Adding upstream version 4.9.0.upstream/4.9.0upstream

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

1 files changed, 1133 insertions, 0 deletions

diff --git a/resize.c b/resize.c
new file mode 100644
index 0000000..070d3ed
--- /dev/null
+++ b/resize.c
@@ -0,0 +1,1133 @@
+/* Copyright (c) 2008, 2009
+ *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
+ *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
+ *      Micah Cowan (micah@cowan.name)
+ *      Sadrul Habib Chowdhury (sadrul@users.sourceforge.net)
+ * Copyright (c) 1993-2002, 2003, 2005, 2006, 2007
+ *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
+ *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
+ * Copyright (c) 1987 Oliver Laumann
+ *
+ * This program 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, or (at your option)
+ * any later version.
+ *
+ * This program 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 this program (see the file COPYING); if not, see
+ * https://www.gnu.org/licenses/, or contact Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
+ *
+ ****************************************************************
+ */
+
+#include <sys/types.h>
+#include <signal.h>
+#ifndef sun
+#include <sys/ioctl.h>
+#endif
+
+#ifdef ISC
+# include <sys/tty.h>
+# include <sys/sioctl.h>
+# include <sys/pty.h>
+#endif
+
+#include "config.h"
+#include "screen.h"
+#include "extern.h"
+
+/* maximum window width */
+#define MAXWIDTH 1000
+
+static void CheckMaxSize __P((int));
+static void FreeMline  __P((struct mline *));
+static int  AllocMline __P((struct mline *ml, int));
+static void MakeBlankLine __P((unsigned char *, int));
+static void kaablamm __P((void));
+static int  BcopyMline __P((struct mline *, int, struct mline *, int, int, int));
+static void SwapAltScreen __P((struct win *));
+
+extern struct layer *flayer;
+extern struct display *display, *displays;
+extern unsigned char *blank, *null;
+extern struct mline mline_blank, mline_null, mline_old;
+extern struct win *windows;
+extern const int Z0width, Z1width;
+extern int captionalways;
+
+#if defined(TIOCGWINSZ) || defined(TIOCSWINSZ)
+struct winsize glwz;
+#endif
+
+static struct mline mline_zero = {
+ (unsigned char *)0,
+ (unsigned char *)0
+#ifdef FONT
+ ,(unsigned char *)0
+#endif
+#ifdef COLOR
+ ,(unsigned char *)0
+# ifdef COLORS256
+ ,(unsigned char *)0
+# endif
+#endif
+};
+
+/*
+ * ChangeFlag:   0: try to modify no window
+ *               1: modify fore (and try to modify no other) + redisplay
+ *               2: modify all windows
+ *
+ * Note: Activate() is only called if change_flag == 1
+ *       i.e. on a WINCH event
+ */
+
+void
+CheckScreenSize(change_flag)
+int change_flag;
+{
+  int wi, he;
+
+  if (display == 0)
+    {
+      debug("CheckScreenSize: No display -> no check.\n");
+      return;
+    }
+#ifdef TIOCGWINSZ
+  if (ioctl(D_userfd, TIOCGWINSZ, (char *)&glwz) != 0)
+    {
+      debug2("CheckScreenSize: ioctl(%d, TIOCGWINSZ) errno %d\n", D_userfd, errno);
+      wi = D_CO;
+      he = D_LI;
+    }
+  else
+    {
+      wi = glwz.ws_col;
+      he = glwz.ws_row;
+      if (wi == 0)
+        wi = D_CO;
+      if (he == 0)
+        he = D_LI;
+    }
+#else
+  wi = D_CO;
+  he = D_LI;
+#endif
+  
+  debug2("CheckScreenSize: screen is (%d,%d)\n", wi, he);
+
+#if 0 /* XXX: Fixme */
+  if (change_flag == 2)
+    {
+      debug("Trying to adapt all windows (-A)\n");
+      for (p = windows; p; p = p->w_next)
+	if (p->w_display == 0 || p->w_display == display)
+          ChangeWindowSize(p, wi, he, p->w_histheight);
+    }
+#endif
+  if (D_width == wi && D_height == he)
+    {
+      debug("CheckScreenSize: No change -> return.\n");
+      return;
+    }
+#ifdef BLANKER_PRG
+  KillBlanker();
+#endif
+  ResetIdle();
+  ChangeScreenSize(wi, he, change_flag);
+/* XXX Redisplay logic */
+#if 0
+  if (change_flag == 1)
+    Redisplay(D_fore ? D_fore->w_norefresh : 0);
+#endif
+}
+
+void
+ChangeScreenSize(wi, he, change_fore)
+int wi, he;
+int change_fore;
+{
+  struct win *p;
+  struct canvas *cv;
+  int wwi;
