xcf-load.c

/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * 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 of the License, 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.  If not, see <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <string.h>
#include <zlib.h>

#include <cairo.h>
#include <gegl.h>
#include <gdk-pixbuf/gdk-pixbuf.h>

#include "libgimpbase/gimpbase.h"
#include "libgimpcolor/gimpcolor.h"

#include "core/core-types.h"

#include "config/gimpcoreconfig.h"

#include "gegl/gimp-babl.h"
#include "gegl/gimp-gegl-tile-compat.h"

#include "core/gimp.h"
#include "core/gimpcontainer.h"
#include "core/gimpdrawable-private.h" /* eek */
#include "core/gimpgrid.h"
#include "core/gimpgrouplayer.h"
#include "core/gimpimage.h"
#include "core/gimpimage-colormap.h"
#include "core/gimpimage-grid.h"
#include "core/gimpimage-guides.h"
#include "core/gimpimage-metadata.h"
#include "core/gimpimage-private.h"
#include "core/gimpimage-sample-points.h"
#include "core/gimpimage-symmetry.h"
#include "core/gimpimage-undo.h"
#include "core/gimpitemstack.h"
#include "core/gimplayer-floating-selection.h"
#include "core/gimplayer-new.h"
#include "core/gimplayermask.h"
#include "core/gimpparasitelist.h"
#include "core/gimpprogress.h"
#include "core/gimpselection.h"
#include "core/gimpsymmetry.h"
#include "core/gimptemplate.h"

#include "operations/layer-modes/gimp-layer-modes.h"

#include "text/gimptextlayer.h"
#include "text/gimptextlayer-xcf.h"

#include "vectors/gimpanchor.h"
#include "vectors/gimpstroke.h"
#include "vectors/gimpbezierstroke.h"
#include "vectors/gimpvectors.h"
#include "vectors/gimpvectors-compat.h"

#include "xcf-private.h"
#include "xcf-load.h"
#include "xcf-read.h"
#include "xcf-seek.h"
#include "xcf-utils.h"

#include "gimp-log.h"
#include "gimp-intl.h"


#define MAX_XCF_PARASITE_DATA_LEN (256L * 1024 * 1024)

/* #define GIMP_XCF_PATH_DEBUG */


static void            xcf_load_add_masks     (GimpImage     *image);
static gboolean        xcf_load_image_props   (XcfInfo       *info,
                                               GimpImage     *image);
static gboolean        xcf_load_layer_props   (XcfInfo       *info,
                                               GimpImage     *image,
                                               GimpLayer    **layer,
                                               GList        **item_path,
                                               gboolean      *apply_mask,
                                               gboolean      *edit_mask,
                                               gboolean      *show_mask,
                                               guint32       *text_layer_flags,
                                               guint32       *group_layer_flags);
static gboolean        xcf_check_layer_props  (XcfInfo       *info,
                                               GList        **item_path,
                                               gboolean      *is_group_layer,
                                               gboolean      *is_text_layer);
static gboolean        xcf_load_channel_props (XcfInfo       *info,
                                               GimpImage     *image,
                                               GimpChannel  **channel);
static gboolean        xcf_load_prop          (XcfInfo       *info,
                                               PropType      *prop_type,
                                               guint32       *prop_size);
static GimpLayer     * xcf_load_layer         (XcfInfo       *info,
                                               GimpImage     *image,
                                               GList        **item_path);
static GimpChannel   * xcf_load_channel       (XcfInfo       *info,
                                               GimpImage     *image);
static GimpLayerMask * xcf_load_layer_mask    (XcfInfo       *info,
                                               GimpImage     *image);
static gboolean        xcf_load_buffer        (XcfInfo       *info,
                                               GeglBuffer    *buffer);
static gboolean        xcf_load_level         (XcfInfo       *info,
                                               GeglBuffer    *buffer);
static gboolean        xcf_load_tile          (XcfInfo       *info,
                                               GeglBuffer    *buffer,
                                               GeglRectangle *tile_rect,
                                               const Babl    *format);
static gboolean        xcf_load_tile_rle      (XcfInfo       *info,
                                               GeglBuffer    *buffer,
                                               GeglRectangle *tile_rect,
                                               const Babl    *format,
                                               gint           data_length);
static gboolean        xcf_load_tile_zlib     (XcfInfo       *info,
                                               GeglBuffer    *buffer,
                                               GeglRectangle *tile_rect,
                                               const Babl    *format,
                                               gint           data_length);
static GimpParasite  * xcf_load_parasite      (XcfInfo       *info);
static gboolean        xcf_load_old_paths     (XcfInfo       *info,
                                               GimpImage     *image);
static gboolean        xcf_load_old_path      (XcfInfo       *info,
                                               GimpImage     *image);
static gboolean        xcf_load_vectors       (XcfInfo       *info,
                                               GimpImage     *image);
static gboolean        xcf_load_vector        (XcfInfo       *info,
                                               GimpImage     *image);

