/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * GIMP PSD Plug-in
 * Copyright 2007 by John Marshall
 *
 * 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 <errno.h>

#include <glib/gstdio.h>
#include <zlib.h>
#include <libgimp/gimp.h>

#include "psd.h"
#include "psd-util.h"
#include "psd-image-res-load.h"
#include "psd-layer-res-load.h"
#include "psd-load.h"

#include "libgimp/stdplugins-intl.h"


#define COMP_MODE_SIZE sizeof(guint16)


/*  Local function prototypes  */
static gint             read_header_block          (PSDimage     *img_a,
                                                    FILE         *f,
                                                    GError      **error);

static gint             read_color_mode_block      (PSDimage     *img_a,
                                                    FILE         *f,
                                                    GError      **error);

static gint             read_image_resource_block  (PSDimage     *img_a,
                                                    FILE         *f,
                                                    GError      **error);

static PSDlayer **      read_layer_block           (PSDimage     *img_a,
                                                    FILE         *f,
                                                    GError      **error);

static gint             read_merged_image_block    (PSDimage     *img_a,
                                                    FILE         *f,
                                                    GError      **error);

static gint32           create_gimp_image          (PSDimage     *img_a,
                                                    const gchar  *filename);

static gint             add_color_map              (gint32        image_id,
                                                    PSDimage     *img_a);

static gint             add_image_resources        (gint32        image_id,
                                                    PSDimage     *img_a,
                                                    FILE         *f,
                                                    gboolean     *resolution_loaded,
                                                    gboolean     *profile_loaded,
                                                    GError      **error);

static gint             add_layers                 (gint32        image_id,
                                                    PSDimage     *img_a,
                                                    PSDlayer    **lyr_a,
                                                    FILE         *f,
                                                    GError      **error);

static gint             add_merged_image           (gint32        image_id,
                                                    PSDimage     *img_a,
                                                    FILE         *f,
                                                    GError      **error);

/*  Local utility function prototypes  */
static gint32           add_clipping_group         (gint32        image_id,
                                                    gint32        parent_id);

static gchar          * get_psd_color_mode_name    (PSDColorMode  mode);

static void             psd_to_gimp_color_map      (guchar       *map256);

static GimpImageType    get_gimp_image_type        (GimpImageBaseType image_base_type,
                                                    gboolean          alpha);

static gint             read_channel_data          (PSDchannel     *channel,
                                                    guint16         bps,
                                                    guint16         compression,
                                                    const guint16  *rle_pack_len,
                                                    FILE           *f,
                                                    guint32         comp_len,
                                                    GError        **error);

static void             convert_1_bit              (const gchar *src,
                                                    gchar       *dst,
                                                    guint32      rows,
                                                    guint32      columns);

static const Babl*      get_layer_format           (PSDimage    *img_a,
                                                    gboolean     alpha);
static const Babl*      get_channel_format         (PSDimage    *img_a);
static const Babl*      get_mask_format            (PSDimage    *img_a);


/* Main file load function */
gint32
load_image (const gchar  *filename,
            gboolean      merged_image_only,
            gboolean     *resolution_loaded,
            gboolean     *profile_loaded,
            GError      **load_error)
{
  FILE         *f;
  GStatBuf      st;
  PSDimage      img_a;
  PSDlayer    **lyr_a;
  gint32        image_id = -1;
  GError       *error    = NULL;

  img_a.cmyk_transform = img_a.cmyk_transform_alpha = NULL;
  img_a.cmyk_profile = NULL;
  /* ----- Open PSD file ----- */
  if (g_stat (filename, &st) == -1)
    return -1;

  gimp_progress_init_printf (_("Opening '%s'"),
                             gimp_filename_to_utf8 (filename));

  IFDBG(1) g_debug ("Open file %s", gimp_filename_to_utf8 (filename));
  f = g_fopen (filename, "rb");
  if (f == NULL)
    {
      g_set_error (load_error, G_FILE_ERROR, g_file_error_from_errno (errno),
                   _("Could not open '%s' for reading: %s"),
                   gimp_filename_to_utf8 (filename), g_strerror (errno));
      return -1;
    }

  img_a.merged_image_only = merged_image_only;

  /* ----- Read the PSD file Header block ----- */
  IFDBG(2) g_debug ("Read header block");
  if (read_header_block (&img_a, f, &error) < 0)
    goto load_error;
  gimp_progress_update (0.1);