+
+  debug2("ChangeScreenSize from (%d,%d) ", D_width, D_height);
+  debug3("to (%d,%d) (change_fore: %d)\n",wi, he, change_fore);
+
+  cv = &D_canvas;
+  cv->c_xe = wi - 1;
+  cv->c_ys = (D_has_hstatus == HSTATUS_FIRSTLINE);
+  cv->c_ye = he - 1 - ((cv->c_slperp && cv->c_slperp->c_slnext) || captionalways) - (D_has_hstatus == HSTATUS_LASTLINE);
+  cv->c_blank.l_height = cv->c_ye - cv->c_ys + 1;
+  if (cv->c_slperp)
+    {
+      ResizeCanvas(cv);
+      RecreateCanvasChain();
+      RethinkDisplayViewports();
+    }
+  if (D_forecv == 0)
+    D_forecv = D_cvlist;
+  if (D_forecv)
+    D_fore = Layer2Window(D_forecv->c_layer);
+
+  D_width = wi;
+  D_height = he;
+
+  CheckMaxSize(wi);
+  if (D_CWS)
+    {
+      D_defwidth = D_CO;
+      D_defheight = D_LI;
+    }
+  else
+    {
+      if (D_CZ0 && (wi == Z0width || wi == Z1width) &&
+          (D_CO == Z0width || D_CO == Z1width))
+        D_defwidth = D_CO;
+      else
+        D_defwidth = wi;
+      D_defheight = he;
+    }
+  debug2("Default size: (%d,%d)\n", D_defwidth, D_defheight);
+  if (change_fore)
+    ResizeLayersToCanvases();
+  if (change_fore == 2 && D_CWS == NULL && displays->d_next == 0)
+    {
+      /* adapt all windows  -  to be removed ? */
+      for (p = windows; p; p = p->w_next)
+        {
+          debug1("Trying to change window %d.\n", p->w_number);
+          wwi = wi;
+#if 0
+          if (D_CZ0 && p->w_width != wi && (wi == Z0width || wi == Z1width))
+	    {
+	      if (p->w_width > (Z0width + Z1width) / 2)
+		wwi = Z0width;
+	      else
+		wwi = Z1width;
+	    }
+#endif
+	  if (p->w_savelayer && p->w_savelayer->l_cvlist == 0)
+	    ResizeLayer(p->w_savelayer, wwi, he, 0);
+#if 0
+          ChangeWindowSize(p, wwi, he, p->w_histheight);
+#endif
+        }
+    }
+}
+
+void
+ResizeLayersToCanvases()
+{
+  struct canvas *cv;
+  struct layer *l;
+  int lx, ly;
+
+  debug("ResizeLayersToCanvases\n");
+  D_kaablamm = 0;
+  for (cv = D_cvlist; cv; cv = cv->c_next)
+    {
+      l = cv->c_layer;
+      if (l == 0)
+	continue;
+      debug("Doing canvas: ");
+      if (l->l_width  == cv->c_xe - cv->c_xs + 1 &&
+          l->l_height == cv->c_ye - cv->c_ys + 1)
+        {
+          debug("already fitting.\n");
+          continue;
+        }
+      if (!MayResizeLayer(l))
+        {
+          debug("may not resize.\n");
+        }
+      else
+	{
+	  debug("doing resize.\n");
+	  ResizeLayer(l, cv->c_xe - cv->c_xs + 1, cv->c_ye - cv->c_ys + 1, display);
+	}
+
+      /* normalize window, see screen.c */
+      lx = cv->c_layer->l_x;
+      ly = cv->c_layer->l_y;
+      if (ly + cv->c_yoff < cv->c_ys)
+	{
+          cv->c_yoff = cv->c_ys - ly;
+          RethinkViewportOffsets(cv);
+	}
+      else if (ly + cv->c_yoff > cv->c_ye)
+	{
+	  cv->c_yoff = cv->c_ye - ly;
+          RethinkViewportOffsets(cv);
+	}
+      if (lx + cv->c_xoff < cv->c_xs)
+        {
+	  int n = cv->c_xs - (lx + cv->c_xoff);
+	  if (n < (cv->c_xe - cv->c_xs + 1) / 2)
+	    n = (cv->c_xe - cv->c_xs + 1) / 2;
+	  if (cv->c_xoff + n > cv->c_xs)
+	    n = cv->c_xs - cv->c_xoff;
+	  cv->c_xoff += n;
+	  RethinkViewportOffsets(cv);
+        }
+      else if (lx + cv->c_xoff > cv->c_xe)
+	{
+	  int n = lx + cv->c_xoff - cv->c_xe;
+	  if (n < (cv->c_xe - cv->c_xs + 1) / 2)
+	    n = (cv->c_xe - cv->c_xs + 1) / 2;
+	  if (cv->c_xoff - n + cv->c_layer->l_width - 1 < cv->c_xe)
+	    n = cv->c_xoff + cv->c_layer->l_width - 1 - cv->c_xe;
+	  cv->c_xoff -= n;
+	  RethinkViewportOffsets(cv);
+	}
+    }
+  Redisplay(0);
+  if (D_kaablamm)
+    {
+      kaablamm();
+      D_kaablamm = 0;
+    }
+}
+
+int
+MayResizeLayer(l)
+struct layer *l;
+{
+  int cvs = 0;
+  debug("MayResizeLayer:\n");
+  for (; l; l = l->l_next)
+    {
+      if (l->l_cvlist)
+        if (++cvs > 1 || l->l_cvlist->c_lnext)
+	  {
+	    debug1("may not - cvs %d\n", cvs);
+	    return 0;
+	  }
+    }
+  debug("may resize\n");
+  return 1;
+}
+
+/*
+ *  Easy implementation: rely on the fact that the only layers
+ *  supporting resize are Win and Blank. So just kill all overlays.
