) / screen_columns;
+		yold += l;
+		if (yold >= screen_lines)
+		    l -= (yold - screen_lines - 1);
+
+		if (l > 0) {
+		    if (carriage_return) {
+			TPUTS_TRACE("carriage_return");
+			putp(carriage_return);
+		    } else
+			_nc_outch('\r');
+		    xold = 0;
+
+		    while (l > 0) {
+			if (newline) {
+			    TPUTS_TRACE("newline");
+			    putp(newline);
+			} else
+			    _nc_outch('\n');
+			l--;
+		    }
+		}
+	    } else {
+		/*
+		 * If caller set nonl(), we cannot really use newlines to
+		 * position to the next row.
+		 */
+		xold = -1;
+		yold = -1;
+	    }
+	}
+
+	if (yold > screen_lines - 1)
+	    yold = screen_lines - 1;
+	if (ynew > screen_lines - 1)
+	    ynew = screen_lines - 1;
+
+	/* destination location is on screen now */
+	code = onscreen_mvcur(yold, xold, ynew, xnew, TRUE);
+
+	/*
+	 * Restore attributes if we disabled them before moving.
+	 */
+	if (!SameAttrOf(oldattr, SCREEN_ATTRS(SP))) {
+	    TR(TRACE_CHARPUT, ("turning on (%#lx) %s after move",
+			       (unsigned long) AttrOf(oldattr),
+			       _traceattr(AttrOf(oldattr))));
+	    (void) VIDATTR(AttrOf(oldattr), GetPair(oldattr));
+	}
+    }
+    returnCode(code);
+}
+
+#if defined(TRACE) || defined(NCURSES_TEST)
+NCURSES_EXPORT_VAR(int) _nc_optimize_enable = OPTIMIZE_ALL;
+#endif
+
+#if defined(MAIN) || defined(NCURSES_TEST)
+/****************************************************************************
+ *
+ * Movement optimizer test code
+ *
+ ****************************************************************************/
+
+#include <tic.h>
+#include <dump_entry.h>
+#include <time.h>
+
+NCURSES_EXPORT_VAR(const char *) _nc_progname = "mvcur";
+
+static unsigned long xmits;
+
+/* these override lib_tputs.c */
+NCURSES_EXPORT(int)
+tputs(const char *string, int affcnt GCC_UNUSED, int (*outc) (int) GCC_UNUSED)
+/* stub tputs() that dumps sequences in a visible form */
+{
+    if (profiling)
+	xmits += strlen(string);
+    else
+	(void) fputs(_nc_visbuf(string), stdout);
+    return (OK);
+}
+
+NCURSES_EXPORT(int)
+putp(const char *string)
+{
+    return (tputs(string, 1, _nc_outch));
+}
+
+NCURSES_EXPORT(int)
+_nc_outch(int ch)
+{
+    putc(ch, stdout);
+    return OK;
+}
+
+NCURSES_EXPORT(int)
+delay_output(int ms GCC_UNUSED)
+{
+    return OK;
+}
+
+static char tname[PATH_MAX];
+
+static void
+load_term(void)
+{
+    (void) setupterm(tname, STDOUT_FILENO, NULL);
+}
+
+static int
+roll(int n)
+{
+    int i, j;
+
+    i = (RAND_MAX / n) * n;
+    while ((j = rand()) >= i)
+	continue;
+    return (j % n);
+}
+
+int
+main(int argc GCC_UNUSED, char *argv[]GCC_UNUSED)
+{
+    strcpy(tname, getenv("TERM"));
+    load_term();
+    _nc_setupscreen(lines, columns, stdout, FALSE, 0);
+    baudrate();
+
+    _nc_mvcur_init();
+    NC_BUFFERED(FALSE);
+
+    (void) puts("The mvcur tester.  Type ? for help");
+
+    fputs("smcup:", stdout);
+    putchar('\n');
+
+    for (;;) {
+	int fy, fx, ty, tx, n, i;
+	char buf[BUFSIZ], capname[BUFSIZ];
+
+	(void) fputs("> ", stdout);
+	(void) fgets(buf, sizeof(buf), stdin);
+
+	if (buf[0] == '?') {
+	    (void) puts("?                -- display this help message");
+	    (void)
+		puts("fy fx ty tx      -- (4 numbers) display (fy,fx)->(ty,tx) move");
+	    (void) puts("s[croll] n t b m -- display scrolling sequence");
+	    (void)
+		printf("r[eload]         -- reload terminal info for %s\n",
