Adding upstream version 2.10.22.upstream/2.10.22upstream

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

1 files changed, 2266 insertions, 0 deletions

diff --git a/app/xcf/xcf-save.c b/app/xcf/xcf-save.c
new file mode 100644
index 0000000..ee5cdcf
--- /dev/null
+++ b/app/xcf/xcf-save.c
@@ -0,0 +1,2266 @@
+/* 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 "gegl/gimp-babl-compat.h"
+#include "gegl/gimp-gegl-tile-compat.h"
+
+#include "core/gimp.h"
+#include "core/gimpcontainer.h"
+#include "core/gimpchannel.h"
+#include "core/gimpdrawable.h"
+#include "core/gimpgrid.h"
+#include "core/gimpguide.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/gimplayer.h"
+#include "core/gimplayermask.h"
+#include "core/gimpparasitelist.h"
+#include "core/gimpprogress.h"
+#include "core/gimpsamplepoint.h"
+#include "core/gimpsymmetry.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-read.h"
+#include "xcf-save.h"
+#include "xcf-seek.h"
+#include "xcf-write.h"
+
+#include "gimp-intl.h"
+
+
+static gboolean xcf_save_image_props   (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        GError           **error);
+static gboolean xcf_save_layer_props   (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        GimpLayer         *layer,
+                                        GError           **error);
+static gboolean xcf_save_channel_props (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        GimpChannel       *channel,
+                                        GError           **error);
+static gboolean xcf_save_prop          (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        PropType           prop_type,
+                                        GError           **error,
+                                        ...);
+static gboolean xcf_save_layer         (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        GimpLayer         *layer,
+                                        GError           **error);
+static gboolean xcf_save_channel       (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        GimpChannel       *channel,
+                                        GError           **error);
+static gboolean xcf_save_buffer        (XcfInfo           *info,
+                                        GeglBuffer        *buffer,
+                                        GError           **error);
+static gboolean xcf_save_level         (XcfInfo           *info,
+                                        GeglBuffer        *buffer,
+                                        GError           **error);
+static gboolean xcf_save_tile          (XcfInfo           *info,
+                                        GeglBuffer        *buffer,
+                                        GeglRectangle     *tile_rect,
+                                        const Babl        *format,
+                                        GError           **error);
+static gboolean xcf_save_tile_rle      (XcfInfo           *info,
+                                        GeglBuffer        *buffer,
+                                        GeglRectangle     *tile_rect,
+                                        const Babl        *format,
+                                        guchar            *rlebuf,
+                                        GError           **error);
+static gboolean xcf_save_tile_zlib     (XcfInfo           *info,
+                                        GeglBuffer        *buffer,
+                                        GeglRectangle     *tile_rect,
+                                        const Babl        *format,
+                                        GError           **error);
+static gboolean xcf_save_parasite      (XcfInfo           *info,
+                                        GimpParasite      *parasite,
+                                        GError           **error);
+static gboolean xcf_save_parasite_list (XcfInfo           *info,
+                                        GimpParasiteList  *parasite,
+                                        GError           **error);
+static gboolean xcf_save_old_paths     (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        GError           **error);
+static gboolean xcf_save_vectors       (XcfInfo           *info,
+                                        GimpImage         *image,
+                                        GError           **error);
+
+
+/* private convenience macros */
+#define xcf_write_int32_check_error(info, data, count) G_STMT_START { \
+  xcf_write_int32 (info, data, count, &tmp_error);                    \
+  if (tmp_error)                                                      \
+    {                                                                 \
+      g_propagate_error (error, tmp_error);                           \
+      return FALSE;                                                   \
+    }                                                                 \
+  } G_STMT_END
+
+#define xcf_write_offset_check_error(info, data, count) G_STMT_START { \
+  xcf_write_offset (info, data, count, &tmp_error);                    \
+  if (tmp_error)                                                       \
+    {                                                                  \
+      g_propagate_error (error, tmp_error);                            \
+      return FALSE;                                                    \
+    }                                                                  \
+  } G_STMT_END
+
+#define xcf_write_zero_offset_check_error(info, count) G_STMT_START { \
+  xcf_write_zero_offset (info, count, &tmp_error);                    \
+  if (tmp_error)                                                      \
+    {                                                                 \
+      g_propagate_error (error, tmp_error);                           \
+      return FALSE;                                                   \
+    }                                                                 \
+  } G_STMT_END
+
+#define xcf_write_int8_check_error(info, data, count) G_STMT_START { \
+  xcf_write_int8 (info, data, count, &tmp_error);                    \
+  if (tmp_error)                                                     \
+    {                                                                \
+      g_propagate_error (error, tmp_error);                          \
+      return FALSE;                                                  \
+    }                                                                \
+  } G_STMT_END
+
+#define xcf_write_float_check_error(info, data, count) G_STMT_START { \
+  xcf_write_float (info, data, count, &tmp_error);                    \
+  if (tmp_error)                                                      \
+    {                                                                 \
+      g_propagate_error (error, tmp_error);                           \
+      return FALSE;                                                   \
+    }                                                                 \
+  } G_STMT_END
+
+#define xcf_write_string_check_error(info, data, count) G_STMT_START { \
+  xcf_write_string (info, data, count, &tmp_error);                    \
+  if (tmp_error)                                                       \
+    {                                                                  \
+      g_propagate_error (error, tmp_error);                            \
+      return FALSE;                                                    \
+    }                                                                  \
+  } G_STMT_END
+
+#define xcf_write_component_check_error(info, bpc, data, count) G_STMT_START { \
+  xcf_write_component (info, bpc, data, count, &tmp_error);          \
+  if (tmp_error)                                                     \
+    {                                                                \
+      g_propagate_error (error, tmp_error);                          \
+      return FALSE;                                                  \
+    }                                                                \
+  } G_STMT_END
+
+#define xcf_write_prop_type_check_error(info, prop_type) G_STMT_START { \
+  guint32 _prop_int32 = prop_type;                                      \
+  xcf_write_int32_check_error (info, &_prop_int32, 1);                  \
+  } G_STMT_END
+
+#define xcf_check_error(x) G_STMT_START { \
+  if (! (x))                              \
+    return FALSE;                         \
+  } G_STMT_END
+
+#define xcf_progress_update(info) G_STMT_START  \
+  {                                             \
+    progress++;                                 \
+    if (info->progress)                         \
+      gimp_progress_set_value (info->progress,  \
+                               (gdouble) progress / (gdouble) max_progress); \
+  } G_STMT_END
+
+
+gboolean
+xcf_save_image (XcfInfo    *info,
+                GimpImage  *image,
+                GError    **error)
+{
+  GList   *all_layers;
+  GList   *all_channels;
+  GList   *list;
+  goffset  saved_pos;
+  goffset  offset;
+  guint32  value;
+  guint    n_layers;
+  guint    n_channels;
+  guint    progress = 0;
+  guint    max_progress;
+  gchar    version_tag[16];
+  GError  *tmp_error = NULL;
+
+  /* write out the tag information for the image */
+  if (info->file_version > 0)
+    {
+      g_snprintf (version_tag, sizeof (version_tag),
+                  "gimp xcf v%03d", info->file_version);
+    }
+  else
+    {
+      strcpy (version_tag, "gimp xcf file");
+    }
+
