Adding upstream version 8.2.upstream/8.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3583 insertions, 0 deletions

diff --git a/display.c b/display.c
new file mode 100644
index 0000000..c1135ec
--- /dev/null
+++ b/display.c
@@ -0,0 +1,3583 @@
+/* display.c -- readline redisplay facility. */
+
+/* Copyright (C) 1987-2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU Readline Library (Readline), a library    
+   for reading lines of text with interactive input and history editing.
+
+   Readline is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Readline is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Readline.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define READLINE_LIBRARY
+
+#if defined (HAVE_CONFIG_H)
+#  include <config.h>
+#endif
+
+#include <sys/types.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+
+#include "posixstat.h"
+
+#if defined (HAVE_STDLIB_H)
+#  include <stdlib.h>
+#else
+#  include "ansi_stdlib.h"
+#endif /* HAVE_STDLIB_H */
+
+#include <stdio.h>
+
+#ifdef __MSDOS__
+#  include <pc.h>
+#endif
+
+/* System-specific feature definitions and include files. */
+#include "rldefs.h"
+#include "rlmbutil.h"
+
+/* Termcap library stuff. */
+#include "tcap.h"
+
+/* Some standard library routines. */
+#include "readline.h"
+#include "history.h"
+
+#include "rlprivate.h"
+#include "xmalloc.h"
+
+#if !defined (strchr) && !defined (__STDC__)
+extern char *strchr (), *strrchr ();
+#endif /* !strchr && !__STDC__ */
+
+static void putc_face (int, int, char *);
+static void puts_face (const char *, const char *, int);
+static void norm_face (char *, int);
+
+static void update_line (char *, char *, char *, char *, int, int, int, int);
+static void space_to_eol (int);
+static void delete_chars (int);
+static void insert_some_chars (char *, int, int);
+static void open_some_spaces (int);
+static void cr (void);
+static void redraw_prompt (char *);
+static void _rl_move_cursor_relative (int, const char *, const char *);
+
+/* Values for FLAGS */
+#define PMT_MULTILINE	0x01
+
+static char *expand_prompt (char *, int, int *, int *, int *, int *);
+
+#define DEFAULT_LINE_BUFFER_SIZE	1024
+
+/* State of visible and invisible lines. */
+struct line_state
+  {
+    char *line;
+    char *lface;
+    int *lbreaks;
+    int lbsize;
+#if defined (HANDLE_MULTIBYTE)
+    int wbsize;
+    int *wrapped_line;
+#endif
+  };
+
+/* The line display buffers.  One is the line currently displayed on
+   the screen.  The other is the line about to be displayed. */
+static struct line_state line_state_array[2];
+static struct line_state *line_state_visible = &line_state_array[0];
+static struct line_state *line_state_invisible = &line_state_array[1];
+static int line_structures_initialized = 0;
+
+/* Backwards-compatible names. */
+#define inv_lbreaks	(line_state_invisible->lbreaks)
+#define inv_lbsize	(line_state_invisible->lbsize)
+#define vis_lbreaks	(line_state_visible->lbreaks)
+#define vis_lbsize	(line_state_visible->lbsize)
+
+#define visible_line	(line_state_visible->line)
+#define vis_face	(line_state_visible->lface)
+#define invisible_line	(line_state_invisible->line)
+#define inv_face	(line_state_invisible->lface)
+
+#if defined (HANDLE_MULTIBYTE)
+static int _rl_col_width (const char *, int, int, int);
+#else
+#  define _rl_col_width(l, s, e, f)	(((e) <= (s)) ? 0 : (e) - (s))
+#endif
+
+/* Heuristic used to decide whether it is faster to move from CUR to NEW
+   by backing up or outputting a carriage return and moving forward.  CUR
+   and NEW are either both buffer positions or absolute screen positions. */
+#define CR_FASTER(new, cur) (((new) + 1) < ((cur) - (new)))
+
+/* _rl_last_c_pos is an absolute cursor position in multibyte locales and a
+   buffer index in others.  This macro is used when deciding whether the
+   current cursor position is in the middle of a prompt string containing
+   invisible characters.  XXX - might need to take `modmark' into account. */
+/* XXX - only valid when tested against _rl_last_c_pos; buffer indices need
+   to use prompt_last_invisible directly. */
+#define PROMPT_ENDING_INDEX \
+  ((MB_CUR_MAX > 1 && rl_byte_oriented == 0) ? prompt_physical_chars : prompt_last_invisible+1)
+
+#define FACE_NORMAL	'0'
+#define FACE_STANDOUT	'1'
+#define FACE_INVALID	((char)1)
+  
+/* **************************************************************** */
+/*								    */
+/*			Display stuff				    */
+/*								    */
+/* **************************************************************** */
+
+/* This is the stuff that is hard for me.  I never seem to write good
+   display routines in C.  Let's see how I do this time. */
+
+/* (PWP) Well... Good for a simple line updater, but totally ignores
+   the problems of input lines longer than the screen width.
+
+   update_line and the code that calls it makes a multiple line,
+   automatically wrapping line update.  Careful attention needs
+   to be paid to the vertical position variables. */
+
+/* Keep two buffers; one which reflects the current contents of the
+   screen, and the other to draw what we think the new contents should
+   be.  Then compare the buffers, and make whatever changes to the
+   screen itself that we should.  Finally, make the buffer that we
+   just drew into be the one which reflects the current contents of the
+   screen, and place the cursor where it belongs.
+
+   Commands that want to can fix the display themselves, and then let
+   this function know that the display has been fixed by setting the
+   RL_DISPLAY_FIXED variable.  This is good for efficiency. */
+
+/* Application-specific redisplay function. */
+rl_voidfunc_t *rl_redisplay_function = rl_redisplay;
+
+/* Global variables declared here. */
+/* What YOU turn on when you have handled all redisplay yourself. */
+int rl_display_fixed = 0;
+
+/* The stuff that gets printed out before the actual text of the line.
+   This is usually pointing to rl_prompt. */
+char *rl_display_prompt = (char *)NULL;
+
+/* Variables used to include the editing mode in the prompt. */
+char *_rl_emacs_mode_str;
+int _rl_emacs_modestr_len;
+
+char *_rl_vi_ins_mode_str;
+int _rl_vi_ins_modestr_len;
+
+char *_rl_vi_cmd_mode_str;
+int _rl_vi_cmd_modestr_len;
+
+/* Pseudo-global variables declared here. */
+
+/* Hints for other parts of readline to give to the display engine. */
+int _rl_suppress_redisplay = 0;
+int _rl_want_redisplay = 0;
+
+/* The visible cursor position.  If you print some text, adjust this. */
+/* NOTE: _rl_last_c_pos is used as a buffer index when not in a locale
+   supporting multibyte characters, and an absolute cursor position when
+   in such a locale.  This is an artifact of the donated multibyte support.
+   Care must be taken when modifying its value. */
+int _rl_last_c_pos = 0;
+int _rl_last_v_pos = 0;
+
+/* Number of physical lines consumed by the current line buffer currently
+  on screen minus 1. */
+int _rl_vis_botlin = 0;
+
+static int _rl_quick_redisplay = 0;
+
+/* This is a hint update_line gives to rl_redisplay that it has adjusted the
+   value of _rl_last_c_pos *and* taken the presence of any invisible chars in
+   the prompt into account.  rl_redisplay notes this and does not do the
+   adjustment itself. */
+static int cpos_adjusted;
+
+/* The index into the line buffer corresponding to the cursor position */
+static int cpos_buffer_position;
+
+/* A flag to note when we're displaying the first line of the prompt */
+static int displaying_prompt_first_line;
+/* The number of multibyte characters in the prompt, if any */
+static int prompt_multibyte_chars;
+
+static int _rl_inv_botlin = 0;
+
+/* Variables used only in this file. */
+/* The last left edge of text that was displayed.  This is used when
+   doing horizontal scrolling.  It shifts in thirds of a screenwidth. */
+static int last_lmargin;
+
+/* A buffer for `modeline' messages. */
+static char *msg_buf = 0;
+static int msg_bufsiz = 0;
+
+/* Non-zero forces the redisplay even if we thought it was unnecessary. */
+static int forced_display;
+
+/* Default and initial buffer size.  Can grow. */
+static int line_size  = 0;
+
+/* Set to a non-zero value if horizontal scrolling has been enabled
+   automatically because the terminal was resized to height 1. */
+static int horizontal_scrolling_autoset = 0;	/* explicit initialization */
+
+/* Variables to keep track of the expanded prompt string, which may
+   include invisible characters. */
+
+static char *local_prompt, *local_prompt_prefix;
+static int local_prompt_len;
+static int prompt_prefix_length;
+/* Number of chars in the buffer that contribute to visible chars on the screen.
+   This might be different from the number of physical chars in the presence
+   of multibyte characters */
+static int prompt_visible_length;
+
+/* The number of invisible characters in the line currently being
+   displayed on the screen. */
+static int visible_wrap_offset;
+
+/* The number of invisible characters in the prompt string.  Static so it
+   can be shared between rl_redisplay and update_line */
+static int wrap_offset;
+
+/* The index of the last invisible character in the prompt string. */
+static int prompt_last_invisible;
+
+/* The length (buffer offset) of the first line of the last (possibly
+   multi-line) buffer displayed on the screen. */
+static int visible_first_line_len;
+
+/* Number of invisible characters on the first physical line of the prompt.
+   Only valid when the number of physical characters in the prompt exceeds
+   (or is equal to) _rl_screenwidth. */
+static int prompt_invis_chars_first_line;
+
+static int prompt_last_screen_line;
+
+static int prompt_physical_chars;
+
+/* An array of indexes into the prompt string where we will break physical
+   screen lines.  It's easier to compute in expand_prompt and use later in
+   rl_redisplay instead of having rl_redisplay try to guess about invisible
+   characters in the prompt or use heuristics about where they are. */
+static int *local_prompt_newlines;
+
+/* set to a non-zero value by rl_redisplay if we are marking modified history
+   lines and the current line is so marked. */
+static int modmark;
+
+static int line_totbytes;
+
+/* Variables to save and restore prompt and display information. */
+
+/* These are getting numerous enough that it's time to create a struct. */
+
+static char *saved_local_prompt;
+static char *saved_local_prefix;
+static int *saved_local_prompt_newlines;
+
+static int saved_last_invisible;
+static int saved_visible_length;
+static int saved_prefix_length;
+static int saved_local_length;
+static int saved_invis_chars_first_line;
+static int saved_physical_chars;
+
+/* Return a string indicating the editing mode, for use in the prompt. */
+
+static char *
+prompt_modestr (int *lenp)
+{
+  if (rl_editing_mode == emacs_mode)
+    {
+      if (lenp)
+	*lenp = _rl_emacs_mode_str ? _rl_emacs_modestr_len : RL_EMACS_MODESTR_DEFLEN;
+      return _rl_emacs_mode_str ? _rl_emacs_mode_str : RL_EMACS_MODESTR_DEFAULT;
+    }
+  else if (_rl_keymap == vi_insertion_keymap)
+    {
+      if (lenp)
+	*lenp = _rl_vi_ins_mode_str ? _rl_vi_ins_modestr_len : RL_VI_INS_MODESTR_DEFLEN;
+      return _rl_vi_ins_mode_str ? _rl_vi_ins_mode_str : RL_VI_INS_MODESTR_DEFAULT;		/* vi insert mode */
+    }
+  else
+    {
+      if (lenp)
+	*lenp = _rl_vi_cmd_mode_str ? _rl_vi_cmd_modestr_len : RL_VI_CMD_MODESTR_DEFLEN;
+      return _rl_vi_cmd_mode_str ? _rl_vi_cmd_mode_str : RL_VI_CMD_MODESTR_DEFAULT;		/* vi command mode */
+    }
+}
+
+/* Expand the prompt string S and return the number of visible
+   characters in *LP, if LP is not null.  This is currently more-or-less
+   a placeholder for expansion.  LIP, if non-null is a place to store the
+   index of the last invisible character in the returned string. NIFLP,
+   if non-zero, is a place to store the number of invisible characters in
+   the first prompt line.  The previous are used as byte counts -- indexes
+   into a character buffer.  *VLP gets the number of physical characters in
+   the expanded prompt (visible length) */
+
+/* Current implementation:
+	\001 (^A) start non-visible characters
+	\002 (^B) end non-visible characters
+   all characters except \001 and \002 (following a \001) are copied to
+   the returned string; all characters except those between \001 and
+   \002 are assumed to be `visible'. */	
+
+/* Possible values for FLAGS:
+	PMT_MULTILINE	caller indicates that this is part of a multiline prompt
+*/
+
+/* This approximates the number of lines the prompt will take when displayed */
+#define APPROX_DIV(n, d)	(((n) < (d)) ? 1 : ((n) / (d)) + 1)
+
+static char *
+expand_prompt (char *pmt, int flags, int *lp, int *lip, int *niflp, int *vlp)
+{
+  char *r, *ret, *p, *igstart, *nprompt, *ms;
+  int l, rl, last, ignoring, ninvis, invfl, invflset, ind, pind, physchars;
+  int mlen, newlines, newlines_guess, bound, can_add_invis;
+  int mb_cur_max;
+
+  /* We only expand the mode string for the last line of a multiline prompt
+     (a prompt with embedded newlines). */
+  ms = (((pmt == rl_prompt) ^ (flags & PMT_MULTILINE)) && _rl_show_mode_in_prompt) ? prompt_modestr (&mlen) : 0;
+  if (ms)
+    {
+      l = strlen (pmt);
+      nprompt = (char *)xmalloc (l + mlen + 1);
+      memcpy (nprompt, ms, mlen);
+      strcpy (nprompt + mlen, pmt);
+    }
+  else
+    nprompt = pmt;
+
+  can_add_invis = 0;
+  mb_cur_max = MB_CUR_MAX;
+
+  if (_rl_screenwidth == 0)
+    _rl_get_screen_size (0, 0);	/* avoid division by zero */
+
+  /* Short-circuit if we can.  We can do this if we are treating the prompt as
+     a sequence of bytes and there are no invisible characters in the prompt
+     to deal with. Since we populate local_prompt_newlines, we have to run
+     through the rest of the function if this prompt looks like it's going to
+     be longer than one screen line. */
+  if ((mb_cur_max <= 1 || rl_byte_oriented) && strchr (nprompt, RL_PROMPT_START_IGNORE) == 0)
+    {
+      l = strlen (nprompt);
+      if (l < (_rl_screenwidth > 0 ? _rl_screenwidth : 80))
+        {
+	  r = (nprompt == pmt) ? savestring (pmt) : nprompt;
+	  if (lp)
+	    *lp = l;
+	  if (lip)
+	    *lip = 0;
+	  if (niflp)
+	    *niflp = 0;
+	  if (vlp)
+	    *vlp = l;
+
+	  local_prompt_newlines = (int *) xrealloc (local_prompt_newlines, sizeof (int) * 2);
+	  local_prompt_newlines[0] = 0;
+	  local_prompt_newlines[1] = -1;
+
+	  return r;
+        }
+    }
+
+  l = strlen (nprompt);			/* XXX */
+  r = ret = (char *)xmalloc (l + 1);
+
+  /* Guess at how many screen lines the prompt will take to size the array that
+     keeps track of where the line wraps happen */
+  newlines_guess = (_rl_screenwidth > 0) ? APPROX_DIV(l,  _rl_screenwidth) : APPROX_DIV(l, 80);
+  local_prompt_newlines = (int *) xrealloc (local_prompt_newlines, sizeof (int) * (newlines_guess + 1));
+  local_prompt_newlines[newlines = 0] = 0;
+  for (rl = 1; rl <= newlines_guess; rl++)
+    local_prompt_newlines[rl] = -1;
+
+  rl = physchars = 0;	/* mode string now part of nprompt */
+  invfl = 0;		/* invisible chars in first line of prompt */
+  invflset = 0;		/* we only want to set invfl once */
+  igstart = 0;		/* we're not ignoring any characters yet */
+
+  for (ignoring = last = ninvis = 0, p = nprompt; p && *p; p++)
+    {
+      /* This code strips the invisible character string markers
+	 RL_PROMPT_START_IGNORE and RL_PROMPT_END_IGNORE */
+      if (ignoring == 0 && *p == RL_PROMPT_START_IGNORE)		/* XXX - check ignoring? */
+	{
+	  ignoring = 1;
+	  igstart = p;
+	  continue;
+	}
+      else if (ignoring && *p == RL_PROMPT_END_IGNORE)
+	{
+	  ignoring = 0;
+	  /* If we have a run of invisible characters, adjust local_prompt_newlines
+	     to add them, since update_line expects them to be counted before
+	     wrapping the line. */
+	  if (can_add_invis)
+	    {
+	      local_prompt_newlines[newlines] = r - ret;
+	      /* If we're adding to the number of invisible characters on the
+		 first line of the prompt, but we've already set the number of
+		 invisible characters on that line, we need to adjust the
+		 counter. */
+	      if (invflset && newlines == 1)
+		invfl = ninvis;
+	    }
+	  if (p != (igstart + 1))
+	    last = r - ret - 1;
+	  continue;
+	}
+      else
+	{
+#if defined (HANDLE_MULTIBYTE)
+	  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	    {
+	      pind = p - nprompt;
+	      ind = _rl_find_next_mbchar (nprompt, pind, 1, MB_FIND_NONZERO);
+	      l = ind - pind;
+	      while (l--)
+	        *r++ = *p++;
+	      if (!ignoring)
+		{
+		  /* rl ends up being assigned to prompt_visible_length,
+		     which is the number of characters in the buffer that
+		     contribute to characters on the screen, which might
+		     not be the same as the number of physical characters
+		     on the screen in the presence of multibyte characters */
+		  rl += ind - pind;
+		  physchars += _rl_col_width (nprompt, pind, ind, 0);
+		}
+	      else
+		ninvis += ind - pind;
+	      p--;			/* compensate for later increment */
+	    }
+	  else
+#endif
+	    {
+	      *r++ = *p;
+	      if (!ignoring)
+		{
+		  rl++;			/* visible length byte counter */
+		  physchars++;
+		}
+	      else
+		ninvis++;		/* invisible chars byte counter */
+	    }
+
+	  if (invflset == 0 && physchars >= _rl_screenwidth)
+	    {
+	      invfl = ninvis;
+	      invflset = 1;
+	    }
+
+	  if (physchars >= (bound = (newlines + 1) * _rl_screenwidth) && local_prompt_newlines[newlines+1] == -1)
+	    {
+	      int new;
+	      if (physchars > bound)		/* should rarely happen */
+		{
+#if defined (HANDLE_MULTIBYTE)
+		  *r = '\0';	/* need null-termination for strlen */
+		  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		    new = _rl_find_prev_mbchar (ret, r - ret, MB_FIND_ANY);
+		  else
+#endif
+		    new = r - ret - (physchars - bound);	/* XXX */
+		}
+	      else
+	        new = r - ret;
+	      local_prompt_newlines[++newlines] = new;
+	    }
+
+	  /* What if a physical character of width >= 2 is split? There is
+	     code that wraps before the physical screen width if the character
+	     width would exceed it, but it needs to be checked against this
+	     code and local_prompt_newlines[]. */
+	  if (ignoring == 0)
+	    can_add_invis = (physchars == bound); 
+	}
+    }
+
+  if (rl <= _rl_screenwidth)
+    invfl = ninvis;
+
+  *r = '\0';
+  if (lp)
+    *lp = rl;
+  if (lip)
+    *lip = last;
+  if (niflp)
+    *niflp = invfl;
+  if  (vlp)
+    *vlp = physchars;
+
+  if (nprompt != pmt)
+    xfree (nprompt);
+
+  return ret;
+}
+
+/* Just strip out RL_PROMPT_START_IGNORE and RL_PROMPT_END_IGNORE from
+   PMT and return the rest of PMT. */
+char *
+_rl_strip_prompt (char *pmt)
+{
+  char *ret;
+
+  ret = expand_prompt (pmt, 0, (int *)NULL, (int *)NULL, (int *)NULL, (int *)NULL);
+  return ret;
+}
+
+void
+_rl_reset_prompt (void)
+{
+  rl_visible_prompt_length = rl_expand_prompt (rl_prompt);
+}
+
+/*
+ * Expand the prompt string into the various display components, if
+ * necessary.
