Rename catsh to 1sh

Yes it's another rename because I felt like catsh was too long. 1sh is
short and unique.

1 files changed, 1219 insertions, 0 deletions

diff --git a/bin/1sh/libedit/refresh.c b/bin/1sh/libedit/refresh.c
new file mode 100644
index 00000000..37c6041d
--- /dev/null
+++ b/bin/1sh/libedit/refresh.c
@@ -0,0 +1,1219 @@
+/*	$NetBSD: refresh.c,v 1.51.8.1 2017/07/23 14:41:26 snj Exp $	*/
+
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Christos Zoulas of Cornell University.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "config.h"
+#if !defined(lint) && !defined(SCCSID)
+#if 0
+static char sccsid[] = "@(#)refresh.c	8.1 (Berkeley) 6/4/93";
+#else
+__RCSID("$NetBSD: refresh.c,v 1.51.8.1 2017/07/23 14:41:26 snj Exp $");
+#endif
+#endif /* not lint && not SCCSID */
+
+/*
+ * refresh.c: Lower level screen refreshing functions
+ */
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "el.h"
+
+static void	re_nextline(EditLine *);
+static void	re_addc(EditLine *, wint_t);
+static void	re_update_line(EditLine *, wchar_t *, wchar_t *, int);
+static void	re_insert (EditLine *, wchar_t *, int, int, wchar_t *, int);
+static void	re_delete(EditLine *, wchar_t *, int, int, int);
+static void	re_fastputc(EditLine *, wint_t);
+static void	re_clear_eol(EditLine *, int, int, int);
+static void	re__strncopy(wchar_t *, wchar_t *, size_t);
+static void	re__copy_and_pad(wchar_t *, const wchar_t *, size_t);
+
+#ifdef DEBUG_REFRESH
+static void	re_printstr(EditLine *, const char *, wchar_t *, wchar_t *);
+#define	__F el->el_errfile
+#define	ELRE_ASSERT(a, b, c)	do				\
+				    if (/*CONSTCOND*/ a) {	\
+					(void) fprintf b;	\
+					c;			\
+				    }				\
+				while (/*CONSTCOND*/0)
+#define	ELRE_DEBUG(a, b)	ELRE_ASSERT(a,b,;)
+
+/* re_printstr():
+ *	Print a string on the debugging pty
+ */
+static void
+re_printstr(EditLine *el, const char *str, wchar_t *f, wchar_t *t)
+{
+
+	ELRE_DEBUG(1, (__F, "%s:\"", str));
+	while (f < t)
+		ELRE_DEBUG(1, (__F, "%c", *f++ & 0177));
+	ELRE_DEBUG(1, (__F, "\"\r\n"));
+}
+#else
+#define	ELRE_ASSERT(a, b, c)
+#define	ELRE_DEBUG(a, b)
+#endif
+
+/* re_nextline():
+ *	Move to the next line or scroll
+ */
+static void
+re_nextline(EditLine *el)
+{
+	el->el_refresh.r_cursor.h = 0;	/* reset it. */
+
+	/*
+	 * If we would overflow (input is longer than terminal size),
+	 * emulate scroll by dropping first line and shuffling the rest.
+	 * We do this via pointer shuffling - it's safe in this case
+	 * and we avoid memcpy().
+	 */
+	if (el->el_refresh.r_cursor.v + 1 >= el->el_terminal.t_size.v) {
+		int i, lins = el->el_terminal.t_size.v;
+		wchar_t *firstline = el->el_vdisplay[0];
+
+		for(i = 1; i < lins; i++)
+			el->el_vdisplay[i - 1] = el->el_vdisplay[i];
+
+		firstline[0] = '\0';		/* empty the string */
+		el->el_vdisplay[i - 1] = firstline;
+	} else
+		el->el_refresh.r_cursor.v++;
+
+	ELRE_ASSERT(el->el_refresh.r_cursor.v >= el->el_terminal.t_size.v,
+	    (__F, "\r\nre_putc: overflow! r_cursor.v == %d > %d\r\n",
+	    el->el_refresh.r_cursor.v, el->el_terminal.t_size.v),
+	    abort());
+}
+
+/* re_addc():
+ *	Draw c, expanding tabs, control chars etc.
