xfns.c

/* Functions for the X window system.

Copyright (C) 1989, 1992-2014 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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.

GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>

#include "lisp.h"
#include "xterm.h"
#include "menu.h"
#include "frame.h"
#include "window.h"
#include "character.h"
#include "buffer.h"
#include "intervals.h"
#include "dispextern.h"
#include "keyboard.h"
#include "blockinput.h"
#include <epaths.h>
#include "charset.h"
#include "coding.h"
#include "fontset.h"
#include "systime.h"
#include "termhooks.h"
#include "atimer.h"
#include "termchar.h"
#include "font.h"

#include <sys/types.h>
#include <sys/stat.h>

#if 1 /* Used to be #ifdef EMACS_BITMAP_FILES, but this should always work.  */
#include "bitmaps/gray.xbm"
#else
#include <X11/bitmaps/gray>
#endif

#include "xsettings.h"

#ifdef HAVE_XRANDR
#include <X11/extensions/Xrandr.h>
#endif
#ifdef HAVE_XINERAMA
#include <X11/extensions/Xinerama.h>
#endif

#ifdef USE_GTK
#include "gtkutil.h"
#endif

#ifdef USE_X_TOOLKIT
#include <X11/Shell.h>

#ifndef USE_MOTIF
#ifdef HAVE_XAW3D
#include <X11/Xaw3d/Paned.h>
#include <X11/Xaw3d/Label.h>
#else /* !HAVE_XAW3D */
#include <X11/Xaw/Paned.h>
#include <X11/Xaw/Label.h>
#endif /* HAVE_XAW3D */
#endif /* USE_MOTIF */

#ifdef USG
#undef USG	/* ####KLUDGE for Solaris 2.2 and up */
#include <X11/Xos.h>
#define USG
#ifdef USG /* Pacify gcc -Wunused-macros.  */
#endif
#else
#include <X11/Xos.h>
#endif

#include "widget.h"

#include "../lwlib/lwlib.h"

#ifdef USE_MOTIF
#include <Xm/Xm.h>
#include <Xm/DialogS.h>
#include <Xm/FileSB.h>
#include <Xm/List.h>
#include <Xm/TextF.h>
#endif

#ifdef USE_LUCID
#include "../lwlib/xlwmenu.h"
#endif

#if !defined (NO_EDITRES)
#define HACK_EDITRES
extern void _XEditResCheckMessages (Widget, XtPointer, XEvent *, Boolean *);
#endif /* not defined NO_EDITRES */

/* Unique id counter for widgets created by the Lucid Widget Library.  */

extern LWLIB_ID widget_id_tick;

#ifdef USE_MOTIF

#endif /* USE_MOTIF */

#endif /* USE_X_TOOLKIT */

#ifdef USE_GTK

#endif /* USE_GTK */

#define MAXREQUEST(dpy) (XMaxRequestSize (dpy))

static Lisp_Object Qundefined_color;
static Lisp_Object Qcompound_text, Qcancel_timer;
Lisp_Object Qfont_param;

#ifdef GLYPH_DEBUG
static ptrdiff_t image_cache_refcount;
static int dpyinfo_refcount;
#endif

static struct x_display_info *x_display_info_for_name (Lisp_Object);

/* Let the user specify an X display with a Lisp object.
   OBJECT may be nil, a frame or a terminal object.
   nil stands for the selected frame--or, if that is not an X frame,
   the first X display on the list.  */

struct x_display_info *
check_x_display_info (Lisp_Object object)
{
  struct x_display_info *dpyinfo = NULL;

  if (NILP (object))
    {
      struct frame *sf = XFRAME (selected_frame);

      if (FRAME_X_P (sf) && FRAME_LIVE_P (sf))
	dpyinfo = FRAME_DISPLAY_INFO (sf);
      else if (x_display_list != 0)
	dpyinfo = x_display_list;
      else
	error ("X windows are not in use or not initialized");
    }
  else if (TERMINALP (object))
    {
      struct terminal *t = get_terminal (object, 1);

      if (t->type != output_x_window)
        error ("Terminal %d is not an X display", t->id);

      dpyinfo = t->display_info.x;
    }
  else if (STRINGP (object))
    dpyinfo = x_display_info_for_name (object);
  else
    {
      struct frame *f = decode_window_system_frame (object);
      dpyinfo = FRAME_DISPLAY_INFO (f);
    }