+ *
+ * local_prompt = expanded last line of string in rl_display_prompt
+ *		  (portion after the final newline)
+ * local_prompt_prefix = portion before last newline of rl_display_prompt,
+ *			 expanded via expand_prompt
+ * prompt_visible_length = number of visible characters in local_prompt
+ * prompt_prefix_length = number of visible characters in local_prompt_prefix
+ *
+ * It also tries to keep track of the number of invisible characters in the
+ * prompt string, and where they are.
+ *
+ * This function is called once per call to readline().  It may also be
+ * called arbitrarily to expand the primary prompt.
+ *
+ * The return value is the number of visible characters on the last line
+ * of the (possibly multi-line) prompt.  In this case, multi-line means
+ * there are embedded newlines in the prompt string itself, not that the
+ * number of physical characters exceeds the screen width and the prompt
+ * wraps.
+ */
+int
+rl_expand_prompt (char *prompt)
+{
+  char *p, *t;
+  int c;
+
+  /* Clear out any saved values. */
+  FREE (local_prompt);
+  FREE (local_prompt_prefix);
+
+  local_prompt = local_prompt_prefix = (char *)0;
+  local_prompt_len = 0;
+  prompt_last_invisible = prompt_invis_chars_first_line = 0;
+  prompt_visible_length = prompt_physical_chars = 0;
+
+  if (prompt == 0 || *prompt == 0)
+    return (0);
+
+  p = strrchr (prompt, '\n');
+  if (p == 0)
+    {
+      /* The prompt is only one logical line, though it might wrap. */
+      local_prompt = expand_prompt (prompt, 0, &prompt_visible_length,
+					       &prompt_last_invisible,
+					       &prompt_invis_chars_first_line,
+					       &prompt_physical_chars);
+      local_prompt_prefix = (char *)0;
+      local_prompt_len = local_prompt ? strlen (local_prompt) : 0;
+      return (prompt_visible_length);
+    }
+  else
+    {
+      /* The prompt spans multiple lines. */
+      t = ++p;
+      c = *t; *t = '\0';
+      /* The portion of the prompt string up to and including the
+	 final newline is now null-terminated. */
+      local_prompt_prefix = expand_prompt (prompt, PMT_MULTILINE,
+						   &prompt_prefix_length,
+						   (int *)NULL,
+						   (int *)NULL,
+						   (int *)NULL);
+      *t = c;
+
+      local_prompt = expand_prompt (p, PMT_MULTILINE,
+				       &prompt_visible_length,
+				       &prompt_last_invisible,
+				       &prompt_invis_chars_first_line,
+				       &prompt_physical_chars);
+      local_prompt_len = local_prompt ? strlen (local_prompt) : 0;
+      return (prompt_prefix_length);
+    }
+}
+
+/* Allocate the various line structures, making sure they can hold MINSIZE
+   bytes. If the existing line size can accommodate MINSIZE bytes, don't do
+   anything. */
+static void
+realloc_line (int minsize)
+{
+  int minimum_size;
+  int newsize, delta;
+
+  minimum_size = DEFAULT_LINE_BUFFER_SIZE;
+  if (minsize < minimum_size)
+    minsize = minimum_size;
+  if (minsize <= _rl_screenwidth)	/* XXX - for gdb */
+    minsize = _rl_screenwidth + 1;
+  if (line_size >= minsize)
+    return;
+
+  newsize = minimum_size;
+  while (newsize < minsize)
+    newsize *= 2;
+
+  visible_line = (char *)xrealloc (visible_line, newsize);
+  vis_face = (char *)xrealloc (vis_face, newsize);
+
+  invisible_line = (char *)xrealloc (invisible_line, newsize);
+  inv_face = (char *)xrealloc (inv_face, newsize);
+
+  delta = newsize - line_size;  
+  memset (visible_line + line_size, 0, delta);
+  memset (vis_face + line_size, FACE_NORMAL, delta);
+  memset (invisible_line + line_size, 1, delta);
+  memset (inv_face + line_size, FACE_INVALID, delta);
+
+  line_size = newsize;
+}
+
+/* Initialize the VISIBLE_LINE and INVISIBLE_LINE arrays, and their associated
+   arrays of line break markers.  MINSIZE is the minimum size of VISIBLE_LINE
+   and INVISIBLE_LINE; if it is greater than LINE_SIZE, LINE_SIZE is
+   increased.  If the lines have already been allocated, this ensures that
+   they can hold at least MINSIZE characters. */
+static void
+init_line_structures (int minsize)
+{
+  if (invisible_line == 0)	/* initialize it */
+    {
+      if (line_size > minsize)
+	minsize = line_size;
+    }
+   realloc_line (minsize); 
+
+  if (vis_lbreaks == 0)
+    {
+      /* should be enough. */
+      inv_lbsize = vis_lbsize = 256;
+
+#if defined (HANDLE_MULTIBYTE)
+      line_state_visible->wbsize = vis_lbsize;
+      line_state_visible->wrapped_line = (int *)xmalloc (line_state_visible->wbsize * sizeof (int));
+
+      line_state_invisible->wbsize = inv_lbsize;
+      line_state_invisible->wrapped_line = (int *)xmalloc (line_state_invisible->wbsize * sizeof (int));
+#endif
+
+      inv_lbreaks = (int *)xmalloc (inv_lbsize * sizeof (int));
+      vis_lbreaks = (int *)xmalloc (vis_lbsize * sizeof (int));
+      inv_lbreaks[0] = vis_lbreaks[0] = 0;
+    }
+
+  line_structures_initialized = 1;
+}
+
+/* Convenience functions to add chars to the invisible line that update the
+   face information at the same time. */
+static void		/* XXX - change this */
+invis_addc (int *outp, char c, char face)
+{
+  realloc_line (*outp + 1);
+  invisible_line[*outp] = c;
+  inv_face[*outp] = face;
+  *outp += 1;
+}
+
+static void
+invis_adds (int *outp, const char *str, int n, char face)
+{
+  int i;
+
+  for (i = 0; i < n; i++)
+    invis_addc (outp, str[i], face);
+}
+
+static void
+invis_nul (int *outp)
+{
+  invis_addc (outp, '\0', 0);
+  *outp -= 1;
+}
+
+static void
+set_active_region (int *beg, int *end)
+{
+  if (rl_point >= 0 && rl_point <= rl_end && rl_mark >= 0 && rl_mark <= rl_end)
+    {
+      *beg = (rl_mark < rl_point) ? rl_mark : rl_point;
+      *end = (rl_mark < rl_point) ? rl_point : rl_mark;
+    }
+}
+
+/* Do whatever tests are necessary and tell update_line that it can do a
+   quick, dumb redisplay on the assumption that there are so many
+   differences between the old and new lines that it would be a waste to
+   compute all the differences.
+   Right now, it just sets _rl_quick_redisplay if the current visible line
+   is a single line (so we don't have to move vertically or mess with line
+   wrapping). */
+void
+_rl_optimize_redisplay (void)
+{
+  if (_rl_vis_botlin == 0)
+    _rl_quick_redisplay = 1;
+}  
+
+/* Basic redisplay algorithm.  See comments inline. */
+void
+rl_redisplay (void)
+{
+  int in, out, c, linenum, cursor_linenum;
+  int inv_botlin, lb_botlin, lb_linenum, o_cpos;
+  int newlines, lpos, temp, n0, num, prompt_lines_estimate;
+  char *prompt_this_line;
+  char cur_face;
+  int hl_begin, hl_end;
+  int mb_cur_max = MB_CUR_MAX;
+#if defined (HANDLE_MULTIBYTE)
+  WCHAR_T wc;
+  size_t wc_bytes;
+  int wc_width;
+  mbstate_t ps;
+  int _rl_wrapped_multicolumn = 0;
+#endif
+
+  if (_rl_echoing_p == 0)
+    return;
+
+  /* Block keyboard interrupts because this function manipulates global
+     data structures. */
+  _rl_block_sigint ();  
+  RL_SETSTATE (RL_STATE_REDISPLAYING);
+
+  cur_face = FACE_NORMAL;
+  /* Can turn this into an array for multiple highlighted objects in addition
+     to the region */
+  hl_begin = hl_end = -1;
+
+  if (rl_mark_active_p ())
+    set_active_region (&hl_begin, &hl_end);
+
+  if (!rl_display_prompt)
+    rl_display_prompt = "";
+
+  if (line_structures_initialized == 0)
+    {
+      init_line_structures (0);
+      rl_on_new_line ();
+    }
+  else if (line_size <= _rl_screenwidth)
+    init_line_structures (_rl_screenwidth + 1);
+
+  /* Enable horizontal scrolling automatically for terminals of height 1
+     where wrapping lines doesn't work. Disable it as soon as the terminal
+     height is increased again if it was automatically enabled. */
+  if (_rl_screenheight <= 1)
+    {
+      if (_rl_horizontal_scroll_mode == 0)
+	 horizontal_scrolling_autoset = 1;
+      _rl_horizontal_scroll_mode = 1;
+    }
+  else if (horizontal_scrolling_autoset)
+    _rl_horizontal_scroll_mode = 0;
+
+  /* Draw the line into the buffer. */
+  cpos_buffer_position = -1;
+
+  prompt_multibyte_chars = prompt_visible_length - prompt_physical_chars;
+
+  out = inv_botlin = 0;
+
+  /* Mark the line as modified or not.  We only do this for history
+     lines. */
+  modmark = 0;
+  if (_rl_mark_modified_lines && current_history () && rl_undo_list)
+    {
+      invis_addc (&out, '*', cur_face);
+      invis_nul (&out);
+      modmark = 1;
+    }
+
+  /* If someone thought that the redisplay was handled, but the currently
+     visible line has a different modification state than the one about
+     to become visible, then correct the caller's misconception. */
+  if (visible_line[0] != invisible_line[0])
+    rl_display_fixed = 0;
+
+  /* If the prompt to be displayed is the `primary' readline prompt (the
+     one passed to readline()), use the values we have already expanded.
+     If not, use what's already in rl_display_prompt.  WRAP_OFFSET is the
+     number of non-visible characters (bytes) in the prompt string. */
+  /* This is where we output the characters in the prompt before the last
+     newline, if any.  If there aren't any embedded newlines, we don't
+     write anything. Copy the last line of the prompt string into the line in
+     any case */
+  if (rl_display_prompt == rl_prompt || local_prompt)
+    {
+      if (local_prompt_prefix && forced_display)
+	_rl_output_some_chars (local_prompt_prefix, strlen (local_prompt_prefix));
+
+      if (local_prompt_len > 0)
+	invis_adds (&out, local_prompt, local_prompt_len, cur_face);
+      invis_nul (&out);
+      wrap_offset = local_prompt_len - prompt_visible_length;
+    }
+  else
+    {
+      int pmtlen;
+      prompt_this_line = strrchr (rl_display_prompt, '\n');
+      if (!prompt_this_line)
+	prompt_this_line = rl_display_prompt;
+      else
+	{
+	  prompt_this_line++;
+	  pmtlen = prompt_this_line - rl_display_prompt;	/* temp var */
+	  if (forced_display)
+	    {
+	      _rl_output_some_chars (rl_display_prompt, pmtlen);
+	      /* Make sure we are at column zero even after a newline,
+		 regardless of the state of terminal output processing. */
+	      if (pmtlen < 2 || prompt_this_line[-2] != '\r')
+		cr ();
+	    }
+	}
+
+      prompt_physical_chars = pmtlen = strlen (prompt_this_line);	/* XXX */
+      invis_adds (&out, prompt_this_line, pmtlen, cur_face);
+      invis_nul (&out);
+      wrap_offset = prompt_invis_chars_first_line = 0;
+    }
+
+#if defined (HANDLE_MULTIBYTE)
+#define CHECK_INV_LBREAKS() \
+      do { \
+	if (newlines >= (inv_lbsize - 2)) \
+	  { \
+	    inv_lbsize *= 2; \
+	    inv_lbreaks = (int *)xrealloc (inv_lbreaks, inv_lbsize * sizeof (int)); \
+	  } \
+	if (newlines >= (line_state_invisible->wbsize - 2)) \
+	  { \
+	    line_state_invisible->wbsize *= 2; \
+	    line_state_invisible->wrapped_line = (int *)xrealloc (line_state_invisible->wrapped_line, line_state_invisible->wbsize * sizeof(int)); \
+	  } \
+      } while (0)
+#else
+#define CHECK_INV_LBREAKS() \
+      do { \
+	if (newlines >= (inv_lbsize - 2)) \
+	  { \
+	    inv_lbsize *= 2; \
+	    inv_lbreaks = (int *)xrealloc (inv_lbreaks, inv_lbsize * sizeof (int)); \
+	  } \
+      } while (0)
+#endif /* !HANDLE_MULTIBYTE */
+
+#if defined (HANDLE_MULTIBYTE)	  
+#define CHECK_LPOS() \
+      do { \
+	lpos++; \
+	if (lpos >= _rl_screenwidth) \
+	  { \
+	    if (newlines >= (inv_lbsize - 2)) \
+	      { \
+		inv_lbsize *= 2; \
+		inv_lbreaks = (int *)xrealloc (inv_lbreaks, inv_lbsize * sizeof (int)); \
+	      } \
+	    inv_lbreaks[++newlines] = out; \
+	    if (newlines >= (line_state_invisible->wbsize - 2)) \
+	      { \
+		line_state_invisible->wbsize *= 2; \
+		line_state_invisible->wrapped_line = (int *)xrealloc (line_state_invisible->wrapped_line, line_state_invisible->wbsize * sizeof(int)); \
+	      } \
+	    line_state_invisible->wrapped_line[newlines] = _rl_wrapped_multicolumn; \
+	    lpos = 0; \
+	  } \
+      } while (0)
+#else
+#define CHECK_LPOS() \
+      do { \
+	lpos++; \
+	if (lpos >= _rl_screenwidth) \
+	  { \
+	    if (newlines >= (inv_lbsize - 2)) \
+	      { \
+		inv_lbsize *= 2; \
+		inv_lbreaks = (int *)xrealloc (inv_lbreaks, inv_lbsize * sizeof (int)); \
+	      } \
+	    inv_lbreaks[++newlines] = out; \
+	    lpos = 0; \
+	  } \
+      } while (0)
+#endif
+
+  /* inv_lbreaks[i] is where line i starts in the buffer. */
+  inv_lbreaks[newlines = 0] = 0;
+  /* lpos is a physical cursor position, so it needs to be adjusted by the
+     number of invisible characters in the prompt, per line.  We compute
+     the line breaks in the prompt string in expand_prompt, taking invisible
+     characters into account, and if lpos exceeds the screen width, we copy
+     the data in the loop below. */
+  lpos = prompt_physical_chars + modmark;
+
+#if defined (HANDLE_MULTIBYTE)
+  memset (line_state_invisible->wrapped_line, 0, line_state_invisible->wbsize * sizeof (int));
+  num = 0;
+#endif
+
+  /* prompt_invis_chars_first_line is the number of invisible characters (bytes)
+     in the first physical line of the prompt.