+  xcf_write_int8_check_error (info, (guint8 *) version_tag, 14);
+
+  /* write out the width, height and image type information for the image */
+  value = gimp_image_get_width (image);
+  xcf_write_int32_check_error (info, (guint32 *) &value, 1);
+
+  value = gimp_image_get_height (image);
+  xcf_write_int32_check_error (info, (guint32 *) &value, 1);
+
+  value = gimp_image_get_base_type (image);
+  xcf_write_int32_check_error (info, &value, 1);
+
+  if (info->file_version >= 4)
+    {
+      value = gimp_image_get_precision (image);
+      xcf_write_int32_check_error (info, &value, 1);
+    }
+
+  /* determine the number of layers and channels in the image */
+  all_layers   = gimp_image_get_layer_list (image);
+  all_channels = gimp_image_get_channel_list (image);
+
+  /* check and see if we have to save out the selection */
+  if (! gimp_channel_is_empty (gimp_image_get_mask (image)))
+    {
+      all_channels = g_list_append (all_channels, gimp_image_get_mask (image));
+    }
+
+  n_layers   = (guint) g_list_length (all_layers);
+  n_channels = (guint) g_list_length (all_channels);
+
+  max_progress = 1 + n_layers + n_channels;
+
+  /* write the property information for the image */
+  xcf_check_error (xcf_save_image_props (info, image, error));
+
+  xcf_progress_update (info);
+
+  /* 'saved_pos' is the next slot in the offset table */
+  saved_pos = info->cp;
+
+  /* write an empty offset table */
+  xcf_write_zero_offset_check_error (info, n_layers + n_channels + 2);
+
+  /* 'offset' is where we will write the next layer or channel */
+  offset = info->cp;
+
+  for (list = all_layers; list; list = g_list_next (list))
+    {
+      GimpLayer *layer = list->data;
+
+      /* seek back to the next slot in the offset table and write the
+       * offset of the layer
+       */
+      xcf_check_error (xcf_seek_pos (info, saved_pos, error));
+      xcf_write_offset_check_error (info, &offset, 1);
+
+      /* remember the next slot in the offset table */
+      saved_pos = info->cp;
+
+      /* seek to the layer offset and save the layer */
+      xcf_check_error (xcf_seek_pos (info, offset, error));
+      xcf_check_error (xcf_save_layer (info, image, layer, error));
+
+      /* the next layer's offset is after the layer we just wrote */
+      offset = info->cp;
+
+      xcf_progress_update (info);
+    }
+
+  /* skip a '0' in the offset table to indicate the end of the layer
+   * offsets
+   */
+  saved_pos += info->bytes_per_offset;
+
+  for (list = all_channels; list; list = g_list_next (list))
+    {
+      GimpChannel *channel = list->data;
+
+      /* seek back to the next slot in the offset table and write the
+       * offset of the channel
+       */
+      xcf_check_error (xcf_seek_pos (info, saved_pos, error));
+      xcf_write_offset_check_error (info, &offset, 1);
+
+      /* remember the next slot in the offset table */
+      saved_pos = info->cp;
+
+      /* seek to the channel offset and save the channel */
+      xcf_check_error (xcf_seek_pos (info, offset, error));
+      xcf_check_error (xcf_save_channel (info, image, channel, error));
+
+      /* the next channels's offset is after the channel we just wrote */
+      offset = info->cp;
+
+      xcf_progress_update (info);
+    }
+
+  /* there is already a '0' at the end of the offset table to indicate
+   * the end of the channel offsets
+   */
+
+  g_list_free (all_layers);
+  g_list_free (all_channels);
+
+  return ! g_output_stream_is_closed (info->output);
+}
+
+static gboolean
+xcf_save_image_props (XcfInfo    *info,
+                      GimpImage  *image,
+                      GError    **error)
+{
+  GimpImagePrivate *private       = GIMP_IMAGE_GET_PRIVATE (image);
+  GimpParasite     *grid_parasite = NULL;
+  GimpParasite     *meta_parasite = NULL;
+  GList            *symmetry_parasites = NULL;
+  GList            *iter;
+  GimpUnit          unit          = gimp_image_get_unit (image);
+  gdouble           xres;
+  gdouble           yres;
+
+  gimp_image_get_resolution (image, &xres, &yres);
+
+  /* check and see if we should save the colormap property */
+  if (gimp_image_get_colormap (image))
+    xcf_check_error (xcf_save_prop (info, image, PROP_COLORMAP, error,
+                                    gimp_image_get_colormap_size (image),
+                                    gimp_image_get_colormap (image)));
+
+  if (info->compression != COMPRESS_NONE)
+    xcf_check_error (xcf_save_prop (info, image, PROP_COMPRESSION, error,
+                                    info->compression));
+
+  if (gimp_image_get_guides (image))
+    xcf_check_error (xcf_save_prop (info, image, PROP_GUIDES, error,
+                                    gimp_image_get_guides (image)));
+
+  if (gimp_image_get_sample_points (image))
+    {
+      /* save the new property before the old one, so loading can skip
+       * the latter
+       */
+      xcf_check_error (xcf_save_prop (info, image, PROP_SAMPLE_POINTS, error,
+                                      gimp_image_get_sample_points (image)));
+      xcf_check_error (xcf_save_prop (info, image, PROP_OLD_SAMPLE_POINTS, error,
+                                      gimp_image_get_sample_points (image)));
+    }
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_RESOLUTION, error,
+                                  xres, yres));
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_TATTOO, error,
+                                  gimp_image_get_tattoo_state (image)));
+
+  if (unit < gimp_unit_get_number_of_built_in_units ())
+    xcf_check_error (xcf_save_prop (info, image, PROP_UNIT, error, unit));
+
+  if (gimp_container_get_n_children (gimp_image_get_vectors (image)) > 0)
+    {
+      if (gimp_vectors_compat_is_compatible (image))
+        xcf_check_error (xcf_save_prop (info, image, PROP_PATHS, error));
+      else
+        xcf_check_error (xcf_save_prop (info, image, PROP_VECTORS, error));
+    }
+
+  if (unit >= gimp_unit_get_number_of_built_in_units ())
+    xcf_check_error (xcf_save_prop (info, image, PROP_USER_UNIT, error, unit));
+
+  if (gimp_image_get_grid (image))
+    {
+      GimpGrid *grid = gimp_image_get_grid (image);
+
+      grid_parasite = gimp_grid_to_parasite (grid);
+      gimp_parasite_list_add (private->parasites, grid_parasite);
+    }
+
+  if (gimp_image_get_metadata (image))
+    {
+      GimpMetadata *metadata = gimp_image_get_metadata (image);
+      gchar        *meta_string;
+
+      meta_string = gimp_metadata_serialize (metadata);
+
+      if (meta_string)
+        {
+          meta_parasite = gimp_parasite_new ("gimp-image-metadata",
+                                             GIMP_PARASITE_PERSISTENT,
+                                             strlen (meta_string) + 1,
+                                             meta_string);
+          gimp_parasite_list_add (private->parasites, meta_parasite);
+          g_free (meta_string);
+        }
+    }
+
+  if (g_list_length (gimp_image_symmetry_get (image)))
+    {
+      GimpParasite *parasite  = NULL;
+      GimpSymmetry *symmetry;
+
+      for (iter = gimp_image_symmetry_get (image); iter; iter = g_list_next (iter))
+        {
+          symmetry = GIMP_SYMMETRY (iter->data);
+          if (G_TYPE_FROM_INSTANCE (symmetry) == GIMP_TYPE_SYMMETRY)
+            /* Do not save the identity symmetry. */
+            continue;
+          parasite = gimp_symmetry_to_parasite (GIMP_SYMMETRY (iter->data));
+          gimp_parasite_list_add (private->parasites, parasite);
+          symmetry_parasites = g_list_prepend (symmetry_parasites, parasite);
+        }
+    }
+
+  if (gimp_parasite_list_length (private->parasites) > 0)
+    {
+      xcf_check_error (xcf_save_prop (info, image, PROP_PARASITES, error,
+                                      private->parasites));
+    }
+
+  if (grid_parasite)
+    {
+      gimp_parasite_list_remove (private->parasites,
+                                 gimp_parasite_name (grid_parasite));
+      gimp_parasite_free (grid_parasite);
+    }
+
+  if (meta_parasite)
+    {
+      gimp_parasite_list_remove (private->parasites,
+                                 gimp_parasite_name (meta_parasite));
+      gimp_parasite_free (meta_parasite);
+    }
+
+  for (iter = symmetry_parasites; iter; iter = g_list_next (iter))
+    {
+      GimpParasite *parasite = iter->data;
+
+      gimp_parasite_list_remove (private->parasites,
+                                 gimp_parasite_name (parasite));
+    }
+  g_list_free_full (symmetry_parasites,
+                    (GDestroyNotify) gimp_parasite_free);
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_END, error));
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_layer_props (XcfInfo    *info,
+                      GimpImage  *image,
+                      GimpLayer  *layer,
+                      GError    **error)
+{
+  GimpParasiteList *parasites;
+  gint              offset_x;
+  gint              offset_y;
+
+  if (gimp_viewable_get_children (GIMP_VIEWABLE (layer)))
+    xcf_check_error (xcf_save_prop (info, image, PROP_GROUP_ITEM, error));
+
+  if (gimp_viewable_get_parent (GIMP_VIEWABLE (layer)))
+    {
+      GList *path;
+
+      path = gimp_item_get_path (GIMP_ITEM (layer));
+      xcf_check_error (xcf_save_prop (info, image, PROP_ITEM_PATH, error,
+                                      path));
+      g_list_free (path);
+    }
+
+  if (layer == gimp_image_get_active_layer (image))
+    xcf_check_error (xcf_save_prop (info, image, PROP_ACTIVE_LAYER, error));
+
+  if (layer == gimp_image_get_floating_selection (image))
+    {