+ *
+ *  This is a lot harder if done the right way...
+ */
+
+static void
+kaablamm()
+{
+  Msg(0, "Aborted because of window size change.");
+}
+
+/* Kills non-resizable layers. */
+#define RESIZE_OR_KILL_LAYERS(l, wi, he) do \
+  {	\
+    struct layer *_last = NULL;	\
+    flayer = (l);	\
+    while (flayer->l_next)	\
+      {	\
+	if (LayResize(wi, he) == 0)	\
+	  {	\
+	    _last = flayer;	\
+	    flayer = flayer->l_next;	\
+	  }	\
+	else	\
+	  {	\
+	    struct canvas *_cv;	\
+	    for (_cv = flayer->l_cvlist; _cv; _cv = _cv->c_lnext)	\
+	      _cv->c_display->d_kaablamm = 1;	\
+	    ExitOverlayPage();	\
+	    if (_last)	\
+	      _last->l_next = flayer;	\
+	  }	\
+      }	\
+    /* We assume that the bottom-most layer, i.e. when flayer->l_next == 0,	\
+     * is always resizable. Currently, WinLf and BlankLf can be the bottom-most layers.	\
+     */	\
+    LayResize(wi, he);	\
+  } while (0)
+
+void
+ResizeLayer(l, wi, he, norefdisp)
+struct layer *l;
+int wi, he;
+struct display *norefdisp;
+{
+  struct win *p;
+  struct canvas *cv;
+  struct layer *oldflayer = flayer;
+  struct display *d, *olddisplay = display;
+
+  if (l->l_width == wi && l->l_height == he)
+    return;
+  p = Layer2Window(l);
+
+  /* If 'flayer' and 'l' are for the same window, then we will not
+   * restore 'flayer'. */
+  if (oldflayer && (l == oldflayer || Layer2Window(oldflayer) == p))
+    oldflayer = NULL;
+
+  flayer = l;
+
+  if (p)
+    {
+      /* It's a window layer. Kill the overlays on it in all displays. */
+      for (d = displays; d; d = d->d_next)
+	for (cv = d->d_cvlist; cv; cv = cv->c_next)
+	  {
+	    if (p == Layer2Window(cv->c_layer))
+	      {
+		/* Canvas 'cv' on display 'd' shows this window. Remove any non-resizable
+		 * layers over it. */
+		RESIZE_OR_KILL_LAYERS(cv->c_layer, wi, he);
+	      }
+	  }
+    }
+  else
+    {
+      /* It's a Blank layer. Just kill the non-resizable overlays over it. */
+      RESIZE_OR_KILL_LAYERS(flayer, wi, he);
+    }
+
+  for (display = displays; display; display = display->d_next)
+    {
+      if (display == norefdisp)
+	continue;
+      for (cv = D_cvlist; cv; cv = cv->c_next)
+	if (Layer2Window(cv->c_layer) == p)
+	  {
+            CV_CALL(cv, LayRedisplayLine(-1, -1, -1, 0));
+            RefreshArea(cv->c_xs, cv->c_ys, cv->c_xe, cv->c_ye, 0);
+	  }
+      if (D_kaablamm)
+	{
+	  kaablamm();
+	  D_kaablamm = 0;
+	}
+    }
+
+  /* If we started resizing a non-flayer layer, then restore the flayer.