+     wrap_offset - prompt_invis_chars_first_line is usually the number of
+     invis chars on the second (or, more generally, last) line. */
+
+  /* This is zero-based, used to set the newlines */
+  prompt_lines_estimate = lpos / _rl_screenwidth;
+
+  /* what if lpos is already >= _rl_screenwidth before we start drawing the
+     contents of the command line? */
+  if (lpos >= _rl_screenwidth)
+    {
+      temp = 0;
+
+      /* first copy the linebreaks array we computed in expand_prompt */
+      while (local_prompt_newlines[newlines+1] != -1)
+	{
+	  temp = local_prompt_newlines[newlines+1];
+	  inv_lbreaks[++newlines] = temp;
+	}  
+
+      /* Now set lpos from the last newline */
+      if (mb_cur_max > 1 && rl_byte_oriented == 0 && prompt_multibyte_chars > 0)
+        lpos = _rl_col_width (local_prompt, temp, local_prompt_len, 1) - (wrap_offset - prompt_invis_chars_first_line);
+      else
+        lpos -= (_rl_screenwidth * newlines);
+    }
+
+  prompt_last_screen_line = newlines;
+
+  /* Draw the rest of the line (after the prompt) into invisible_line, keeping
+     track of where the cursor is (cpos_buffer_position), the number of the
+     line containing the cursor (lb_linenum), the last line number (lb_botlin
+     and inv_botlin).
+     It maintains an array of line breaks for display (inv_lbreaks).
+     This handles expanding tabs for display and displaying meta characters. */
+  lb_linenum = 0;
+#if defined (HANDLE_MULTIBYTE)
+  in = 0;
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    {
+      memset (&ps, 0, sizeof (mbstate_t));
+      if (_rl_utf8locale && UTF8_SINGLEBYTE(rl_line_buffer[0]))
+	{
+	  wc = (WCHAR_T)rl_line_buffer[0];
+	  wc_bytes = 1;
+	}
+      else
+	wc_bytes = MBRTOWC (&wc, rl_line_buffer, rl_end, &ps);
+    }
+  else
+    wc_bytes = 1;
+  while (in < rl_end)
+#else
+  for (in = 0; in < rl_end; in++)
+#endif
+    {
+      if (in == hl_begin)
+	cur_face = FACE_STANDOUT;
+      else if (in == hl_end)
+	cur_face = FACE_NORMAL;
+
+      c = (unsigned char)rl_line_buffer[in];
+
+#if defined (HANDLE_MULTIBYTE)
+      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	{
+	  if (MB_INVALIDCH (wc_bytes))
+	    {
+	      /* Byte sequence is invalid or shortened.  Assume that the
+	         first byte represents a character. */
+	      wc_bytes = 1;
+	      /* Assume that a character occupies a single column. */
+	      wc_width = 1;
+	      memset (&ps, 0, sizeof (mbstate_t));
+	    }
+	  else if (MB_NULLWCH (wc_bytes))
+	    break;			/* Found '\0' */
+	  else
+	    {
+	      temp = WCWIDTH (wc);
+	      wc_width = (temp >= 0) ? temp : 1;
+	    }
+	}
+#endif
+
+      if (in == rl_point)
+	{
+	  cpos_buffer_position = out;
+	  lb_linenum = newlines;
+	}
+
+#if defined (HANDLE_MULTIBYTE)
+      if (META_CHAR (c) && _rl_output_meta_chars == 0)	/* XXX - clean up */
+#else
+      if (META_CHAR (c))
+#endif
+	{
+	  if (_rl_output_meta_chars == 0)
+	    {
+	      char obuf[5];
+	      int olen;
+
+	      olen = sprintf (obuf, "\\%o", c);
+	  
+	      if (lpos + olen >= _rl_screenwidth)
+		{
+		  temp = _rl_screenwidth - lpos;
+		  CHECK_INV_LBREAKS ();
+		  inv_lbreaks[++newlines] = out + temp;
+#if defined (HANDLE_MULTIBYTE)
+		  line_state_invisible->wrapped_line[newlines] = _rl_wrapped_multicolumn;
+#endif
+		  lpos = olen - temp;
+		}
+	      else
+		lpos += olen;
+
+	      for (temp = 0; temp < olen; temp++)
+		{
+		  invis_addc (&out, obuf[temp], cur_face);
+		  CHECK_LPOS ();
+		}
+	    }
+	  else
+	    {
+	      invis_addc (&out, c, cur_face);
+	      CHECK_LPOS();
+	    }
+	}
+#if defined (DISPLAY_TABS)
+      else if (c == '\t')
+	{
+	  register int newout;
+
+	  newout = out + 8 - lpos % 8;
+	  temp = newout - out;
+	  if (lpos + temp >= _rl_screenwidth)
+	    {
+	      register int temp2;
+	      temp2 = _rl_screenwidth - lpos;
+	      CHECK_INV_LBREAKS ();
+	      inv_lbreaks[++newlines] = out + temp2;
+#if defined (HANDLE_MULTIBYTE)
+	      line_state_invisible->wrapped_line[newlines] = _rl_wrapped_multicolumn;
+#endif
+	      lpos = temp - temp2;
+	      while (out < newout)
+		invis_addc (&out, ' ', cur_face);
+	    }
+	  else
+	    {
+	      while (out < newout)
+		invis_addc (&out, ' ', cur_face);
+	      lpos += temp;
+	    }
+	}
+#endif
+      else if (c == '\n' && _rl_horizontal_scroll_mode == 0 && _rl_term_up && *_rl_term_up)
+	{
+	  invis_addc (&out, '\0', cur_face);
+	  CHECK_INV_LBREAKS ();
+	  inv_lbreaks[++newlines] = out;
+#if defined (HANDLE_MULTIBYTE)
+	  line_state_invisible->wrapped_line[newlines] = _rl_wrapped_multicolumn;
+#endif
+	  lpos = 0;
+	}
+      else if (CTRL_CHAR (c) || c == RUBOUT)
+	{
+	  invis_addc (&out, '^', cur_face);
+	  CHECK_LPOS();
+	  invis_addc (&out, CTRL_CHAR (c) ? UNCTRL (c) : '?', cur_face);
+	  CHECK_LPOS();
+	}
+      else
+	{
+#if defined (HANDLE_MULTIBYTE)
+	  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	    {
+	      register int i;
+
+	      _rl_wrapped_multicolumn = 0;
+
+	      if (_rl_screenwidth < lpos + wc_width)
+		for (i = lpos; i < _rl_screenwidth; i++)
+		  {
+		    /* The space will be removed in update_line() */
+		    invis_addc (&out, ' ', cur_face);
+		    _rl_wrapped_multicolumn++;
+		    CHECK_LPOS();
+		  }
+	      if (in == rl_point)
+		{
+		  cpos_buffer_position = out;
+		  lb_linenum = newlines;
+		}
+	      for (i = in; i < in+wc_bytes; i++)
+		invis_addc (&out, rl_line_buffer[i], cur_face);
+	      for (i = 0; i < wc_width; i++)
+		CHECK_LPOS();
+	    }
+	  else
+	    {
+	      invis_addc (&out, c, cur_face);
+	      CHECK_LPOS();
+	    }
+#else
+	  invis_addc (&out, c, cur_face);
+	  CHECK_LPOS();
+#endif
+	}
+
+#if defined (HANDLE_MULTIBYTE)
+      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	{
+	  in += wc_bytes;
+	  if (_rl_utf8locale && UTF8_SINGLEBYTE(rl_line_buffer[in]))
+	    {
+	      wc = (WCHAR_T)rl_line_buffer[in];
+	      wc_bytes = 1;
+	      memset (&ps, 0, sizeof (mbstate_t));	/* re-init state */
+	    }
+	  else
+	    wc_bytes = MBRTOWC (&wc, rl_line_buffer + in, rl_end - in, &ps);
+	}
+      else
+        in++;
+#endif
+    }
+  invis_nul (&out);
+  line_totbytes = out;
+  if (cpos_buffer_position < 0)
+    {
+      cpos_buffer_position = out;
+      lb_linenum = newlines;
+    }
+
+  /* If we are switching from one line to multiple wrapped lines, we don't
+     want to do a dumb update (or we want to make it smarter). */
+  if (_rl_quick_redisplay && newlines > 0)
+    _rl_quick_redisplay = 0;
+
+  inv_botlin = lb_botlin = _rl_inv_botlin = newlines;
+  CHECK_INV_LBREAKS ();
+  inv_lbreaks[newlines+1] = out;
+#if defined (HANDLE_MULTIBYTE)
+  /* This should be 0 anyway */
+  line_state_invisible->wrapped_line[newlines+1] = _rl_wrapped_multicolumn;
+#endif
+  cursor_linenum = lb_linenum;
+
+  /* CPOS_BUFFER_POSITION == position in buffer where cursor should be placed.
+     CURSOR_LINENUM == line number where the cursor should be placed. */
+
+  /* PWP: now is when things get a bit hairy.  The visible and invisible
+     line buffers are really multiple lines, which would wrap every
+     (screenwidth - 1) characters.  Go through each in turn, finding
+     the changed region and updating it.  The line order is top to bottom. */
+
+  /* If we can move the cursor up and down, then use multiple lines,
+     otherwise, let long lines display in a single terminal line, and
+     horizontally scroll it. */
+  displaying_prompt_first_line = 1;
+  if (_rl_horizontal_scroll_mode == 0 && _rl_term_up && *_rl_term_up)
+    {
+      int nleft, pos, changed_screen_line, tx;
+
+      if (!rl_display_fixed || forced_display)
+	{
+	  forced_display = 0;
+
+	  /* If we have more than a screenful of material to display, then
+	     only display a screenful.  We should display the last screen,
+	     not the first.  */
+	  if (out >= _rl_screenchars)
+	    {
+#if defined (HANDLE_MULTIBYTE)
+	      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		out = _rl_find_prev_mbchar (invisible_line, _rl_screenchars, MB_FIND_ANY);
+	      else
+#endif
+		out = _rl_screenchars - 1;
+	    }
+
+	  /* The first line is at character position 0 in the buffer.  The
+	     second and subsequent lines start at inv_lbreaks[N], offset by
+	     OFFSET (which has already been calculated above).  */
+
+#define INVIS_FIRST()	(prompt_physical_chars > _rl_screenwidth ? prompt_invis_chars_first_line : wrap_offset)
+#define WRAP_OFFSET(line, offset)  ((line == 0) \
+					? (offset ? INVIS_FIRST() : 0) \
+					: ((line == prompt_last_screen_line) ? wrap_offset-prompt_invis_chars_first_line : 0))
+#define W_OFFSET(line, offset) ((line) == 0 ? offset : 0)
+#define VIS_LLEN(l)	((l) > _rl_vis_botlin ? 0 : (vis_lbreaks[l+1] - vis_lbreaks[l]))
+#define INV_LLEN(l)	(inv_lbreaks[l+1] - inv_lbreaks[l])
+#define VIS_CHARS(line) (visible_line + vis_lbreaks[line])
+#define VIS_FACE(line) (vis_face + vis_lbreaks[line])
+#define VIS_LINE(line) ((line) > _rl_vis_botlin) ? "" : VIS_CHARS(line)
+#define VIS_LINE_FACE(line) ((line) > _rl_vis_botlin) ? "" : VIS_FACE(line)
+#define INV_LINE(line) (invisible_line + inv_lbreaks[line])
+#define INV_LINE_FACE(line) (inv_face + inv_lbreaks[line])
+
+#define OLD_CPOS_IN_PROMPT() (cpos_adjusted == 0 && \
+			_rl_last_c_pos != o_cpos && \
+			_rl_last_c_pos > wrap_offset && \
+			o_cpos < prompt_last_invisible)
+
+
+	  /* We don't want to highlight anything that's going to be off the top
+	     of the display; if the current line takes up more than an entire
+	    screen, just mark the lines that won't be displayed as having a
+	    `normal' face.