+      info->floating_sel_drawable = gimp_layer_get_floating_sel_drawable (layer);
+      xcf_check_error (xcf_save_prop (info, image, PROP_FLOATING_SELECTION,
+                                      error));
+    }
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_OPACITY, error,
+                                  gimp_layer_get_opacity (layer)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_FLOAT_OPACITY, error,
+                                  gimp_layer_get_opacity (layer)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_VISIBLE, error,
+                                  gimp_item_get_visible (GIMP_ITEM (layer))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_LINKED, error,
+                                  gimp_item_get_linked (GIMP_ITEM (layer))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_COLOR_TAG, error,
+                                  gimp_item_get_color_tag (GIMP_ITEM (layer))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_LOCK_CONTENT, error,
+                                  gimp_item_get_lock_content (GIMP_ITEM (layer))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_LOCK_ALPHA, error,
+                                  gimp_layer_get_lock_alpha (layer)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_LOCK_POSITION, error,
+                                  gimp_item_get_lock_position (GIMP_ITEM (layer))));
+
+  if (gimp_layer_get_mask (layer))
+    {
+      xcf_check_error (xcf_save_prop (info, image, PROP_APPLY_MASK, error,
+                                      gimp_layer_get_apply_mask (layer)));
+      xcf_check_error (xcf_save_prop (info, image, PROP_EDIT_MASK, error,
+                                      gimp_layer_get_edit_mask (layer)));
+      xcf_check_error (xcf_save_prop (info, image, PROP_SHOW_MASK, error,
+                                      gimp_layer_get_show_mask (layer)));
+    }
+  else
+    {
+      xcf_check_error (xcf_save_prop (info, image, PROP_APPLY_MASK, error,
+                                      FALSE));
+      xcf_check_error (xcf_save_prop (info, image, PROP_EDIT_MASK, error,
+                                      FALSE));
+      xcf_check_error (xcf_save_prop (info, image, PROP_SHOW_MASK, error,
+                                      FALSE));
+    }
+
+  gimp_item_get_offset (GIMP_ITEM (layer), &offset_x, &offset_y);
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_OFFSETS, error,
+                                  offset_x, offset_y));
+  xcf_check_error (xcf_save_prop (info, image, PROP_MODE, error,
+                                  gimp_layer_get_mode (layer)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_BLEND_SPACE, error,
+                                  gimp_layer_get_mode (layer),
+                                  gimp_layer_get_blend_space (layer)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_COMPOSITE_SPACE, error,
+                                  gimp_layer_get_mode (layer),
+                                  gimp_layer_get_composite_space (layer)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_COMPOSITE_MODE, error,
+                                  gimp_layer_get_mode (layer),
+                                  gimp_layer_get_composite_mode (layer)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_TATTOO, error,
+                                  gimp_item_get_tattoo (GIMP_ITEM (layer))));
+
+  if (GIMP_IS_TEXT_LAYER (layer) && GIMP_TEXT_LAYER (layer)->text)
+    {
+      GimpTextLayer *text_layer = GIMP_TEXT_LAYER (layer);
+      guint32        flags      = gimp_text_layer_get_xcf_flags (text_layer);
+
+      gimp_text_layer_xcf_save_prepare (text_layer);
+
+      if (flags)
+        xcf_check_error (xcf_save_prop (info,
+                                        image, PROP_TEXT_LAYER_FLAGS, error,
+                                        flags));
+    }
+
+  if (gimp_viewable_get_children (GIMP_VIEWABLE (layer)))
+    {
+      gint32 flags = 0;
+
+      if (gimp_viewable_get_expanded (GIMP_VIEWABLE (layer)))
+        flags |= XCF_GROUP_ITEM_EXPANDED;
+
+      xcf_check_error (xcf_save_prop (info,
+                                      image, PROP_GROUP_ITEM_FLAGS, error,
+                                      flags));
+    }
+
+  parasites = gimp_item_get_parasites (GIMP_ITEM (layer));
+
+  if (gimp_parasite_list_length (parasites) > 0)
+    {
+      xcf_check_error (xcf_save_prop (info, image, PROP_PARASITES, error,
+                                      parasites));
+    }
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_END, error));
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_channel_props (XcfInfo      *info,
+                        GimpImage    *image,
+                        GimpChannel  *channel,
+                        GError      **error)
+{
+  GimpParasiteList *parasites;
+
+  if (channel == gimp_image_get_active_channel (image))
+    xcf_check_error (xcf_save_prop (info, image, PROP_ACTIVE_CHANNEL, error));
+
+  if (channel == gimp_image_get_mask (image))
+    xcf_check_error (xcf_save_prop (info, image, PROP_SELECTION, error));
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_OPACITY, error,
+                                  gimp_channel_get_opacity (channel)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_FLOAT_OPACITY, error,
+                                  gimp_channel_get_opacity (channel)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_VISIBLE, error,
+                                  gimp_item_get_visible (GIMP_ITEM (channel))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_LINKED, error,
+                                  gimp_item_get_linked (GIMP_ITEM (channel))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_COLOR_TAG, error,
+                                  gimp_item_get_color_tag (GIMP_ITEM (channel))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_LOCK_CONTENT, error,
+                                  gimp_item_get_lock_content (GIMP_ITEM (channel))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_LOCK_POSITION, error,
+                                  gimp_item_get_lock_position (GIMP_ITEM (channel))));
+  xcf_check_error (xcf_save_prop (info, image, PROP_SHOW_MASKED, error,
+                                  gimp_channel_get_show_masked (channel)));
+  xcf_check_error (xcf_save_prop (info, image, PROP_COLOR, error,
+                                  &channel->color));
+  xcf_check_error (xcf_save_prop (info, image, PROP_FLOAT_COLOR, error,
+                                  &channel->color));
+  xcf_check_error (xcf_save_prop (info, image, PROP_TATTOO, error,
+                                  gimp_item_get_tattoo (GIMP_ITEM (channel))));
+
+  parasites = gimp_item_get_parasites (GIMP_ITEM (channel));
+
+  if (gimp_parasite_list_length (parasites) > 0)
+    {
+      xcf_check_error (xcf_save_prop (info, image, PROP_PARASITES, error,
+                                      parasites));
+    }
+
+  xcf_check_error (xcf_save_prop (info, image, PROP_END, error));
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_prop (XcfInfo    *info,
+               GimpImage  *image,
+               PropType    prop_type,
+               GError    **error,
+               ...)
+{
+  guint32  size;
+  va_list  args;
+  GError  *tmp_error = NULL;
+
+  va_start (args, error);
+
+  switch (prop_type)
+    {
+    case PROP_END:
+      size = 0;
+
+      xcf_write_prop_type_check_error (info, prop_type);
+      xcf_write_int32_check_error (info, &size, 1);
+      break;
+
+    case PROP_COLORMAP:
+      {
+        guint32  n_colors = va_arg (args, guint32);
+        guchar  *colors   = va_arg (args, guchar *);
+
+        size = 4 + n_colors * 3;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &n_colors, 1);
+        xcf_write_int8_check_error  (info, colors,    n_colors * 3);
+      }
+      break;
+
+    case PROP_ACTIVE_LAYER:
+    case PROP_ACTIVE_CHANNEL:
+    case PROP_SELECTION:
+    case PROP_GROUP_ITEM:
+      size = 0;
+
+      xcf_write_prop_type_check_error (info, prop_type);
+      xcf_write_int32_check_error (info, &size, 1);
+      break;
+
+    case PROP_FLOATING_SELECTION:
+      size = info->bytes_per_offset;
+
+      xcf_write_prop_type_check_error (info, prop_type);
+      xcf_write_int32_check_error (info, &size, 1);
+
+      info->floating_sel_offset = info->cp;
+      xcf_write_zero_offset_check_error (info, 1);
+      break;
+
+    case PROP_OPACITY:
+      {
+        gdouble opacity      = va_arg (args, gdouble);
+        guint32 uint_opacity = opacity * 255.999;
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &uint_opacity, 1);
+      }
+      break;
+
+    case PROP_FLOAT_OPACITY:
+      {
+        gfloat opacity = va_arg (args, gdouble);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_float_check_error (info, &opacity, 1);
+      }
+      break;
+
+    case PROP_MODE:
+      {
+        gint32 mode = va_arg (args, gint32);
+
+        size = 4;
+
+        if (mode == GIMP_LAYER_MODE_OVERLAY_LEGACY)
+          mode = GIMP_LAYER_MODE_SOFTLIGHT_LEGACY;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, (guint32 *) &mode, 1);
+      }
+      break;
+
+    case PROP_BLEND_SPACE:
+      {
+        GimpLayerMode mode        = va_arg (args, GimpLayerMode);
+        gint32        blend_space = va_arg (args, gint32);
+
+        G_STATIC_ASSERT (GIMP_LAYER_COLOR_SPACE_AUTO == 0);
+
+        /* if blend_space is AUTO, save the negative of the actual value AUTO
+         * maps to for the given mode, so that we can correctly load it even if
+         * the mapping changes in the future.