+ */
+static void
+re_addc(EditLine *el, wint_t c)
+{
+	switch (ct_chr_class(c)) {
+	case CHTYPE_TAB:        /* expand the tab */
+		for (;;) {
+			re_putc(el, ' ', 1);
+			if ((el->el_refresh.r_cursor.h & 07) == 0)
+				break;			/* go until tab stop */
+		}
+		break;
+	case CHTYPE_NL: {
+		int oldv = el->el_refresh.r_cursor.v;
+		re_putc(el, '\0', 0);			/* assure end of line */
+		if (oldv == el->el_refresh.r_cursor.v)	/* XXX */
+			re_nextline(el);
+		break;
+	}
+	case CHTYPE_PRINT:
+		re_putc(el, c, 1);
+		break;
+	default: {
+		wchar_t visbuf[VISUAL_WIDTH_MAX];
+		ssize_t i, n =
+		    ct_visual_char(visbuf, VISUAL_WIDTH_MAX, c);
+		for (i = 0; n-- > 0; ++i)
+		    re_putc(el, visbuf[i], 1);
+		break;
+	}
+	}
+}
+
+/* re_putliteral():
+ *	Place the literal string given
+ */
+libedit_private void
+re_putliteral(EditLine *el, const wchar_t *begin, const wchar_t *end)
+{
+	coord_t *cur = &el->el_refresh.r_cursor;
+	wint_t c;
+	int sizeh = el->el_terminal.t_size.h;
+	int i, w;
+
+	c = literal_add(el, begin, end, &w);
+	if (c == 0 || w <= 0)
+		return;
+	el->el_vdisplay[cur->v][cur->h] = c;
+
+	i = w;
+	if (i > sizeh - cur->h)		/* avoid overflow */
+		i = sizeh - cur->h;
+	while (--i > 0)
+		el->el_vdisplay[cur->v][cur->h + i] = MB_FILL_CHAR;
+
+	cur->h += w;
+	if (cur->h >= sizeh) {
+		/* assure end of line */
+		el->el_vdisplay[cur->v][sizeh] = '\0';
+		re_nextline(el);
+	}
+}
+
+/* re_putc():
+ *	Draw the character given
+ */
+libedit_private void
+re_putc(EditLine *el, wint_t c, int shift)
+{
+	coord_t *cur = &el->el_refresh.r_cursor;
+	int i, w = wcwidth(c);
+	int sizeh = el->el_terminal.t_size.h;
+
+	ELRE_DEBUG(1, (__F, "printing %5x '%lc'\r\n", c, c));
+	if (w == -1)
+		w = 0;
+
+	while (shift && (cur->h + w > sizeh))
+	    re_putc(el, ' ', 1);
+
+	el->el_vdisplay[cur->v][cur->h] = c;
+	/* assumes !shift is only used for single-column chars */
+	i = w;
+	while (--i > 0)
+		el->el_vdisplay[cur->v][cur->h + i] = MB_FILL_CHAR;
+
+	if (!shift)
+		return;
+
+	cur->h += w;	/* advance to next place */
+	if (cur->h >= sizeh) {
+		/* assure end of line */
+		el->el_vdisplay[cur->v][sizeh] = '\0';
+		re_nextline(el);
+	}
+}
+
+
+/* re_refresh():
+ *	draws the new virtual screen image from the current input
+ *	line, then goes line-by-line changing the real image to the new
+ *	virtual image. The routine to re-draw a line can be replaced
+ *	easily in hopes of a smarter one being placed there.
+ */
+libedit_private void
+re_refresh(EditLine *el)
+{
+	int i, rhdiff;
+	wchar_t *cp, *st;
+	coord_t cur;
+#ifdef notyet
+	size_t termsz;
+#endif
+
+	ELRE_DEBUG(1, (__F, "el->el_line.buffer = :%ls:\r\n",
+	    el->el_line.buffer));
+
+	literal_clear(el);
+	/* reset the Drawing cursor */
+	el->el_refresh.r_cursor.h = 0;
+	el->el_refresh.r_cursor.v = 0;
+
+	terminal_move_to_char(el, 0);
+
+	/* temporarily draw rprompt to calculate its size */
+	prompt_print(el, EL_RPROMPT);
+
+	/* reset the Drawing cursor */
+	el->el_refresh.r_cursor.h = 0;
+	el->el_refresh.r_cursor.v = 0;
+
+	if (el->el_line.cursor >= el->el_line.lastchar) {
+		if (el->el_map.current == el->el_map.alt
+		    && el->el_line.lastchar != el->el_line.buffer)
+			el->el_line.cursor = el->el_line.lastchar - 1;
+		else
+			el->el_line.cursor = el->el_line.lastchar;
+	}
+
+	cur.h = -1;		/* set flag in case I'm not set */
+	cur.v = 0;
+
+	prompt_print(el, EL_PROMPT);
+
+	/* draw the current input buffer */
+#if notyet
+	termsz = el->el_terminal.t_size.h * el->el_terminal.t_size.v;
+	if (el->el_line.lastchar - el->el_line.buffer > termsz) {
+		/*
+		 * If line is longer than terminal, process only part
+		 * of line which would influence display.
+		 */
+		size_t rem = (el->el_line.lastchar-el->el_line.buffer)%termsz;
+
+		st = el->el_line.lastchar - rem
+			- (termsz - (((rem / el->el_terminal.t_size.v) - 1)
+					* el->el_terminal.t_size.v));
+	} else
+#endif
+		st = el->el_line.buffer;
+
+	for (cp = st; cp < el->el_line.lastchar; cp++) {
+		if (cp == el->el_line.cursor) {
+                        int w = wcwidth(*cp);
+			/* save for later */
+			cur.h = el->el_refresh.r_cursor.h;
+			cur.v = el->el_refresh.r_cursor.v;
+                        /* handle being at a linebroken doublewidth char */
+                        if (w > 1 && el->el_refresh.r_cursor.h + w >
+			    el->el_terminal.t_size.h) {
+				cur.h = 0;
+				cur.v++;
+                        }
+		}
+		re_addc(el, *cp);
+	}
+
+	if (cur.h == -1) {	/* if I haven't been set yet, I'm at the end */
+		cur.h = el->el_refresh.r_cursor.h;
+		cur.v = el->el_refresh.r_cursor.v;
+	}
+	rhdiff = el->el_terminal.t_size.h - el->el_refresh.r_cursor.h -
+	    el->el_rprompt.p_pos.h;
+	if (el->el_rprompt.p_pos.h && !el->el_rprompt.p_pos.v &&
+	    !el->el_refresh.r_cursor.v && rhdiff > 1) {
+		/*
+		 * have a right-hand side prompt that will fit
+		 * on the end of the first line with at least
+		 * one character gap to the input buffer.