+	    It's imperfect, but better than display corruption. */
+	  if (rl_mark_active_p () && inv_botlin > _rl_screenheight)
+	    {
+	      int extra;
+
+	      extra = inv_botlin - _rl_screenheight;
+	      for (linenum = 0; linenum <= extra; linenum++)
+		norm_face (INV_LINE_FACE(linenum), INV_LLEN (linenum));
+	    }
+
+	  /* For each line in the buffer, do the updating display. */
+	  for (linenum = 0; linenum <= inv_botlin; linenum++)
+	    {
+	      /* This can lead us astray if we execute a program that changes
+		 the locale from a non-multibyte to a multibyte one. */
+	      o_cpos = _rl_last_c_pos;
+	      cpos_adjusted = 0;
+	      update_line (VIS_LINE(linenum), VIS_LINE_FACE(linenum),
+			   INV_LINE(linenum), INV_LINE_FACE(linenum),
+			   linenum,
+			   VIS_LLEN(linenum), INV_LLEN(linenum), inv_botlin);
+
+	      /* update_line potentially changes _rl_last_c_pos, but doesn't
+		 take invisible characters into account, since _rl_last_c_pos
+		 is an absolute cursor position in a multibyte locale.  We
+		 choose to (mostly) compensate for that here, rather than
+		 change update_line itself.  There are several cases in which
+		 update_line adjusts _rl_last_c_pos itself (so it can pass
+		 _rl_move_cursor_relative accurate values); it communicates
+		 this back by setting cpos_adjusted.  If we assume that
+		 _rl_last_c_pos is correct (an absolute cursor position) each
+		 time update_line is called, then we can assume in our
+		 calculations that o_cpos does not need to be adjusted by
+		 wrap_offset. */
+	      if (linenum == 0 && (mb_cur_max > 1 && rl_byte_oriented == 0) && OLD_CPOS_IN_PROMPT())
+		_rl_last_c_pos -= prompt_invis_chars_first_line;	/* XXX - was wrap_offset */
+	      else if (cpos_adjusted == 0 &&
+			linenum == prompt_last_screen_line &&
+			prompt_physical_chars > _rl_screenwidth &&
+			(mb_cur_max > 1 && rl_byte_oriented == 0) &&
+			_rl_last_c_pos != o_cpos &&
+			_rl_last_c_pos > (prompt_last_invisible - _rl_screenwidth - prompt_invis_chars_first_line))	/* XXX - rethink this last one */
+		/* This assumes that all the invisible characters are split
+		   between the first and last lines of the prompt, if the 
+		   prompt consumes more than two lines. It's usually right */
+		/* XXX - not sure this is ever executed */
+		_rl_last_c_pos -= (wrap_offset-prompt_invis_chars_first_line);
+
+	      /* If this is the line with the prompt, we might need to
+		 compensate for invisible characters in the new line. Do
+		 this only if there is not more than one new line (which
+		 implies that we completely overwrite the old visible line)
+		 and the new line is shorter than the old.  Make sure we are
+		 at the end of the new line before clearing. */
+	      if (linenum == 0 &&
+		  inv_botlin == 0 && _rl_last_c_pos == out &&
+		  (wrap_offset > visible_wrap_offset) &&
+		  (_rl_last_c_pos < visible_first_line_len))
+		{
+		  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		    nleft = _rl_screenwidth - _rl_last_c_pos;
+		  else
+		    nleft = _rl_screenwidth + wrap_offset - _rl_last_c_pos;
+		  if (nleft)
+		    _rl_clear_to_eol (nleft);
+		}
+#if 0
+	      /* This segment is intended to handle the case where the old
+		 visible prompt has invisible characters and the new line
+		 to be displayed needs to clear the rest of the old characters
+		 out (e.g., when printing the i-search prompt): in general,
+		 the case of the new line being shorter than the old.  We need
+		 to be at the end of the new line and the old line needs to be
+		 longer than the current cursor position. It's not perfect,
+		 since it uses the byte length of the first line, but this will
+		 at worst result in some extra clear-to-end-of-lines. We can't
+		 use the prompt length variables because they may not
+		 correspond to the visible line (see printing the i-search
+		 prompt above). The tests for differing numbers of invisible
+		 characters may not matter and can probably be removed. */
+	      else if (linenum == 0 &&
+		       linenum == prompt_last_screen_line &&
+		       _rl_last_c_pos == out &&
+		       _rl_last_c_pos < visible_first_line_len &&
+		       visible_wrap_offset &&
+		       visible_wrap_offset != wrap_offset)
+		{
+		  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		    nleft = _rl_screenwidth - _rl_last_c_pos;
+		  else
+		    nleft = _rl_screenwidth + wrap_offset - _rl_last_c_pos;
+		  if (nleft)
+		    _rl_clear_to_eol (nleft);
+		}
+#endif
+
+	      /* Since the new first line is now visible, save its length. */
+	      if (linenum == 0)
+		visible_first_line_len = (inv_botlin > 0) ? inv_lbreaks[1] : out - wrap_offset;
+	    }
+
+	  /* We may have deleted some lines.  If so, clear the left over
+	     blank ones at the bottom out. */
+	  if (_rl_vis_botlin > inv_botlin)
+	    {
+	      char *tt;
+	      for (; linenum <= _rl_vis_botlin; linenum++)
+		{
+		  tt = VIS_CHARS (linenum);
+		  _rl_move_vert (linenum);
+		  _rl_move_cursor_relative (0, tt, VIS_FACE(linenum));
+		  _rl_clear_to_eol
+		    ((linenum == _rl_vis_botlin) ? strlen (tt) : _rl_screenwidth);
+		}
+	    }
+	  _rl_vis_botlin = inv_botlin;
+
+	  /* CHANGED_SCREEN_LINE is set to 1 if we have moved to a
+	     different screen line during this redisplay. */
+	  changed_screen_line = _rl_last_v_pos != cursor_linenum;
+	  if (changed_screen_line)
+	    {
+	      _rl_move_vert (cursor_linenum);
+	      /* If we moved up to the line with the prompt using _rl_term_up,
+		 the physical cursor position on the screen stays the same,
+		 but the buffer position needs to be adjusted to account
+		 for invisible characters. */
+	      if ((mb_cur_max == 1 || rl_byte_oriented) && cursor_linenum == 0 && wrap_offset)
+		_rl_last_c_pos += wrap_offset;
+	    }
+
+	  /* Now we move the cursor to where it needs to be.  First, make
+	     sure we are on the correct line (cursor_linenum). */
+
+	  /* We have to reprint the prompt if it contains invisible
+	     characters, since it's not generally OK to just reprint
+	     the characters from the current cursor position.  But we
+	     only need to reprint it if the cursor is before the last
+	     invisible character in the prompt string. */
+	  /* XXX - why not use local_prompt_len? */
+	  nleft = prompt_visible_length + wrap_offset;
+	  if (cursor_linenum == 0 && wrap_offset > 0 && _rl_last_c_pos > 0 &&
+	      _rl_last_c_pos < PROMPT_ENDING_INDEX && local_prompt)
+	    {
+	      _rl_cr ();
+	      if (modmark)
+		_rl_output_some_chars ("*", 1);
+
+	      _rl_output_some_chars (local_prompt, nleft);
+	      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		_rl_last_c_pos = _rl_col_width (local_prompt, 0, nleft, 1) - wrap_offset + modmark;
+	      else
+		_rl_last_c_pos = nleft + modmark;
+	    }
+
+	  /* Where on that line?  And where does that line start
+	     in the buffer? */
+	  pos = inv_lbreaks[cursor_linenum];
+	  /* nleft == number of characters (bytes) in the line buffer between
+	     the start of the line and the desired cursor position. */
+	  nleft = cpos_buffer_position - pos;
+
+	  /* NLEFT is now a number of characters in a buffer.  When in a
+	     multibyte locale, however, _rl_last_c_pos is an absolute cursor
+	     position that doesn't take invisible characters in the prompt
+	     into account.  We use a fudge factor to compensate. */
+
+	  /* Since _rl_backspace() doesn't know about invisible characters in
+	     the prompt, and there's no good way to tell it, we compensate for
+	     those characters here and call _rl_backspace() directly if
+	     necessary */
+	  if (wrap_offset && cursor_linenum == 0 && nleft < _rl_last_c_pos)
+	    {
+	      /* TX == new physical cursor position in multibyte locale. */
+	      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		tx = _rl_col_width (&visible_line[pos], 0, nleft, 1) - visible_wrap_offset;
+	      else
+		tx = nleft;
+	      if (tx >= 0 && _rl_last_c_pos > tx)
+		{
+	          _rl_backspace (_rl_last_c_pos - tx);	/* XXX */
+	          _rl_last_c_pos = tx;
+		}
+	    }
+
+	  /* We need to note that in a multibyte locale we are dealing with
+	     _rl_last_c_pos as an absolute cursor position, but moving to a
+	     point specified by a buffer position (NLEFT) that doesn't take
+	     invisible characters into account. */
+	  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	    _rl_move_cursor_relative (nleft, &invisible_line[pos], &inv_face[pos]);
+	  else if (nleft != _rl_last_c_pos)
+	    _rl_move_cursor_relative (nleft, &invisible_line[pos], &inv_face[pos]);
+	}
+    }
+  else				/* Do horizontal scrolling. Much simpler */
+    {
+#define M_OFFSET(margin, offset) ((margin) == 0 ? offset : 0)
+      int lmargin, ndisp, nleft, phys_c_pos, t;
+
+      /* Always at top line. */
+      _rl_last_v_pos = 0;
+
+      /* Compute where in the buffer the displayed line should start.  This
+	 will be LMARGIN. */
+
+      /* The number of characters that will be displayed before the cursor. */
+      ndisp = cpos_buffer_position - wrap_offset;
+      nleft  = prompt_visible_length + wrap_offset;
+      /* Where the new cursor position will be on the screen.  This can be
+	 longer than SCREENWIDTH; if it is, lmargin will be adjusted. */
+      phys_c_pos = cpos_buffer_position - (last_lmargin ? last_lmargin : wrap_offset);
+      t = _rl_screenwidth / 3;
+
+      /* If the number of characters had already exceeded the screenwidth,
+	 last_lmargin will be > 0. */
+
+      /* If the number of characters to be displayed is more than the screen
+	 width, compute the starting offset so that the cursor is about
+	 two-thirds of the way across the screen. */
+      if (phys_c_pos > _rl_screenwidth - 2)
+	{
+	  lmargin = cpos_buffer_position - (2 * t);
+	  if (lmargin < 0)
+	    lmargin = 0;
+	  /* If the left margin would be in the middle of a prompt with
+	     invisible characters, don't display the prompt at all. */
+	  if (wrap_offset && lmargin > 0 && lmargin < nleft)
+	    lmargin = nleft;
+	}
+      else if (ndisp < _rl_screenwidth - 2)		/* XXX - was -1 */
+	lmargin = 0;
+      else if (phys_c_pos < 1)
+	{
+	  /* If we are moving back towards the beginning of the line and
+	     the last margin is no longer correct, compute a new one. */
+	  lmargin = ((cpos_buffer_position - 1) / t) * t;	/* XXX */
+	  if (wrap_offset && lmargin > 0 && lmargin < nleft)
+	    lmargin = nleft;
+	}
+      else
+	lmargin = last_lmargin;
+
+      displaying_prompt_first_line = lmargin < nleft;
+
+      /* If the first character on the screen isn't the first character
+	 in the display line, indicate this with a special character. */
+      if (lmargin > 0)
+	invisible_line[lmargin] = '<';
+
+      /* If SCREENWIDTH characters starting at LMARGIN do not encompass
+	 the whole line, indicate that with a special character at the
+	 right edge of the screen.  If LMARGIN is 0, we need to take the
+	 wrap offset into account. */
+      t = lmargin + M_OFFSET (lmargin, wrap_offset) + _rl_screenwidth;
+      if (t > 0 && t < out)
+	invisible_line[t - 1] = '>';
+
+      if (rl_display_fixed == 0 || forced_display || lmargin != last_lmargin)
+	{
+	  forced_display = 0;
+	  o_cpos = _rl_last_c_pos;
+	  cpos_adjusted = 0;
+	  update_line (&visible_line[last_lmargin], &vis_face[last_lmargin],
+		       &invisible_line[lmargin], &inv_face[lmargin],
+		       0,
+		       _rl_screenwidth + visible_wrap_offset,
+		       _rl_screenwidth + (lmargin ? 0 : wrap_offset),
+		       0);
+
+	  if ((mb_cur_max > 1 && rl_byte_oriented == 0) &&
+		displaying_prompt_first_line && OLD_CPOS_IN_PROMPT())
+	    _rl_last_c_pos -= prompt_invis_chars_first_line;	/* XXX - was wrap_offset */
+
+	  /* If the visible new line is shorter than the old, but the number
+	     of invisible characters is greater, and we are at the end of
+	     the new line, we need to clear to eol. */
+	  t = _rl_last_c_pos - M_OFFSET (lmargin, wrap_offset);
+	  if ((M_OFFSET (lmargin, wrap_offset) > visible_wrap_offset) &&
+	      (_rl_last_c_pos == out) && displaying_prompt_first_line &&
+	      t < visible_first_line_len)
+	    {
+	      nleft = _rl_screenwidth - t;
+	      _rl_clear_to_eol (nleft);
+	    }
+	  visible_first_line_len = out - lmargin - M_OFFSET (lmargin, wrap_offset);
+	  if (visible_first_line_len > _rl_screenwidth)
+	    visible_first_line_len = _rl_screenwidth;
+
+	  _rl_move_cursor_relative (cpos_buffer_position - lmargin, &invisible_line[lmargin], &inv_face[lmargin]);
+	  last_lmargin = lmargin;
+	}
+    }
+  fflush (rl_outstream);
+
+  /* Swap visible and non-visible lines. */
+  {
+    struct line_state *vtemp = line_state_visible;
+
+    line_state_visible = line_state_invisible;
+    line_state_invisible = vtemp;
+
+    rl_display_fixed = 0;
+    /* If we are displaying on a single line, and last_lmargin is > 0, we
+       are not displaying any invisible characters, so set visible_wrap_offset
+       to 0. */
+    if (_rl_horizontal_scroll_mode && last_lmargin)
+      visible_wrap_offset = 0;
+    else
+      visible_wrap_offset = wrap_offset;
+
+    _rl_quick_redisplay = 0;
+  }
+
+  RL_UNSETSTATE (RL_STATE_REDISPLAYING);
+  _rl_release_sigint ();
+}
+
+static void
+putc_face (int c, int face, char *cur_face)
+{
+  char cf;
+  cf = *cur_face;
+  if (cf != face)
+    {
+      if (cf != FACE_NORMAL && cf != FACE_STANDOUT)
+	return;
+      if (face != FACE_NORMAL && face != FACE_STANDOUT)
+	return;
+      if (face == FACE_STANDOUT && cf == FACE_NORMAL)
+	_rl_region_color_on ();
+      if (face == FACE_NORMAL && cf == FACE_STANDOUT)
+	_rl_region_color_off ();
+      *cur_face = face;
+    }
+  if (c != EOF)
+    putc (c, rl_outstream);
+}
+
+static void
+puts_face (const char *str, const char *face, int n)
+{
+  int i;
+  char cur_face;
+
+  for (cur_face = FACE_NORMAL, i = 0; i < n; i++)
+    putc_face ((unsigned char) str[i], face[i], &cur_face);
+  putc_face (EOF, FACE_NORMAL, &cur_face);
+}
+
+static void
+norm_face (char *face, int n)
+{
+  memset (face, FACE_NORMAL, n);
+}
+
+#define ADJUST_CPOS(x) do { _rl_last_c_pos -= (x) ; cpos_adjusted = 1; } while (0)
+
+/* PWP: 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.
+
+   Could be made even smarter, but this works well enough */
+static void
+update_line (char *old, char *old_face, char *new, char *new_face, int current_line, int omax, int nmax, int inv_botlin)
+{
+  char *ofd, *ols, *oe, *nfd, *nls, *ne;
+  char *ofdf, *nfdf, *olsf, *nlsf;
+  int temp, lendiff, wsatend, od, nd, twidth, o_cpos;
+  int current_invis_chars;
+  int col_lendiff, col_temp;
+  int bytes_to_insert;
+  int mb_cur_max = MB_CUR_MAX;
+#if defined (HANDLE_MULTIBYTE)
+  mbstate_t ps_new, ps_old;
+  int new_offset, old_offset;
+#endif
+
+  /* If we're at the right edge of a terminal that supports xn, we're
+     ready to wrap around, so do so.  This fixes problems with knowing
+     the exact cursor position and cut-and-paste with certain terminal
+     emulators.  In this calculation, TEMP is the physical screen
+     position of the cursor. */
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    temp = _rl_last_c_pos;
+  else
+    temp = _rl_last_c_pos - WRAP_OFFSET (_rl_last_v_pos, visible_wrap_offset);
+  if (temp == _rl_screenwidth && _rl_term_autowrap && !_rl_horizontal_scroll_mode
+	&& _rl_last_v_pos == current_line - 1)
+    {
+      /* We're going to wrap around by writing the first character of NEW to
+	 the screen and dealing with changes to what's visible by modifying
+	 OLD to match it.  Complicated by the presence of multi-width
+	 characters at the end of the line or beginning of the new one. */
+      /* old is always somewhere in visible_line; new is always somewhere in
+         invisible_line.  These should always be null-terminated. */
+#if defined (HANDLE_MULTIBYTE)
+      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	{
+	  WCHAR_T wc;
+	  mbstate_t ps;
+	  int oldwidth, newwidth;
+	  int oldbytes, newbytes;
+	  size_t ret;
+
+	  /* This fixes only double-column characters, but if the wrapped
+	     character consumes more than three columns, spaces will be
+	     inserted in the string buffer. */
+	  /* XXX remember that we are working on the invisible line right now;
+	     we don't swap visible and invisible until just before rl_redisplay
+	     returns */
+	  /* This will remove the extra placeholder space we added with
+	     _rl_wrapped_multicolumn */
+	  if (current_line < line_state_invisible->wbsize && line_state_invisible->wrapped_line[current_line] > 0)
+	    _rl_clear_to_eol (line_state_invisible->wrapped_line[current_line]);
+
+	  /* 1. how many screen positions does first char in old consume? */
+	  memset (&ps, 0, sizeof (mbstate_t));
+	  ret = MBRTOWC (&wc, old, mb_cur_max, &ps);
+	  oldbytes = ret;
+	  if (MB_INVALIDCH (ret))
+	    {
+	      oldwidth = 1;
+	      oldbytes = 1;
+	    }
+	  else if (MB_NULLWCH (ret))
+	    oldwidth = 0;
+	  else
+	    oldwidth = WCWIDTH (wc);
+	  if (oldwidth < 0)
+	    oldwidth = 1;
+
+	  /* 2. how many screen positions does the first char in new consume? */
+	  memset (&ps, 0, sizeof (mbstate_t));
+	  ret = MBRTOWC (&wc, new, mb_cur_max, &ps);
+	  newbytes = ret;
+	  if (MB_INVALIDCH (ret))
+	    {
+	      newwidth = 1;
+	      newbytes = 1;
+	    }
+	  else if (MB_NULLWCH (ret))
+	    newwidth = 0;
+	  else
+	    newwidth = WCWIDTH (wc);
+	  if (newwidth < 0)
+	    newwidth = 1;
+
+	  /* 3. if the new width is less than the old width, we need to keep
+	     going in new until we have consumed at least that many screen
+	     positions, and figure out how many bytes that will take */
+	  while (newbytes < nmax && newwidth < oldwidth)
+	    {
+	      int t;
+
+	      ret = MBRTOWC (&wc, new+newbytes, mb_cur_max, &ps);
+	      if (MB_INVALIDCH (ret))
+		{
+		  newwidth += 1;
+		  newbytes += 1;
+		}
+	      else if (MB_NULLWCH (ret))
+	        break;
+	      else
+		{
+		  t = WCWIDTH (wc);
+		  newwidth += (t >= 0) ? t : 1;
+		  newbytes += ret;
+		}
+	    }
+	  /* 4. If the new width is more than the old width, keep going in old
+	     until we have consumed exactly that many screen positions, and
+	     figure out how many bytes that will take.  This is an optimization */
+	  while (oldbytes < omax && oldwidth < newwidth)
+	    {
+	      int t;
+
+	      ret = MBRTOWC (&wc, old+oldbytes, mb_cur_max, &ps);
+	      if (MB_INVALIDCH (ret))
+		{
+		  oldwidth += 1;
+		  oldbytes += 1;
+		}
+	      else if (MB_NULLWCH (ret))
+	        break;
+	      else
+		{
+		  t = WCWIDTH (wc);
+		  oldwidth += (t >= 0) ? t : 1;
+		  oldbytes += ret;
+		}
+	    }
+	  /* 5. write the first newbytes of new, which takes newwidth.  This is
+	     where the screen wrapping takes place, and we are now writing
+	     characters onto the new line. We need to fix up old so it
+	     accurately reflects what is on the screen after the
+	     _rl_output_some_chars below. */
+	  if (newwidth > 0)
+	    {
+	      int count, i, j;
+	      char *optr;
+
+	      puts_face (new, new_face, newbytes);
+	      _rl_last_c_pos = newwidth;
+	      _rl_last_v_pos++;
+
+	      /* 5a. If the number of screen positions doesn't match, punt
+		 and do a dumb update.