+         */
+        if (blend_space == GIMP_LAYER_COLOR_SPACE_AUTO)
+          blend_space = -gimp_layer_mode_get_blend_space (mode);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, (guint32 *) &blend_space, 1);
+      }
+      break;
+
+    case PROP_COMPOSITE_SPACE:
+      {
+        GimpLayerMode mode            = va_arg (args, GimpLayerMode);
+        gint32        composite_space = va_arg (args, gint32);
+
+        G_STATIC_ASSERT (GIMP_LAYER_COLOR_SPACE_AUTO == 0);
+
+        /* if composite_space is AUTO, save the negative of the actual value
+         * AUTO maps to for the given mode, so that we can correctly load it
+         * even if the mapping changes in the future.
+         */
+        if (composite_space == GIMP_LAYER_COLOR_SPACE_AUTO)
+          composite_space = -gimp_layer_mode_get_composite_space (mode);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, (guint32 *) &composite_space, 1);
+      }
+      break;
+
+    case PROP_COMPOSITE_MODE:
+      {
+        GimpLayerMode mode           = va_arg (args, GimpLayerMode);
+        gint32        composite_mode = va_arg (args, gint32);
+
+        G_STATIC_ASSERT (GIMP_LAYER_COMPOSITE_AUTO == 0);
+
+        /* if composite_mode is AUTO, save the negative of the actual value
+         * AUTO maps to for the given mode, so that we can correctly load it
+         * even if the mapping changes in the future.
+         */
+        if (composite_mode == GIMP_LAYER_COMPOSITE_AUTO)
+          composite_mode = -gimp_layer_mode_get_composite_mode (mode);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, (guint32 *) &composite_mode, 1);
+      }
+      break;
+
+    case PROP_VISIBLE:
+      {
+        guint32 visible = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &visible, 1);
+      }
+      break;
+
+    case PROP_LINKED:
+      {
+        guint32 linked = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &linked, 1);
+      }
+      break;
+
+    case PROP_COLOR_TAG:
+      {
+        guint32 color_tag = va_arg (args, gint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &color_tag, 1);
+      }
+      break;
+
+    case PROP_LOCK_CONTENT:
+      {
+        guint32 lock_content = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &lock_content, 1);
+      }
+      break;
+
+    case PROP_LOCK_ALPHA:
+      {
+        guint32 lock_alpha = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &lock_alpha, 1);
+      }
+      break;
+
+    case PROP_LOCK_POSITION:
+      {
+        guint32 lock_position = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &lock_position, 1);
+      }
+      break;
+
+    case PROP_APPLY_MASK:
+      {
+        guint32 apply_mask = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &apply_mask, 1);
+      }
+      break;
+
+    case PROP_EDIT_MASK:
+      {
+        guint32 edit_mask = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &edit_mask, 1);
+      }
+      break;
+
+    case PROP_SHOW_MASK:
+      {
+        guint32 show_mask = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &show_mask, 1);
+      }
+      break;
+
+    case PROP_SHOW_MASKED:
+      {
+        guint32 show_masked = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &show_masked, 1);
+      }
+      break;
+
+    case PROP_OFFSETS:
+      {
+        gint32 offsets[2];
+
+        offsets[0] = va_arg (args, gint32);
+        offsets[1] = va_arg (args, gint32);
+
+        size = 8;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, (guint32 *) offsets, 2);
+      }
+      break;
+
+    case PROP_COLOR:
+      {
+        GimpRGB *color = va_arg (args, GimpRGB *);
+        guchar   col[3];
+
+        gimp_rgb_get_uchar (color, &col[0], &col[1], &col[2]);
+
+        size = 3;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int8_check_error (info, col, 3);
+      }
+      break;
+
+    case PROP_FLOAT_COLOR:
+      {
+        GimpRGB *color = va_arg (args, GimpRGB *);
+        gfloat   col[3];
+
+        col[0] = color->r;
+        col[1] = color->g;
+        col[2] = color->b;
+
+        size = 3 * 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_float_check_error (info, col, 3);
+      }
+      break;
+
+    case PROP_COMPRESSION:
+      {
+        guint8 compression = (guint8) va_arg (args, guint32);
+
+        size = 1;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int8_check_error (info, &compression, 1);
+      }
+      break;
+
+    case PROP_GUIDES:
+      {
+        GList *guides   = va_arg (args, GList *);
+        gint   n_guides = g_list_length (guides);
+        GList *iter;
+
+        for (iter = guides; iter; iter = g_list_next (iter))
+          {
+            /* Do not save custom guides. */
+            if (gimp_guide_is_custom (GIMP_GUIDE (iter->data)))
+              n_guides--;
+          }
+
+        if (n_guides > 0)
+          {
+            size = n_guides * (4 + 1);
+
+            xcf_write_prop_type_check_error (info, prop_type);
+            xcf_write_int32_check_error (info, &size, 1);
+
+            for (; guides; guides = g_list_next (guides))
+              {
+                GimpGuide *guide    = guides->data;
+                gint32     position = gimp_guide_get_position (guide);
+                gint8      orientation;
+
+                if (gimp_guide_is_custom (guide))
+                  continue;
+
+                switch (gimp_guide_get_orientation (guide))
+                  {
+                  case GIMP_ORIENTATION_HORIZONTAL:
+                    orientation = XCF_ORIENTATION_HORIZONTAL;
+                    break;
+
+                  case GIMP_ORIENTATION_VERTICAL:
+                    orientation = XCF_ORIENTATION_VERTICAL;
+                    break;
+
+                  default:
+                    g_warning ("%s: skipping guide with bad orientation",
+                               G_STRFUNC);
+                    continue;
+                  }
+
+                xcf_write_int32_check_error (info, (guint32 *) &position,    1);
+                xcf_write_int8_check_error  (info, (guint8 *)  &orientation, 1);
+              }
+          }
+      }
+      break;
+
+    case PROP_SAMPLE_POINTS:
+      {
+        GList *sample_points   = va_arg (args, GList *);
+        gint   n_sample_points = g_list_length (sample_points);
+
+        size = n_sample_points * (5 * 4);
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        for (; sample_points; sample_points = g_list_next (sample_points))
+          {
+            GimpSamplePoint   *sample_point = sample_points->data;
+            gint32             x, y;
+            GimpColorPickMode  pick_mode;
+            guint32            padding[2] = { 0, };
+
+            gimp_sample_point_get_position (sample_point, &x, &y);
+            pick_mode = gimp_sample_point_get_pick_mode (sample_point);
+
+            xcf_write_int32_check_error (info, (guint32 *) &x,         1);
+            xcf_write_int32_check_error (info, (guint32 *) &y,         1);
+            xcf_write_int32_check_error (info, (guint32 *) &pick_mode, 1);
+            xcf_write_int32_check_error (info, (guint32 *) padding,    2);
+          }
+      }
+      break;
+
+    case PROP_OLD_SAMPLE_POINTS:
+      {
+        GList *sample_points   = va_arg (args, GList *);
+        gint   n_sample_points = g_list_length (sample_points);
+
+        size = n_sample_points * (4 + 4);
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        for (; sample_points; sample_points = g_list_next (sample_points))
+          {
+            GimpSamplePoint *sample_point = sample_points->data;
+            gint32           x, y;
+
+            gimp_sample_point_get_position (sample_point, &x, &y);
+
+            xcf_write_int32_check_error (info, (guint32 *) &x, 1);
+            xcf_write_int32_check_error (info, (guint32 *) &y, 1);
+          }
+      }
+      break;
+
+    case PROP_RESOLUTION:
+      {
+        gfloat resolution[2];
+
+        resolution[0] = va_arg (args, double);
+        resolution[1] = va_arg (args, double);
+