+		 */
+		while (--rhdiff > 0)	/* pad out with spaces */
+			re_putc(el, ' ', 1);
+		prompt_print(el, EL_RPROMPT);
+	} else {
+		el->el_rprompt.p_pos.h = 0;	/* flag "not using rprompt" */
+		el->el_rprompt.p_pos.v = 0;
+	}
+
+	re_putc(el, '\0', 0);	/* make line ended with NUL, no cursor shift */
+
+	el->el_refresh.r_newcv = el->el_refresh.r_cursor.v;
+
+	ELRE_DEBUG(1, (__F,
+		"term.h=%d vcur.h=%d vcur.v=%d vdisplay[0]=\r\n:%80.80s:\r\n",
+		el->el_terminal.t_size.h, el->el_refresh.r_cursor.h,
+		el->el_refresh.r_cursor.v, ct_encode_string(el->el_vdisplay[0],
+		&el->el_scratch)));
+
+	ELRE_DEBUG(1, (__F, "updating %d lines.\r\n", el->el_refresh.r_newcv));
+	for (i = 0; i <= el->el_refresh.r_newcv; i++) {
+		/* NOTE THAT re_update_line MAY CHANGE el_display[i] */
+		re_update_line(el, el->el_display[i], el->el_vdisplay[i], i);
+
+		/*
+		 * Copy the new line to be the current one, and pad out with
+		 * spaces to the full width of the terminal so that if we try
+		 * moving the cursor by writing the character that is at the
+		 * end of the screen line, it won't be a NUL or some old
+		 * leftover stuff.
+		 */
+		re__copy_and_pad(el->el_display[i], el->el_vdisplay[i],
+		    (size_t) el->el_terminal.t_size.h);
+	}
+	ELRE_DEBUG(1, (__F,
+	"\r\nel->el_refresh.r_cursor.v=%d,el->el_refresh.r_oldcv=%d i=%d\r\n",
+	    el->el_refresh.r_cursor.v, el->el_refresh.r_oldcv, i));
+
+	if (el->el_refresh.r_oldcv > el->el_refresh.r_newcv)
+		for (; i <= el->el_refresh.r_oldcv; i++) {
+			terminal_move_to_line(el, i);
+			terminal_move_to_char(el, 0);
+                        /* This wcslen should be safe even with MB_FILL_CHARs */
+			terminal_clear_EOL(el, (int) wcslen(el->el_display[i]));
+#ifdef DEBUG_REFRESH
+			terminal_overwrite(el, L"C\b", 2);
+#endif /* DEBUG_REFRESH */
+			el->el_display[i][0] = '\0';
+		}
+
+	el->el_refresh.r_oldcv = el->el_refresh.r_newcv; /* set for next time */
+	ELRE_DEBUG(1, (__F,
+	    "\r\ncursor.h = %d, cursor.v = %d, cur.h = %d, cur.v = %d\r\n",
+	    el->el_refresh.r_cursor.h, el->el_refresh.r_cursor.v,
+	    cur.h, cur.v));
+	terminal_move_to_line(el, cur.v);	/* go to where the cursor is */
+	terminal_move_to_char(el, cur.h);
+}
+
+
+/* re_goto_bottom():
+ *	 used to go to last used screen line
+ */
+libedit_private void
+re_goto_bottom(EditLine *el)
+{
+
+	terminal_move_to_line(el, el->el_refresh.r_oldcv);
+	terminal__putc(el, '\n');
+	re_clear_display(el);
+	terminal__flush(el);
+}
+
+
+/* re_insert():
+ *	insert num characters of s into d (in front of the character)
+ *	at dat, maximum length of d is dlen
+ */
+static void
+/*ARGSUSED*/
+re_insert(EditLine *el __attribute__((__unused__)),
+    wchar_t *d, int dat, int dlen, wchar_t *s, int num)
+{
+	wchar_t *a, *b;
+
+	if (num <= 0)
+		return;
+	if (num > dlen - dat)
+		num = dlen - dat;
+
+	ELRE_DEBUG(1,
+	    (__F, "re_insert() starting: %d at %d max %d, d == \"%s\"\n",
+	    num, dat, dlen, ct_encode_string(d, &el->el_scratch)));
+	ELRE_DEBUG(1, (__F, "s == \"%s\"\n", ct_encode_string(s,
+	    &el->el_scratch)));
+
+	/* open up the space for num chars */
+	if (num > 0) {
+		b = d + dlen - 1;
+		a = b - num;
+		while (a >= &d[dat])
+			*b-- = *a--;
+		d[dlen] = '\0';	/* just in case */
+	}
+
+	ELRE_DEBUG(1, (__F,
+		"re_insert() after insert: %d at %d max %d, d == \"%s\"\n",
+		num, dat, dlen, ct_encode_string(d, &el->el_scratch)));
+	ELRE_DEBUG(1, (__F, "s == \"%s\"\n", ct_encode_string(s,
+		&el->el_scratch)));
+
+	/* copy the characters */
+	for (a = d + dat; (a < d + dlen) && (num > 0); num--)
+		*a++ = *s++;
+
+#ifdef notyet
+        /* ct_encode_string() uses a static buffer, so we can't conveniently
+         * encode both d & s here */
+	ELRE_DEBUG(1,
+	    (__F, "re_insert() after copy: %d at %d max %d, %s == \"%s\"\n",
+	    num, dat, dlen, d, s));
+	ELRE_DEBUG(1, (__F, "s == \"%s\"\n", s));
+#endif
+}
+
+
+/* re_delete():
+ *	delete num characters d at dat, maximum length of d is dlen
+ */
+static void
+/*ARGSUSED*/
+re_delete(EditLine *el __attribute__((__unused__)),
+    wchar_t *d, int dat, int dlen, int num)
+{
+	wchar_t *a, *b;
+
+	if (num <= 0)
+		return;
+	if (dat + num >= dlen) {
+		d[dat] = '\0';
+		return;
+	}
+	ELRE_DEBUG(1,
+	    (__F, "re_delete() starting: %d at %d max %d, d == \"%s\"\n",
+	    num, dat, dlen, ct_encode_string(d, &el->el_scratch)));
+
+	/* open up the space for num chars */
+	if (num > 0) {
+		b = d + dat;
+		a = b + num;
+		while (a < &d[dlen])
+			*b++ = *a++;
+		d[dlen] = '\0';	/* just in case */
+	}
+	ELRE_DEBUG(1,
+	    (__F, "re_delete() after delete: %d at %d max %d, d == \"%s\"\n",
+	    num, dat, dlen, ct_encode_string(d, &el->el_scratch)));
+}
+
+
+/* re__strncopy():
+ *	Like strncpy without padding.