  /* ----- Read the PSD file Color Mode block ----- */
  IFDBG(2) g_debug ("Read color mode block");
  if (read_color_mode_block (&img_a, f, &error) < 0)
    goto load_error;
  gimp_progress_update (0.2);

  /* ----- Read the PSD file Image Resource block ----- */
  IFDBG(2) g_debug ("Read image resource block");
  if (read_image_resource_block (&img_a, f, &error) < 0)
    goto load_error;
  gimp_progress_update (0.3);

  /* ----- Read the PSD file Layer & Mask block ----- */
  IFDBG(2) g_debug ("Read layer & mask block");
  lyr_a = read_layer_block (&img_a, f, &error);
  if (! img_a.merged_image_only && img_a.num_layers != 0 && lyr_a == NULL)
    goto load_error;
  gimp_progress_update (0.4);

  /* ----- Read the PSD file Merged Image Data block ----- */
  IFDBG(2) g_debug ("Read merged image and extra alpha channel block");
  if (read_merged_image_block (&img_a, f, &error) < 0)
    goto load_error;
  gimp_progress_update (0.5);

  /* ----- Create GIMP image ----- */
  IFDBG(2) g_debug ("Create GIMP image");
  image_id = create_gimp_image (&img_a, filename);
  if (image_id < 0)
    goto load_error;
  gimp_progress_update (0.6);

  /* ----- Add color map ----- */
  IFDBG(2) g_debug ("Add color map");
  if (add_color_map (image_id, &img_a) < 0)
    goto load_error;
  gimp_progress_update (0.7);

  /* ----- Add image resources ----- */
  IFDBG(2) g_debug ("Add image resources");
  if (add_image_resources (image_id, &img_a, f,
                           resolution_loaded, profile_loaded,
                           &error) < 0)
    goto load_error;
  gimp_progress_update (0.8);

  /* ----- Add layers -----*/
  IFDBG(2) g_debug ("Add layers");
  if (add_layers (image_id, &img_a, lyr_a, f, &error) < 0)
    goto load_error;
  gimp_progress_update (0.9);

  /* ----- Add merged image data and extra alpha channels ----- */
  IFDBG(2) g_debug ("Add merged image data and extra alpha channels");
  if (add_merged_image (image_id, &img_a, f, &error) < 0)
    goto load_error;
  gimp_progress_update (1.0);

  IFDBG(2) g_debug ("Close file & return, image id: %d", image_id);
  IFDBG(1) g_debug ("\n----------------------------------------"
                    "----------------------------------------\n");

  gimp_image_clean_all (image_id);
  gimp_image_undo_enable (image_id);
  fclose (f);
  return image_id;

  /* ----- Process load errors ----- */
 load_error:
  if (error)
    {
      g_set_error (load_error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                   _("Error loading PSD file: %s"), error->message);
      g_error_free (error);
    }

  /* Delete partially loaded image */
  if (image_id > 0)
    gimp_image_delete (image_id);

  /* Close file if Open */
  if (! (f == NULL))
    fclose (f);

  return -1;
}


/* Local functions */

static gint
read_header_block (PSDimage  *img_a,
                   FILE      *f,
                   GError   **error)
{
  guint16  version;
  gchar    sig[4];
  gchar    buf[6];

  if (fread (sig, 4, 1, f) < 1
      || fread (&version, 2, 1, f) < 1
      || fread (buf, 6, 1, f) < 1
      || fread (&img_a->channels, 2, 1, f) < 1
      || fread (&img_a->rows, 4, 1, f) < 1
      || fread (&img_a->columns, 4, 1, f) < 1
      || fread (&img_a->bps, 2, 1, f) < 1
      || fread (&img_a->color_mode, 2, 1, f) < 1)
    {
      psd_set_error (feof (f), errno, error);
      return -1;
    }
  version = GUINT16_FROM_BE (version);
  img_a->channels = GUINT16_FROM_BE (img_a->channels);
  img_a->rows = GUINT32_FROM_BE (img_a->rows);
  img_a->columns = GUINT32_FROM_BE (img_a->columns);
  img_a->bps = GUINT16_FROM_BE (img_a->bps);
  img_a->color_mode = GUINT16_FROM_BE (img_a->color_mode);