+        size = 2 * 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_float_check_error (info, resolution, 2);
+      }
+      break;
+
+    case PROP_TATTOO:
+      {
+        guint32 tattoo = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &tattoo, 1);
+      }
+      break;
+
+    case PROP_PARASITES:
+      {
+        GimpParasiteList *list = va_arg (args, GimpParasiteList *);
+
+        if (gimp_parasite_list_persistent_length (list) > 0)
+          {
+            goffset base;
+            goffset pos;
+
+            size = 0;
+
+            xcf_write_prop_type_check_error (info, prop_type);
+
+            /* because we don't know how much room the parasite list
+             * will take we save the file position and write the
+             * length later
+             */
+            pos = info->cp;
+            xcf_write_int32_check_error (info, &size, 1);
+
+            base = info->cp;
+
+            xcf_check_error (xcf_save_parasite_list (info, list, error));
+
+            size = info->cp - base;
+
+            /* go back to the saved position and write the length */
+            xcf_check_error (xcf_seek_pos (info, pos, error));
+            xcf_write_int32_check_error (info, &size, 1);
+
+            xcf_check_error (xcf_seek_pos (info, base + size, error));
+          }
+      }
+      break;
+
+    case PROP_UNIT:
+      {
+        guint32 unit = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &unit, 1);
+      }
+      break;
+
+    case PROP_PATHS:
+      {
+        goffset base;
+        goffset pos;
+
+        size = 0;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+
+        /* because we don't know how much room the paths list will
+         * take we save the file position and write the length later
+         */
+        pos = info->cp;
+        xcf_write_int32_check_error (info, &size, 1);
+
+        base = info->cp;
+
+        xcf_check_error (xcf_save_old_paths (info, image, error));
+
+        size = info->cp - base;
+
+        /* go back to the saved position and write the length */
+        xcf_check_error (xcf_seek_pos (info, pos, error));
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_check_error (xcf_seek_pos (info, base + size, error));
+      }
+      break;
+
+    case PROP_USER_UNIT:
+      {
+        GimpUnit     unit = va_arg (args, guint32);
+        const gchar *unit_strings[5];
+        gfloat       factor;
+        guint32      digits;
+
+        /* write the entire unit definition */
+        unit_strings[0] = gimp_unit_get_identifier (unit);
+        factor          = gimp_unit_get_factor (unit);
+        digits          = gimp_unit_get_digits (unit);
+        unit_strings[1] = gimp_unit_get_symbol (unit);
+        unit_strings[2] = gimp_unit_get_abbreviation (unit);
+        unit_strings[3] = gimp_unit_get_singular (unit);
+        unit_strings[4] = gimp_unit_get_plural (unit);
+
+        size =
+          2 * 4 +
+          strlen (unit_strings[0]) ? strlen (unit_strings[0]) + 5 : 4 +
+          strlen (unit_strings[1]) ? strlen (unit_strings[1]) + 5 : 4 +
+          strlen (unit_strings[2]) ? strlen (unit_strings[2]) + 5 : 4 +
+          strlen (unit_strings[3]) ? strlen (unit_strings[3]) + 5 : 4 +
+          strlen (unit_strings[4]) ? strlen (unit_strings[4]) + 5 : 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_float_check_error  (info, &factor,                 1);
+        xcf_write_int32_check_error  (info, &digits,                 1);
+        xcf_write_string_check_error (info, (gchar **) unit_strings, 5);
+      }
+      break;
+
+    case PROP_VECTORS:
+      {
+        goffset base;
+        goffset pos;
+
+        size = 0;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+
+        /* because we don't know how much room the paths list will
+         * take we save the file position and write the length later
+         */
+        pos = info->cp;
+        xcf_write_int32_check_error (info, &size, 1);
+
+        base = info->cp;
+
+        xcf_check_error (xcf_save_vectors (info, image, error));
+
+        size = info->cp - base;
+
+        /* go back to the saved position and write the length */
+        xcf_check_error (xcf_seek_pos (info, pos, error));
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_check_error (xcf_seek_pos (info, base + size, error));
+      }
+      break;
+
+    case PROP_TEXT_LAYER_FLAGS:
+      {
+        guint32 flags = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        xcf_write_int32_check_error (info, &flags, 1);
+      }
+      break;
+
+    case PROP_ITEM_PATH:
+      {
+        GList *path = va_arg (args, GList *);
+
+        size = 4 * g_list_length (path);
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+
+        while (path)
+          {
+            guint32 index = GPOINTER_TO_UINT (path->data);
+
+            xcf_write_int32_check_error (info, &index, 1);
+
+            path = g_list_next (path);
+          }
+      }
+      break;
+
+    case PROP_GROUP_ITEM_FLAGS:
+      {
+        guint32 flags = va_arg (args, guint32);
+
+        size = 4;
+
+        xcf_write_prop_type_check_error (info, prop_type);
+        xcf_write_int32_check_error (info, &size, 1);
+        xcf_write_int32_check_error (info, &flags, 1);
+      }
+      break;
+    }
+
+  va_end (args);
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_layer (XcfInfo    *info,
+                GimpImage  *image,
+                GimpLayer  *layer,
+                GError    **error)
+{
+  goffset      saved_pos;
+  goffset      offset;
+  guint32      value;
+  const gchar *string;
+  GError      *tmp_error = NULL;
+
+  /* check and see if this is the drawable that the floating
+   *  selection is attached to.
+   */
+  if (GIMP_DRAWABLE (layer) == info->floating_sel_drawable)
+    {
+      saved_pos = info->cp;
+      xcf_check_error (xcf_seek_pos (info, info->floating_sel_offset, error));
+      xcf_write_offset_check_error (info, &saved_pos, 1);
+      xcf_check_error (xcf_seek_pos (info, saved_pos, error));
+    }
+
+  /* write out the width, height and image type information for the layer */
+  value = gimp_item_get_width (GIMP_ITEM (layer));
+  xcf_write_int32_check_error (info, &value, 1);
+
+  value = gimp_item_get_height (GIMP_ITEM (layer));
+  xcf_write_int32_check_error (info, &value, 1);
+
+  value = gimp_babl_format_get_image_type (gimp_drawable_get_format (GIMP_DRAWABLE (layer)));
+  xcf_write_int32_check_error (info, &value, 1);
+
+  /* write out the layers name */
+  string = gimp_object_get_name (layer);
+  xcf_write_string_check_error (info, (gchar **) &string, 1);
+
+  /* write out the layer properties */
+  xcf_save_layer_props (info, image, layer, error);
+
+  /* write out the layer tile hierarchy */
+  offset = info->cp + 2 * info->bytes_per_offset;
+  xcf_write_offset_check_error (info, &offset, 1);
+
+  saved_pos = info->cp;
+
+  /* write a zero layer mask offset */
+  xcf_write_zero_offset_check_error (info, 1);
+
+  xcf_check_error (xcf_save_buffer (info,
+                                    gimp_drawable_get_buffer (GIMP_DRAWABLE (layer)),
+                                    error));
+
+  offset = info->cp;
+
+  /* write out the layer mask */
+  if (gimp_layer_get_mask (layer))
+    {
+      GimpLayerMask *mask = gimp_layer_get_mask (layer);
+
+      xcf_check_error (xcf_seek_pos (info, saved_pos, error));
+      xcf_write_offset_check_error (info, &offset, 1);
+
+      xcf_check_error (xcf_seek_pos (info, offset, error));
+      xcf_check_error (xcf_save_channel (info, image, GIMP_CHANNEL (mask),
+                                         error));
+    }
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_channel (XcfInfo      *info,
+                  GimpImage    *image,
+                  GimpChannel  *channel,
+                  GError      **error)
+{
+  goffset      saved_pos;
+  goffset      offset;
+  guint32      value;
+  const gchar *string;
+  GError      *tmp_error = NULL;
+
+  /* check and see if this is the drawable that the floating
+   *  selection is attached to.