+ */
+static void
+re__strncopy(wchar_t *a, wchar_t *b, size_t n)
+{
+
+	while (n-- && *b)
+		*a++ = *b++;
+}
+
+/* re_clear_eol():
+ *	Find the number of characters we need to clear till the end of line
+ *	in order to make sure that we have cleared the previous contents of
+ *	the line. fx and sx is the number of characters inserted or deleted
+ *	in the first or second diff, diff is the difference between the
+ *	number of characters between the new and old line.
+ */
+static void
+re_clear_eol(EditLine *el, int fx, int sx, int diff)
+{
+
+	ELRE_DEBUG(1, (__F, "re_clear_eol sx %d, fx %d, diff %d\n",
+	    sx, fx, diff));
+
+	if (fx < 0)
+		fx = -fx;
+	if (sx < 0)
+		sx = -sx;
+	if (fx > diff)
+		diff = fx;
+	if (sx > diff)
+		diff = sx;
+
+	ELRE_DEBUG(1, (__F, "re_clear_eol %d\n", diff));
+	terminal_clear_EOL(el, diff);
+}
+
+/*****************************************************************
+    re_update_line() is based on finding the middle difference of each line
+    on the screen; vis:
+
+			     /old first difference
+	/beginning of line   |              /old last same       /old EOL
+	v		     v              v                    v
+old:	eddie> Oh, my little gruntle-buggy is to me, as lurgid as
+new:	eddie> Oh, my little buggy says to me, as lurgid as
+	^		     ^        ^			   ^
+	\beginning of line   |        \new last same	   \new end of line
+			     \new first difference
+
+    all are character pointers for the sake of speed.  Special cases for
+    no differences, as well as for end of line additions must be handled.
+**************************************************************** */
+
+/* Minimum at which doing an insert it "worth it".  This should be about
+ * half the "cost" of going into insert mode, inserting a character, and
+ * going back out.  This should really be calculated from the termcap
+ * data...  For the moment, a good number for ANSI terminals.
+ */
+#define	MIN_END_KEEP	4
+
+static void
+re_update_line(EditLine *el, wchar_t *old, wchar_t *new, int i)
+{
+	wchar_t *o, *n, *p, c;
+	wchar_t *ofd, *ols, *oe, *nfd, *nls, *ne;
+	wchar_t *osb, *ose, *nsb, *nse;
+	int fx, sx;
+	size_t len;
+
+	/*
+         * find first diff
+         */
+	for (o = old, n = new; *o && (*o == *n); o++, n++)
+		continue;
+	ofd = o;
+	nfd = n;
+
+	/*
+         * Find the end of both old and new
+         */
+	while (*o)
+		o++;
+	/*
+         * Remove any trailing blanks off of the end, being careful not to
+         * back up past the beginning.