+   * Otherwise, flayer should already be updated to the topmost foreground layer. */
+  if (oldflayer)
+    flayer = oldflayer;
+  display = olddisplay;
+}
+
+static void
+FreeMline(ml)
+struct mline *ml;
+{
+  if (ml->image)
+    free(ml->image);
+  if (ml->attr && ml->attr != null)
+    free(ml->attr);
+#ifdef FONT
+  if (ml->font && ml->font != null)
+    free(ml->font);
+  if (ml->fontx && ml->fontx != null)
+    free(ml->fontx);
+#endif
+#ifdef COLOR
+  if (ml->color && ml->color != null)
+    free(ml->color);
+# ifdef COLORS256
+  if (ml->colorx && ml->colorx != null)
+    free(ml->colorx);
+# endif
+#endif
+  *ml = mline_zero;
+}
+
+static int
+AllocMline(ml, w)
+struct mline *ml;
+int w;
+{
+  ml->image = malloc(w);
+  ml->attr  = null;
+#ifdef FONT
+  ml->font  = null;
+  ml->fontx = null;
+#endif
+#ifdef COLOR
+  ml->color = null;
+# ifdef COLORS256
+  ml->colorx = null;
+# endif
+#endif
+  if (ml->image == 0)
+    return -1;
+  return 0;
+}
+
+
+static int
+BcopyMline(mlf, xf, mlt, xt, l, w)
+struct mline *mlf, *mlt;
+int xf, xt, l, w;
+{
+  int r = 0;
+
+  bcopy((char *)mlf->image + xf, (char *)mlt->image + xt, l);
+  if (mlf->attr != null && mlt->attr == null)
+    {
+      if ((mlt->attr = (unsigned char *)calloc(w, 1)) == 0)
+	mlt->attr = null, r = -1;
+    }
+  if (mlt->attr != null)
+    bcopy((char *)mlf->attr + xf, (char *)mlt->attr + xt, l);
+#ifdef FONT
+  if (mlf->font != null && mlt->font == null)
+    {
+      if ((mlt->font = (unsigned char *)calloc(w, 1)) == 0)
+	mlt->font = null, r = -1;
+    }
+  if (mlt->font != null)
+    bcopy((char *)mlf->font + xf, (char *)mlt->font + xt, l);
+  if (mlf->fontx != null && mlt->fontx == null)
+    {
+      if ((mlt->fontx = (unsigned char *)calloc(w, 1)) == 0)
+	mlt->fontx = null, r = -1;
+    }
+  if (mlt->fontx != null)
+    bcopy((char *)mlf->fontx + xf, (char *)mlt->fontx + xt, l);
+#endif
+#ifdef COLOR
+  if (mlf->color != null && mlt->color == null)
+    {
+      if ((mlt->color = (unsigned char *)calloc(w, 1)) == 0)
+	mlt->color = null, r = -1;
+    }
+  if (mlt->color != null)
+    bcopy((char *)mlf->color + xf, (char *)mlt->color + xt, l);
+# ifdef COLORS256
+  if (mlf->colorx != null && mlt->colorx == null)
+    {
+      if ((mlt->colorx = (unsigned char *)calloc(w, 1)) == 0)
+	mlt->colorx = null, r = -1;
+    }
+  if (mlt->colorx != null)
+    bcopy((char *)mlf->colorx + xf, (char *)mlt->colorx + xt, l);
+# endif
+#endif
+  return r;
+}
+
+
+static int maxwidth;
+
+static void
+CheckMaxSize(wi)
+int wi;
+{
+  unsigned char *oldnull = null;
+  unsigned char *oldblank = blank;
+  struct win *p;
+  int i;
+  struct mline *ml;
+
+  if (wi > MAXWIDTH)
+	  wi = MAXWIDTH;
+  if (wi <= maxwidth)
+    return;
+  maxwidth = wi + 1;
+  debug1("New maxwidth: %d\n", maxwidth);
+  blank = (unsigned char *)xrealloc((char *)blank, maxwidth);
+  null = (unsigned char *)xrealloc((char *)null, maxwidth);
+  mline_old.image = (unsigned char *)xrealloc((char *)mline_old.image, maxwidth);
+  mline_old.attr = (unsigned char *)xrealloc((char *)mline_old.attr, maxwidth);
+#ifdef FONT
+  mline_old.font = (unsigned char *)xrealloc((char *)mline_old.font, maxwidth);
+  mline_old.fontx = (unsigned char *)xrealloc((char *)mline_old.fontx, maxwidth);
+#endif
+#ifdef COLOR