  IFDBG(1) g_debug ("\n\n\tSig: %.4s\n\tVer: %d\n\tChannels: "
                    "%d\n\tSize: %dx%d\n\tBPS: %d\n\tMode: %d\n",
                    sig, version, img_a->channels,
                    img_a->columns, img_a->rows,
                    img_a->bps, img_a->color_mode);

  if (memcmp (sig, "8BPS", 4) != 0)
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                  _("Not a valid Photoshop document file"));
      return -1;
    }

  if (version != 1)
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                  _("Unsupported file format version: %d"), version);
      return -1;
    }

  if (img_a->channels > MAX_CHANNELS)
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                  _("Too many channels in file: %d"), img_a->channels);
      return -1;
    }

    /* Photoshop CS (version 8) supports 300000 x 300000, but this
       is currently larger than GIMP_MAX_IMAGE_SIZE */

  if (img_a->rows < 1 || img_a->rows > GIMP_MAX_IMAGE_SIZE)
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                  _("Unsupported or invalid image height: %d"),
                  img_a->rows);
      return -1;
    }

  if (img_a->columns < 1 || img_a->columns > GIMP_MAX_IMAGE_SIZE)
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                  _("Unsupported or invalid image width: %d"),
                  img_a->columns);
      return -1;
    }

  /* img_a->rows is sanitized above, so a division by zero is avoided here */
  if (img_a->columns > G_MAXINT32 / img_a->rows)
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                   _("Unsupported or invalid image size: %dx%d"),
                   img_a->columns, img_a->rows);
      return -1;
    }

  if (img_a->color_mode != PSD_BITMAP
      && img_a->color_mode != PSD_GRAYSCALE
      && img_a->color_mode != PSD_INDEXED
      && img_a->color_mode != PSD_RGB
      && img_a->color_mode != PSD_MULTICHANNEL
      && img_a->color_mode != PSD_CMYK
      && img_a->color_mode != PSD_DUOTONE)
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                   _("Unsupported color mode: %s"),
                   get_psd_color_mode_name (img_a->color_mode));
      return -1;
    }

  if (img_a->color_mode == PSD_CMYK)
    {
      if (img_a->bps != 8)
        {
          g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                       _("Unsupported color mode: %s"),
                       get_psd_color_mode_name (img_a->color_mode));
          return -1;
        }
    }

  /* Warning for unsupported bit depth */
  switch (img_a->bps)
    {
      case 32:
        IFDBG(3) g_debug ("32 Bit Data");
        break;

      case 16:
        IFDBG(3) g_debug ("16 Bit Data");
        break;

      case 8:
        IFDBG(3) g_debug ("8 Bit Data");
        break;

      case 1:
        IFDBG(3) g_debug ("1 Bit Data");
        break;

      default:
        g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                    _("Unsupported bit depth: %d"), img_a->bps);
        return -1;
        break;
    }

  return 0;
}

static gint
read_color_mode_block (PSDimage  *img_a,
                       FILE      *f,
                       GError   **error)
{
  static guchar cmap[] = { 0, 0, 0, 255, 255, 255 };
  guint32       block_len;

  img_a->color_map_entries = 0;
  img_a->color_map_len = 0;
  if (fread (&block_len, 4, 1, f) < 1)
    {
      psd_set_error (feof (f), errno, error);
      return -1;
    }
  block_len = GUINT32_FROM_BE (block_len);

  IFDBG(1) g_debug ("Color map block size = %d", block_len);

  if (block_len == 0)
    {
      if (img_a->color_mode == PSD_INDEXED ||
          img_a->color_mode == PSD_DUOTONE )
        {
          IFDBG(1) g_debug ("No color block for indexed or duotone image");
          g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                      _("The file is corrupt!"));
          return -1;
        }
    }
  else if (img_a->color_mode == PSD_INDEXED)
    {
      if (block_len != 768)
        {
          IFDBG(1) g_debug ("Invalid color block size for indexed image");
          g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                      _("The file is corrupt!"));
          return -1;
        }
      else
        {
          img_a->color_map_len = block_len;
          img_a->color_map = g_malloc (img_a->color_map_len);
          if (fread (img_a->color_map, block_len, 1, f) < 1)
            {
              psd_set_error (feof (f), errno, error);
              return -1;
            }
          else
            {
              psd_to_gimp_color_map (img_a->color_map);
              img_a->color_map_entries = 256;
            }
        }
    }
  else if (img_a->color_mode == PSD_DUOTONE)
    {
      img_a->color_map_len = block_len;
      img_a->color_map = g_malloc (img_a->color_map_len);
      if (fread (img_a->color_map, block_len, 1, f) < 1)
        {
          psd_set_error (feof (f), errno, error);
          return -1;
        }
    }