+         */
+	while (ofd < o) {
+		if (o[-1] != ' ')
+			break;
+		o--;
+	}
+	oe = o;
+	*oe = '\0';
+
+	while (*n)
+		n++;
+
+	/* remove blanks from end of new */
+	while (nfd < n) {
+		if (n[-1] != ' ')
+			break;
+		n--;
+	}
+	ne = n;
+	*ne = '\0';
+
+	/*
+         * if no diff, continue to next line of redraw
+         */
+	if (*ofd == '\0' && *nfd == '\0') {
+		ELRE_DEBUG(1, (__F, "no difference.\r\n"));
+		return;
+	}
+	/*
+         * find last same pointer
+         */
+	while ((o > ofd) && (n > nfd) && (*--o == *--n))
+		continue;
+	ols = ++o;
+	nls = ++n;
+
+	/*
+         * find same beginning and same end
+         */
+	osb = ols;
+	nsb = nls;
+	ose = ols;
+	nse = nls;
+
+	/*
+         * case 1: insert: scan from nfd to nls looking for *ofd
+         */
+	if (*ofd) {
+		for (c = *ofd, n = nfd; n < nls; n++) {
+			if (c == *n) {
+				for (o = ofd, p = n;
+				    p < nls && o < ols && *o == *p;
+				    o++, p++)
+					continue;
+				/*
+				 * if the new match is longer and it's worth
+				 * keeping, then we take it
+				 */
+				if (((nse - nsb) < (p - n)) &&
+				    (2 * (p - n) > n - nfd)) {
+					nsb = n;
+					nse = p;
+					osb = ofd;
+					ose = o;
+				}
+			}
+		}
+	}
+	/*
+         * case 2: delete: scan from ofd to ols looking for *nfd
+         */
+	if (*nfd) {
+		for (c = *nfd, o = ofd; o < ols; o++) {
+			if (c == *o) {
+				for (n = nfd, p = o;
+				    p < ols && n < nls && *p == *n;
+				    p++, n++)
+					continue;
+				/*
+				 * if the new match is longer and it's worth
+				 * keeping, then we take it
+				 */
+				if (((ose - osb) < (p - o)) &&
+				    (2 * (p - o) > o - ofd)) {
+					nsb = nfd;
+					nse = n;
+					osb = o;
+					ose = p;
+				}
+			}
+		}
+	}
+	/*
+         * Pragmatics I: If old trailing whitespace or not enough characters to
+         * save to be worth it, then don't save the last same info.
+         */
+	if ((oe - ols) < MIN_END_KEEP) {
+		ols = oe;
+		nls = ne;
+	}
+	/*
+         * Pragmatics II: if the terminal isn't smart enough, make the data
+         * dumber so the smart update doesn't try anything fancy
+         */
+
+	/*
+         * fx is the number of characters we need to insert/delete: in the
+         * beginning to bring the two same begins together
+         */
+	fx = (int)((nsb - nfd) - (osb - ofd));
+	/*
+         * sx is the number of characters we need to insert/delete: in the
+         * end to bring the two same last parts together
+         */
+	sx = (int)((nls - nse) - (ols - ose));
+
+	if (!EL_CAN_INSERT) {
+		if (fx > 0) {
+			osb = ols;
+			ose = ols;
+			nsb = nls;
+			nse = nls;
+		}
+		if (sx > 0) {
+			ols = oe;
+			nls = ne;
+		}
+		if ((ols - ofd) < (nls - nfd)) {
+			ols = oe;
+			nls = ne;
+		}
+	}
+	if (!EL_CAN_DELETE) {
+		if (fx < 0) {
+			osb = ols;
+			ose = ols;
+			nsb = nls;
+			nse = nls;
+		}
+		if (sx < 0) {
+			ols = oe;
+			nls = ne;
+		}
+		if ((ols - ofd) > (nls - nfd)) {
+			ols = oe;
+			nls = ne;
+		}
+	}
+	/*
+         * Pragmatics III: make sure the middle shifted pointers are correct if
+         * they don't point to anything (we may have moved ols or nls).
+         */
+	/* if the change isn't worth it, don't bother */
+	/* was: if (osb == ose) */
+	if ((ose - osb) < MIN_END_KEEP) {
+		osb = ols;
+		ose = ols;
+		nsb = nls;
+		nse = nls;
+	}
+	/*
+         * Now that we are done with pragmatics we recompute fx, sx
+         */
+	fx = (int)((nsb - nfd) - (osb - ofd));
+	sx = (int)((nls - nse) - (ols - ose));
+
+	ELRE_DEBUG(1, (__F, "fx %d, sx %d\n", fx, sx));
+	ELRE_DEBUG(1, (__F, "ofd %td, osb %td, ose %td, ols %td, oe %td\n",
+		ofd - old, osb - old, ose - old, ols - old, oe - old));
+	ELRE_DEBUG(1, (__F, "nfd %td, nsb %td, nse %td, nls %td, ne %td\n",
+		nfd - new, nsb - new, nse - new, nls - new, ne - new));
+	ELRE_DEBUG(1, (__F,
+		"xxx-xxx:\"00000000001111111111222222222233333333334\"\r\n"));
+	ELRE_DEBUG(1, (__F,
+		"xxx-xxx:\"01234567890123456789012345678901234567890\"\r\n"));
+#ifdef DEBUG_REFRESH
+	re_printstr(el, "old- oe", old, oe);
+	re_printstr(el, "new- ne", new, ne);
+	re_printstr(el, "old-ofd", old, ofd);
+	re_printstr(el, "new-nfd", new, nfd);
+	re_printstr(el, "ofd-osb", ofd, osb);
+	re_printstr(el, "nfd-nsb", nfd, nsb);
+	re_printstr(el, "osb-ose", osb, ose);
+	re_printstr(el, "nsb-nse", nsb, nse);
+	re_printstr(el, "ose-ols", ose, ols);
+	re_printstr(el, "nse-nls", nse, nls);
+	re_printstr(el, "ols- oe", ols, oe);
+	re_printstr(el, "nls- ne", nls, ne);
+#endif /* DEBUG_REFRESH */
+
+	/*
+         * el_cursor.v to this line i MUST be in this routine so that if we
+         * don't have to change the line, we don't move to it. el_cursor.h to
+         * first diff char
+         */
+	terminal_move_to_line(el, i);
+
+	/*
+         * at this point we have something like this:
+         *
+         * /old                  /ofd    /osb               /ose    /ols     /oe
+         * v.....................v       v..................v       v........v
+         * eddie> Oh, my fredded gruntle-buggy is to me, as foo var lurgid as
+         * eddie> Oh, my fredded quiux buggy is to me, as gruntle-lurgid as
+         * ^.....................^     ^..................^       ^........^
+         * \new                  \nfd  \nsb               \nse     \nls    \ne
+         *
+         * fx is the difference in length between the chars between nfd and
+         * nsb, and the chars between ofd and osb, and is thus the number of
+         * characters to delete if < 0 (new is shorter than old, as above),
+         * or insert (new is longer than short).