+		 5b. If the number of bytes is greater in the new line than
+		 the old, do a dumb update, because there is no guarantee we
+		 can extend the old line enough to fit the new bytes. */
+	      if (newwidth != oldwidth || newbytes > oldbytes)
+		{
+		  oe = old + omax;
+		  ne = new + nmax;
+		  nd = newbytes;
+		  nfd = new + nd;
+		  ofdf = old_face + oldbytes;
+		  nfdf = new_face + newbytes;
+
+		  goto dumb_update;
+		}
+	      if (oldbytes != 0 && newbytes != 0)
+		{
+		  /* We have written as many bytes from new as we need to
+		     consume the first character of old. Fix up `old' so it
+		     reflects the new screen contents.  We use +1 in the
+		     memmove call to copy the trailing NUL. */
+		  /* (strlen(old+oldbytes) == (omax - oldbytes - 1)) */
+
+		  /* Don't bother trying to fit the bytes if the number of bytes
+		     doesn't change. */
+		  if (oldbytes != newbytes)
+		    {
+		      memmove (old+newbytes, old+oldbytes, strlen (old+oldbytes) + 1);
+		      memmove (old_face+newbytes, old_face+oldbytes, strlen (old+oldbytes) + 1);
+		    }
+		  memcpy (old, new, newbytes);
+		  memcpy (old_face, new_face, newbytes);
+		  j = newbytes - oldbytes;
+		  omax += j;
+		  /* Fix up indices if we copy data from one line to another */
+		  for (i = current_line+1; j != 0 && i <= inv_botlin+1 && i <=_rl_vis_botlin+1; i++)
+		    vis_lbreaks[i] += j;
+		}
+	    }
+	  else
+	    {
+	      putc (' ', rl_outstream);
+	      _rl_last_c_pos = 1;
+	      _rl_last_v_pos++;
+	      if (old[0] && new[0])
+		{
+		  old[0] = new[0];
+		  old_face[0] = new_face[0];
+		}
+	    }
+	}
+      else
+#endif
+	{
+	  if (new[0])
+	    puts_face (new, new_face, 1);
+	  else
+	    putc (' ', rl_outstream);
+	  _rl_last_c_pos = 1;
+	  _rl_last_v_pos++;
+	  if (old[0] && new[0])
+	    {
+	      old[0] = new[0];
+	      old_face[0] = new_face[0];
+	    }
+	}
+    }
+
+  /* We know that we are dealing with a single screen line here */
+  if (_rl_quick_redisplay)
+    {
+      nfd = new;
+      nfdf = new_face;
+      ofd = old;
+      ofdf = old_face;
+      for (od = 0, oe = ofd; od < omax && *oe; oe++, od++);
+      for (nd = 0, ne = nfd; nd < nmax && *ne; ne++, nd++);
+      od = nd = 0;
+      _rl_move_cursor_relative (0, old, old_face);
+
+      bytes_to_insert = ne - nfd;
+      if (bytes_to_insert < local_prompt_len)	/* ??? */
+	goto dumb_update;
+
+      /* output the prompt, output the line contents, clear the rest */
+      _rl_output_some_chars (nfd, local_prompt_len);
+      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	_rl_last_c_pos = prompt_physical_chars;
+      else
+	_rl_last_c_pos = local_prompt_len;
+
+      bytes_to_insert -= local_prompt_len;
+      if (bytes_to_insert > 0)
+	{
+	  puts_face (new+local_prompt_len, nfdf+local_prompt_len, bytes_to_insert);
+	  if (mb_cur_max > 1 && rl_byte_oriented)
+	    _rl_last_c_pos += _rl_col_width (new, local_prompt_len, ne-new, 1);
+	  else
+	    _rl_last_c_pos += bytes_to_insert;
+	}
+
+      /* See comments at dumb_update: for an explanation of this heuristic */
+      if (nmax < omax)
+	goto clear_rest_of_line;
+      else if ((nmax - W_OFFSET(current_line, wrap_offset)) < (omax - W_OFFSET (current_line, visible_wrap_offset)))
+	goto clear_rest_of_line;
+      else
+	return;
+    }
+
+  /* Find first difference. */
+#if defined (HANDLE_MULTIBYTE)
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    {
+      /* See if the old line is a subset of the new line, so that the
+	 only change is adding characters. */
+      temp = (omax < nmax) ? omax : nmax;
+      if (memcmp (old, new, temp) == 0 && memcmp (old_face, new_face, temp) == 0)
+	{
+	  new_offset = old_offset = temp;	/* adding at the end */
+	  ofd = old + temp;
+	  ofdf = old_face + temp;
+	  nfd = new + temp;
+	  nfdf = new_face + temp;
+	}
+      else
+	{      
+	  memset (&ps_new, 0, sizeof(mbstate_t));
+	  memset (&ps_old, 0, sizeof(mbstate_t));
+
+	  /* Are the old and new lines the same? */
+	  if (omax == nmax && memcmp (new, old, omax) == 0 && memcmp (new_face, old_face, omax) == 0)
+	    {
+	      old_offset = omax;
+	      new_offset = nmax;
+	      ofd = old + omax;
+	      ofdf = old_face + omax;
+	      nfd = new + nmax;
+	      nfdf = new_face + nmax;
+	    }
+	  else
+	    {
+	      /* Go through the line from the beginning and find the first
+		 difference. We assume that faces change at (possibly multi-
+		 byte) character boundaries. */
+	      new_offset = old_offset = 0;
+	      for (ofd = old, ofdf = old_face, nfd = new, nfdf = new_face;
+		    (ofd - old < omax) && *ofd &&
+		    _rl_compare_chars(old, old_offset, &ps_old, new, new_offset, &ps_new) &&
+		    *ofdf == *nfdf; )
+		{
+		  old_offset = _rl_find_next_mbchar (old, old_offset, 1, MB_FIND_ANY);
+		  new_offset = _rl_find_next_mbchar (new, new_offset, 1, MB_FIND_ANY);
+
+		  ofd = old + old_offset;
+		  ofdf = old_face + old_offset;
+		  nfd = new + new_offset;
+		  nfdf = new_face + new_offset;
+		}
+	    }
+	}
+    }
+  else
+#endif
+  for (ofd = old, ofdf = old_face, nfd = new, nfdf = new_face;
+       (ofd - old < omax) && *ofd && (*ofd == *nfd) && (*ofdf == *nfdf);
+       ofd++, nfd++, ofdf++, nfdf++)
+    ;
+
+  /* Move to the end of the screen line.  ND and OD are used to keep track
+     of the distance between ne and new and oe and old, respectively, to
+     move a subtraction out of each loop. */
+  for (od = ofd - old, oe = ofd; od < omax && *oe; oe++, od++);
+  for (nd = nfd - new, ne = nfd; nd < nmax && *ne; ne++, nd++);
+
+  /* If no difference, continue to next line. */
+  if (ofd == oe && nfd == ne)
+    return;
+
+#if defined (HANDLE_MULTIBYTE)
+  if (mb_cur_max > 1 && rl_byte_oriented == 0 && _rl_utf8locale)
+    {
+      WCHAR_T wc;
+      mbstate_t ps = { 0 };
+      int t;
+
+      /* If the first character in the difference is a zero-width character,
+	 assume it's a combining character and back one up so the two base
+	 characters no longer compare equivalently. */
+      t = MBRTOWC (&wc, ofd, mb_cur_max, &ps);
+      if (t > 0 && UNICODE_COMBINING_CHAR (wc) && WCWIDTH (wc) == 0)
+	{
+	  old_offset = _rl_find_prev_mbchar (old, ofd - old, MB_FIND_ANY);
+	  new_offset = _rl_find_prev_mbchar (new, nfd - new, MB_FIND_ANY);
+	  ofd = old + old_offset;	/* equal by definition */
+	  ofdf = old_face + old_offset;
+	  nfd = new + new_offset;
+	  nfdf = new_face + new_offset;
+	}
+    }
+#endif
+
+  wsatend = 1;			/* flag for trailing whitespace */
+
+#if defined (HANDLE_MULTIBYTE)
+  /* Find the last character that is the same between the two lines.  This
+     bounds the region that needs to change. */
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    {
+      ols = old + _rl_find_prev_mbchar (old, oe - old, MB_FIND_ANY);
+      olsf = old_face + (ols - old);
+      nls = new + _rl_find_prev_mbchar (new, ne - new, MB_FIND_ANY);
+      nlsf = new_face + (nls - new);
+
+      while ((ols > ofd) && (nls > nfd))
+	{
+	  memset (&ps_old, 0, sizeof (mbstate_t));
+	  memset (&ps_new, 0, sizeof (mbstate_t));
+
+	  if (_rl_compare_chars (old, ols - old, &ps_old, new, nls - new, &ps_new) == 0 ||
+		*olsf != *nlsf)
+	    break;
+
+	  if (*ols == ' ')
+	    wsatend = 0;
+
+	  ols = old + _rl_find_prev_mbchar (old, ols - old, MB_FIND_ANY);
+	  olsf = old_face + (ols - old);
+	  nls = new + _rl_find_prev_mbchar (new, nls - new, MB_FIND_ANY);
+	  nlsf = new_face + (nls - new);
+	}
+    }
+  else
+    {
+#endif /* HANDLE_MULTIBYTE */
+  ols = oe - 1;			/* find last same */
+  olsf = old_face + (ols - old);
+  nls = ne - 1;
+  nlsf = new_face + (nls - new);
+  while ((ols > ofd) && (nls > nfd) && (*ols == *nls) && (*olsf == *nlsf))
+    {
+      if (*ols != ' ')
+	wsatend = 0;
+      ols--; olsf--;
+      nls--; nlsf--;
+    }
+#if defined (HANDLE_MULTIBYTE)
+    }
+#endif
+
+  if (wsatend)
+    {
+      ols = oe;
+      olsf = old_face + (ols - old);
+      nls = ne;
+      nlsf = new_face + (nls - new);
+    }
+#if defined (HANDLE_MULTIBYTE)
+  /* This may not work for stateful encoding, but who cares?  To handle
+     stateful encoding properly, we have to scan each string from the
+     beginning and compare. */
+  else if (_rl_compare_chars (ols, 0, NULL, nls, 0, NULL) == 0 || *olsf != *nlsf)
+#else
+  else if (*ols != *nls || *olsf != *nlsf)
+#endif
+    {
+      if (*ols)			/* don't step past the NUL */
+	{
+	  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	    ols = old + _rl_find_next_mbchar (old, ols - old, 1, MB_FIND_ANY);
+	  else
+	    ols++;
+	}
+      if (*nls)
+	{
+	  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	    nls = new + _rl_find_next_mbchar (new, nls - new, 1, MB_FIND_ANY);
+	  else
+	    nls++;
+	}
+      olsf = old_face + (ols - old);
+      nlsf = new_face + (nls - new);
+    }
+
+  /* count of invisible characters in the current invisible line. */
+  current_invis_chars = W_OFFSET (current_line, wrap_offset);
+  if (_rl_last_v_pos != current_line)
+    {
+      _rl_move_vert (current_line);
+      /* We have moved up to a new screen line.  This line may or may not have
+         invisible characters on it, but we do our best to recalculate
+         visible_wrap_offset based on what we know. */
+      if (current_line == 0)
+	visible_wrap_offset = prompt_invis_chars_first_line;	/* XXX */
+#if 0		/* XXX - not yet */
+      else if (current_line == prompt_last_screen_line && wrap_offset > prompt_invis_chars_first_line)
+	visible_wrap_offset = wrap_offset - prompt_invis_chars_first_line
+#endif
+      if ((mb_cur_max == 1 || rl_byte_oriented) && current_line == 0 && visible_wrap_offset)
+	_rl_last_c_pos += visible_wrap_offset;
+    }
+
+  /* If this is the first line and there are invisible characters in the
+     prompt string, and the prompt string has not changed, and the current
+     cursor position is before the last invisible character in the prompt,
+     and the index of the character to move to is past the end of the prompt
+     string, then redraw the entire prompt string.  We can only do this
+     reliably if the terminal supports a `cr' capability.
+
+     This can also happen if the prompt string has changed, and the first
+     difference in the line is in the middle of the prompt string, after a
+     sequence of invisible characters (worst case) and before the end of
+     the prompt.  In this case, we have to redraw the entire prompt string
+     so that the entire sequence of invisible characters is drawn.  We need
+     to handle the worst case, when the difference is after (or in the middle
+     of) a sequence of invisible characters that changes the text color and
+     before the sequence that restores the text color to normal.  Then we have
+     to make sure that the lines still differ -- if they don't, we can
+     return immediately.
+
+     This is not an efficiency hack -- there is a problem with redrawing
+     portions of the prompt string if they contain terminal escape
+     sequences (like drawing the `unbold' sequence without a corresponding
+     `bold') that manifests itself on certain terminals. */
+
+  lendiff = local_prompt_len;
+  if (lendiff > nmax)
+    lendiff = nmax;
+  od = ofd - old;	/* index of first difference in visible line */
+  nd = nfd - new;	/* nd, od are buffer indexes */
+  if (current_line == 0 && !_rl_horizontal_scroll_mode &&
+      _rl_term_cr && lendiff > prompt_visible_length && _rl_last_c_pos > 0 &&
+      (((od > 0 || nd > 0) && (od <= prompt_last_invisible || nd <= prompt_last_invisible)) ||
+		((od >= lendiff) && _rl_last_c_pos < PROMPT_ENDING_INDEX)))
+    {
+      _rl_cr ();
+      if (modmark)
+	_rl_output_some_chars ("*", 1);
+      _rl_output_some_chars (local_prompt, lendiff);
+      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	{
+	  /* If we just output the entire prompt string we can take advantage
+	     of knowing the number of physical characters in the prompt. If
+	     the prompt wraps lines (lendiff clamped at nmax), we can't. */
+	  if (lendiff == local_prompt_len)
+	    _rl_last_c_pos = prompt_physical_chars + modmark;
+	  else
+	    /* We take wrap_offset into account here so we can pass correct
+	       information to _rl_move_cursor_relative. */
+	    _rl_last_c_pos = _rl_col_width (local_prompt, 0, lendiff, 1) - wrap_offset + modmark;
+	  cpos_adjusted = 1;
+	}
+      else
+	_rl_last_c_pos = lendiff + modmark;
+
+      /* Now if we have printed the prompt string because the first difference
+	 was within the prompt, see if we need to recompute where the lines
+	 differ.  Check whether where we are now is past the last place where
+	 the old and new lines are the same and short-circuit now if we are. */
+      if ((od <= prompt_last_invisible || nd <= prompt_last_invisible) &&
+          omax == nmax &&
+	  lendiff > (ols-old) && lendiff > (nls-new))
+	return;
+
+      /* XXX - we need to fix up our calculations if we are now past the
+	 old ofd/nfd and the prompt length (or line length) has changed.
+	 We punt on the problem and do a dumb update.  We'd like to be able
+	 to just output the prompt from the beginning of the line up to the
+	 first difference, but you don't know the number of invisible
+	 characters in that case.