  /* Create color map for bitmap image */
  if (img_a->color_mode == PSD_BITMAP)
    {
      img_a->color_map_len = 6;
      img_a->color_map = g_malloc (img_a->color_map_len);
      memcpy (img_a->color_map, cmap, img_a->color_map_len);
      img_a->color_map_entries = 2;
    }
  IFDBG(2) g_debug ("Color map data length %d", img_a->color_map_len);

  return 0;
}

static gint
read_image_resource_block (PSDimage  *img_a,
                           FILE      *f,
                           GError   **error)
{
  guint32 block_len;
  guint32 block_end;

  if (fread (&block_len, 4, 1, f) < 1)
    {
      psd_set_error (feof (f), errno, error);
      return -1;
    }
  img_a->image_res_len = GUINT32_FROM_BE (block_len);

  IFDBG(1) g_debug ("Image resource block size = %d", (int)img_a->image_res_len);

  img_a->image_res_start = ftell (f);
  block_end = img_a->image_res_start + img_a->image_res_len;

  if (fseek (f, block_end, SEEK_SET) < 0)
    {
      psd_set_error (feof (f), errno, error);
      return -1;
    }

  return 0;
}

static PSDlayer **
read_layer_info (PSDimage  *img_a,
                 FILE      *f,
                 GError   **error)
{
  PSDlayer **lyr_a = NULL;
  guint32    block_len;
  guint32    block_rem;
  gint32     read_len;
  gint32     write_len;
  gint       lidx;                  /* Layer index */
  gint       cidx;                  /* Channel index */

  /* Get number of layers */
  if (fread (&img_a->num_layers, 2, 1, f) < 1)
    {
      psd_set_error (feof (f), errno, error);
      img_a->num_layers = -1;
      return NULL;
    }

  img_a->num_layers = GINT16_FROM_BE (img_a->num_layers);
  IFDBG(2) g_debug ("Number of layers: %d", img_a->num_layers);

  if (img_a->num_layers < 0)
    {
      img_a->transparency = TRUE;
      img_a->num_layers = -img_a->num_layers;
    }

  if (! img_a->merged_image_only && img_a->num_layers)
    {
      /* Read layer records */
      PSDlayerres           res_a;

      /* Create pointer array for the layer records */
      lyr_a = g_new (PSDlayer *, img_a->num_layers);

      for (lidx = 0; lidx < img_a->num_layers; ++lidx)
        {
          /* Allocate layer record */
          lyr_a[lidx] = (PSDlayer *) g_malloc (sizeof (PSDlayer) );

          /* Initialise record */
          lyr_a[lidx]->drop = FALSE;
          lyr_a[lidx]->id = 0;
          lyr_a[lidx]->group_type = 0;

          if (fread (&lyr_a[lidx]->top, 4, 1, f) < 1
              || fread (&lyr_a[lidx]->left, 4, 1, f) < 1
              || fread (&lyr_a[lidx]->bottom, 4, 1, f) < 1
              || fread (&lyr_a[lidx]->right, 4, 1, f) < 1
              || fread (&lyr_a[lidx]->num_channels, 2, 1, f) < 1)
            {
              psd_set_error (feof (f), errno, error);
              return NULL;
            }

          lyr_a[lidx]->top = GINT32_FROM_BE (lyr_a[lidx]->top);
          lyr_a[lidx]->left = GINT32_FROM_BE (lyr_a[lidx]->left);
          lyr_a[lidx]->bottom = GINT32_FROM_BE (lyr_a[lidx]->bottom);
          lyr_a[lidx]->right = GINT32_FROM_BE (lyr_a[lidx]->right);
          lyr_a[lidx]->num_channels = GUINT16_FROM_BE (lyr_a[lidx]->num_channels);

          if (lyr_a[lidx]->num_channels > MAX_CHANNELS)
            {
              g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                           _("Too many channels in layer: %d"),
                           lyr_a[lidx]->num_channels);
              return NULL;
            }
          if (lyr_a[lidx]->bottom < lyr_a[lidx]->top ||
              lyr_a[lidx]->bottom - lyr_a[lidx]->top > GIMP_MAX_IMAGE_SIZE)
            {
              g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                           _("Unsupported or invalid layer height: %d"),
                           lyr_a[lidx]->bottom - lyr_a[lidx]->top);
              return NULL;
            }
          if (lyr_a[lidx]->right < lyr_a[lidx]->left ||
              lyr_a[lidx]->right - lyr_a[lidx]->left > GIMP_MAX_IMAGE_SIZE)
            {
              g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                           _("Unsupported or invalid layer width: %d"),
                           lyr_a[lidx]->right - lyr_a[lidx]->left);
              return NULL;
            }