+         *
+         * sx is the same for the second differences.
+         */
+
+	/*
+         * if we have a net insert on the first difference, AND inserting the
+         * net amount ((nsb-nfd) - (osb-ofd)) won't push the last useful
+         * character (which is ne if nls != ne, otherwise is nse) off the edge
+	 * of the screen (el->el_terminal.t_size.h) else we do the deletes first
+	 * so that we keep everything we need to.
+         */
+
+	/*
+         * if the last same is the same like the end, there is no last same
+         * part, otherwise we want to keep the last same part set p to the
+         * last useful old character
+         */
+	p = (ols != oe) ? oe : ose;
+
+	/*
+         * if (There is a diffence in the beginning) && (we need to insert
+         *   characters) && (the number of characters to insert is less than
+         *   the term width)
+	 *	We need to do an insert!
+	 * else if (we need to delete characters)
+	 *	We need to delete characters!
+	 * else
+	 *	No insert or delete
+         */
+	if ((nsb != nfd) && fx > 0 &&
+	    ((p - old) + fx <= el->el_terminal.t_size.h)) {
+		ELRE_DEBUG(1,
+		    (__F, "first diff insert at %td...\r\n", nfd - new));
+		/*
+		 * Move to the first char to insert, where the first diff is.
+		 */
+		terminal_move_to_char(el, (int)(nfd - new));
+		/*
+		 * Check if we have stuff to keep at end
+		 */
+		if (nsb != ne) {
+			ELRE_DEBUG(1, (__F, "with stuff to keep at end\r\n"));
+			/*
+		         * insert fx chars of new starting at nfd
+		         */
+			if (fx > 0) {
+				ELRE_DEBUG(!EL_CAN_INSERT, (__F,
+				"ERROR: cannot insert in early first diff\n"));
+				terminal_insertwrite(el, nfd, fx);
+				re_insert(el, old, (int)(ofd - old),
+				    el->el_terminal.t_size.h, nfd, fx);
+			}
+			/*
+		         * write (nsb-nfd) - fx chars of new starting at
+		         * (nfd + fx)
+			 */
+			len = (size_t) ((nsb - nfd) - fx);
+			terminal_overwrite(el, (nfd + fx), len);
+			re__strncopy(ofd + fx, nfd + fx, len);
+		} else {
+			ELRE_DEBUG(1, (__F, "without anything to save\r\n"));
+			len = (size_t)(nsb - nfd);
+			terminal_overwrite(el, nfd, len);
+			re__strncopy(ofd, nfd, len);
+			/*
+		         * Done
+		         */
+			return;
+		}
+	} else if (fx < 0) {
+		ELRE_DEBUG(1,
+		    (__F, "first diff delete at %td...\r\n", ofd - old));
+		/*
+		 * move to the first char to delete where the first diff is
+		 */
+		terminal_move_to_char(el, (int)(ofd - old));
+		/*
+		 * Check if we have stuff to save
+		 */
+		if (osb != oe) {
+			ELRE_DEBUG(1, (__F, "with stuff to save at end\r\n"));
+			/*
+		         * fx is less than zero *always* here but we check
+		         * for code symmetry
+		         */
+			if (fx < 0) {
+				ELRE_DEBUG(!EL_CAN_DELETE, (__F,
+				    "ERROR: cannot delete in first diff\n"));
+				terminal_deletechars(el, -fx);
+				re_delete(el, old, (int)(ofd - old),
+				    el->el_terminal.t_size.h, -fx);
+			}
+			/*
+		         * write (nsb-nfd) chars of new starting at nfd
+		         */
+			len = (size_t) (nsb - nfd);
+			terminal_overwrite(el, nfd, len);
+			re__strncopy(ofd, nfd, len);
+
+		} else {
+			ELRE_DEBUG(1, (__F,
+			    "but with nothing left to save\r\n"));
+			/*
+		         * write (nsb-nfd) chars of new starting at nfd
+		         */
+			terminal_overwrite(el, nfd, (size_t)(nsb - nfd));
+			re_clear_eol(el, fx, sx,
+			    (int)((oe - old) - (ne - new)));
+			/*
+		         * Done
+		         */
+			return;
+		}
+	} else
+		fx = 0;
+
+	if (sx < 0 && (ose - old) + fx < el->el_terminal.t_size.h) {
+		ELRE_DEBUG(1, (__F,
+		    "second diff delete at %td...\r\n", (ose - old) + fx));
+		/*
+		 * Check if we have stuff to delete
+		 */
+		/*
+		 * fx is the number of characters inserted (+) or deleted (-)
+		 */
+
+		terminal_move_to_char(el, (int)((ose - old) + fx));
+		/*
+		 * Check if we have stuff to save
+		 */
+		if (ols != oe) {
+			ELRE_DEBUG(1, (__F, "with stuff to save at end\r\n"));
+			/*
+		         * Again a duplicate test.