+	 This needs a lot of work to be efficient, but it usually doesn't matter. */
+      if ((od <= prompt_last_invisible || nd <= prompt_last_invisible))
+	{
+	  nfd = new + lendiff;	/* number of characters we output above */
+	  nfdf = new_face + lendiff;
+	  nd = lendiff;
+
+	  /* Do a dumb update and return */
+dumb_update:
+	  temp = ne - nfd;
+	  if (temp > 0)
+	    {
+	      puts_face (nfd, nfdf, temp);
+	      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		{
+		  _rl_last_c_pos += _rl_col_width (new, nd, ne - new, 1);
+		  /* Need to adjust here based on wrap_offset. Guess that if
+		     this is the line containing the last line of the prompt
+		     we need to adjust by
+		     	wrap_offset-prompt_invis_chars_first_line
+		     on the assumption that this is the number of invisible
+		     characters in the last line of the prompt. */
+		  if (wrap_offset > prompt_invis_chars_first_line &&
+		      current_line == prompt_last_screen_line &&
+		      prompt_physical_chars > _rl_screenwidth &&
+		      _rl_horizontal_scroll_mode == 0)
+		    ADJUST_CPOS (wrap_offset - prompt_invis_chars_first_line);
+
+		  /* If we just output a new line including the prompt, and
+		     the prompt includes invisible characters, we need to
+		     account for them in the _rl_last_c_pos calculation, since
+		     _rl_col_width does not. This happens when other code does
+		     a goto dumb_update; */
+		  else if (current_line == 0 &&
+			   nfd == new &&
+			   prompt_invis_chars_first_line &&
+			   local_prompt_len <= temp &&
+			   wrap_offset >= prompt_invis_chars_first_line &&
+			   _rl_horizontal_scroll_mode == 0)
+		    ADJUST_CPOS (prompt_invis_chars_first_line);
+		}
+	      else
+		_rl_last_c_pos += temp;
+	    }
+	  /* This is a useful heuristic, but what we really want is to clear
+	     if the new number of visible screen characters is less than the
+	     old number of visible screen characters. If the prompt has changed,
+	     we don't really have enough information about the visible line to
+	     know for sure, so we use another heuristic calclulation below. */
+	  if (nmax < omax)
+	    goto clear_rest_of_line;	/* XXX */
+	  else if ((nmax - W_OFFSET(current_line, wrap_offset)) < (omax - W_OFFSET (current_line, visible_wrap_offset)))
+	    goto clear_rest_of_line;
+	  else
+	    return;
+	}
+    }
+
+  o_cpos = _rl_last_c_pos;
+
+  /* When this function returns, _rl_last_c_pos is correct, and an absolute
+     cursor position in multibyte mode, but a buffer index when not in a
+     multibyte locale. */
+  _rl_move_cursor_relative (od, old, old_face);
+
+#if defined (HANDLE_MULTIBYTE)
+  /* We need to indicate that the cursor position is correct in the presence of
+     invisible characters in the prompt string.  Let's see if setting this when
+     we make sure we're at the end of the drawn prompt string works. */
+  if (current_line == 0 && mb_cur_max > 1 && rl_byte_oriented == 0 &&
+      (_rl_last_c_pos > 0 || o_cpos > 0) &&
+      _rl_last_c_pos == prompt_physical_chars)
+    cpos_adjusted = 1;
+#endif
+
+  /* if (len (new) > len (old))
+     lendiff == difference in buffer (bytes)
+     col_lendiff == difference on screen (columns)
+     When not using multibyte characters, these are equal */
+  lendiff = (nls - nfd) - (ols - ofd);
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    {
+      int newchars, newwidth, newind;
+      int oldchars, oldwidth, oldind;
+
+      newchars = nls - new;
+      oldchars = ols - old;
+
+      /* If we can do it, try to adjust nls and ols so that nls-new will
+	 contain the entire new prompt string. That way we can use
+	 prompt_physical_chars and not have to recompute column widths.
+	 _rl_col_width adds wrap_offset and expects the caller to compensate,
+	 which we do below, so we do the same thing if we don't call
+	 _rl_col_width.
+	 We don't have to compare, since we know the characters are the same.
+	 The check of differing numbers of invisible chars may be extraneous.
+	 XXX - experimental */
+      if (current_line == 0 && nfd == new && newchars > prompt_last_invisible &&
+	  newchars <= local_prompt_len &&
+	  local_prompt_len <= nmax &&
+	  current_invis_chars != visible_wrap_offset)
+	{
+	  while (newchars < nmax && oldchars < omax &&  newchars < local_prompt_len)
+	    {
+#if defined (HANDLE_MULTIBYTE)
+	      newind = _rl_find_next_mbchar (new, newchars, 1, MB_FIND_NONZERO);
+	      oldind = _rl_find_next_mbchar (old, oldchars, 1, MB_FIND_NONZERO);
+
+	      nls += newind - newchars;
+	      ols += oldind - oldchars;
+
+	      newchars = newind;
+	      oldchars = oldind;
+#else
+	      nls++; ols++;
+	      newchars++; oldchars++;
+#endif
+	    }
+	  newwidth = (newchars == local_prompt_len) ? prompt_physical_chars + wrap_offset
+	  					    : _rl_col_width (new, 0, nls - new, 1);
+	  /* if we changed nls and ols, we need to recompute lendiff */
+	  lendiff = (nls - nfd) - (ols - ofd);
+
+	  nlsf = new_face + (nls - new);
+	  olsf = old_face + (ols - old);
+	}
+      else
+	newwidth = _rl_col_width (new, nfd - new, nls - new, 1);
+
+      oldwidth = _rl_col_width (old, ofd - old, ols - old, 1);
+
+      col_lendiff = newwidth - oldwidth;
+    }
+  else
+    col_lendiff = lendiff;
+
+  /* col_lendiff uses _rl_col_width(), which doesn't know about whether or not
+     the multibyte characters it counts are invisible, so unless we're printing
+     the entire prompt string (in which case we can use prompt_physical_chars)
+     the count is short by the number of bytes in the invisible multibyte
+     characters - the number of multibyte characters.
+
+     We don't have a good way to solve this without moving to something like
+     a bitmap that indicates which characters are visible and which are
+     invisible. We fix it up (imperfectly) in the caller and by trying to use
+     the entire prompt string wherever we can. */
+     
+  /* If we are changing the number of invisible characters in a line, and
+     the spot of first difference is before the end of the invisible chars,
+     lendiff needs to be adjusted. */
+  if (current_line == 0 && current_invis_chars != visible_wrap_offset)
+    {
+      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	{
+	  lendiff += visible_wrap_offset - current_invis_chars;
+	  col_lendiff += visible_wrap_offset - current_invis_chars;
+	}
+      else
+	{
+	  lendiff += visible_wrap_offset - current_invis_chars;
+	  col_lendiff = lendiff;
+	}
+    }
+
+  /* We use temp as a count of the number of bytes from the first difference
+     to the end of the new line.  col_temp is the corresponding number of
+     screen columns.  A `dumb' update moves to the spot of first difference
+     and writes TEMP bytes. */
+  /* Insert (diff (len (old), len (new)) ch. */
+  temp = ne - nfd;
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    col_temp = _rl_col_width (new, nfd - new, ne - new, 1);
+  else
+    col_temp = temp;
+
+  /* how many bytes from the new line buffer to write to the display */
+  bytes_to_insert = nls - nfd;
+
+  /* col_lendiff > 0 if we are adding characters to the line */
+  if (col_lendiff > 0)	/* XXX - was lendiff */
+    {
+      /* Non-zero if we're increasing the number of lines. */
+      int gl = current_line >= _rl_vis_botlin && inv_botlin > _rl_vis_botlin;
+
+      /* If col_lendiff is > 0, implying that the new string takes up more
+	 screen real estate than the old, but lendiff is < 0, meaning that it
+	 takes fewer bytes, we need to just output the characters starting
+	 from the first difference.  These will overwrite what is on the
+	 display, so there's no reason to do a smart update.  This can really
+	 only happen in a multibyte environment. */
+      if (lendiff < 0)
+	{
+	  puts_face (nfd, nfdf, temp);
+	  _rl_last_c_pos += col_temp;
+	  /* If nfd begins before any invisible characters in the prompt,
+	     adjust _rl_last_c_pos to account for wrap_offset and set
+	     cpos_adjusted to let the caller know. */
+	  if (current_line == 0 && displaying_prompt_first_line && wrap_offset && ((nfd - new) <= prompt_last_invisible))
+	    ADJUST_CPOS (wrap_offset);	/* XXX - prompt_invis_chars_first_line? */
+	  return;
+	}
+      /* Sometimes it is cheaper to print the characters rather than
+	 use the terminal's capabilities.  If we're growing the number
+	 of lines, make sure we actually cause the new line to wrap
+	 around on auto-wrapping terminals. */
+      else if (_rl_terminal_can_insert && ((2 * col_temp) >= col_lendiff || _rl_term_IC) && (!_rl_term_autowrap || !gl))
+	{
+	  /* If lendiff > prompt_visible_length and _rl_last_c_pos == 0 and
+	     _rl_horizontal_scroll_mode == 1, inserting the characters with
+	     _rl_term_IC or _rl_term_ic will screw up the screen because of the
+	     invisible characters.  We need to just draw them. */
+	  /* The same thing happens if we're trying to draw before the last
+	     invisible character in the prompt string or we're increasing the
+	     number of invisible characters in the line and we're not drawing
+	     the entire prompt string. */
+	  if (*ols && ((_rl_horizontal_scroll_mode &&
+			_rl_last_c_pos == 0 &&
+			lendiff > prompt_visible_length &&
+			current_invis_chars > 0) == 0) &&
+		      (((mb_cur_max > 1 && rl_byte_oriented == 0) &&
+		        current_line == 0 && wrap_offset &&
+		        ((nfd - new) <= prompt_last_invisible) &&
+		        (col_lendiff < prompt_visible_length)) == 0) &&
+		      (visible_wrap_offset >= current_invis_chars))
+	    {
+	      open_some_spaces (col_lendiff);
+	      puts_face (nfd, nfdf, bytes_to_insert);
+	      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		_rl_last_c_pos += _rl_col_width (nfd, 0, bytes_to_insert, 1);
+	      else
+		_rl_last_c_pos += bytes_to_insert;
+	    }
+	  else if ((mb_cur_max == 1 || rl_byte_oriented != 0) && *ols == 0 && lendiff > 0)
+	    {
+	      /* At the end of a line the characters do not have to
+		 be "inserted".  They can just be placed on the screen. */
+	      puts_face (nfd, nfdf, temp);
+	      _rl_last_c_pos += col_temp;
+	      return;
+	    }
+	  else	/* just write from first difference to end of new line */
+	    {
+	      puts_face (nfd, nfdf, temp);
+	      _rl_last_c_pos += col_temp;
+	      /* If nfd begins before the last invisible character in the
+		 prompt, adjust _rl_last_c_pos to account for wrap_offset
+		 and set cpos_adjusted to let the caller know. */
+	      if ((mb_cur_max > 1 && rl_byte_oriented == 0) && current_line == 0 && displaying_prompt_first_line && wrap_offset && ((nfd - new) <= prompt_last_invisible))
+		ADJUST_CPOS (wrap_offset);	/* XXX - prompt_invis_chars_first_line? */
+	      return;
+	    }
+
+	  if (bytes_to_insert > lendiff)
+	    {
+	      /* If nfd begins before the last invisible character in the
+		 prompt, adjust _rl_last_c_pos to account for wrap_offset
+		 and set cpos_adjusted to let the caller know. */
+	      if ((mb_cur_max > 1 && rl_byte_oriented == 0) && current_line == 0 && displaying_prompt_first_line && wrap_offset && ((nfd - new) <= prompt_last_invisible))
+		ADJUST_CPOS (wrap_offset);	/* XXX - prompt_invis_chars_first_line? */
+	    }
+	}
+      else
+	{
+	  /* cannot insert chars, write to EOL */
+	  puts_face (nfd, nfdf, temp);
+	  _rl_last_c_pos += col_temp;
+	  /* If we're in a multibyte locale and were before the last invisible
+	     char in the current line (which implies we just output some invisible
+	     characters) we need to adjust _rl_last_c_pos, since it represents
+	     a physical character position. */
+	  /* The current_line*rl_screenwidth+prompt_invis_chars_first_line is a
+	     crude attempt to compute how far into the new line buffer we are.
+	     It doesn't work well in the face of multibyte characters and needs
+	     to be rethought. XXX */
+	  if ((mb_cur_max > 1 && rl_byte_oriented == 0) &&
+		current_line == prompt_last_screen_line && wrap_offset &&
+		displaying_prompt_first_line &&
+		wrap_offset != prompt_invis_chars_first_line &&
+		((nfd-new) < (prompt_last_invisible-(current_line*_rl_screenwidth+prompt_invis_chars_first_line))))
+	    ADJUST_CPOS (wrap_offset - prompt_invis_chars_first_line);
+
+	  /* What happens if wrap_offset == prompt_invis_chars_first_line
+	     and we are drawing the first line (current_line == 0), or if we
+	     are drawing the first line and changing the number of invisible
+	     characters in the line? If we're starting to draw before the last
+	     invisible character in the prompt, we need to adjust by
+	     _rl_last_c_pos -= prompt_invis_chars_first_line. This can happen
+	     when we finish reading a digit argument (with the "(arg: N)"
+	     prompt) and are switching back to displaying a line with a prompt
+	     containing invisible characters, since we have to redraw the
+	     entire prompt string. */
+	  if ((mb_cur_max > 1 && rl_byte_oriented == 0) &&
+		current_line == 0 && wrap_offset &&
+		displaying_prompt_first_line &&
+		wrap_offset == prompt_invis_chars_first_line &&
+		visible_wrap_offset != current_invis_chars &&
+		visible_wrap_offset != prompt_invis_chars_first_line &&
+		((nfd-new) < prompt_last_invisible))
+	    ADJUST_CPOS (prompt_invis_chars_first_line);
+	}
+    }
+  else				/* Delete characters from line. */
+    {
+      /* If possible and inexpensive to use terminal deletion, then do so. */
+      if (_rl_term_dc && (2 * col_temp) >= -col_lendiff)
+	{
+	  /* If all we're doing is erasing the invisible characters in the
+	     prompt string, don't bother.  It screws up the assumptions
+	     about what's on the screen. */
+	  if (_rl_horizontal_scroll_mode && _rl_last_c_pos == 0 &&
+	      displaying_prompt_first_line &&
+	      -lendiff == visible_wrap_offset)
+	    col_lendiff = 0;
+
+	  /* If we have moved lmargin and we're shrinking the line, we've
+	     already moved the cursor to the first character of the new line,
+	     so deleting -col_lendiff characters will mess up the cursor
+	     position calculation */
+	  if (_rl_horizontal_scroll_mode && displaying_prompt_first_line == 0 &&
+		col_lendiff && _rl_last_c_pos < -col_lendiff)
+	    col_lendiff = 0;
+
+	  if (col_lendiff)
+	    delete_chars (-col_lendiff); /* delete (diff) characters */
+
+	  /* Copy (new) chars to screen from first diff to last match,
+	     overwriting what is there. */
+	  if (bytes_to_insert > 0)
+	    {
+	      /* If nfd begins at the prompt, or before the invisible
+		 characters in the prompt, we need to adjust _rl_last_c_pos
+		 in a multibyte locale to account for the wrap offset and
+		 set cpos_adjusted accordingly. */
+	      puts_face (nfd, nfdf, bytes_to_insert);
+	      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		{
+		  /* This still doesn't take into account whether or not the
+		     characters that this counts are invisible. */
+		  _rl_last_c_pos += _rl_col_width (nfd, 0, bytes_to_insert, 1);
+		  if (current_line == 0 && wrap_offset &&
+			displaying_prompt_first_line &&
+			prompt_invis_chars_first_line &&
+			_rl_last_c_pos >= prompt_invis_chars_first_line &&
+			((nfd - new) <= prompt_last_invisible))
+		    ADJUST_CPOS (prompt_invis_chars_first_line);
+
+#if 1
+#ifdef HANDLE_MULTIBYTE
+		  /* If we write a non-space into the last screen column,
+		     remove the note that we added a space to compensate for
+		     a multibyte double-width character that didn't fit, since
+		     it's only valid for what was previously there. */
+		  /* XXX - watch this */
+		  if (_rl_last_c_pos == _rl_screenwidth &&
+			line_state_invisible->wrapped_line[current_line+1] &&
+			nfd[bytes_to_insert-1] != ' ')
+		    line_state_invisible->wrapped_line[current_line+1] = 0;
+#endif
+#endif
+		}
+	      else
+		_rl_last_c_pos += bytes_to_insert;
+
+	      /* XXX - we only want to do this if we are at the end of the line
+		 so we move there with _rl_move_cursor_relative */
+	      if (_rl_horizontal_scroll_mode && ((oe-old) > (ne-new)))
+		{
+		  _rl_move_cursor_relative (ne-new, new, new_face);
+		  goto clear_rest_of_line;
+		}
+	    }
+	}
+      /* Otherwise, print over the existing material. */
+      else
+	{
+	  if (temp > 0)
+	    {
+	      /* If nfd begins at the prompt, or before the invisible
+		 characters in the prompt, we need to adjust _rl_last_c_pos
+		 in a multibyte locale to account for the wrap offset and
+		 set cpos_adjusted accordingly. */
+	      puts_face (nfd, nfdf, temp);
+	      _rl_last_c_pos += col_temp;		/* XXX */
+	      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+		{
+		  if (current_line == 0 && wrap_offset &&
+			displaying_prompt_first_line &&
+			_rl_last_c_pos > wrap_offset &&
+			((nfd - new) <= prompt_last_invisible))
+		    ADJUST_CPOS (wrap_offset);	/* XXX - prompt_invis_chars_first_line? */
+		}
+	    }
+clear_rest_of_line:
+	  lendiff = (oe - old) - (ne - new);
+	  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	    col_lendiff = _rl_col_width (old, 0, oe - old, 1) - _rl_col_width (new, 0, ne - new, 1);
+	  else
+	    col_lendiff = lendiff;
+
+	  /* If we've already printed over the entire width of the screen,
+	     including the old material, then col_lendiff doesn't matter and
+	     space_to_eol will insert too many spaces.  XXX - maybe we should
+	     adjust col_lendiff based on the difference between _rl_last_c_pos
+	     and _rl_screenwidth */
+	  if (col_lendiff && ((mb_cur_max == 1 || rl_byte_oriented) || (_rl_last_c_pos < _rl_screenwidth)))
+	    {	  
+	      if (_rl_term_autowrap && current_line < inv_botlin)
+		space_to_eol (col_lendiff);
+	      else
+		_rl_clear_to_eol (col_lendiff);
+	    }
+	}
+    }
+}
+
+/* Tell the update routines that we have moved onto a new (empty) line. */
+int
+rl_on_new_line (void)
+{
+  if (visible_line)
+    visible_line[0] = '\0';
+
+  _rl_last_c_pos = _rl_last_v_pos = 0;
+  _rl_vis_botlin = last_lmargin = 0;
+  if (vis_lbreaks)
+    vis_lbreaks[0] = vis_lbreaks[1] = 0;
+  visible_wrap_offset = 0;
+  return 0;
+}
+
+/* Clear all screen lines occupied by the current readline line buffer
+   (visible line) */
+int
+rl_clear_visible_line (void)
+{
+  int curr_line;
+
+  /* Make sure we move to column 0 so we clear the entire line */
+  _rl_cr ();
+  _rl_last_c_pos = 0;
+
+  /* Move to the last screen line of the current visible line */
+  _rl_move_vert (_rl_vis_botlin);
+
+  /* And erase screen lines going up to line 0 (first visible line) */
+  for (curr_line = _rl_last_v_pos; curr_line >= 0; curr_line--)
+    {
+      _rl_move_vert (curr_line);
+      _rl_clear_to_eol (_rl_screenwidth);
+      _rl_cr ();		/* in case we use space_to_eol() */
+    }
+
+  return 0;
+}
+
+/* Tell the update routines that we have moved onto a new line with the
+   prompt already displayed.  Code originally from the version of readline
+   distributed with CLISP.  rl_expand_prompt must have already been called
+   (explicitly or implicitly).  This still doesn't work exactly right; it
+   should use expand_prompt() */
+int
+rl_on_new_line_with_prompt (void)
+{
+  int prompt_size, i, l, real_screenwidth, newlines;
+  char *prompt_last_line, *lprompt;
+
+  /* Initialize visible_line and invisible_line to ensure that they can hold
+     the already-displayed prompt. */
+  prompt_size = strlen (rl_prompt) + 1;
+  init_line_structures (prompt_size);
+
+  /* Make sure the line structures hold the already-displayed prompt for
+     redisplay. */
+  lprompt = local_prompt ? local_prompt : rl_prompt;
+  strcpy (visible_line, lprompt);
+  strcpy (invisible_line, lprompt);
+
+  /* If the prompt contains newlines, take the last tail. */
+  prompt_last_line = strrchr (rl_prompt, '\n');
+  if (!prompt_last_line)
+    prompt_last_line = rl_prompt;
+
+  l = strlen (prompt_last_line);
+  if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
+    _rl_last_c_pos = _rl_col_width (prompt_last_line, 0, l, 1);	/* XXX */
+  else
+    _rl_last_c_pos = l;
+
+  /* Dissect prompt_last_line into screen lines. Note that here we have
+     to use the real screenwidth. Readline's notion of screenwidth might be
+     one less, see terminal.c. */
+  real_screenwidth = _rl_screenwidth + (_rl_term_autowrap ? 0 : 1);
+  _rl_last_v_pos = l / real_screenwidth;
+  /* If the prompt length is a multiple of real_screenwidth, we don't know
+     whether the cursor is at the end of the last line, or already at the
+     beginning of the next line. Output a newline just to be safe. */
+  if (l > 0 && (l % real_screenwidth) == 0)
+    _rl_output_some_chars ("\n", 1);
+  last_lmargin = 0;
+
+  newlines = 0; i = 0;
+  while (i <= l)
+    {
+      _rl_vis_botlin = newlines;
+      vis_lbreaks[newlines++] = i;
+      i += real_screenwidth;
+    }
+  vis_lbreaks[newlines] = l;
+  visible_wrap_offset = 0;
+
+  rl_display_prompt = rl_prompt;	/* XXX - make sure it's set */
+
+  return 0;
+}
+
+/* Actually update the display, period. */
+int
+rl_forced_update_display (void)
+{
+  register char *temp;
+
+  if (visible_line)
+    {
+      temp = visible_line;
+      while (*temp)
+	*temp++ = '\0';
+    }
+  rl_on_new_line ();
+  forced_display++;
+  (*rl_redisplay_function) ();
+  return 0;
+}
+
+/* Redraw only the last line of a multi-line prompt. */
+void
+rl_redraw_prompt_last_line (void)
+{
+  char *t;
+
+  t = strrchr (rl_display_prompt, '\n');
+  if (t)
+    redraw_prompt (++t);
+  else
+    rl_forced_update_display ();
+}
+
+/* Move the cursor from _rl_last_c_pos to NEW, which are buffer indices.