+  mline_old.color = (unsigned char *)xrealloc((char *)mline_old.color, maxwidth);
+# ifdef COLORS256
+  mline_old.colorx = (unsigned char *)xrealloc((char *)mline_old.colorx, maxwidth);
+# endif
+#endif
+  if (!(blank && null && mline_old.image && mline_old.attr IFFONT(&& mline_old.font) IFFONTX(&& mline_old.fontx) IFCOLOR(&& mline_old.color) IFCOLORX(&& mline_old.colorx)))
+    Panic(0, "%s", strnomem);
+
+  MakeBlankLine(blank, maxwidth);
+  bzero((char *)null, maxwidth);
+
+  mline_blank.image = blank;
+  mline_blank.attr  = null;
+  mline_null.image = null;
+  mline_null.attr  = null;
+#ifdef FONT
+  mline_blank.font  = null;
+  mline_null.font   = null;
+  mline_blank.fontx = null;
+  mline_null.fontx  = null;
+#endif
+#ifdef COLOR
+  mline_blank.color = null;
+  mline_null.color = null;
+# ifdef COLORS256
+  mline_blank.colorx = null;
+  mline_null.colorx = null;
+# endif
+#endif
+
+#define RESET_AFC(x, bl) do { if (x == old##bl) x = bl; } while (0)
+
+#define RESET_LINES(lines, count) \
+  do { \
+    ml = lines; \
+    for (i = 0; i < count; i++, ml++) \
+      { \
+	RESET_AFC(ml->image, blank); \
+	RESET_AFC(ml->attr, null); \
+	IFFONT(RESET_AFC(ml->font, null)); \
+	IFFONT(RESET_AFC(ml->fontx, null)); \
+	IFCOLOR(RESET_AFC(ml->color, null)); \
+	IFCOLORX(RESET_AFC(ml->colorx, null)); \
+      } \
+  } while (0)
+
+  /* We have to run through all windows to substitute
+   * the null and blank references.
+   */
+  for (p = windows; p; p = p->w_next)
+    {
+      RESET_LINES(p->w_mlines, p->w_height);
+
+#ifdef COPY_PASTE
+      RESET_LINES(p->w_hlines, p->w_histheight);
+      RESET_LINES(p->w_alt.hlines, p->w_alt.histheight);
+#endif
+
+      RESET_LINES(p->w_alt.mlines, p->w_alt.height);
+    }
+}
+
+
+char *
+xrealloc(mem, len)
+char *mem;
+int len;
+{
+  register char *nmem;
+
+  if (mem == 0)
+    return malloc(len);
+  if ((nmem = realloc(mem, len)))
+    return nmem;
+  free(mem);
+  return (char *)0;
+}
+
+static void
+MakeBlankLine(p, n)
+register unsigned char *p;
+register int n;
+{
+  while (n--)
+    *p++ = ' ';
+}
+
+
+
+
+#ifdef COPY_PASTE
+
+#define OLDWIN(y) ((y < p->w_histheight) \
+        ? &p->w_hlines[(p->w_histidx + y) % p->w_histheight] \
+        : &p->w_mlines[y - p->w_histheight])
+
+#define NEWWIN(y) ((y < hi) ? &nhlines[y] : &nmlines[y - hi])
+	
+#else
+
+#define OLDWIN(y) (&p->w_mlines[y])
+#define NEWWIN(y) (&nmlines[y])
+
+#endif
+
+
+int
+ChangeWindowSize(p, wi, he, hi)
+struct win *p;
+int wi, he, hi;
+{
+  struct mline *mlf = 0, *mlt = 0, *ml, *nmlines, *nhlines;
+  int fy, ty, l, lx, lf, lt, yy, oty, addone;
+  int ncx, ncy, naka, t;
+  int y, shift;
+
+  if (wi <= 0 || he <= 0)
+    wi = he = hi = 0;
+
+  if (p->w_type == W_TYPE_GROUP)
+    return 0;
+
+  if (wi > MAXWIDTH)
+    {
+      Msg(0, "Window width too large. Truncated to %d.", MAXWIDTH);
+      wi = MAXWIDTH;
+    }
+
+  if (he > MAXWIDTH)
+    {
+      Msg(0, "Window height too large. Truncated to %d.", MAXWIDTH);
+      he = MAXWIDTH;
+    }
+
+  if (p->w_width == wi && p->w_height == he && p->w_histheight == hi)
+    {
+      debug("ChangeWindowSize: No change.\n");
+      return 0;
+    }
+
+  CheckMaxSize(wi);
+
+  /* XXX */
+#if 0
+  /* just in case ... */
+  if (wi && (p->w_width != wi || p->w_height != he) && p->w_lay != &p->w_winlay)