+		         */
+			if (sx < 0) {
+				ELRE_DEBUG(!EL_CAN_DELETE, (__F,
+				    "ERROR: cannot delete in second diff\n"));
+				terminal_deletechars(el, -sx);
+			}
+			/*
+		         * write (nls-nse) chars of new starting at nse
+		         */
+			terminal_overwrite(el, nse, (size_t)(nls - nse));
+		} else {
+			ELRE_DEBUG(1, (__F,
+			    "but with nothing left to save\r\n"));
+			terminal_overwrite(el, nse, (size_t)(nls - nse));
+			re_clear_eol(el, fx, sx,
+			    (int)((oe - old) - (ne - new)));
+		}
+	}
+	/*
+         * if we have a first insert AND WE HAVEN'T ALREADY DONE IT...
+         */
+	if ((nsb != nfd) && (osb - ofd) <= (nsb - nfd) && (fx == 0)) {
+		ELRE_DEBUG(1, (__F, "late first diff insert at %td...\r\n",
+		    nfd - new));
+
+		terminal_move_to_char(el, (int)(nfd - new));
+		/*
+		 * Check if we have stuff to keep at the end
+		 */
+		if (nsb != ne) {
+			ELRE_DEBUG(1, (__F, "with stuff to keep at end\r\n"));
+			/*
+		         * We have to recalculate fx here because we set it
+		         * to zero above as a flag saying that we hadn't done
+		         * an early first insert.
+		         */
+			fx = (int)((nsb - nfd) - (osb - ofd));
+			if (fx > 0) {
+				/*
+				 * insert fx chars of new starting at nfd
+				 */
+				ELRE_DEBUG(!EL_CAN_INSERT, (__F,
+				 "ERROR: cannot insert in late first diff\n"));
+				terminal_insertwrite(el, nfd, fx);
+				re_insert(el, old, (int)(ofd - old),
+				    el->el_terminal.t_size.h, nfd, fx);
+			}
+			/*
+		         * write (nsb-nfd) - fx chars of new starting at
+		         * (nfd + fx)
+			 */
+			len = (size_t) ((nsb - nfd) - fx);
+			terminal_overwrite(el, (nfd + fx), len);
+			re__strncopy(ofd + fx, nfd + fx, len);
+		} else {
+			ELRE_DEBUG(1, (__F, "without anything to save\r\n"));
+			len = (size_t) (nsb - nfd);
+			terminal_overwrite(el, nfd, len);
+			re__strncopy(ofd, nfd, len);
+		}
+	}
+	/*
+         * line is now NEW up to nse
+         */
+	if (sx >= 0) {
+		ELRE_DEBUG(1, (__F,
+		    "second diff insert at %d...\r\n", (int)(nse - new)));
+		terminal_move_to_char(el, (int)(nse - new));
+		if (ols != oe) {
+			ELRE_DEBUG(1, (__F, "with stuff to keep at end\r\n"));
+			if (sx > 0) {
+				/* insert sx chars of new starting at nse */
+				ELRE_DEBUG(!EL_CAN_INSERT, (__F,
+				    "ERROR: cannot insert in second diff\n"));
+				terminal_insertwrite(el, nse, sx);
+			}
+			/*
+		         * write (nls-nse) - sx chars of new starting at
+			 * (nse + sx)
+		         */
+			terminal_overwrite(el, (nse + sx),
+			    (size_t)((nls - nse) - sx));
+		} else {
+			ELRE_DEBUG(1, (__F, "without anything to save\r\n"));
+			terminal_overwrite(el, nse, (size_t)(nls - nse));
+
+			/*
+	                 * No need to do a clear-to-end here because we were
+	                 * doing a second insert, so we will have over
+	                 * written all of the old string.
+		         */
+		}
+	}
+	ELRE_DEBUG(1, (__F, "done.\r\n"));
+}
+
+
+/* re__copy_and_pad():
+ *	Copy string and pad with spaces
+ */
+static void
+re__copy_and_pad(wchar_t *dst, const wchar_t *src, size_t width)
+{
+	size_t i;
+
+	for (i = 0; i < width; i++) {
+		if (*src == '\0')
+			break;
+		*dst++ = *src++;
+	}
+
+	for (; i < width; i++)
+		*dst++ = ' ';
+
+	*dst = '\0';
+}
+
+
+/* re_refresh_cursor():
+ *	Move to the new cursor position
+ */
+libedit_private void
+re_refresh_cursor(EditLine *el)
+{
+	wchar_t *cp;
+	int h, v, th, w;
+
+	if (el->el_line.cursor >= el->el_line.lastchar) {
+		if (el->el_map.current == el->el_map.alt
+		    && el->el_line.lastchar != el->el_line.buffer)
+			el->el_line.cursor = el->el_line.lastchar - 1;
+		else
+			el->el_line.cursor = el->el_line.lastchar;
+	}
+
+	/* first we must find where the cursor is... */
+	h = el->el_prompt.p_pos.h;
+	v = el->el_prompt.p_pos.v;
+	th = el->el_terminal.t_size.h;	/* optimize for speed */
+
+	/* do input buffer to el->el_line.cursor */
+	for (cp = el->el_line.buffer; cp < el->el_line.cursor; cp++) {
+                switch (ct_chr_class(*cp)) {
+		case CHTYPE_NL:  /* handle newline in data part too */
+			h = 0;
+			v++;
+			break;
+		case CHTYPE_TAB: /* if a tab, to next tab stop */
+			while (++h & 07)
+				continue;
+			break;
+		default:
+			w = wcwidth(*cp);
+			if (w > 1 && h + w > th) { /* won't fit on line */
+				h = 0;
+				v++;
+			}
+			h += ct_visual_width(*cp);
+			break;
+                }
+
+		if (h >= th) {	/* check, extra long tabs picked up here also */
+			h -= th;
+			v++;
+		}
+	}
+        /* if we have a next character, and it's a doublewidth one, we need to
+         * check whether we need to linebreak for it to fit */
+        if (cp < el->el_line.lastchar && (w = wcwidth(*cp)) > 1)
+                if (h + w > th) {
+                    h = 0;
+                    v++;
+                }
+
+	/* now go there */
+	terminal_move_to_line(el, v);
+	terminal_move_to_char(el, h);
+	terminal__flush(el);
+}
+
+
+/* re_fastputc():
+ *	Add a character fast.