static gboolean        xcf_skip_unknown_prop  (XcfInfo       *info,
                                               gsize          size);

static gboolean        xcf_item_path_is_parent (GList        *path,
                                                GList        *parent_path);
static void            xcf_fix_item_path       (GimpLayer    *layer,
                                                GList       **path,
                                                GList        *broken_paths);

#define xcf_progress_update(info) G_STMT_START  \
  {                                             \
    if (info->progress)                         \
      gimp_progress_pulse (info->progress);     \
  } G_STMT_END


GimpImage *
xcf_load_image (Gimp     *gimp,
                XcfInfo  *info,
                GError  **error)
{
  GimpImage          *image = NULL;
  const GimpParasite *parasite;
  gboolean            has_metadata = FALSE;
  goffset             saved_pos;
  goffset             offset;
  gint                width;
  gint                height;
  gint                image_type;
  GimpPrecision       precision = GIMP_PRECISION_U8_GAMMA;
  gint                num_successful_elements = 0;
  gint                n_broken_layers         = 0;
  gint                n_broken_channels       = 0;
  GList              *broken_paths            = NULL;
  GList              *group_layers            = NULL;
  GList              *syms;
  GList              *iter;

  /* read in the image width, height and type */
  xcf_read_int32 (info, (guint32 *) &width, 1);
  xcf_read_int32 (info, (guint32 *) &height, 1);
  xcf_read_int32 (info, (guint32 *) &image_type, 1);
  if (image_type < GIMP_RGB || image_type > GIMP_INDEXED)
    goto hard_error;

  /* Be lenient with corrupt image dimensions.
   * Hopefully layer dimensions will be valid. */
  if (width <= 0 || height <= 0 ||
      width > GIMP_MAX_IMAGE_SIZE || height > GIMP_MAX_IMAGE_SIZE)
    {
      GIMP_LOG (XCF, "Invalid image size %d x %d, setting to 1x1.", width, height);
      width  = 1;
      height = 1;
    }

  if (info->file_version >= 4)
    {
      gint p;

      xcf_read_int32 (info, (guint32 *) &p, 1);