+    {
+      debug("ChangeWindowSize: No resize because of overlay?\n");
+      return -1;
+    }
+#endif
+
+  debug("ChangeWindowSize");
+  debug3(" from (%d,%d)+%d", p->w_width, p->w_height, p->w_histheight);
+  debug3(" to(%d,%d)+%d\n", wi, he, hi);
+
+  fy = p->w_histheight + p->w_height - 1;
+  ty = hi + he - 1;
+
+  nmlines = nhlines = 0;
+  ncx = 0;
+  ncy = 0;
+  naka = 0;
+
+  if (wi)
+    {
+      if (wi != p->w_width || he != p->w_height)
+	{
+	  if ((nmlines = (struct mline *)calloc(he, sizeof(struct mline))) == 0)
+	    {
+	      KillWindow(p);
+	      Msg(0, "%s", strnomem);
+	      return -1;
+	    }
+	}
+      else
+	{
+	  debug1("image stays the same: %d lines\n", he);
+	  nmlines = p->w_mlines;
+	  fy -= he;
+	  ty -= he;
+	  ncx = p->w_x;
+	  ncy = p->w_y;
+	  naka = p->w_autoaka;
+	}
+    }
+#ifdef COPY_PASTE
+  if (hi)
+    {
+      if ((nhlines = (struct mline *)calloc(hi, sizeof(struct mline))) == 0)
+	{
+	  Msg(0, "No memory for history buffer - turned off");
+	  hi = 0;
+	  ty = he - 1;
+	}
+    }
+#endif
+
+  /* special case: cursor is at magic margin position */
+  addone = 0;
+  if (p->w_width && p->w_x == p->w_width)
+    {
+      debug2("Special addone case: %d %d\n", p->w_x, p->w_y);
+      addone = 1;
+      p->w_x--;
+    }
+
+  /* handle the cursor and autoaka lines now if the widths are equal */
+  if (p->w_width == wi)
+    {
+      ncx = p->w_x + addone;
+      ncy = p->w_y + he - p->w_height;
+      /* never lose sight of the line with the cursor on it */
+      shift = -ncy;
+      for (yy = p->w_y + p->w_histheight - 1; yy >= 0 && ncy + shift < he; yy--)
+	{
+	  ml = OLDWIN(yy);
+	  if (!ml->image)
+	    break;
+	  if (ml->image[p->w_width] == ' ')
+	    break;
+	  shift++;
+	}
+      if (shift < 0)
+	shift = 0;
+      else
+	debug1("resize: cursor out of bounds, shifting %d\n", shift);
+      ncy += shift;
+      if (p->w_autoaka > 0)
+	{
+	  naka = p->w_autoaka + he - p->w_height + shift;
+	  if (naka < 1 || naka > he)
+	    naka = 0;
+	}
+      while (shift-- > 0)
+	{
+	  ml = OLDWIN(fy);
+	  FreeMline(ml);
+	  fy--;
+	}
+    }
+  debug2("fy %d ty %d\n", fy, ty);
+  if (fy >= 0)
+    mlf = OLDWIN(fy);
+  if (ty >= 0)
+    mlt = NEWWIN(ty);
+
+  while (fy >= 0 && ty >= 0)
+    {
+      if (p->w_width == wi)
+	{
+	  /* here is a simple shortcut: just copy over */
+	  *mlt = *mlf;
+          *mlf = mline_zero;
+	  if (--fy >= 0)
+	    mlf = OLDWIN(fy);
+	  if (--ty >= 0)
+	    mlt = NEWWIN(ty);
+	  continue;
+	}
+
+      /* calculate lenght */
+      for (l = p->w_width - 1; l > 0; l--)
+	if (mlf->image[l] != ' ' || mlf->attr[l])
+	  break;
+      if (fy == p->w_y + p->w_histheight && l < p->w_x)
+	l = p->w_x;	/* cursor is non blank */
+      l++;
+      lf = l;
+
+      /* add wrapped lines to length */
+      for (yy = fy - 1; yy >= 0; yy--)
+	{
+	  ml = OLDWIN(yy);
+	  if (ml->image[p->w_width] == ' ')
+	    break;
+	  l += p->w_width;
+	}
+
+      /* rewrap lines */
+      lt = (l - 1) % wi + 1;	/* lf is set above */
+      oty = ty;
+      while (l > 0 && fy >= 0 && ty >= 0)
+	{
+	  lx = lt > lf ? lf : lt;
+	  if (mlt->image == 0)
+	    {
+	      if (AllocMline(mlt, wi + 1))
+		goto nomem;
+    	      MakeBlankLine(mlt->image + lt, wi - lt);