+   */
+  if (GIMP_DRAWABLE (channel) == info->floating_sel_drawable)
+    {
+      saved_pos = info->cp;
+      xcf_check_error (xcf_seek_pos (info, info->floating_sel_offset, error));
+      xcf_write_offset_check_error (info, &saved_pos, 1);
+      xcf_check_error (xcf_seek_pos (info, saved_pos, error));
+    }
+
+  /* write out the width and height information for the channel */
+  value = gimp_item_get_width (GIMP_ITEM (channel));
+  xcf_write_int32_check_error (info, &value, 1);
+
+  value = gimp_item_get_height (GIMP_ITEM (channel));
+  xcf_write_int32_check_error (info, &value, 1);
+
+  /* write out the channels name */
+  string = gimp_object_get_name (channel);
+  xcf_write_string_check_error (info, (gchar **) &string, 1);
+
+  /* write out the channel properties */
+  xcf_save_channel_props (info, image, channel, error);
+
+  /* write out the channel tile hierarchy */
+  offset = info->cp + info->bytes_per_offset;
+  xcf_write_offset_check_error (info, &offset, 1);
+
+  xcf_check_error (xcf_save_buffer (info,
+                                    gimp_drawable_get_buffer (GIMP_DRAWABLE (channel)),
+                                    error));
+
+  return TRUE;
+}
+
+static gint
+xcf_calc_levels (gint size,
+                 gint tile_size)
+{
+  gint levels;
+
+  levels = 1;
+  while (size > tile_size)
+    {
+      size /= 2;
+      levels += 1;
+    }
+
+  return levels;
+}
+
+
+static gboolean
+xcf_save_buffer (XcfInfo     *info,
+                 GeglBuffer  *buffer,
+                 GError     **error)
+{
+  const Babl *format;
+  goffset     saved_pos;
+  goffset     offset;
+  guint32     width;
+  guint32     height;
+  guint32     bpp;
+  gint        i;
+  gint        nlevels;
+  gint        tmp1, tmp2;
+  GError     *tmp_error = NULL;
+
+  format = gegl_buffer_get_format (buffer);
+
+  width  = gegl_buffer_get_width (buffer);
+  height = gegl_buffer_get_height (buffer);
+  bpp    = babl_format_get_bytes_per_pixel (format);
+
+  xcf_write_int32_check_error (info, (guint32 *) &width,  1);
+  xcf_write_int32_check_error (info, (guint32 *) &height, 1);
+  xcf_write_int32_check_error (info, (guint32 *) &bpp,    1);
+
+  tmp1 = xcf_calc_levels (width,  XCF_TILE_WIDTH);
+  tmp2 = xcf_calc_levels (height, XCF_TILE_HEIGHT);
+  nlevels = MAX (tmp1, tmp2);
+
+  /* 'saved_pos' is the next slot in the offset table */
+  saved_pos = info->cp;
+
+  /* write an empty offset table */
+  xcf_write_zero_offset_check_error (info, nlevels + 1);
+
+  /* 'offset' is where we will write the next level */
+  offset = info->cp;
+
+  for (i = 0; i < nlevels; i++)
+    {
+      /* seek back to the next slot in the offset table and write the
+       * offset of the level
+       */
+      xcf_check_error (xcf_seek_pos (info, saved_pos, error));
+      xcf_write_offset_check_error (info, &offset, 1);
+
+      /* remember the next slot in the offset table */
+      saved_pos = info->cp;
+
+      /* seek to the level offset and save the level */
+      xcf_check_error (xcf_seek_pos (info, offset, error));
+
+      if (i == 0)
+        {
+          /* write out the level. */
+          xcf_check_error (xcf_save_level (info, buffer, error));
+        }
+      else
+        {
+          /* fake an empty level */
+          tmp1 = 0;
+          width  /= 2;
+          height /= 2;
+          xcf_write_int32_check_error (info, (guint32 *) &width,  1);
+          xcf_write_int32_check_error (info, (guint32 *) &height, 1);
+
+          /* NOTE:  this should be an offset, not an int32!  however...
+           * since there are already 64-bit-offsets XCFs out there in
+           * which this field is 32-bit, and since it's not actually
+           * being used, we're going to keep this field 32-bit for the
+           * dummy levels, to remain consistent.  if we ever make use
+           * of levels above the first, we should turn this field into
+           * an offset, and bump the xcf version.
+           */
+          xcf_write_int32_check_error (info, (guint32 *) &tmp1,   1);
+        }
+
+      /* the next level's offset if after the level we just wrote */
+      offset = info->cp;
+    }
+
+  /* there is already a '0' at the end of the offset table to indicate
+   * the end of the level offsets
+   */
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_level (XcfInfo     *info,
+                GeglBuffer  *buffer,
+                GError     **error)
+{
+  const Babl *format;
+  goffset    *offset_table;
+  goffset    *next_offset;
+  goffset     saved_pos;
+  goffset     offset;
+  goffset     max_data_length;
+  guint32     width;
+  guint32     height;
+  gint        bpp;
+  gint        n_tile_rows;
+  gint        n_tile_cols;
+  guint       ntiles;
+  gint        i;
+  guchar     *rlebuf    = NULL;
+  GError     *tmp_error = NULL;
+
+  format = gegl_buffer_get_format (buffer);
+
+  width  = gegl_buffer_get_width (buffer);
+  height = gegl_buffer_get_height (buffer);
+  bpp    = babl_format_get_bytes_per_pixel (format);
+
+  xcf_write_int32_check_error (info, (guint32 *) &width,  1);
+  xcf_write_int32_check_error (info, (guint32 *) &height, 1);
+
+  saved_pos = info->cp;
+
+  /* maximal allowable size of on-disk tile data.  make it somewhat bigger than
+   * the uncompressed tile size, to allow for the possibility of negative
+   * compression.  xcf_load_level() enforces this limit.
+   */
+  max_data_length = XCF_TILE_WIDTH * XCF_TILE_HEIGHT * bpp *
+                    XCF_TILE_MAX_DATA_LENGTH_FACTOR /* = 1.5, currently */;
+
+  /* allocate a temporary buffer to store the rle data before it is
+   * written to disk
+   */
+  if (info->compression == COMPRESS_RLE)
+    rlebuf = g_alloca (max_data_length);
+
+  n_tile_rows = gimp_gegl_buffer_get_n_tile_rows (buffer, XCF_TILE_HEIGHT);
+  n_tile_cols = gimp_gegl_buffer_get_n_tile_cols (buffer, XCF_TILE_WIDTH);
+
+  ntiles = n_tile_rows * n_tile_cols;
+
+  /* allocate an offset table so we don't have to seek back after each
+   * tile, see bug #686862. allocate ntiles + 1 slots because a zero
+   * offset indicates the offset table's end.
+   */
+  offset_table = g_alloca ((ntiles + 1) * sizeof (goffset));
+  memset (offset_table, 0, (ntiles + 1) * sizeof (goffset));
+  next_offset = offset_table;
+
+  /* 'saved_pos' is the offset of the tile offset table  */
+  saved_pos = info->cp;
+
+  /* write an empty offset table */
+  xcf_write_zero_offset_check_error (info, ntiles + 1);
+
+  /* 'offset' is where we will write the next tile */
+  offset = info->cp;
+
+  for (i = 0; i < ntiles; i++)
+    {
+      GeglRectangle rect;
+
+      /* store the offset in the table and increment the next pointer */
+      *next_offset++ = offset;
+
+      gimp_gegl_buffer_get_tile_rect (buffer,
+                                      XCF_TILE_WIDTH, XCF_TILE_HEIGHT,
+                                      i, &rect);
+
+      /* write out the tile. */
+      switch (info->compression)
+        {
+        case COMPRESS_NONE:
+          xcf_check_error (xcf_save_tile (info, buffer, &rect, format,
+                                          error));
+          break;
+        case COMPRESS_RLE:
+          xcf_check_error (xcf_save_tile_rle (info, buffer, &rect, format,
+                                              rlebuf, error));
+          break;
+        case COMPRESS_ZLIB:
+          xcf_check_error (xcf_save_tile_zlib (info, buffer, &rect, format,
+                                               error));
+          break;
+        case COMPRESS_FRACTAL:
+          g_warning ("xcf: fractal compression unimplemented");
+          return FALSE;
+        }
+
+      /* make sure the on-disk tile data didn't end up being too big.
+       * xcf_load_level() would refuse to load the file if it did.