      if (info->file_version == 4)
        {
          switch (p)
            {
            case 0: precision = GIMP_PRECISION_U8_GAMMA;     break;
            case 1: precision = GIMP_PRECISION_U16_GAMMA;    break;
            case 2: precision = GIMP_PRECISION_U32_LINEAR;   break;
            case 3: precision = GIMP_PRECISION_HALF_LINEAR;  break;
            case 4: precision = GIMP_PRECISION_FLOAT_LINEAR; break;
            default:
              goto hard_error;
            }
        }
      else if (info->file_version == 5 ||
               info->file_version == 6)
        {
          switch (p)
            {
            case 100: precision = GIMP_PRECISION_U8_LINEAR; break;
            case 150: precision = GIMP_PRECISION_U8_GAMMA; break;
            case 200: precision = GIMP_PRECISION_U16_LINEAR; break;
            case 250: precision = GIMP_PRECISION_U16_GAMMA; break;
            case 300: precision = GIMP_PRECISION_U32_LINEAR; break;
            case 350: precision = GIMP_PRECISION_U32_GAMMA; break;
            case 400: precision = GIMP_PRECISION_HALF_LINEAR; break;
            case 450: precision = GIMP_PRECISION_HALF_GAMMA; break;
            case 500: precision = GIMP_PRECISION_FLOAT_LINEAR; break;
            case 550: precision = GIMP_PRECISION_FLOAT_GAMMA; break;
            default:
              goto hard_error;
            }
        }
      else
        {
          precision = p;
        }
    }

  GIMP_LOG (XCF, "version=%d, width=%d, height=%d, image_type=%d, precision=%d",
            info->file_version, width, height, image_type, precision);

  if (! gimp_babl_is_valid (image_type, precision))
    {
      gimp_message_literal (gimp, G_OBJECT (info->progress),
                            GIMP_MESSAGE_ERROR,
                            _("Invalid image mode and precision combination."));
      goto hard_error;
    }

  image = gimp_create_image (gimp, width, height, image_type, precision,
                             FALSE);

  gimp_image_undo_disable (image);

  xcf_progress_update (info);

  /* read the image properties */
  if (! xcf_load_image_props (info, image))
    goto hard_error;

  GIMP_LOG (XCF, "image props loaded");

  /* check for a GimpGrid parasite */
  parasite = gimp_image_parasite_find (GIMP_IMAGE (image),
                                       gimp_grid_parasite_name ());
  if (parasite)
    {
      GimpGrid *grid = gimp_grid_from_parasite (parasite);

      if (grid)
        {
          GimpImagePrivate *private = GIMP_IMAGE_GET_PRIVATE (image);

          gimp_parasite_list_remove (private->parasites,
                                     gimp_parasite_name (parasite));

          gimp_image_set_grid (GIMP_IMAGE (image), grid, FALSE);
          g_object_unref (grid);
        }
    }

  /* check for a metadata parasite */
  parasite = gimp_image_parasite_find (GIMP_IMAGE (image),
                                       "gimp-image-metadata");
  if (parasite)
    {
      GimpImagePrivate *private  = GIMP_IMAGE_GET_PRIVATE (image);
      GimpMetadata     *metadata = NULL;
      const gchar      *meta_string;

      meta_string = (gchar *) gimp_parasite_data (parasite);

      if (meta_string)
        metadata = gimp_metadata_deserialize (meta_string);

      if (metadata)
        {
          has_metadata = TRUE;

          gimp_image_set_metadata (image, metadata, FALSE);
          g_object_unref (metadata);
        }

      gimp_parasite_list_remove (private->parasites,
                                 gimp_parasite_name (parasite));
    }

  /* check for symmetry parasites */
  syms = gimp_image_symmetry_list ();
  for (iter = syms; iter; iter = g_list_next (iter))
    {
      GType  type = (GType) iter->data;
      gchar *parasite_name = gimp_symmetry_parasite_name (type);

      parasite = gimp_image_parasite_find (image,
                                           parasite_name);
      g_free (parasite_name);
      if (parasite)
        {
          GimpSymmetry *sym = gimp_symmetry_from_parasite (parasite,
                                                           image,
                                                           type);

          if (sym)
            {
              GimpImagePrivate *private = GIMP_IMAGE_GET_PRIVATE (image);

              gimp_parasite_list_remove (private->parasites,
                                         gimp_parasite_name (parasite));

              gimp_image_symmetry_add (image, sym);

              g_signal_emit_by_name (sym, "active-changed", NULL);
              if (sym->active)
                gimp_image_set_active_symmetry (image, type);
            }
        }
    }
  g_list_free (syms);