+   (Well, when we don't have multibyte characters, _rl_last_c_pos is a
+   buffer index.)
+   DATA is the contents of the screen line of interest; i.e., where
+   the movement is being done.
+   DATA is always the visible line or the invisible line */
+static void
+_rl_move_cursor_relative (int new, const char *data, const char *dataf)
+{
+  register int i;
+  int woff;			/* number of invisible chars on current line */
+  int cpos, dpos;		/* current and desired cursor positions */
+  int adjust;
+  int in_invisline;
+  int mb_cur_max = MB_CUR_MAX;
+
+  woff = WRAP_OFFSET (_rl_last_v_pos, wrap_offset);
+  cpos = _rl_last_c_pos;
+
+  if (cpos == 0 && cpos == new)
+    return;
+
+#if defined (HANDLE_MULTIBYTE)
+  /* If we have multibyte characters, NEW is indexed by the buffer point in
+     a multibyte string, but _rl_last_c_pos is the display position.  In
+     this case, NEW's display position is not obvious and must be
+     calculated.  We need to account for invisible characters in this line,
+     as long as we are past them and they are counted by _rl_col_width. */
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    {
+      adjust = 1;
+      /* Try to short-circuit common cases and eliminate a bunch of multibyte
+	 character function calls. */
+      /* 1.  prompt string */
+      if (new == local_prompt_len && memcmp (data, local_prompt, new) == 0)
+	{
+	  dpos = prompt_physical_chars;
+	  cpos_adjusted = 1;
+	  adjust = 0;
+	}
+      /* 2.  prompt_string + line contents */
+      else if (new > local_prompt_len && local_prompt && memcmp (data, local_prompt, local_prompt_len) == 0)
+	{
+	  dpos = prompt_physical_chars + _rl_col_width (data, local_prompt_len, new, 1);
+	  cpos_adjusted = 1;
+	  adjust = 0;
+	}
+      else
+        dpos = _rl_col_width (data, 0, new, 1);
+
+      if (displaying_prompt_first_line == 0)
+	adjust = 0;
+
+      /* yet another special case: printing the last line of a prompt with
+	 multibyte characters and invisible characters whose printable length
+	 exceeds the screen width with the last invisible character
+	 (prompt_last_invisible) in the last line.  IN_INVISLINE is the
+	 offset of DATA in invisible_line */
+      in_invisline = 0;
+      if (data > invisible_line && data < invisible_line+inv_lbreaks[_rl_inv_botlin+1])
+	in_invisline = data - invisible_line;
+
+      /* Use NEW when comparing against the last invisible character in the
+	 prompt string, since they're both buffer indices and DPOS is a
+	 desired display position. */
+      /* NEW is relative to the current displayed line, while
+	 PROMPT_LAST_INVISIBLE is relative to the entire (wrapped) line.
+	 Need a way to reconcile these two variables by turning NEW into a
+	 buffer position relative to the start of the line */
+      if (adjust && ((new > prompt_last_invisible) ||		/* XXX - don't use woff here */
+		     (new+in_invisline > prompt_last_invisible) ||	/* invisible line */
+	  (prompt_physical_chars >= _rl_screenwidth &&		/* visible line */
+	   _rl_last_v_pos == prompt_last_screen_line &&
+	   wrap_offset >= woff && dpos >= woff &&
+	   new > (prompt_last_invisible-(vis_lbreaks[_rl_last_v_pos])-wrap_offset))))
+	   /* XXX last comparison might need to be >= */
+	{
+	  dpos -= woff;
+	  /* Since this will be assigned to _rl_last_c_pos at the end (more
+	     precisely, _rl_last_c_pos == dpos when this function returns),
+	     let the caller know. */
+	  cpos_adjusted = 1;
+	}
+    }
+  else
+#endif
+    dpos = new;
+
+  /* If we don't have to do anything, then return. */
+  if (cpos == dpos)
+    return;
+
+  /* It may be faster to output a CR, and then move forwards instead
+     of moving backwards. */
+  /* i == current physical cursor position. */
+#if defined (HANDLE_MULTIBYTE)
+  if (mb_cur_max > 1 && rl_byte_oriented == 0)
+    i = _rl_last_c_pos;
+  else
+#endif
+  i = _rl_last_c_pos - woff;
+  if (dpos == 0 || CR_FASTER (dpos, _rl_last_c_pos) ||
+      (_rl_term_autowrap && i == _rl_screenwidth))
+    {
+      _rl_cr ();
+      cpos = _rl_last_c_pos = 0;
+    }
+
+  if (cpos < dpos)
+    {
+      /* Move the cursor forward.  We do it by printing the command
+	 to move the cursor forward if there is one, else print that
+	 portion of the output buffer again.  Which is cheaper? */
+
+      /* The above comment is left here for posterity.  It is faster
+	 to print one character (non-control) than to print a control
+	 sequence telling the terminal to move forward one character.
+	 That kind of control is for people who don't know what the
+	 data is underneath the cursor. */
+
+      /* However, we need a handle on where the current display position is
+	 in the buffer for the immediately preceding comment to be true.
+	 In multibyte locales, we don't currently have that info available.
+	 Without it, we don't know where the data we have to display begins
+	 in the buffer and we have to go back to the beginning of the screen
+	 line.  In this case, we can use the terminal sequence to move forward
+	 if it's available. */
+      if (mb_cur_max > 1 && rl_byte_oriented == 0)
+	{
+	  if (_rl_term_forward_char)
+	    {
+	      for (i = cpos; i < dpos; i++)
+	        tputs (_rl_term_forward_char, 1, _rl_output_character_function);
+	    }
+	  else
+	    {
+	      _rl_cr ();
+	      puts_face (data, dataf, new);
+	    }
+	}
+      else
+	puts_face (data + cpos, dataf + cpos, new - cpos);
+    }
+
+#if defined (HANDLE_MULTIBYTE)
+  /* NEW points to the buffer point, but _rl_last_c_pos is the display point.
+     The byte length of the string is probably bigger than the column width
+     of the string, which means that if NEW == _rl_last_c_pos, then NEW's
+     display point is less than _rl_last_c_pos. */
+#endif
+  else if (cpos > dpos)
+    _rl_backspace (cpos - dpos);
+
+  _rl_last_c_pos = dpos;
+}
+
+/* PWP: move the cursor up or down. */
+void
+_rl_move_vert (int to)
+{
+  register int delta, i;
+
+  if (_rl_last_v_pos == to || to > _rl_screenheight)
+    return;
+
+  if ((delta = to - _rl_last_v_pos) > 0)
+    {
+      for (i = 0; i < delta; i++)
+	putc ('\n', rl_outstream);
+      _rl_cr ();
+      _rl_last_c_pos = 0;
+    }
+  else
+    {			/* delta < 0 */
+#ifdef __DJGPP__
+      int row, col;
+
+      fflush (rl_outstream);
+      ScreenGetCursor (&row, &col);
+      ScreenSetCursor (row + delta, col);
+      i = -delta;
+#else
+      if (_rl_term_up && *_rl_term_up)
+	for (i = 0; i < -delta; i++)
+	  tputs (_rl_term_up, 1, _rl_output_character_function);
+#endif /* !__DJGPP__ */
+    }
+
+  _rl_last_v_pos = to;		/* Now TO is here */
+}
+
+/* Physically print C on rl_outstream.  This is for functions which know
+   how to optimize the display.  Return the number of characters output. */
+int
+rl_show_char (int c)
+{
+  int n = 1;
+  if (META_CHAR (c) && (_rl_output_meta_chars == 0))
+    {
+      fprintf (rl_outstream, "M-");
+      n += 2;
+      c = UNMETA (c);
+    }
+
+#if defined (DISPLAY_TABS)
+  if ((CTRL_CHAR (c) && c != '\t') || c == RUBOUT)
+#else
+  if (CTRL_CHAR (c) || c == RUBOUT)
+#endif /* !DISPLAY_TABS */
+    {
+      fprintf (rl_outstream, "C-");
+      n += 2;
+      c = CTRL_CHAR (c) ? UNCTRL (c) : '?';
+    }
+
+  putc (c, rl_outstream);
+  fflush (rl_outstream);
+  return n;
+}
+
+int
+rl_character_len (int c, int pos)
+{
+  unsigned char uc;
+
+  uc = (unsigned char)c;
+
+  if (META_CHAR (uc))
+    return ((_rl_output_meta_chars == 0) ? 4 : 1);
+
+  if (uc == '\t')
+    {
+#if defined (DISPLAY_TABS)
+      return (((pos | 7) + 1) - pos);
+#else
+      return (2);
+#endif /* !DISPLAY_TABS */
+    }
+
+  if (CTRL_CHAR (c) || c == RUBOUT)
+    return (2);
+
+  return ((ISPRINT (uc)) ? 1 : 2);
+}
+/* How to print things in the "echo-area".  The prompt is treated as a
+   mini-modeline. */
+static int msg_saved_prompt = 0;
+
+#if defined (USE_VARARGS)
+int
+#if defined (PREFER_STDARG)
+rl_message (const char *format, ...)