+       */
+      if (info->cp < offset || info->cp - offset > max_data_length)
+        {
+          g_message ("xcf: invalid tile data length: %" G_GOFFSET_FORMAT,
+                     info->cp - offset);
+          return FALSE;
+        }
+
+      /* the next tile's offset is after the tile we just wrote */
+      offset = info->cp;
+    }
+
+  /* seek back to the offset table and write it  */
+  xcf_check_error (xcf_seek_pos (info, saved_pos, error));
+  xcf_write_offset_check_error (info, offset_table, ntiles + 1);
+
+  /* seek to the end of the file */
+  xcf_check_error (xcf_seek_pos (info, offset, error));
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_tile (XcfInfo        *info,
+               GeglBuffer     *buffer,
+               GeglRectangle  *tile_rect,
+               const Babl     *format,
+               GError        **error)
+{
+  gint    bpp       = babl_format_get_bytes_per_pixel (format);
+  gint    tile_size = bpp * tile_rect->width * tile_rect->height;
+  guchar *tile_data = g_alloca (tile_size);
+  GError *tmp_error = NULL;
+
+  gegl_buffer_get (buffer, tile_rect, 1.0, format, tile_data,
+                   GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+  if (info->file_version <= 11)
+    {
+      xcf_write_int8_check_error (info, tile_data, tile_size);
+    }
+  else
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_write_component_check_error (info, bpp / n_components, tile_data,
+                                       tile_size / bpp * n_components);
+    }
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_tile_rle (XcfInfo        *info,
+                   GeglBuffer     *buffer,
+                   GeglRectangle  *tile_rect,
+                   const Babl     *format,
+                   guchar         *rlebuf,
+                   GError        **error)
+{
+  gint    bpp       = babl_format_get_bytes_per_pixel (format);
+  gint    tile_size = bpp * tile_rect->width * tile_rect->height;
+  guchar *tile_data = g_alloca (tile_size);
+  gint    len       = 0;
+  gint    i, j;
+  GError *tmp_error  = NULL;
+
+  gegl_buffer_get (buffer, tile_rect, 1.0, format, tile_data,
+                   GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+  if (info->file_version >= 12)
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_write_to_be (bpp / n_components, tile_data,
+                       tile_size / bpp * n_components);
+    }
+
+  for (i = 0; i < bpp; i++)
+    {
+      const guchar *data   = tile_data + i;
+      gint          state  = 0;
+      gint          length = 0;
+      gint          count  = 0;
+      gint          size   = tile_rect->width * tile_rect->height;
+      guint         last   = -1;
+
+      while (size > 0)
+        {
+          switch (state)
+            {
+            case 0:
+              /* in state 0 we try to find a long sequence of
+               *  matching values.
+               */
+              if ((length == 32768) ||
+                  ((size - length) <= 0) ||
+                  ((length > 1) && (last != *data)))
+                {
+                  count += length;
+
+                  if (length >= 128)
+                    {
+                      rlebuf[len++] = 127;
+                      rlebuf[len++] = (length >> 8);
+                      rlebuf[len++] = length & 0x00FF;
+                      rlebuf[len++] = last;
+                    }
+                  else
+                    {
+                      rlebuf[len++] = length - 1;
+                      rlebuf[len++] = last;
+                    }
+
+                  size -= length;
+                  length = 0;
+                }
+              else if ((length == 1) && (last != *data))
+                {
+                  state = 1;
+                }
+              break;
+
+            case 1:
+              /* in state 1 we try and find a long sequence of
+               *  non-matching values.
+               */
+              if ((length == 32768) ||
+                  ((size - length) == 0) ||
+                  ((length > 0) && (last == *data) &&
+                   ((size - length) == 1 || last == data[bpp])))
+                {
+                  const guchar *t;
+
+                  /* if we came here because of a new run, backup one */
+                  if (!((length == 32768) || ((size - length) == 0)))
+                    {
+                      length--;
+                      data -= bpp;
+                    }
+
+                  count += length;
+                  state = 0;
+
+                  if (length >= 128)
+                    {
+                      rlebuf[len++] = 255 - 127;
+                      rlebuf[len++] = (length >> 8);
+                      rlebuf[len++] = length & 0x00FF;
+                    }
+                  else
+                    {
+                      rlebuf[len++] = 255 - (length - 1);
+                    }
+
+                  t = data - length * bpp;
+
+                  for (j = 0; j < length; j++)
+                    {
+                      rlebuf[len++] = *t;
+                      t += bpp;
+                    }
+
+                  size -= length;
+                  length = 0;
+                }
+              break;
+            }
+
+          if (size > 0)
+            {
+              length += 1;
+              last = *data;
+              data += bpp;
+            }
+        }
+
+      if (count != (tile_rect->width * tile_rect->height))
+        g_message ("xcf: uh oh! xcf rle tile saving error: %d", count);
+    }
+
+  xcf_write_int8_check_error (info, rlebuf, len);
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_tile_zlib (XcfInfo        *info,
+                    GeglBuffer     *buffer,
+                    GeglRectangle  *tile_rect,
+                    const Babl     *format,
+                    GError        **error)
+{
+  gint      bpp       = babl_format_get_bytes_per_pixel (format);
+  gint      tile_size = bpp * tile_rect->width * tile_rect->height;
+  guchar   *tile_data = g_alloca (tile_size);
+  /* The buffer for compressed data. */
+  guchar   *buf       = g_alloca (tile_size);
+  GError   *tmp_error = NULL;
+  z_stream  strm;
+  int       action;
+  int       status;
+
+  gegl_buffer_get (buffer, tile_rect, 1.0, format, tile_data,
+                   GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+  if (info->file_version >= 12)
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_write_to_be (bpp / n_components, tile_data,
+                       tile_size / bpp * n_components);
+    }
+
+  /* allocate deflate state */
+  strm.zalloc = Z_NULL;
+  strm.zfree  = Z_NULL;
+  strm.opaque = Z_NULL;
+
+  status = deflateInit (&strm, Z_DEFAULT_COMPRESSION);
+  if (status != Z_OK)
+    return FALSE;
+
+  strm.next_in   = tile_data;
+  strm.avail_in  = tile_size;
+  strm.next_out  = buf;
+  strm.avail_out = tile_size;
+
+  action = Z_NO_FLUSH;
+
+  while (status == Z_OK || status == Z_BUF_ERROR)
+    {
+      if (strm.avail_in == 0)
+        {
+          /* Finish the encoding. */
+          action = Z_FINISH;
+        }
+
+      status = deflate (&strm, action);
+
+      if (status == Z_STREAM_END || status == Z_BUF_ERROR)
+        {
+          size_t write_size = tile_size - strm.avail_out;
+
+          xcf_write_int8_check_error (info, buf, write_size);
+
+          /* Reset next_out and avail_out. */
+          strm.next_out  = buf;
+          strm.avail_out = tile_size;
+        }
+      else if (status != Z_OK)
+        {
+          g_printerr ("xcf: tile compression failed: %s", zError (status));
+          deflateEnd (&strm);
+          return FALSE;
+        }
+    }
+
+  deflateEnd (&strm);
+  return TRUE;
+}
+
+static gboolean
+xcf_save_parasite (XcfInfo       *info,
+                   GimpParasite  *parasite,
+                   GError       **error)
+{
+  if (gimp_parasite_is_persistent (parasite))
+    {
+      guint32      value;
+      const gchar *string;
+      GError      *tmp_error = NULL;
+
+      string = gimp_parasite_name (parasite);
+      xcf_write_string_check_error (info, (gchar **) &string, 1);
+
+      value = gimp_parasite_flags (parasite);
+      xcf_write_int32_check_error (info, &value, 1);
+
+      value = gimp_parasite_data_size (parasite);
+      xcf_write_int32_check_error (info, &value, 1);
+
+      xcf_write_int8_check_error (info,
+                                  gimp_parasite_data (parasite),
+                                  gimp_parasite_data_size (parasite));
+    }
+
+  return TRUE;
+}
+
+typedef struct
+{
+  XcfInfo *info;
+  GError  *error;
+} XcfParasiteData;
+
+static void
+xcf_save_parasite_func (gchar           *key,
+                        GimpParasite    *parasite,
+                        XcfParasiteData *data)
+{
+  if (! data->error)
+    xcf_save_parasite (data->info, parasite, &data->error);
+}
+
+static gboolean
+xcf_save_parasite_list (XcfInfo           *info,
+                        GimpParasiteList  *list,
+                        GError           **error)
+{
+  XcfParasiteData data;
+
+  data.info  = info;
+  data.error = NULL;
+
+  gimp_parasite_list_foreach (list, (GHFunc) xcf_save_parasite_func, &data);
+
+  if (data.error)
+    {
+      g_propagate_error (error, data.error);
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_old_paths (XcfInfo    *info,
+                    GimpImage  *image,
+                    GError    **error)
+{
+  GimpVectors *active_vectors;
+  guint32      num_paths;
+  guint32      active_index = 0;
+  GList       *list;
+  GError      *tmp_error = NULL;
+
+  /* Write out the following:-
+   *
+   * last_selected_row (gint)
+   * number_of_paths (gint)
+   *
+   * then each path:-
+   */
+
+  num_paths = gimp_container_get_n_children (gimp_image_get_vectors (image));
+
+  active_vectors = gimp_image_get_active_vectors (image);
+
+  if (active_vectors)
+    active_index = gimp_container_get_child_index (gimp_image_get_vectors (image),
+                                                   GIMP_OBJECT (active_vectors));
+
+  xcf_write_int32_check_error (info, &active_index, 1);
+  xcf_write_int32_check_error (info, &num_paths,    1);
+
+  for (list = gimp_image_get_vectors_iter (image);
+       list;
+       list = g_list_next (list))
+    {
+      GimpVectors            *vectors = list->data;
+      gchar                  *name;
+      guint32                 locked;
+      guint8                  state;
+      guint32                 version;
+      guint32                 pathtype;
+      guint32                 tattoo;
+      GimpVectorsCompatPoint *points;
+      guint32                 num_points;
+      guint32                 closed;
+      gint                    i;
+
+      /*
+       * name (string)
+       * locked (gint)
+       * state (gchar)
+       * closed (gint)
+       * number points (gint)
+       * version (gint)
+       * pathtype (gint)
+       * tattoo (gint)
+       * then each point.