  /* migrate the old "exif-data" parasite */
  parasite = gimp_image_parasite_find (GIMP_IMAGE (image),
                                       "exif-data");
  if (parasite)
    {
      GimpImagePrivate *private = GIMP_IMAGE_GET_PRIVATE (image);

      if (has_metadata)
        {
          g_printerr ("xcf-load: inconsistent metadata discovered: XCF file "
                      "has both 'gimp-image-metadata' and 'exif-data' "
                      "parasites, dropping old 'exif-data'\n");
        }
      else
        {
          GimpMetadata *metadata = gimp_image_get_metadata (image);
          GError       *my_error = NULL;

          if (metadata)
            g_object_ref (metadata);
          else
            metadata = gimp_metadata_new ();

          if (! gimp_metadata_set_from_exif (metadata,
                                             gimp_parasite_data (parasite),
                                             gimp_parasite_data_size (parasite),
                                             &my_error))
            {
              gimp_message (gimp, G_OBJECT (info->progress),
                            GIMP_MESSAGE_WARNING,
                            _("Corrupt 'exif-data' parasite discovered.\n"
                              "Exif data could not be migrated: %s"),
                            my_error->message);
              g_clear_error (&my_error);
            }
          else
            {
              gimp_image_set_metadata (image, metadata, FALSE);
            }

          g_object_unref (metadata);
        }

      gimp_parasite_list_remove (private->parasites,
                                 gimp_parasite_name (parasite));
    }

  /* migrate the old "gimp-metadata" parasite */
  parasite = gimp_image_parasite_find (GIMP_IMAGE (image),
                                       "gimp-metadata");
  if (parasite)
    {
      GimpImagePrivate *private    = GIMP_IMAGE_GET_PRIVATE (image);
      const gchar      *xmp_data   = gimp_parasite_data (parasite);
      gint              xmp_length = gimp_parasite_data_size (parasite);

      if (has_metadata)
        {
          g_printerr ("xcf-load: inconsistent metadata discovered: XCF file "
                      "has both 'gimp-image-metadata' and 'gimp-metadata' "
                      "parasites, dropping old 'gimp-metadata'\n");
        }
      else if (xmp_length < 14 ||
               strncmp (xmp_data, "GIMP_XMP_1", 10) != 0)
        {
          gimp_message (gimp, G_OBJECT (info->progress),
                        GIMP_MESSAGE_WARNING,
                        _("Corrupt 'gimp-metadata' parasite discovered.\n"
                          "XMP data could not be migrated."));
        }
      else
        {
          GimpMetadata *metadata = gimp_image_get_metadata (image);
          GError       *my_error = NULL;

          if (metadata)
            g_object_ref (metadata);
          else
            metadata = gimp_metadata_new ();

          if (! gimp_metadata_set_from_xmp (metadata,
                                            (const guint8 *) xmp_data + 10,
                                            xmp_length - 10,
                                            &my_error))
            {
              /* XMP metadata from 2.8.x or earlier can be really messed up.
               * Let's make the message more user friendly so they will
               * understand that we can't do anything about it.
               * See issue #987. */
              gimp_message (gimp, G_OBJECT (info->progress),
                            GIMP_MESSAGE_WARNING,
                            _("Corrupt XMP metadata saved by an older version of "
                              "GIMP could not be converted and will be ignored.\n"
                              "If you don't know what XMP is, you most likely don't "
                              "need it. Reported error: %s."),
                            my_error->message);
              g_clear_error (&my_error);
            }
          else
            {
              gimp_image_set_metadata (image, metadata, FALSE);
            }

          g_object_unref (metadata);
        }

      gimp_parasite_list_remove (private->parasites,
                                 gimp_parasite_name (parasite));
    }

  /* check for a gimp-xcf-compatibility-mode parasite */
  parasite = gimp_image_parasite_find (GIMP_IMAGE (image),
                                       "gimp-xcf-compatibility-mode");
  if (parasite)
    {
      GimpImagePrivate *private = GIMP_IMAGE_GET_PRIVATE (image);