          if ((lyr_a[lidx]->right - lyr_a[lidx]->left) >
              G_MAXINT32 / MAX (lyr_a[lidx]->bottom - lyr_a[lidx]->top, 1))
            {
              g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                           _("Unsupported or invalid layer size: %dx%d"),
                           lyr_a[lidx]->right - lyr_a[lidx]->left,
                           lyr_a[lidx]->bottom - lyr_a[lidx]->top);
              return NULL;
            }

          IFDBG(2) g_debug ("Layer %d, Coords %d %d %d %d, channels %d, ",
                            lidx, lyr_a[lidx]->left, lyr_a[lidx]->top,
                            lyr_a[lidx]->right, lyr_a[lidx]->bottom,
                            lyr_a[lidx]->num_channels);

          lyr_a[lidx]->chn_info = g_new (ChannelLengthInfo, lyr_a[lidx]->num_channels);

          for (cidx = 0; cidx < lyr_a[lidx]->num_channels; ++cidx)
            {
              if (fread (&lyr_a[lidx]->chn_info[cidx].channel_id, 2, 1, f) < 1
                  || fread (&lyr_a[lidx]->chn_info[cidx].data_len, 4, 1, f) < 1)
                {
                  psd_set_error (feof (f), errno, error);
                  return NULL;
                }
              lyr_a[lidx]->chn_info[cidx].channel_id =
                GINT16_FROM_BE (lyr_a[lidx]->chn_info[cidx].channel_id);
              lyr_a[lidx]->chn_info[cidx].data_len =
                GUINT32_FROM_BE (lyr_a[lidx]->chn_info[cidx].data_len);
              img_a->layer_data_len += lyr_a[lidx]->chn_info[cidx].data_len;
              IFDBG(3) g_debug ("Channel ID %d, data len %d",
                                lyr_a[lidx]->chn_info[cidx].channel_id,
                                lyr_a[lidx]->chn_info[cidx].data_len);
            }

          if (fread (lyr_a[lidx]->mode_key, 4, 1, f) < 1
              || fread (lyr_a[lidx]->blend_mode, 4, 1, f) < 1
              || fread (&lyr_a[lidx]->opacity, 1, 1, f) < 1
              || fread (&lyr_a[lidx]->clipping, 1, 1, f) < 1
              || fread (&lyr_a[lidx]->flags, 1, 1, f) < 1
              || fread (&lyr_a[lidx]->filler, 1, 1, f) < 1
              || fread (&lyr_a[lidx]->extra_len, 4, 1, f) < 1)
            {
              psd_set_error (feof (f), errno, error);
              return NULL;
            }
          if (memcmp (lyr_a[lidx]->mode_key, "8BIM", 4) != 0)
            {
              IFDBG(1) g_debug ("Incorrect layer mode signature %.4s",
                                lyr_a[lidx]->mode_key);
              g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                           _("The file is corrupt!"));
              return NULL;
            }

          lyr_a[lidx]->layer_flags.trans_prot = lyr_a[lidx]->flags & 1 ? TRUE : FALSE;
          lyr_a[lidx]->layer_flags.visible = lyr_a[lidx]->flags & 2 ? FALSE : TRUE;

          if (lyr_a[lidx]->flags & 8)
            lyr_a[lidx]->layer_flags.irrelevant = lyr_a[lidx]->flags & 16 ? TRUE : FALSE;
          else
            lyr_a[lidx]->layer_flags.irrelevant = FALSE;

          lyr_a[lidx]->extra_len = GUINT32_FROM_BE (lyr_a[lidx]->extra_len);
          block_rem = lyr_a[lidx]->extra_len;
          IFDBG(2) g_debug ("\n\tLayer mode sig: %.4s\n\tBlend mode: %.4s\n\t"
                            "Opacity: %d\n\tClipping: %d\n\tExtra data len: %d\n\t"
                            "Alpha lock: %d\n\tVisible: %d\n\tIrrelevant: %d",
                            lyr_a[lidx]->mode_key,
                            lyr_a[lidx]->blend_mode,
                            lyr_a[lidx]->opacity,
                            lyr_a[lidx]->clipping,
                            lyr_a[lidx]->extra_len,
                            lyr_a[lidx]->layer_flags.trans_prot,
                            lyr_a[lidx]->layer_flags.visible,
                            lyr_a[lidx]->layer_flags.irrelevant);
          IFDBG(3) g_debug ("Remaining length %d", block_rem);