+#else
+rl_message (va_alist)
+     va_dcl
+#endif
+{
+  va_list args;
+#if defined (PREFER_VARARGS)
+  char *format;
+#endif
+#if defined (HAVE_VSNPRINTF)
+  int bneed;
+#endif
+
+#if defined (PREFER_STDARG)
+  va_start (args, format);
+#else
+  va_start (args);
+  format = va_arg (args, char *);
+#endif
+
+  if (msg_buf == 0)
+    msg_buf = xmalloc (msg_bufsiz = 128);
+
+#if defined (HAVE_VSNPRINTF)
+  bneed = vsnprintf (msg_buf, msg_bufsiz, format, args);
+  if (bneed >= msg_bufsiz - 1)
+    {
+      msg_bufsiz = bneed + 1;
+      msg_buf = xrealloc (msg_buf, msg_bufsiz);
+      va_end (args);
+
+#if defined (PREFER_STDARG)
+      va_start (args, format);
+#else
+      va_start (args);
+      format = va_arg (args, char *);
+#endif
+      vsnprintf (msg_buf, msg_bufsiz - 1, format, args);
+    }
+#else
+  vsprintf (msg_buf, format, args);
+  msg_buf[msg_bufsiz - 1] = '\0';	/* overflow? */
+#endif
+  va_end (args);
+
+  if (saved_local_prompt == 0)
+    {
+      rl_save_prompt ();
+      msg_saved_prompt = 1;
+    }
+  else if (local_prompt != saved_local_prompt)
+    {
+      FREE (local_prompt);
+      FREE (local_prompt_prefix);
+      local_prompt = (char *)NULL;
+    }
+  rl_display_prompt = msg_buf;
+  local_prompt = expand_prompt (msg_buf, 0, &prompt_visible_length,
+					    &prompt_last_invisible,
+					    &prompt_invis_chars_first_line,
+					    &prompt_physical_chars);
+  local_prompt_prefix = (char *)NULL;
+  local_prompt_len = local_prompt ? strlen (local_prompt) : 0;
+  (*rl_redisplay_function) ();
+
+  return 0;
+}
+#else /* !USE_VARARGS */
+int
+rl_message (format, arg1, arg2)
+     char *format;
+{
+  if (msg_buf == 0)
+    msg_buf = xmalloc (msg_bufsiz = 128);
+
+  sprintf (msg_buf, format, arg1, arg2);
+  msg_buf[msg_bufsiz - 1] = '\0';	/* overflow? */
+
+  rl_display_prompt = msg_buf;
+  if (saved_local_prompt == 0)
+    {
+      rl_save_prompt ();
+      msg_saved_prompt = 1;
+    }
+  else if (local_prompt != saved_local_prompt)
+    {
+      FREE (local_prompt);
+      FREE (local_prompt_prefix);
+      local_prompt = (char *)NULL;
+    }
+  local_prompt = expand_prompt (msg_buf, 0, &prompt_visible_length,
+					    &prompt_last_invisible,
+					    &prompt_invis_chars_first_line,
+					    &prompt_physical_chars);
+  local_prompt_prefix = (char *)NULL;
+  local_prompt_len = local_prompt ? strlen (local_prompt) : 0;
+  (*rl_redisplay_function) ();
+      
+  return 0;
+}
+#endif /* !USE_VARARGS */
+
+/* How to clear things from the "echo-area". */
+int
+rl_clear_message (void)
+{
+  rl_display_prompt = rl_prompt;
+  if (msg_saved_prompt)
+    {
+      rl_restore_prompt ();
+      msg_saved_prompt = 0;
+    }
+  (*rl_redisplay_function) ();
+  return 0;
+}
+
+int
+rl_reset_line_state (void)
+{
+  rl_on_new_line ();
+
+  rl_display_prompt = rl_prompt ? rl_prompt : "";
+  forced_display = 1;
+  return 0;
+}
+
+/* Save all of the variables associated with the prompt and its display. Most
+   of the complexity is dealing with the invisible characters in the prompt
+   string and where they are. There are enough of these that I should consider
+   a struct. */
+void
+rl_save_prompt (void)
+{
+  saved_local_prompt = local_prompt;
+  saved_local_prefix = local_prompt_prefix;
+  saved_prefix_length = prompt_prefix_length;
+  saved_local_length = local_prompt_len;
+  saved_last_invisible = prompt_last_invisible;
+  saved_visible_length = prompt_visible_length;
+  saved_invis_chars_first_line = prompt_invis_chars_first_line;
+  saved_physical_chars = prompt_physical_chars;
+  saved_local_prompt_newlines = local_prompt_newlines;
+
+  local_prompt = local_prompt_prefix = (char *)0;
+  local_prompt_len = 0;
+  local_prompt_newlines = (int *)0;
+
+  prompt_last_invisible = prompt_visible_length = prompt_prefix_length = 0;
+  prompt_invis_chars_first_line = prompt_physical_chars = 0;
+}
+
+void
+rl_restore_prompt (void)
+{
+  FREE (local_prompt);
+  FREE (local_prompt_prefix);
+  FREE (local_prompt_newlines);
+
+  local_prompt = saved_local_prompt;
+  local_prompt_prefix = saved_local_prefix;
+  local_prompt_len = saved_local_length;
+  local_prompt_newlines = saved_local_prompt_newlines;
+
+  prompt_prefix_length = saved_prefix_length;
+  prompt_last_invisible = saved_last_invisible;
+  prompt_visible_length = saved_visible_length;
+  prompt_invis_chars_first_line = saved_invis_chars_first_line;
+  prompt_physical_chars = saved_physical_chars;
+
+  /* can test saved_local_prompt to see if prompt info has been saved. */
+  saved_local_prompt = saved_local_prefix = (char *)0;
+  saved_local_length = 0;
+  saved_last_invisible = saved_visible_length = saved_prefix_length = 0;
+  saved_invis_chars_first_line = saved_physical_chars = 0;
+  saved_local_prompt_newlines = 0;
+}
+
+char *
+_rl_make_prompt_for_search (int pchar)
+{
+  int len;
+  char *pmt, *p;
+
+  rl_save_prompt ();
+
+  /* We've saved the prompt, and can do anything with the various prompt
+     strings we need before they're restored.  We want the unexpanded
+     portion of the prompt string after any final newline. */
+  p = rl_prompt ? strrchr (rl_prompt, '\n') : 0;
+  if (p == 0)
+    {
+      len = (rl_prompt && *rl_prompt) ? strlen (rl_prompt) : 0;
+      pmt = (char *)xmalloc (len + 2);
+      if (len)
+	strcpy (pmt, rl_prompt);
+      pmt[len] = pchar;
+      pmt[len+1] = '\0';
+    }
+  else
+    {
+      p++;
+      len = strlen (p);
+      pmt = (char *)xmalloc (len + 2);
+      if (len)
+	strcpy (pmt, p);
+      pmt[len] = pchar;
+      pmt[len+1] = '\0';
+    }  
+
+  /* will be overwritten by expand_prompt, called from rl_message */
+  prompt_physical_chars = saved_physical_chars + 1;
+  return pmt;
+}
+
+/* Quick redisplay hack when erasing characters at the end of the line. */
+void
+_rl_erase_at_end_of_line (int l)
+{
+  register int i;
+
+  _rl_backspace (l);
+  for (i = 0; i < l; i++)
+    putc (' ', rl_outstream);
+  _rl_backspace (l);
+  for (i = 0; i < l; i++)
+    visible_line[--_rl_last_c_pos] = '\0';
+  rl_display_fixed++;
+}
+
+/* Clear to the end of the line.  COUNT is the minimum
+   number of character spaces to clear, but we use a terminal escape
+   sequence if available. */
+void
+_rl_clear_to_eol (int count)
+{
+#ifndef __MSDOS__
+  if (_rl_term_clreol)
+    tputs (_rl_term_clreol, 1, _rl_output_character_function);
+  else
+#endif
+    if (count)
+      space_to_eol (count);
+}
+
+/* Clear to the end of the line using spaces.  COUNT is the minimum
+   number of character spaces to clear, */
+static void
+space_to_eol (int count)
+{
+  register int i;
+
+  for (i = 0; i < count; i++)
+    putc (' ', rl_outstream);
+
+  _rl_last_c_pos += count;
+}
+
+void
+_rl_clear_screen (int clrscr)
+{
+#if defined (__DJGPP__)
+  ScreenClear ();
+  ScreenSetCursor (0, 0);
+#else
+  if (_rl_term_clrpag)
+    {
+      tputs (_rl_term_clrpag, 1, _rl_output_character_function);
+      if (clrscr && _rl_term_clrscroll)
+	tputs (_rl_term_clrscroll, 1, _rl_output_character_function);
+    }
+  else
+    rl_crlf ();
+#endif /* __DJGPP__ */
+}
+
+/* Insert COUNT characters from STRING to the output stream at column COL. */
+static void
+insert_some_chars (char *string, int count, int col)
+{
+  open_some_spaces (col);
+  _rl_output_some_chars (string, count);
+}
+
+/* Insert COL spaces, keeping the cursor at the same position.  We follow the
+   ncurses documentation and use either im/ei with explicit spaces, or IC/ic
+   by itself.  We assume there will either be ei or we don't need to use it. */
+static void
+open_some_spaces (int col)
+{
+#if !defined (__MSDOS__) && (!defined (__MINGW32__) || defined (NCURSES_VERSION))
+  char *buffer;
+  register int i;
+
+  /* If IC is defined, then we do not have to "enter" insert mode. */
+  if (_rl_term_IC)
+    {
+      buffer = tgoto (_rl_term_IC, 0, col);
+      tputs (buffer, 1, _rl_output_character_function);
+    }
+  else if (_rl_term_im && *_rl_term_im)
+    {
+      tputs (_rl_term_im, 1, _rl_output_character_function);
+      /* just output the desired number of spaces */
+      for (i = col; i--; )
+	_rl_output_character_function (' ');
+      /* If there is a string to turn off insert mode, use it now. */
+      if (_rl_term_ei && *_rl_term_ei)
+	tputs (_rl_term_ei, 1, _rl_output_character_function);
+      /* and move back the right number of spaces */
+      _rl_backspace (col);
+    }
+  else if (_rl_term_ic && *_rl_term_ic)
+    {
+      /* If there is a special command for inserting characters, then
+	 use that first to open up the space. */
+      for (i = col; i--; )
+	tputs (_rl_term_ic, 1, _rl_output_character_function);
+    }
+#endif /* !__MSDOS__ && (!__MINGW32__ || NCURSES_VERSION)*/
+}
+
+/* Delete COUNT characters from the display line. */
+static void
+delete_chars (int count)
+{
+  if (count > _rl_screenwidth)	/* XXX */
+    return;
+
+#if !defined (__MSDOS__) && (!defined (__MINGW32__) || defined (NCURSES_VERSION))
+  if (_rl_term_DC && *_rl_term_DC)
+    {
+      char *buffer;
+      buffer = tgoto (_rl_term_DC, count, count);
+      tputs (buffer, count, _rl_output_character_function);
+    }
+  else
+    {
+      if (_rl_term_dc && *_rl_term_dc)
+	while (count--)
+	  tputs (_rl_term_dc, 1, _rl_output_character_function);
+    }
+#endif /* !__MSDOS__ && (!__MINGW32__ || NCURSES_VERSION)*/
+}
+
+void
+_rl_update_final (void)
+{
+  int full_lines, woff, botline_length;
+
+  if (line_structures_initialized == 0)
+    return;
+
+  full_lines = 0;
+  /* If the cursor is the only thing on an otherwise-blank last line,
+     compensate so we don't print an extra CRLF. */
+  if (_rl_vis_botlin && _rl_last_c_pos == 0 &&
+	visible_line[vis_lbreaks[_rl_vis_botlin]] == 0)
+    {
+      _rl_vis_botlin--;
+      full_lines = 1;
+    }
+  _rl_move_vert (_rl_vis_botlin);
+  woff = W_OFFSET(_rl_vis_botlin, wrap_offset);
+  botline_length = VIS_LLEN(_rl_vis_botlin) - woff;
+  /* If we've wrapped lines, remove the final xterm line-wrap flag. */
+  if (full_lines && _rl_term_autowrap && botline_length == _rl_screenwidth)
+    {
+      char *last_line, *last_face;
+
+      /* LAST_LINE includes invisible characters, so if you want to get the
+	 last character of the first line, you have to take WOFF into account.
+	 This needs to be done for both calls to _rl_move_cursor_relative,
+	 which takes a buffer position as the first argument, and any direct
+	 subscripts of LAST_LINE. */
+      last_line = &visible_line[vis_lbreaks[_rl_vis_botlin]]; /* = VIS_CHARS(_rl_vis_botlin); */
+      last_face = &vis_face[vis_lbreaks[_rl_vis_botlin]]; /* = VIS_CHARS(_rl_vis_botlin); */
+      cpos_buffer_position = -1;	/* don't know where we are in buffer */
+      _rl_move_cursor_relative (_rl_screenwidth - 1 + woff, last_line, last_face);	/* XXX */
+      _rl_clear_to_eol (0);
+      puts_face (&last_line[_rl_screenwidth - 1 + woff],
+		 &last_face[_rl_screenwidth - 1 + woff], 1);
+    }
+  _rl_vis_botlin = 0;
+  if (botline_length > 0 || _rl_last_c_pos > 0)
+    rl_crlf ();
+  fflush (rl_outstream);
+  rl_display_fixed++;
+}
+
+/* Move to the start of the current line. */
+static void
+cr (void)
+{
+  _rl_cr ();
+  _rl_last_c_pos = 0;
+}
+
+/* Redraw the last line of a multi-line prompt that may possibly contain
+   terminal escape sequences.  Called with the cursor at column 0 of the
+   line to draw the prompt on. */
+static void
+redraw_prompt (char *t)
+{
+  char *oldp;
+
+  oldp = rl_display_prompt;
+  rl_save_prompt ();
+
+  rl_display_prompt = t;
+  local_prompt = expand_prompt (t, PMT_MULTILINE,
+				   &prompt_visible_length,
+				   &prompt_last_invisible,
+				   &prompt_invis_chars_first_line,
+				   &prompt_physical_chars);
+  local_prompt_prefix = (char *)NULL;
+  local_prompt_len = local_prompt ? strlen (local_prompt) : 0;
+
+  rl_forced_update_display ();
+
+  rl_display_prompt = oldp;
+  rl_restore_prompt();
+}
+      
+/* Redisplay the current line after a SIGWINCH is received. */
+void
+_rl_redisplay_after_sigwinch (void)
+{
+  char *t;
+
+  /* Clear the last line (assuming that the screen size change will result in
+     either more or fewer characters on that line only) and put the cursor at
+     column 0.  Make sure the right thing happens if we have wrapped to a new
+     screen line. */
+  if (_rl_term_cr)
+    {
+      rl_clear_visible_line ();
+      if (_rl_last_v_pos > 0)
+	_rl_move_vert (0);
+    }
+  else
+    rl_crlf ();
+
+  if (_rl_screenwidth < prompt_visible_length)
+    _rl_reset_prompt ();		/* update local_prompt_newlines array */
+
+  /* Redraw only the last line of a multi-line prompt. */
+  t = strrchr (rl_display_prompt, '\n');
+  if (t)
+    redraw_prompt (++t);
+  else
+    rl_forced_update_display ();
+}
+
+void
+_rl_clean_up_for_exit (void)
+{
+  if (_rl_echoing_p)
+    {
+      if (_rl_vis_botlin > 0)	/* minor optimization plus bug fix */
+	_rl_move_vert (_rl_vis_botlin);
+      _rl_vis_botlin = 0;
+      fflush (rl_outstream);
+      rl_restart_output (1, 0);
+    }
+}
+
+void
+_rl_erase_entire_line (void)
+{
+  cr ();
+  _rl_clear_to_eol (0);
+  cr ();
+  fflush (rl_outstream);
+}
+
+void
+_rl_ttyflush (void)
+{
+  fflush (rl_outstream);
+}
+
+/* return the `current display line' of the cursor -- the number of lines to
+   move up to get to the first screen line of the current readline line. */
+int
+_rl_current_display_line (void)
+{
+  int ret, nleft;
+
+  /* Find out whether or not there might be invisible characters in the
+     editing buffer. */
+  if (rl_display_prompt == rl_prompt)
+    nleft = _rl_last_c_pos - _rl_screenwidth - rl_visible_prompt_length;
+  else
+    nleft = _rl_last_c_pos - _rl_screenwidth;
+
+  if (nleft > 0)
+    ret = 1 + nleft / _rl_screenwidth;
+  else
+    ret = 0;
+
+  return ret;
+}
+
+void
+_rl_refresh_line (void)
+{
+  rl_clear_visible_line ();
+  rl_redraw_prompt_last_line ();
+  rl_keep_mark_active ();
+}
+
+#if defined (HANDLE_MULTIBYTE)
+/* Calculate the number of screen columns occupied by STR from START to END.
+   In the case of multibyte characters with stateful encoding, we have to
+   scan from the beginning of the string to take the state into account. */
+static int
+_rl_col_width (const char *str, int start, int end, int flags)
+{
+  WCHAR_T wc;
+  mbstate_t ps;
+  int tmp, point, width, max;
+
+  if (end <= start)
+    return 0;
+  if (MB_CUR_MAX == 1 || rl_byte_oriented)
+    /* this can happen in some cases where it's inconvenient to check */
+    return (end - start);
+
+  memset (&ps, 0, sizeof (mbstate_t));
+
+  point = 0;
+  max = end;
+
+  /* Try to short-circuit common cases.  The adjustment to remove wrap_offset
+     is done by the caller. */
+  /* 1.  prompt string */
+  if (flags && start == 0 && end == local_prompt_len && memcmp (str, local_prompt, local_prompt_len) == 0)
+    return (prompt_physical_chars + wrap_offset);
+  /* 2.  prompt string + line contents */
+  else if (flags && start == 0 && local_prompt_len > 0 && end > local_prompt_len && local_prompt && memcmp (str, local_prompt, local_prompt_len) == 0)
+    {
+      tmp = prompt_physical_chars + wrap_offset;
+      /* XXX - try to call ourselves recursively with non-prompt portion */
+      tmp += _rl_col_width (str, local_prompt_len, end, flags);
+      return (tmp);
+    }
+
+  while (point < start)
+    {
+      if (_rl_utf8locale && UTF8_SINGLEBYTE(str[point]))
+	{
+	  memset (&ps, 0, sizeof (mbstate_t));
+	  tmp = 1;
+	}
+      else
+	tmp = mbrlen (str + point, max, &ps);
+      if (MB_INVALIDCH ((size_t)tmp))
+	{
+	  /* In this case, the bytes are invalid or too short to compose a
+	     multibyte character, so we assume that the first byte represents
+	     a single character. */
+	  point++;
+	  max--;
+
+	  /* Clear the state of the byte sequence, because in this case the
+	     effect of mbstate is undefined. */
+	  memset (&ps, 0, sizeof (mbstate_t));
+	}
+      else if (MB_NULLWCH (tmp))
+	break;		/* Found '\0' */
+      else
+	{
+	  point += tmp;
+	  max -= tmp;
+	}
+    }
+
+  /* If START is not a byte that starts a character, then POINT will be
+     greater than START.  In this case, assume that (POINT - START) gives
+     a byte count that is the number of columns of difference. */
+  width = point - start;
+
+  while (point < end)
+    {
+      if (_rl_utf8locale && UTF8_SINGLEBYTE(str[point]))
+	{
+	  tmp = 1;
+	  wc = (WCHAR_T) str[point];
+	}
+      else
+	tmp = MBRTOWC (&wc, str + point, max, &ps);
+      if (MB_INVALIDCH ((size_t)tmp))
+	{
+	  /* In this case, the bytes are invalid or too short to compose a
+	     multibyte character, so we assume that the first byte represents
+	     a single character. */
+	  point++;
+	  max--;
+
+	  /* and assume that the byte occupies a single column. */
+	  width++;
+
+	  /* Clear the state of the byte sequence, because in this case the
+	     effect of mbstate is undefined. */
+	  memset (&ps, 0, sizeof (mbstate_t));
+	}
+      else if (MB_NULLWCH (tmp))
+	break;			/* Found '\0' */
+      else
+	{
+	  point += tmp;
+	  max -= tmp;
+	  tmp = WCWIDTH(wc);
+	  width += (tmp >= 0) ? tmp : 1;
+	}
+    }
+
+  width += point - end;
+
+  return width;
+}
+#endif /* HANDLE_MULTIBYTE */