      /* just ditch it, it's unused but shouldn't be re-saved */
      gimp_parasite_list_remove (private->parasites,
                                 gimp_parasite_name (parasite));
    }

  xcf_progress_update (info);

  while (TRUE)
    {
      GimpLayer *layer;
      GList     *item_path = NULL;

      /* read in the offset of the next layer */
      xcf_read_offset (info, &offset, 1);

      /* if the offset is 0 then we are at the end
       *  of the layer list.
       */
      if (offset == 0)
        break;

      /* save the current position as it is where the
       *  next layer offset is stored.
       */
      saved_pos = info->cp;

      if (offset < saved_pos)
        {
          GIMP_LOG (XCF, "Invalid layer offset: %" G_GOFFSET_FORMAT
                    " at offset: %" G_GOFFSET_FORMAT, offset, saved_pos);
          goto error;
        }

      /* seek to the layer offset */
      if (! xcf_seek_pos (info, offset, NULL))
        goto error;

      /* read in the layer */
      layer = xcf_load_layer (info, image, &item_path);
      if (! layer)
        {
          n_broken_layers++;

          if (! xcf_seek_pos (info, saved_pos, NULL))
            {
              if (item_path)
                g_list_free (item_path);

              goto error;
            }

          /* Don't just stop at the first broken layer. Load as much as
           * possible.
           */
          if (! item_path)
            {
              GimpContainer *layers = gimp_image_get_layers (image);

              item_path = g_list_prepend (NULL,
                                          GUINT_TO_POINTER (gimp_container_get_n_children (layers)));

              broken_paths = g_list_prepend (broken_paths, item_path);
            }

          continue;
        }

      if (broken_paths && item_path)
        {
          /* Item paths may be a problem when layers are missing. */
          xcf_fix_item_path (layer, &item_path, broken_paths);
        }

      num_successful_elements++;

      xcf_progress_update (info);

      /* suspend layer-group size updates */
      if (GIMP_IS_GROUP_LAYER (layer))
        {
          GimpGroupLayer *group = GIMP_GROUP_LAYER (layer);

          group_layers = g_list_prepend (group_layers, group);

          gimp_group_layer_suspend_resize (group, FALSE);
        }

      /* add the layer to the image if its not the floating selection */
      if (layer != info->floating_sel)
        {
          GimpContainer *layers = gimp_image_get_layers (image);
          GimpContainer *container;
          GimpLayer     *parent;

          if (item_path)
            {
              if (info->floating_sel)
                {
                  /* there is a floating selection, but it will get
                   * added after all layers are loaded, so toplevel
                   * layer indices are off-by-one. Adjust item paths
                   * accordingly:
                   */
                  gint toplevel_index;

                  toplevel_index = GPOINTER_TO_UINT (item_path->data);

                  toplevel_index--;

                  item_path->data = GUINT_TO_POINTER (toplevel_index);
                }

              parent = GIMP_LAYER
                (gimp_item_stack_get_parent_by_path (GIMP_ITEM_STACK (layers),
                                                     item_path,
                                                     NULL));

              container = gimp_viewable_get_children (GIMP_VIEWABLE (parent));

              g_list_free (item_path);
            }
          else
            {
              parent    = NULL;
              container = layers;
            }

          gimp_image_add_layer (image, layer,
                                parent,
                                gimp_container_get_n_children (container),
                                FALSE);
        }

      /* restore the saved position so we'll be ready to
       *  read the next offset.
       */
      if (! xcf_seek_pos (info, saved_pos, NULL))
        goto error;
    }