          /* Layer mask data */
          if (fread (&block_len, 4, 1, f) < 1)
            {
              psd_set_error (feof (f), errno, error);
              return NULL;
            }
          block_len = GUINT32_FROM_BE (block_len);
          IFDBG(3) g_debug ("Layer mask record size %u", block_len);
          if (block_len + 4 > block_rem)
            {
              g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                           _("Unsupported or invalid mask info size: %d"),
                           block_len);
              return NULL;
            }

          block_rem -= (block_len + 4);
          IFDBG(3) g_debug ("Remaining length %d", block_rem);

          lyr_a[lidx]->layer_mask_extra.top = 0;
          lyr_a[lidx]->layer_mask_extra.left = 0;
          lyr_a[lidx]->layer_mask_extra.bottom = 0;
          lyr_a[lidx]->layer_mask_extra.right = 0;
          lyr_a[lidx]->layer_mask.top = 0;
          lyr_a[lidx]->layer_mask.left = 0;
          lyr_a[lidx]->layer_mask.bottom = 0;
          lyr_a[lidx]->layer_mask.right = 0;
          lyr_a[lidx]->layer_mask.def_color = 0;
          lyr_a[lidx]->layer_mask.extra_def_color = 0;
          lyr_a[lidx]->layer_mask.flags = 0;
          lyr_a[lidx]->layer_mask.extra_flags = 0;
          lyr_a[lidx]->layer_mask.mask_params = 0;
          lyr_a[lidx]->layer_mask.mask_flags.relative_pos = FALSE;
          lyr_a[lidx]->layer_mask.mask_flags.disabled = FALSE;
          lyr_a[lidx]->layer_mask.mask_flags.invert = FALSE;
          lyr_a[lidx]->layer_mask.mask_flags.rendered = FALSE;
          lyr_a[lidx]->layer_mask.mask_flags.params_present = FALSE;

          if (block_len > 0)
            {
              if (fread (&lyr_a[lidx]->layer_mask.top, 4, 1, f) < 1
                  || fread (&lyr_a[lidx]->layer_mask.left, 4, 1, f) < 1
                  || fread (&lyr_a[lidx]->layer_mask.bottom, 4, 1, f) < 1
                  || fread (&lyr_a[lidx]->layer_mask.right, 4, 1, f) < 1
                  || fread (&lyr_a[lidx]->layer_mask.def_color, 1, 1, f) < 1
                  || fread (&lyr_a[lidx]->layer_mask.flags, 1, 1, f) < 1)
                {
                  psd_set_error (feof (f), errno, error);
                  return NULL;
                }

              lyr_a[lidx]->layer_mask.top =
                GINT32_FROM_BE (lyr_a[lidx]->layer_mask.top);
              lyr_a[lidx]->layer_mask.left =
                GINT32_FROM_BE (lyr_a[lidx]->layer_mask.left);
              lyr_a[lidx]->layer_mask.bottom =
                GINT32_FROM_BE (lyr_a[lidx]->layer_mask.bottom);
              lyr_a[lidx]->layer_mask.right =
                GINT32_FROM_BE (lyr_a[lidx]->layer_mask.right);
              lyr_a[lidx]->layer_mask.mask_flags.relative_pos =
                lyr_a[lidx]->layer_mask.flags & 1 ? TRUE : FALSE;
              lyr_a[lidx]->layer_mask.mask_flags.disabled =
                lyr_a[lidx]->layer_mask.flags & 2 ? TRUE : FALSE;
              lyr_a[lidx]->layer_mask.mask_flags.invert =
                lyr_a[lidx]->layer_mask.flags & 4 ? TRUE : FALSE;
              lyr_a[lidx]->layer_mask.mask_flags.rendered =
                lyr_a[lidx]->layer_mask.flags & 8 ? TRUE : FALSE;
              lyr_a[lidx]->layer_mask.mask_flags.params_present =
                lyr_a[lidx]->layer_mask.flags & 16 ? TRUE : FALSE;
              IFDBG(3)
                {
                  if (lyr_a[lidx]->layer_mask.flags &  32) g_debug ("Layer mask flags bit 5 set.");
                  if (lyr_a[lidx]->layer_mask.flags &  64) g_debug ("Layer mask flags bit 6 set.");
                  if (lyr_a[lidx]->layer_mask.flags & 128) g_debug ("Layer mask flags bit 7 set.");
                }

              block_len -= 18;