  return dpyinfo;
}

/* Store the screen positions of frame F into XPTR and YPTR.
   These are the positions of the containing window manager window,
   not Emacs's own window.  */

void
x_real_positions (struct frame *f, int *xptr, int *yptr)
{
  int win_x, win_y, outer_x IF_LINT (= 0), outer_y IF_LINT (= 0);
  int real_x = 0, real_y = 0;
  int had_errors = 0;
  Window win = f->output_data.x->parent_desc;
  Atom actual_type;
  unsigned long actual_size, bytes_remaining;
  int rc, actual_format;
  struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
  long max_len = 400;
  Display *dpy = FRAME_X_DISPLAY (f);
  unsigned char *tmp_data = NULL;
  Atom target_type = XA_CARDINAL;

  block_input ();

  x_catch_errors (dpy);

  if (win == dpyinfo->root_window)
    win = FRAME_OUTER_WINDOW (f);

  /* This loop traverses up the containment tree until we hit the root
     window.  Window managers may intersect many windows between our window
     and the root window.  The window we find just before the root window
     should be the outer WM window. */
  for (;;)
    {
      Window wm_window, rootw;
      Window *tmp_children;
      unsigned int tmp_nchildren;
      int success;

      success = XQueryTree (FRAME_X_DISPLAY (f), win, &rootw,
			    &wm_window, &tmp_children, &tmp_nchildren);

      had_errors = x_had_errors_p (FRAME_X_DISPLAY (f));

      /* Don't free tmp_children if XQueryTree failed.  */
      if (! success)
	break;

      XFree (tmp_children);

      if (wm_window == rootw || had_errors)
        break;

      win = wm_window;
    }

  if (! had_errors)
    {
      unsigned int ign;
      Window child, rootw;

      /* Get the real coordinates for the WM window upper left corner */
      XGetGeometry (FRAME_X_DISPLAY (f), win,
                    &rootw, &real_x, &real_y, &ign, &ign, &ign, &ign);

      /* Translate real coordinates to coordinates relative to our
         window.  For our window, the upper left corner is 0, 0.
         Since the upper left corner of the WM window is outside
         our window, win_x and win_y will be negative:

         ------------------          ---> x
         |      title                |
         | -----------------         v y
         | |  our window
      */
      XTranslateCoordinates (FRAME_X_DISPLAY (f),

			     /* From-window, to-window.  */
			     FRAME_DISPLAY_INFO (f)->root_window,
                             FRAME_X_WINDOW (f),

			     /* From-position, to-position.  */
                             real_x, real_y, &win_x, &win_y,

			     /* Child of win.  */
			     &child);

      if (FRAME_X_WINDOW (f) == FRAME_OUTER_WINDOW (f))
	{
          outer_x = win_x;
          outer_y = win_y;
	}
      else
        {
          XTranslateCoordinates (FRAME_X_DISPLAY (f),

                                 /* From-window, to-window.  */
                                 FRAME_DISPLAY_INFO (f)->root_window,
                                 FRAME_OUTER_WINDOW (f),

                                 /* From-position, to-position.  */
                                 real_x, real_y, &outer_x, &outer_y,

                                 /* Child of win.  */
                                 &child);
	}

      had_errors = x_had_errors_p (FRAME_X_DISPLAY (f));
    }


  if (dpyinfo->root_window == f->output_data.x->parent_desc)
    {
      /* Try _NET_FRAME_EXTENTS if our parent is the root window.  */
      rc = XGetWindowProperty (dpy, win, dpyinfo->Xatom_net_frame_extents,
                               0, max_len, False, target_type,
                               &actual_type, &actual_format, &actual_size,
                               &bytes_remaining, &tmp_data);

      if (rc == Success && actual_type == target_type && !x_had_errors_p (dpy)
          && actual_size == 4 && actual_format == 32)
        {
          unsigned int ign;
          Window rootw;
          long *fe = (long *)tmp_data;

          XGetGeometry (FRAME_X_DISPLAY (f), win,
                        &rootw, &real_x, &real_y, &ign, &ign, &ign, &ign);
          outer_x = -fe[0];
          outer_y = -fe[2];
          real_x -= fe[0];
          real_y -= fe[2];
        }
    }

  if (tmp_data) XFree (tmp_data);

  x_uncatch_errors ();

  unblock_input ();

  if (had_errors) return;

  f->x_pixels_diff = -win_x;
  f->y_pixels_diff = -win_y;