+       */
+
+      points = gimp_vectors_compat_get_points (vectors,
+                                               (gint32 *) &num_points,
+                                               (gint32 *) &closed);
+
+      /* if no points are generated because of a faulty path we should
+       * skip saving the path - this is unfortunately impossible, because
+       * we already saved the number of paths and I won't start seeking
+       * around to fix that cruft  */
+
+      name     = (gchar *) gimp_object_get_name (vectors);
+      locked   = gimp_item_get_linked (GIMP_ITEM (vectors));
+      state    = closed ? 4 : 2;  /* EDIT : ADD  (editing state, 1.2 compat) */
+      version  = 3;
+      pathtype = 1;  /* BEZIER  (1.2 compat) */
+      tattoo   = gimp_item_get_tattoo (GIMP_ITEM (vectors));
+
+      xcf_write_string_check_error (info, &name,       1);
+      xcf_write_int32_check_error  (info, &locked,     1);
+      xcf_write_int8_check_error   (info, &state,      1);
+      xcf_write_int32_check_error  (info, &closed,     1);
+      xcf_write_int32_check_error  (info, &num_points, 1);
+      xcf_write_int32_check_error  (info, &version,    1);
+      xcf_write_int32_check_error  (info, &pathtype,   1);
+      xcf_write_int32_check_error  (info, &tattoo,     1);
+
+      for (i = 0; i < num_points; i++)
+        {
+          gfloat x;
+          gfloat y;
+
+          x = points[i].x;
+          y = points[i].y;
+
+          /*
+           * type (gint)
+           * x (gfloat)
+           * y (gfloat)
+           */
+
+          xcf_write_int32_check_error (info, &points[i].type, 1);
+          xcf_write_float_check_error (info, &x,              1);
+          xcf_write_float_check_error (info, &y,              1);
+        }
+
+      g_free (points);
+    }
+
+  return TRUE;
+}
+
+static gboolean
+xcf_save_vectors (XcfInfo    *info,
+                  GimpImage  *image,
+                  GError    **error)
+{
+  GimpVectors *active_vectors;
+  guint32      version      = 1;
+  guint32      active_index = 0;
+  guint32      num_paths;
+  GList       *list;
+  GList       *stroke_list;
+  GError      *tmp_error = NULL;
+
+  /* Write out the following:-
+   *
+   * version (gint)
+   * active_index (gint)
+   * num_paths (gint)
+   *
+   * then each path:-
+   */
+
+  active_vectors = gimp_image_get_active_vectors (image);
+
+  if (active_vectors)
+    active_index = gimp_container_get_child_index (gimp_image_get_vectors (image),
+                                                   GIMP_OBJECT (active_vectors));
+
+  num_paths = gimp_container_get_n_children (gimp_image_get_vectors (image));
+
+  xcf_write_int32_check_error (info, &version,      1);
+  xcf_write_int32_check_error (info, &active_index, 1);
+  xcf_write_int32_check_error (info, &num_paths,    1);
+
+  for (list = gimp_image_get_vectors_iter (image);
+       list;
+       list = g_list_next (list))
+    {
+      GimpVectors      *vectors = list->data;
+      GimpParasiteList *parasites;
+      const gchar      *name;
+      guint32           tattoo;
+      guint32           visible;
+      guint32           linked;
+      guint32           num_parasites;
+      guint32           num_strokes;
+
+      /*
+       * name (string)
+       * tattoo (gint)
+       * visible (gint)
+       * linked (gint)
+       * num_parasites (gint)
+       * num_strokes (gint)
+       *
+       * then each parasite
+       * then each stroke
+       */
+
+      name          = gimp_object_get_name (vectors);
+      visible       = gimp_item_get_visible (GIMP_ITEM (vectors));
+      linked        = gimp_item_get_linked (GIMP_ITEM (vectors));
+      tattoo        = gimp_item_get_tattoo (GIMP_ITEM (vectors));
+      parasites     = gimp_item_get_parasites (GIMP_ITEM (vectors));
+      num_parasites = gimp_parasite_list_persistent_length (parasites);
+      num_strokes   = g_queue_get_length (vectors->strokes);
+
+      xcf_write_string_check_error (info, (gchar **) &name, 1);
+      xcf_write_int32_check_error  (info, &tattoo,          1);
+      xcf_write_int32_check_error  (info, &visible,         1);
+      xcf_write_int32_check_error  (info, &linked,          1);
+      xcf_write_int32_check_error  (info, &num_parasites,   1);
+      xcf_write_int32_check_error  (info, &num_strokes,     1);
+
+      xcf_check_error (xcf_save_parasite_list (info, parasites, error));
+
+      for (stroke_list = g_list_first (vectors->strokes->head);
+           stroke_list;
+           stroke_list = g_list_next (stroke_list))
+        {
+          GimpStroke *stroke = stroke_list->data;
+          guint32     stroke_type;
+          guint32     closed;
+          guint32     num_axes;
+          GArray     *control_points;
+          gint        i;
+
+          guint32     type;
+          gfloat      coords[6];
+
+          /*
+           * stroke_type (gint)
+           * closed (gint)
+           * num_axes (gint)
+           * num_control_points (gint)
+           *
+           * then each control point.
+           */
+
+          if (GIMP_IS_BEZIER_STROKE (stroke))
+            {
+              stroke_type = XCF_STROKETYPE_BEZIER_STROKE;
+              num_axes = 2;   /* hardcoded, might be increased later */
+            }
+          else
+            {
+              g_printerr ("Skipping unknown stroke type!\n");
+              continue;
+            }
+
+          control_points = gimp_stroke_control_points_get (stroke,
+                                                           (gint32 *) &closed);
+
+          xcf_write_int32_check_error (info, &stroke_type,         1);
+          xcf_write_int32_check_error (info, &closed,              1);
+          xcf_write_int32_check_error (info, &num_axes,            1);
+          xcf_write_int32_check_error (info, &control_points->len, 1);
+
+          for (i = 0; i < control_points->len; i++)
+            {
+              GimpAnchor *anchor;
+
+              anchor = & (g_array_index (control_points, GimpAnchor, i));
+
+              type      = anchor->type;
+              coords[0] = anchor->position.x;
+              coords[1] = anchor->position.y;
+              coords[2] = anchor->position.pressure;
+              coords[3] = anchor->position.xtilt;
+              coords[4] = anchor->position.ytilt;
+              coords[5] = anchor->position.wheel;
+
+              /*
+               * type (gint)
+               *
+               * the first num_axis elements of:
+               * [0] x (gfloat)
+               * [1] y (gfloat)
+               * [2] pressure (gfloat)
+               * [3] xtilt (gfloat)
+               * [4] ytilt (gfloat)
+               * [5] wheel (gfloat)
+               */
+
+              xcf_write_int32_check_error (info, &type,  1);
+              xcf_write_float_check_error (info, coords, num_axes);
+            }
+
+          g_array_free (control_points, TRUE);
+        }
+    }
+
+  return TRUE;
+}