  /* resume layer-group size updates, in reverse order */
  for (iter = group_layers; iter; iter = g_list_next (iter))
    {
      GimpGroupLayer *group = iter->data;

      gimp_group_layer_resume_resize (group, FALSE);
    }
  g_clear_pointer (&group_layers, g_list_free);

  if (broken_paths)
    {
      g_list_free_full (broken_paths, (GDestroyNotify) g_list_free);
      broken_paths = NULL;
    }

  while (TRUE)
    {
      GimpChannel *channel;

      /* read in the offset of the next channel */
      xcf_read_offset (info, &offset, 1);

      /* if the offset is 0 then we are at the end
       *  of the channel list.
       */
      if (offset == 0)
        break;

      /* save the current position as it is where the
       *  next channel offset is stored.
       */
      saved_pos = info->cp;

      if (offset < saved_pos)
        {
          GIMP_LOG (XCF, "Invalid channel offset: %" G_GOFFSET_FORMAT
                    " at offset: % "G_GOFFSET_FORMAT, offset, saved_pos);
          goto error;
        }

      /* seek to the channel offset */
      if (! xcf_seek_pos (info, offset, NULL))
        goto error;

      /* read in the channel */
      channel = xcf_load_channel (info, image);
      if (!channel)
        {
          n_broken_channels++;
          GIMP_LOG (XCF, "Failed to load channel.");

          if (! xcf_seek_pos (info, saved_pos, NULL))
            goto error;

          continue;
        }

      num_successful_elements++;

      xcf_progress_update (info);

      /* add the channel to the image if its not the selection */
      if (channel != gimp_image_get_mask (image))
        gimp_image_add_channel (image, channel,
                                NULL, /* FIXME tree */
                                gimp_container_get_n_children (gimp_image_get_channels (image)),
                                FALSE);

      /* restore the saved position so we'll be ready to
       *  read the next offset.
       */
      if (! xcf_seek_pos (info, saved_pos, NULL))
        goto error;
    }

  if (n_broken_layers == 0 && n_broken_channels == 0)
    xcf_load_add_masks (image);

  if (info->floating_sel && info->floating_sel_drawable)
    floating_sel_attach (info->floating_sel, info->floating_sel_drawable);

  if (info->active_layer)
    gimp_image_set_active_layer (image, info->active_layer);

  if (info->active_channel)
    gimp_image_set_active_channel (image, info->active_channel);

  if (info->file)
    gimp_image_set_file (image, info->file);

  if (info->tattoo_state > 0)
    gimp_image_set_tattoo_state (image, info->tattoo_state);

  if (n_broken_layers > 0 || n_broken_channels > 0)
    goto error;

  gimp_image_undo_enable (image);

  return image;

 error:
  if (num_successful_elements == 0)
    goto hard_error;

  g_clear_pointer (&group_layers, g_list_free);

  if (broken_paths)
    {
      g_list_free_full (broken_paths, (GDestroyNotify) g_list_free);
      broken_paths = NULL;
    }

  gimp_message_literal (gimp, G_OBJECT (info->progress), GIMP_MESSAGE_WARNING,
                        _("This XCF file is corrupt!  I have loaded as much "
                          "of it as I can, but it is incomplete."));

  xcf_load_add_masks (image);

  gimp_image_undo_enable (image);

  return image;

 hard_error:
  g_clear_pointer (&group_layers, g_list_free);

  if (broken_paths)
    {
      g_list_free_full (broken_paths, (GDestroyNotify) g_list_free);
      broken_paths = NULL;
    }

  g_set_error_literal (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                       _("This XCF file is corrupt!  I could not even "
                         "salvage any partial image data from it."));

  g_clear_object (&image);

  return NULL;
}

static void
xcf_load_add_masks (GimpImage *image)
{
  GList *layers;
  GList *list;

  layers = gimp_image_get_layer_list (image);

  for (list = layers; list; list = g_list_next (list))
    {
      GimpLayer     *layer = list->data;
      GimpLayerMask *mask;

      mask = g_object_get_data (G_OBJECT (layer), "gimp-layer-mask");