  FRAME_X_OUTPUT (f)->x_pixels_outer_diff = -outer_x;
  FRAME_X_OUTPUT (f)->y_pixels_outer_diff = -outer_y;

  *xptr = real_x;
  *yptr = real_y;
}

/* Get the mouse position in frame relative coordinates.  */

void
x_relative_mouse_position (struct frame *f, int *x, int *y)
{
  Window root, dummy_window;
  int dummy;

  eassert (FRAME_X_P (f));

  block_input ();

  XQueryPointer (FRAME_X_DISPLAY (f),
                 DefaultRootWindow (FRAME_X_DISPLAY (f)),

                 /* The root window which contains the pointer.  */
                 &root,

                 /* Window pointer is on, not used  */
                 &dummy_window,

                 /* The position on that root window.  */
                 x, y,

                 /* x/y in dummy_window coordinates, not used.  */
                 &dummy, &dummy,

                 /* Modifier keys and pointer buttons, about which
                    we don't care.  */
                 (unsigned int *) &dummy);

  unblock_input ();

  /* Translate root window coordinates to window coordinates.  */
  *x -= f->left_pos + FRAME_OUTER_TO_INNER_DIFF_X (f);
  *y -= f->top_pos + FRAME_OUTER_TO_INNER_DIFF_Y (f);
}

/* Gamma-correct COLOR on frame F.  */

void
gamma_correct (struct frame *f, XColor *color)
{
  if (f->gamma)
    {
      color->red = pow (color->red / 65535.0, f->gamma) * 65535.0 + 0.5;
      color->green = pow (color->green / 65535.0, f->gamma) * 65535.0 + 0.5;
      color->blue = pow (color->blue / 65535.0, f->gamma) * 65535.0 + 0.5;
    }
}


/* Decide if color named COLOR_NAME is valid for use on frame F.  If
   so, return the RGB values in COLOR.  If ALLOC_P,
   allocate the color.  Value is false if COLOR_NAME is invalid, or
   no color could be allocated.  */

bool
x_defined_color (struct frame *f, const char *color_name,
		 XColor *color, bool alloc_p)
{
  bool success_p = 0;
  Display *dpy = FRAME_X_DISPLAY (f);
  Colormap cmap = FRAME_X_COLORMAP (f);

  block_input ();
#ifdef USE_GTK
  success_p = xg_check_special_colors (f, color_name, color);
#endif
  if (!success_p)
    success_p = XParseColor (dpy, cmap, color_name, color) != 0;
  if (success_p && alloc_p)
    success_p = x_alloc_nearest_color (f, cmap, color);
  unblock_input ();

  return success_p;
}


/* Return the pixel color value for color COLOR_NAME on frame F.  If F
   is a monochrome frame, return MONO_COLOR regardless of what ARG says.
   Signal an error if color can't be allocated.  */

static int
x_decode_color (struct frame *f, Lisp_Object color_name, int mono_color)
{
  XColor cdef;

  CHECK_STRING (color_name);

#if 0 /* Don't do this.  It's wrong when we're not using the default
	 colormap, it makes freeing difficult, and it's probably not
	 an important optimization.  */
  if (strcmp (SDATA (color_name), "black") == 0)
    return BLACK_PIX_DEFAULT (f);
  else if (strcmp (SDATA (color_name), "white") == 0)
    return WHITE_PIX_DEFAULT (f);
#endif

  /* Return MONO_COLOR for monochrome frames.  */
  if (FRAME_DISPLAY_INFO (f)->n_planes == 1)
    return mono_color;

  /* x_defined_color is responsible for coping with failures
     by looking for a near-miss.  */
  if (x_defined_color (f, SSDATA (color_name), &cdef, 1))
    return cdef.pixel;

  signal_error ("Undefined color", color_name);
}



/* Change the `wait-for-wm' frame parameter of frame F.  OLD_VALUE is
   the previous value of that parameter, NEW_VALUE is the new value.
   See also the comment of wait_for_wm in struct x_output.  */

static void
x_set_wait_for_wm (struct frame *f, Lisp_Object new_value, Lisp_Object old_value)
{
  f->output_data.x->wait_for_wm = !NILP (new_value);
}

static void
x_set_tool_bar_position (struct frame *f,
                         Lisp_Object new_value,
                         Lisp_Object old_value)
{
  Lisp_Object choice = list4 (Qleft, Qright, Qtop, Qbottom);

  if (!NILP (Fmemq (new_value, choice)))
    {
#ifdef USE_GTK
      if (!EQ (new_value, old_value))
	{
	  xg_change_toolbar_position (f, new_value);
	  fset_tool_bar_position (f, new_value);
	}
#else
      if (!EQ (new_value, Qtop))
	error ("The only supported tool bar position is top");
#endif
    }
  else
    wrong_choice (choice, new_value);
}