+	      mlt->image[wi] = ((oty == ty) ? ' ' : 0);
+	    }
+	  if (BcopyMline(mlf, lf - lx, mlt, lt - lx, lx, wi + 1))
+	    goto nomem;
+
+	  /* did we copy the cursor ? */
+	  if (fy == p->w_y + p->w_histheight && lf - lx <= p->w_x && lf > p->w_x)
+	    {
+	      ncx = p->w_x + lt - lf + addone;
+	      ncy = ty - hi;
+	      shift = wi ? -ncy + (l - lx) / wi : 0;
+	      if (ty + shift > hi + he - 1)
+		shift = hi + he - 1 - ty;
+	      if (shift > 0)
+		{
+	          debug3("resize: cursor out of bounds, shifting %d [%d/%d]\n", shift, lt - lx, wi);
+		  for (y = hi + he - 1; y >= ty; y--)
+		    {
+		      mlt = NEWWIN(y);
+		      FreeMline(mlt);
+		      if (y - shift < ty)
+			continue;
+		      ml  = NEWWIN(y - shift);
+		      *mlt = *ml;
+		      *ml = mline_zero;
+		    }
+		  ncy += shift;
+		  ty += shift;
+		  mlt = NEWWIN(ty);
+		  if (naka > 0)
+		    naka = naka + shift > he ? 0 : naka + shift;
+		}
+	      ASSERT(ncy >= 0);
+	    }
+	  /* did we copy autoaka line ? */
+	  if (p->w_autoaka > 0 && fy == p->w_autoaka - 1 + p->w_histheight && lf - lx <= 0)
+	    naka = ty - hi >= 0 ? 1 + ty - hi : 0;
+
+	  lf -= lx;
+	  lt -= lx;
+	  l  -= lx;
+	  if (lf == 0)
+	    {
+	      FreeMline(mlf);
+	      lf = p->w_width;
+	      if (--fy >= 0)
+	        mlf = OLDWIN(fy);
+	    }
+	  if (lt == 0)
+	    {
+	      lt = wi;
+	      if (--ty >= 0)
+	        mlt = NEWWIN(ty);
+	    }
+	}
+      ASSERT(l != 0 || fy == yy);
+    }
+  while (fy >= 0)
+    {
+      FreeMline(mlf);
+      if (--fy >= 0)
+	mlf = OLDWIN(fy);
+    }
+  while (ty >= 0)
+    {
+      if (AllocMline(mlt, wi + 1))
+	goto nomem;
+      MakeBlankLine(mlt->image, wi + 1);
+      if (--ty >= 0)
+	mlt = NEWWIN(ty);
+    }
+
+#ifdef DEBUG
+  if (nmlines != p->w_mlines)
+    for (fy = 0; fy < p->w_height + p->w_histheight; fy++)
+      {
+	ml = OLDWIN(fy);
+	ASSERT(ml->image == 0);
+      }
+#endif
+
+  if (p->w_mlines && p->w_mlines != nmlines)
+    free((char *)p->w_mlines);
+  p->w_mlines = nmlines;
+#ifdef COPY_PASTE
+  if (p->w_hlines && p->w_hlines != nhlines)
+    free((char *)p->w_hlines);
+  p->w_hlines = nhlines;
+#endif
+  nmlines = nhlines = 0;
+
+  /* change tabs */
+  if (p->w_width != wi)
+    {
+      if (wi)
+	{
+	  t = p->w_tabs ? p->w_width : 0;
+	  p->w_tabs = xrealloc(p->w_tabs, wi + 1);
+	  if (p->w_tabs == 0)
+            goto nomem;
+	  for (; t < wi; t++)
+	    p->w_tabs[t] = t && !(t & 7) ? 1 : 0; 
+	  p->w_tabs[wi] = 0; 
+	}
+      else
+	{
+	  if (p->w_tabs)
+	    free(p->w_tabs);
+	  p->w_tabs = 0;
+	}
+    }
+
+  /* Change w_saved.y - this is only an estimate... */
+  p->w_saved.y += ncy - p->w_y;
+
+  p->w_x = ncx;
+  p->w_y = ncy;
+  if (p->w_autoaka > 0)
+    p->w_autoaka = naka;
+
+  /* do sanity checks */
+  if (p->w_x > wi)
+    p->w_x = wi;
+  if (p->w_y >= he)
+    p->w_y = he - 1;
+  if (p->w_saved.x > wi)
+    p->w_saved.x = wi;
+  if (p->w_saved.y >= he)
+    p->w_saved.y = he - 1;
+  if (p->w_saved.y < 0)
+    p->w_saved.y = 0;
+  if (p->w_alt.cursor.x > wi)
+    p->w_alt.cursor.x = wi;
+  if (p->w_alt.cursor.y >= he)
+    p->w_alt.cursor.y = he - 1;
+  if (p->w_alt.cursor.y < 0)
+    p->w_alt.cursor.y = 0;
+
+  /* reset scrolling region */
+  p->w_top = 0;
+  p->w_bot = he - 1;
+
+  /* signal new size to window */
+#ifdef TIOCSWINSZ