      if (mask)
        {
          gboolean apply_mask;
          gboolean edit_mask;
          gboolean show_mask;

          apply_mask = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (layer),
                                                           "gimp-layer-mask-apply"));
          edit_mask = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (layer),
                                                          "gimp-layer-mask-edit"));
          show_mask = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (layer),
                                                          "gimp-layer-mask-show"));

          gimp_layer_add_mask (layer, mask, FALSE, NULL);

          gimp_layer_set_apply_mask (layer, apply_mask, FALSE);
          gimp_layer_set_edit_mask  (layer, edit_mask);
          gimp_layer_set_show_mask  (layer, show_mask, FALSE);

          g_object_set_data (G_OBJECT (layer), "gimp-layer-mask",       NULL);
          g_object_set_data (G_OBJECT (layer), "gimp-layer-mask-apply", NULL);
          g_object_set_data (G_OBJECT (layer), "gimp-layer-mask-edit",  NULL);
          g_object_set_data (G_OBJECT (layer), "gimp-layer-mask-show",  NULL);
        }
    }

  g_list_free (layers);
}

static gboolean
xcf_load_image_props (XcfInfo   *info,
                      GimpImage *image)
{
  PropType prop_type;
  guint32  prop_size;

  while (TRUE)
    {
      if (! xcf_load_prop (info, &prop_type, &prop_size))
        return FALSE;

      switch (prop_type)
        {
        case PROP_END:
          return TRUE;

        case PROP_COLORMAP:
          {
            guint32 n_colors;
            guchar  cmap[GIMP_IMAGE_COLORMAP_SIZE];

            xcf_read_int32 (info, &n_colors, 1);

            if (n_colors > (GIMP_IMAGE_COLORMAP_SIZE / 3))
              {
                gimp_message (info->gimp, G_OBJECT (info->progress),
                              GIMP_MESSAGE_ERROR,
                              "Maximum colormap size (%d) exceeded",
                              GIMP_IMAGE_COLORMAP_SIZE);
                return FALSE;
              }

            if (info->file_version == 0)
              {
                gint i;

                gimp_message_literal (info->gimp, G_OBJECT (info->progress),
                                      GIMP_MESSAGE_WARNING,
                                      _("XCF warning: version 0 of XCF file format\n"
                                        "did not save indexed colormaps correctly.\n"
                                        "Substituting grayscale map."));

                if (! xcf_seek_pos (info, info->cp + n_colors, NULL))
                  return FALSE;

                for (i = 0; i < n_colors; i++)
                  {
                    cmap[i * 3 + 0] = i;
                    cmap[i * 3 + 1] = i;
                    cmap[i * 3 + 2] = i;
                  }
              }
            else
              {
                xcf_read_int8 (info, cmap, n_colors * 3);
              }

            /* only set color map if image is indexed, this is just
             * sanity checking to make sure gimp doesn't end up with
             * an image state that is impossible.
             */
            if (gimp_image_get_base_type (image) == GIMP_INDEXED)
              gimp_image_set_colormap (image, cmap, n_colors, FALSE);

            GIMP_LOG (XCF, "prop colormap n_colors=%d", n_colors);
          }
          break;

        case PROP_COMPRESSION:
          {
            guint8 compression;

            xcf_read_int8 (info, (guint8 *) &compression, 1);

            if ((compression != COMPRESS_NONE) &&
                (compression != COMPRESS_RLE) &&
                (compression != COMPRESS_ZLIB) &&
                (compression != COMPRESS_FRACTAL))
              {
                gimp_message (info->gimp, G_OBJECT (info->progress),
                              GIMP_MESSAGE_ERROR,
                              "Unknown compression type: %d",
                              (gint) compression);
                return FALSE;
              }

            info->compression = compression;

            gimp_image_set_xcf_compression (image,
                                            compression >= COMPRESS_ZLIB);