#ifdef USE_GTK

/* Set icon from FILE for frame F.  By using GTK functions the icon
   may be any format that GdkPixbuf knows about, i.e. not just bitmaps.  */

int
xg_set_icon (struct frame *f, Lisp_Object file)
{
  int result = 0;
  Lisp_Object found;

  found = x_find_image_file (file);

  if (! NILP (found))
    {
      GdkPixbuf *pixbuf;
      GError *err = NULL;
      char *filename = SSDATA (found);
      block_input ();

      pixbuf = gdk_pixbuf_new_from_file (filename, &err);

      if (pixbuf)
	{
	  gtk_window_set_icon (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)),
			       pixbuf);
	  g_object_unref (pixbuf);

	  result = 1;
	}
      else
	g_error_free (err);

      unblock_input ();
    }

  return result;
}

int
xg_set_icon_from_xpm_data (struct frame *f, const char **data)
{
  GdkPixbuf *pixbuf = gdk_pixbuf_new_from_xpm_data (data);

  if (!pixbuf)
    return 0;

  gtk_window_set_icon (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)), pixbuf);
  g_object_unref (pixbuf);
  return 1;
}
#endif /* USE_GTK */


/* Functions called only from `x_set_frame_param'
   to set individual parameters.

   If FRAME_X_WINDOW (f) is 0,
   the frame is being created and its X-window does not exist yet.
   In that case, just record the parameter's new value
   in the standard place; do not attempt to change the window.  */

static void
x_set_foreground_color (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
{
  struct x_output *x = f->output_data.x;
  unsigned long fg, old_fg;

  fg = x_decode_color (f, arg, BLACK_PIX_DEFAULT (f));
  old_fg = FRAME_FOREGROUND_PIXEL (f);
  FRAME_FOREGROUND_PIXEL (f) = fg;

  if (FRAME_X_WINDOW (f) != 0)
    {
      Display *dpy = FRAME_X_DISPLAY (f);

      block_input ();
      XSetForeground (dpy, x->normal_gc, fg);
      XSetBackground (dpy, x->reverse_gc, fg);

      if (x->cursor_pixel == old_fg)
	{
	  unload_color (f, x->cursor_pixel);
	  x->cursor_pixel = x_copy_color (f, fg);
	  XSetBackground (dpy, x->cursor_gc, x->cursor_pixel);
	}

      unblock_input ();

      update_face_from_frame_parameter (f, Qforeground_color, arg);

      if (FRAME_VISIBLE_P (f))
        redraw_frame (f);
    }

  unload_color (f, old_fg);
}

static void
x_set_background_color (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
{
  struct x_output *x = f->output_data.x;
  unsigned long bg;

  bg = x_decode_color (f, arg, WHITE_PIX_DEFAULT (f));
  unload_color (f, FRAME_BACKGROUND_PIXEL (f));
  FRAME_BACKGROUND_PIXEL (f) = bg;

  if (FRAME_X_WINDOW (f) != 0)
    {
      Display *dpy = FRAME_X_DISPLAY (f);

      block_input ();
      XSetBackground (dpy, x->normal_gc, bg);
      XSetForeground (dpy, x->reverse_gc, bg);
      XSetWindowBackground (dpy, FRAME_X_WINDOW (f), bg);
      XSetForeground (dpy, x->cursor_gc, bg);