+		       termname());
+	    (void)
+		puts("l[oad] <term>    -- load terminal info for type <term>");
+	    (void) puts("d[elete] <cap>   -- delete named capability");
+	    (void) puts("i[nspect]        -- display terminal capabilities");
+	    (void)
+		puts("c[ost]           -- dump cursor-optimization cost table");
+	    (void) puts("o[optimize]      -- toggle movement optimization");
+	    (void)
+		puts("t[orture] <num>  -- torture-test with <num> random moves");
+	    (void) puts("q[uit]           -- quit the program");
+	} else if (sscanf(buf, "%d %d %d %d", &fy, &fx, &ty, &tx) == 4) {
+	    struct timeval before, after;
+
+	    putchar('"');
+
+	    gettimeofday(&before, NULL);
+	    mvcur(fy, fx, ty, tx);
+	    gettimeofday(&after, NULL);
+
+	    printf("\" (%ld msec)\n",
+		   (long) (after.tv_usec - before.tv_usec
+			   + (after.tv_sec - before.tv_sec)
+			   * 1000000));
+	} else if (sscanf(buf, "s %d %d %d %d", &fy, &fx, &ty, &tx) == 4) {
+	    struct timeval before, after;
+
+	    putchar('"');
+
+	    gettimeofday(&before, NULL);
+	    _nc_scrolln(fy, fx, ty, tx);
+	    gettimeofday(&after, NULL);
+
+	    printf("\" (%ld msec)\n",
+		   (long) (after.tv_usec - before.tv_usec + (after.tv_sec -
+							     before.tv_sec)
+			   * 1000000));
+	} else if (buf[0] == 'r') {
+	    (void) strcpy(tname, termname());
+	    load_term();
+	} else if (sscanf(buf, "l %s", tname) == 1) {
+	    load_term();
+	} else if (sscanf(buf, "d %s", capname) == 1) {
+	    struct name_table_entry const *np = _nc_find_entry(capname,
+							       _nc_get_hash_table(FALSE));
+
+	    if (np == NULL)
+		(void) printf("No such capability as \"%s\"\n", capname);
+	    else {
+		switch (np->nte_type) {
+		case BOOLEAN:
+		    cur_term->type.Booleans[np->nte_index] = FALSE;
+		    (void)
+			printf("Boolean capability `%s' (%d) turned off.\n",
+			       np->nte_name, np->nte_index);
+		    break;
+
+		case NUMBER:
+		    cur_term->type.Numbers[np->nte_index] = ABSENT_NUMERIC;
+		    (void) printf("Number capability `%s' (%d) set to -1.\n",
+				  np->nte_name, np->nte_index);
+		    break;
+
+		case STRING:
+		    cur_term->type.Strings[np->nte_index] = ABSENT_STRING;
+		    (void) printf("String capability `%s' (%d) deleted.\n",
+				  np->nte_name, np->nte_index);
+		    break;
+		}
+	    }
+	} else if (buf[0] == 'i') {
+	    dump_init((char *) NULL, F_TERMINFO, S_TERMINFO, 70, 0, FALSE);
+	    dump_entry(&cur_term->type, FALSE, TRUE, 0, 0);
+	    putchar('\n');
+	} else if (buf[0] == 'o') {
+	    if (_nc_optimize_enable & OPTIMIZE_MVCUR) {
+		_nc_optimize_enable &= ~OPTIMIZE_MVCUR;
+		(void) puts("Optimization is now off.");
+	    } else {
+		_nc_optimize_enable |= OPTIMIZE_MVCUR;
+		(void) puts("Optimization is now on.");
+	    }
+	}
+	/*
+	 * You can use the `t' test to profile and tune the movement
+	 * optimizer.  Use iteration values in three digits or more.
+	 * At above 5000 iterations the profile timing averages are stable
+	 * to within a millisecond or three.
+	 *
+	 * The `overhead' field of the report will help you pick a
+	 * COMPUTE_OVERHEAD figure appropriate for your processor and
+	 * expected line speed.  The `total estimated time' is
+	 * computation time plus a character-transmission time
+	 * estimate computed from the number of transmits and the baud
+	 * rate.