            GIMP_LOG (XCF, "prop compression=%d", compression);
          }
          break;

        case PROP_GUIDES:
          {
            GimpImagePrivate *private = GIMP_IMAGE_GET_PRIVATE (image);
            gint32            position;
            gint8             orientation;
            gint              i, nguides;

            nguides = prop_size / (4 + 1);
            for (i = 0; i < nguides; i++)
              {
                xcf_read_int32 (info, (guint32 *) &position,    1);
                xcf_read_int8  (info, (guint8 *)  &orientation, 1);

                /*  skip -1 guides from old XCFs  */
                if (position < 0)
                  continue;

                GIMP_LOG (XCF, "prop guide orientation=%d position=%d",
                          orientation, position);

                switch (orientation)
                  {
                  case XCF_ORIENTATION_HORIZONTAL:
                    gimp_image_add_hguide (image, position, FALSE);
                    break;

                  case XCF_ORIENTATION_VERTICAL:
                    gimp_image_add_vguide (image, position, FALSE);
                    break;

                  default:
                    gimp_message_literal (info->gimp, G_OBJECT (info->progress),
                                          GIMP_MESSAGE_WARNING,
                                          "Guide orientation out of range in XCF file");
                    continue;
                  }
              }

            /*  this is silly as the order of guides doesn't really matter,
             *  but it restores the list to its original order, which
             *  cannot be wrong  --Mitch
             */
            private->guides = g_list_reverse (private->guides);
          }
          break;

        case PROP_SAMPLE_POINTS:
          {
            gint n_sample_points, i;

            n_sample_points = prop_size / (5 * 4);
            for (i = 0; i < n_sample_points; i++)
              {
                GimpSamplePoint   *sample_point;
                gint32             x, y;
                GimpColorPickMode  pick_mode;
                guint32            padding[2] = { 0, };

                xcf_read_int32 (info, (guint32 *) &x,         1);
                xcf_read_int32 (info, (guint32 *) &y,         1);
                xcf_read_int32 (info, (guint32 *) &pick_mode, 1);
                xcf_read_int32 (info, (guint32 *) padding,    2);

                GIMP_LOG (XCF, "prop sample point x=%d y=%d mode=%d",
                          x, y, pick_mode);

                if (pick_mode > GIMP_COLOR_PICK_MODE_LAST)
                  pick_mode = GIMP_COLOR_PICK_MODE_PIXEL;

                sample_point = gimp_image_add_sample_point_at_pos (image,
                                                                   x, y, FALSE);
                gimp_image_set_sample_point_pick_mode (image, sample_point,
                                                       pick_mode, FALSE);
              }
          }
          break;

        case PROP_OLD_SAMPLE_POINTS:
          {
            gint32 x, y;
            gint   i, n_sample_points;

            /* if there are already sample points, we loaded the new
             * prop before
             */
            if (gimp_image_get_sample_points (image))
              {
                if (! xcf_skip_unknown_prop (info, prop_size))
                  return FALSE;

                break;
              }

            n_sample_points = prop_size / (4 + 4);
            for (i = 0; i < n_sample_points; i++)
              {
                xcf_read_int32 (info, (guint32 *) &x, 1);
                xcf_read_int32 (info, (guint32 *) &y, 1);

                GIMP_LOG (XCF, "prop old sample point x=%d y=%d", x, y);

                gimp_image_add_sample_point_at_pos (image, x, y, FALSE);
              }
          }
          break;

        case PROP_RESOLUTION:
          {
            gfloat xres, yres;

            xcf_read_float (info, &xres, 1);
            xcf_read_float (info, &yres, 1);

            GIMP_LOG (XCF, "prop resolution x=%f y=%f", xres, yres);

            if (xres < GIMP_MIN_RESOLUTION || xres > GIMP_MAX_RESOLUTION ||
                yres < GIMP_MIN_RESOLUTION || yres > GIMP_MAX_RESOLUTION)
              {
                GimpTemplate *template = image->gimp->config->default_image;