#ifdef USE_GTK
      xg_set_background_color (f, bg);
#endif

#ifndef USE_TOOLKIT_SCROLL_BARS /* Turns out to be annoying with
				   toolkit scroll bars.  */
      {
	Lisp_Object bar;
	for (bar = FRAME_SCROLL_BARS (f);
	     !NILP (bar);
	     bar = XSCROLL_BAR (bar)->next)
	  {
	    Window window = XSCROLL_BAR (bar)->x_window;
	    XSetWindowBackground (dpy, window, bg);
	  }
      }
#endif /* USE_TOOLKIT_SCROLL_BARS */

      unblock_input ();
      update_face_from_frame_parameter (f, Qbackground_color, arg);

      if (FRAME_VISIBLE_P (f))
        redraw_frame (f);
    }
}

static void
x_set_mouse_color (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
{
  struct x_output *x = f->output_data.x;
  Display *dpy = FRAME_X_DISPLAY (f);
  Cursor cursor, nontext_cursor, mode_cursor, hand_cursor;
  Cursor hourglass_cursor, horizontal_drag_cursor, vertical_drag_cursor;
  unsigned long pixel = x_decode_color (f, arg, BLACK_PIX_DEFAULT (f));
  unsigned long mask_color = FRAME_BACKGROUND_PIXEL (f);

  /* Don't let pointers be invisible.  */
  if (mask_color == pixel)
    {
      x_free_colors (f, &pixel, 1);
      pixel = x_copy_color (f, FRAME_FOREGROUND_PIXEL (f));
    }

  unload_color (f, x->mouse_pixel);
  x->mouse_pixel = pixel;

  block_input ();

  /* It's not okay to crash if the user selects a screwy cursor.  */
  x_catch_errors (dpy);

  if (!NILP (Vx_pointer_shape))
    {
      CHECK_NUMBER (Vx_pointer_shape);
      cursor = XCreateFontCursor (dpy, XINT (Vx_pointer_shape));
    }
  else
    cursor = XCreateFontCursor (dpy, XC_xterm);
  x_check_errors (dpy, "bad text pointer cursor: %s");

  if (!NILP (Vx_nontext_pointer_shape))
    {
      CHECK_NUMBER (Vx_nontext_pointer_shape);
      nontext_cursor
	= XCreateFontCursor (dpy, XINT (Vx_nontext_pointer_shape));
    }
  else
    nontext_cursor = XCreateFontCursor (dpy, XC_left_ptr);
  x_check_errors (dpy, "bad nontext pointer cursor: %s");

  if (!NILP (Vx_hourglass_pointer_shape))
    {
      CHECK_NUMBER (Vx_hourglass_pointer_shape);
      hourglass_cursor
	= XCreateFontCursor (dpy, XINT (Vx_hourglass_pointer_shape));
    }
  else
    hourglass_cursor = XCreateFontCursor (dpy, XC_watch);
  x_check_errors (dpy, "bad hourglass pointer cursor: %s");

  if (!NILP (Vx_mode_pointer_shape))
    {
      CHECK_NUMBER (Vx_mode_pointer_shape);
      mode_cursor = XCreateFontCursor (dpy, XINT (Vx_mode_pointer_shape));
    }
  else
    mode_cursor = XCreateFontCursor (dpy, XC_xterm);
  x_check_errors (dpy, "bad modeline pointer cursor: %s");

  if (!NILP (Vx_sensitive_text_pointer_shape))
    {
      CHECK_NUMBER (Vx_sensitive_text_pointer_shape);
      hand_cursor
	= XCreateFontCursor (dpy, XINT (Vx_sensitive_text_pointer_shape));
    }
  else
    hand_cursor = XCreateFontCursor (dpy, XC_hand2);

  if (!NILP (Vx_window_horizontal_drag_shape))
    {
      CHECK_TYPE_RANGED_INTEGER (unsigned, Vx_window_horizontal_drag_shape);
      horizontal_drag_cursor
	= XCreateFontCursor (dpy, XINT (Vx_window_horizontal_drag_shape));
    }
  else
    horizontal_drag_cursor
      = XCreateFontCursor (dpy, XC_sb_h_double_arrow);

  if (!NILP (Vx_window_vertical_drag_shape))
    {
      CHECK_NUMBER (Vx_window_vertical_drag_shape);
      vertical_drag_cursor
	= XCreateFontCursor (dpy, XINT (Vx_window_vertical_drag_shape));
    }
  else
    vertical_drag_cursor
      = XCreateFontCursor (dpy, XC_sb_v_double_arrow);

  /* Check and report errors with the above calls.  */
  x_check_errors (dpy, "can't set cursor shape: %s");
  x_uncatch_errors ();