+  if (wi && (p->w_width != wi || p->w_height != he)
+      && p->w_width != 0 && p->w_height != 0 && p->w_ptyfd >= 0 && p->w_pid)
+    {
+      glwz.ws_col = wi;
+      glwz.ws_row = he;
+      debug("Setting pty winsize.\n");
+      if (ioctl(p->w_ptyfd, TIOCSWINSZ, (char *)&glwz))
+	debug2("SetPtySize: errno %d (fd:%d)\n", errno, p->w_ptyfd);
+    }
+#endif /* TIOCSWINSZ */
+
+  /* store new size */
+  p->w_width = wi;
+  p->w_height = he;
+  if(p->w_scrollback_height > hi)
+    p->w_scrollback_height = hi;
+#ifdef COPY_PASTE
+  p->w_histidx = 0;
+  p->w_histheight = hi;
+#endif
+
+#ifdef BUILTIN_TELNET
+  if (p->w_type == W_TYPE_TELNET)
+    TelWindowSize(p);
+#endif
+
+#ifdef DEBUG
+  /* Test if everything was ok */
+  for (fy = 0; fy < p->w_height + p->w_histheight; fy++)
+    {
+      ml = OLDWIN(fy);
+      ASSERT(ml->image);
+# ifdef UTF8
+      if (p->w_encoding == UTF8)
+	{
+	  for (l = 0; l < p->w_width; l++)
+	    ASSERT(ml->image[l] >= ' ' || ml->font[l] || ml->fontx);
+	}
+      else
+#endif
+        for (l = 0; l < p->w_width; l++)
+          ASSERT(ml->image[l] >= ' ');
+    }
+#endif
+  return 0;
+
+nomem:
+  if (nmlines || nhlines)
+    {
+      for (ty = he + hi - 1; ty >= 0; ty--)
+        {
+          mlt = NEWWIN(ty);
+          FreeMline(mlt);
+        }
+      if (nmlines && p->w_mlines != nmlines)
+        free((char *)nmlines);
+#ifdef COPY_PASTE
+      if (nhlines && p->w_hlines != nhlines)
+        free((char *)nhlines);
+#endif
+    }
+  KillWindow(p);
+  Msg(0, "%s", strnomem);
+  return -1;
+}
+
+void
+FreeAltScreen(p)
+struct win *p;
+{
+  int i;
+
+  if (p->w_alt.mlines)
+    {
+      for (i = 0; i < p->w_alt.height; i++)
+        FreeMline(p->w_alt.mlines + i);
+      free(p->w_alt.mlines);
+    }
+  p->w_alt.mlines = 0;
+  p->w_alt.width = 0;
+  p->w_alt.height = 0;
+#ifdef COPY_PASTE
+  if (p->w_alt.hlines)
+    {
+      for (i = 0; i < p->w_alt.histheight; i++)
+        FreeMline(p->w_alt.hlines + i);
+      free(p->w_alt.hlines);
+    }
+  p->w_alt.hlines = 0;
+  p->w_alt.histidx = 0;
+  p->w_alt.histheight = 0;
+#endif
+}
+
+static void
+SwapAltScreen(p)
+struct win *p;
+{
+  struct mline *ml;
+  int t;
+
+#define SWAP(item, t) do { (t) = p->w_alt. item; p->w_alt. item = p->w_##item; p->w_##item = (t); } while (0)
+
+  SWAP(mlines, ml);
+  SWAP(width, t);
+  SWAP(height, t);
+
+#ifdef COPY_PASTE
+  SWAP(histheight, t);
+  SWAP(hlines, ml);
+  SWAP(histidx, t);
+#endif
+#undef SWAP
+}
+
+void
+EnterAltScreen(p)
+struct win *p;
+{
+  if (!p->w_alt.on)
+    {
+      /* If not already using the alternate screen buffer, then create
+	 a new one and swap it with the 'real' screen buffer. */
+      FreeAltScreen(p);
+      SwapAltScreen(p);
+    }
+  else
+    {
+      /* Already using the alternate buffer. Just clear the screen. To do so, it
+	 is only necessary to reset the height(s) without resetting the width. */
+      p->w_height = 0;
+      p->w_histheight = 0;
+    }
+  ChangeWindowSize(p, p->w_alt.width, p->w_alt.height, p->w_alt.histheight);
+  p->w_alt.on = 1;
+}
+
+void
+LeaveAltScreen(p)
+struct win *p;
+{
+  if (!p->w_alt.on)
+    return;
+  SwapAltScreen(p);
+  ChangeWindowSize(p, p->w_alt.width, p->w_alt.height, p->w_alt.histheight);
+  FreeAltScreen(p);
+  p->w_alt.on = 0;
+}