+	 *
+	 * Use this together with the `o' command to get a read on the
+	 * optimizer's effectiveness.  Compare the total estimated times
+	 * for `t' runs of the same length in both optimized and un-optimized
+	 * modes.  As long as the optimized times are less, the optimizer
+	 * is winning.
+	 */
+	else if (sscanf(buf, "t %d", &n) == 1) {
+	    float cumtime = 0.0, perchar;
+	    int speeds[] =
+	    {2400, 9600, 14400, 19200, 28800, 38400, 0};
+
+	    srand((unsigned) (getpid() + time((time_t *) 0)));
+	    profiling = TRUE;
+	    xmits = 0;
+	    for (i = 0; i < n; i++) {
+		/*
+		 * This does a move test between two random locations,
+		 * Random moves probably short-change the optimizer,
+		 * which will work better on the short moves probably
+		 * typical of doupdate()'s usage pattern.  Still,
+		 * until we have better data...
+		 */
+#ifdef FIND_COREDUMP
+		int from_y = roll(lines);
+		int to_y = roll(lines);
+		int from_x = roll(columns);
+		int to_x = roll(columns);
+
+		printf("(%d,%d) -> (%d,%d)\n", from_y, from_x, to_y, to_x);
+		mvcur(from_y, from_x, to_y, to_x);
+#else
+		mvcur(roll(lines), roll(columns), roll(lines), roll(columns));
+#endif /* FIND_COREDUMP */
+		if (diff)
+		    cumtime += diff;
+	    }
+	    profiling = FALSE;
+
+	    /*
+	     * Average milliseconds per character optimization time.
+	     * This is the key figure to watch when tuning the optimizer.
+	     */
+	    perchar = cumtime / n;
+
+	    (void) printf("%d moves (%ld chars) in %d msec, %f msec each:\n",
+			  n, xmits, (int) cumtime, perchar);
+
+	    for (i = 0; speeds[i]; i++) {
+		/*
+		 * Total estimated time for the moves, computation and
+		 * transmission both. Transmission time is an estimate
+		 * assuming 9 bits/char, 8 bits + 1 stop bit.
+		 */
+		float totalest = cumtime + xmits * 9 * 1e6 / speeds[i];
+
+		/*
+		 * Per-character optimization overhead in character transmits
+		 * at the current speed.  Round this to the nearest integer
+		 * to figure COMPUTE_OVERHEAD for the speed.
+		 */
+		float overhead = speeds[i] * perchar / 1e6;
+
+		(void)
+		    printf("%6d bps: %3.2f char-xmits overhead; total estimated time %15.2f\n",
+			   speeds[i], overhead, totalest);
+	    }
+	} else if (buf[0] == 'c') {
+	    (void) printf("char padding: %d\n", SP->_char_padding);
+	    (void) printf("cr cost: %d\n", SP->_cr_cost);
+	    (void) printf("cup cost: %d\n", SP->_cup_cost);
+	    (void) printf("home cost: %d\n", SP->_home_cost);
+	    (void) printf("ll cost: %d\n", SP->_ll_cost);
+#if USE_HARD_TABS
+	    (void) printf("ht cost: %d\n", SP->_ht_cost);
+	    (void) printf("cbt cost: %d\n", SP->_cbt_cost);
+#endif /* USE_HARD_TABS */
+	    (void) printf("cub1 cost: %d\n", SP->_cub1_cost);
+	    (void) printf("cuf1 cost: %d\n", SP->_cuf1_cost);
+	    (void) printf("cud1 cost: %d\n", SP->_cud1_cost);
+	    (void) printf("cuu1 cost: %d\n", SP->_cuu1_cost);
+	    (void) printf("cub cost: %d\n", SP->_cub_cost);
+	    (void) printf("cuf cost: %d\n", SP->_cuf_cost);
+	    (void) printf("cud cost: %d\n", SP->_cud_cost);
+	    (void) printf("cuu cost: %d\n", SP->_cuu_cost);
+	    (void) printf("hpa cost: %d\n", SP->_hpa_cost);
+	    (void) printf("vpa cost: %d\n", SP->_vpa_cost);
+	} else if (buf[0] == 'x' || buf[0] == 'q')
+	    break;
+	else
+	    (void) puts("Invalid command.");
+    }
+
+    (void) fputs("rmcup:", stdout);
+    _nc_mvcur_wrap();
+    putchar('\n');
+
+    return (0);
+}
+
+#endif /* MAIN */
+
+/* lib_mvcur.c ends here */