  {
    XColor fore_color, back_color;

    fore_color.pixel = x->mouse_pixel;
    x_query_color (f, &fore_color);
    back_color.pixel = mask_color;
    x_query_color (f, &back_color);

    XRecolorCursor (dpy, cursor, &fore_color, &back_color);
    XRecolorCursor (dpy, nontext_cursor, &fore_color, &back_color);
    XRecolorCursor (dpy, mode_cursor, &fore_color, &back_color);
    XRecolorCursor (dpy, hand_cursor, &fore_color, &back_color);
    XRecolorCursor (dpy, hourglass_cursor, &fore_color, &back_color);
    XRecolorCursor (dpy, horizontal_drag_cursor, &fore_color, &back_color);
    XRecolorCursor (dpy, vertical_drag_cursor, &fore_color, &back_color);
  }

  if (FRAME_X_WINDOW (f) != 0)
    XDefineCursor (dpy, FRAME_X_WINDOW (f),
                   f->output_data.x->current_cursor = cursor);

  if (cursor != x->text_cursor
      && x->text_cursor != 0)
    XFreeCursor (dpy, x->text_cursor);
  x->text_cursor = cursor;

  if (nontext_cursor != x->nontext_cursor
      && x->nontext_cursor != 0)
    XFreeCursor (dpy, x->nontext_cursor);
  x->nontext_cursor = nontext_cursor;

  if (hourglass_cursor != x->hourglass_cursor
      && x->hourglass_cursor != 0)
    XFreeCursor (dpy, x->hourglass_cursor);
  x->hourglass_cursor = hourglass_cursor;

  if (mode_cursor != x->modeline_cursor
      && x->modeline_cursor != 0)
    XFreeCursor (dpy, f->output_data.x->modeline_cursor);
  x->modeline_cursor = mode_cursor;

  if (hand_cursor != x->hand_cursor
      && x->hand_cursor != 0)
    XFreeCursor (dpy, x->hand_cursor);
  x->hand_cursor = hand_cursor;

  if (horizontal_drag_cursor != x->horizontal_drag_cursor
      && x->horizontal_drag_cursor != 0)
    XFreeCursor (dpy, x->horizontal_drag_cursor);
  x->horizontal_drag_cursor = horizontal_drag_cursor;

  if (vertical_drag_cursor != x->vertical_drag_cursor
      && x->vertical_drag_cursor != 0)
    XFreeCursor (dpy, x->vertical_drag_cursor);
  x->vertical_drag_cursor = vertical_drag_cursor;

  XFlush (dpy);
  unblock_input ();

  update_face_from_frame_parameter (f, Qmouse_color, arg);
}

static void
x_set_cursor_color (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
{
  unsigned long fore_pixel, pixel;
  bool fore_pixel_allocated_p = 0, pixel_allocated_p = 0;
  struct x_output *x = f->output_data.x;

  if (!NILP (Vx_cursor_fore_pixel))
    {
      fore_pixel = x_decode_color (f, Vx_cursor_fore_pixel,
				   WHITE_PIX_DEFAULT (f));
      fore_pixel_allocated_p = 1;
    }
  else
    fore_pixel = FRAME_BACKGROUND_PIXEL (f);

  pixel = x_decode_color (f, arg, BLACK_PIX_DEFAULT (f));
  pixel_allocated_p = 1;

  /* Make sure that the cursor color differs from the background color.  */
  if (pixel == FRAME_BACKGROUND_PIXEL (f))
    {
      if (pixel_allocated_p)
	{
	  x_free_colors (f, &pixel, 1);
	  pixel_allocated_p = 0;
	}

      pixel = x->mouse_pixel;
      if (pixel == fore_pixel)
	{
	  if (fore_pixel_allocated_p)
	    {
	      x_free_colors (f, &fore_pixel, 1);
	      fore_pixel_allocated_p = 0;
	    }
	  fore_pixel = FRAME_BACKGROUND_PIXEL (f);
	}
    }

  unload_color (f, x->cursor_foreground_pixel);
  if (!fore_pixel_allocated_p)
    fore_pixel = x_copy_color (f, fore_pixel);
  x->cursor_foreground_pixel = fore_pixel;

  unload_color (f, x->cursor_pixel);
  if (!pixel_allocated_p)
    pixel = x_copy_color (f, pixel);
  x->cursor_pixel = pixel;

  if (FRAME_X_WINDOW (f) != 0)
    {