+ */
+static void
+re_fastputc(EditLine *el, wint_t c)
+{
+	int w = wcwidth(c);
+	while (w > 1 && el->el_cursor.h + w > el->el_terminal.t_size.h)
+	    re_fastputc(el, ' ');
+
+	terminal__putc(el, c);
+	el->el_display[el->el_cursor.v][el->el_cursor.h++] = c;
+	while (--w > 0)
+		el->el_display[el->el_cursor.v][el->el_cursor.h++]
+			= MB_FILL_CHAR;
+
+	if (el->el_cursor.h >= el->el_terminal.t_size.h) {
+		/* if we must overflow */
+		el->el_cursor.h = 0;
+
+		/*
+		 * If we would overflow (input is longer than terminal size),
+		 * emulate scroll by dropping first line and shuffling the rest.
+		 * We do this via pointer shuffling - it's safe in this case
+		 * and we avoid memcpy().
+		 */
+		if (el->el_cursor.v + 1 >= el->el_terminal.t_size.v) {
+			int i, lins = el->el_terminal.t_size.v;
+			wchar_t *firstline = el->el_display[0];
+
+			for(i = 1; i < lins; i++)
+				el->el_display[i - 1] = el->el_display[i];
+
+			re__copy_and_pad(firstline, L"", (size_t)0);
+			el->el_display[i - 1] = firstline;
+		} else {
+			el->el_cursor.v++;
+			el->el_refresh.r_oldcv++;
+		}
+		if (EL_HAS_AUTO_MARGINS) {
+			if (EL_HAS_MAGIC_MARGINS) {
+				terminal__putc(el, ' ');
+				terminal__putc(el, '\b');
+			}
+		} else {
+			terminal__putc(el, '\r');
+			terminal__putc(el, '\n');
+		}
+	}
+}
+
+
+/* re_fastaddc():
+ *	we added just one char, handle it fast.
+ *	Assumes that screen cursor == real cursor
+ */
+libedit_private void
+re_fastaddc(EditLine *el)
+{
+	wchar_t c;
+	int rhdiff;
+
+	c = el->el_line.cursor[-1];
+
+	if (c == '\t' || el->el_line.cursor != el->el_line.lastchar) {
+		re_refresh(el);	/* too hard to handle */
+		return;
+	}
+	rhdiff = el->el_terminal.t_size.h - el->el_cursor.h -
+	    el->el_rprompt.p_pos.h;
+	if (el->el_rprompt.p_pos.h && rhdiff < 3) {
+		re_refresh(el);	/* clear out rprompt if less than 1 char gap */
+		return;
+	}			/* else (only do at end of line, no TAB) */
+	switch (ct_chr_class(c)) {
+	case CHTYPE_TAB: /* already handled, should never happen here */
+		break;
+	case CHTYPE_NL:
+	case CHTYPE_PRINT:
+		re_fastputc(el, c);
+		break;
+	case CHTYPE_ASCIICTL:
+	case CHTYPE_NONPRINT: {
+		wchar_t visbuf[VISUAL_WIDTH_MAX];
+		ssize_t i, n =
+		    ct_visual_char(visbuf, VISUAL_WIDTH_MAX, c);
+		for (i = 0; n-- > 0; ++i)
+			re_fastputc(el, visbuf[i]);
+		break;
+	}
+	}
+	terminal__flush(el);
+}
+
+
+/* re_clear_display():
+ *	clear the screen buffers so that new new prompt starts fresh.
+ */
+libedit_private void
+re_clear_display(EditLine *el)
+{
+	int i;
+
+	el->el_cursor.v = 0;
+	el->el_cursor.h = 0;
+	for (i = 0; i < el->el_terminal.t_size.v; i++)
+		el->el_display[i][0] = '\0';
+	el->el_refresh.r_oldcv = 0;
+}
+
+
+/* re_clear_lines():
+ *	Make sure all lines are *really* blank
+ */
+libedit_private void
+re_clear_lines(EditLine *el)
+{
+
+	if (EL_CAN_CEOL) {
+		int i;
+		for (i = el->el_refresh.r_oldcv; i >= 0; i--) {
+			/* for each line on the screen */
+			terminal_move_to_line(el, i);
+			terminal_move_to_char(el, 0);
+			terminal_clear_EOL(el, el->el_terminal.t_size.h);
+		}
+	} else {
+		terminal_move_to_line(el, el->el_refresh.r_oldcv);
+					/* go to last line */
+		terminal__putc(el, '\r');	/* go to BOL */
+		terminal__putc(el, '\n');	/* go to new line */
+	}
+}