              /* According to psd-tools this part comes before reading the
               * mask parameters. However if all mask parameter flags are
               * set the size of that would also be more than 18. I'm not
               * sure if all those flags could be set at the same time or
               * how to distinguish them. */
              if (block_len >= 18)
                {
                  if (fread (&lyr_a[lidx]->layer_mask.extra_flags, 1, 1, f) < 1
                      || fread (&lyr_a[lidx]->layer_mask.extra_def_color, 1, 1, f) < 1
                      || fread (&lyr_a[lidx]->layer_mask_extra.top, 4, 1, f) < 1
                      || fread (&lyr_a[lidx]->layer_mask_extra.left, 4, 1, f) < 1
                      || fread (&lyr_a[lidx]->layer_mask_extra.bottom, 4, 1, f) < 1
                      || fread (&lyr_a[lidx]->layer_mask_extra.right, 4, 1, f) < 1)
                    {
                      psd_set_error (feof (f), errno, error);
                      return NULL;
                    }
                  block_len -= 18;

                  lyr_a[lidx]->layer_mask_extra.top =
                    GINT32_FROM_BE (lyr_a[lidx]->layer_mask_extra.top);
                  lyr_a[lidx]->layer_mask_extra.left =
                    GINT32_FROM_BE (lyr_a[lidx]->layer_mask_extra.left);
                  lyr_a[lidx]->layer_mask_extra.bottom =
                    GINT32_FROM_BE (lyr_a[lidx]->layer_mask_extra.bottom);
                  lyr_a[lidx]->layer_mask_extra.right =
                    GINT32_FROM_BE (lyr_a[lidx]->layer_mask_extra.right);

                  IFDBG(2) g_debug ("Rect enclosing Layer mask %d %d %d %d",
                                    lyr_a[lidx]->layer_mask_extra.left,
                                    lyr_a[lidx]->layer_mask_extra.top,
                                    lyr_a[lidx]->layer_mask_extra.right,
                                    lyr_a[lidx]->layer_mask_extra.bottom);
                }

              if (block_len > 2 && lyr_a[lidx]->layer_mask.mask_flags.params_present)
                {
                  gint extra_bytes = 0;

                  if (fread (&lyr_a[lidx]->layer_mask.mask_params, 1, 1, f) < 1)
                    {
                      psd_set_error (feof (f), errno, error);
                      return NULL;
                    }
                  block_len--;
                  IFDBG(3) g_debug ("Mask params: %u", lyr_a[lidx]->layer_mask.mask_params);

                  /* FIXME Extra bytes with user/vector mask density and feather follow.
                   * We currently can't handle that so we will skip it. */
                  extra_bytes += (lyr_a[lidx]->layer_mask.mask_params & 1 ? 1 : 0);
                  extra_bytes += (lyr_a[lidx]->layer_mask.mask_params & 2 ? 8 : 0);
                  extra_bytes += (lyr_a[lidx]->layer_mask.mask_params & 4 ? 1 : 0);
                  extra_bytes += (lyr_a[lidx]->layer_mask.mask_params & 8 ? 8 : 0);
                  IFDBG(3) g_debug ("Extra bytes according to mask parameters %d", extra_bytes);
                  if (fseek (f, extra_bytes, SEEK_CUR) < 0)
                    {
                      psd_set_error (feof (f), errno, error);
                      return NULL;
                    }
                  block_len -= extra_bytes;
                }

              if (block_len > 0)
                {
                  /* We have some remaining unknown mask data.
                   * If size is less than 4 it is most likely padding. */
                  IFDBG(1)
                    {
                      if (block_len > 3)
                        g_debug ("Skipping %u bytes of unknown layer mask data", block_len);
                    }

                  if (fseek (f, block_len, SEEK_CUR) < 0)
                    {
                      psd_set_error (feof (f), errno, error);
                      return NULL;
                    }
                }

              IFDBG(2) g_debug ("Layer mask coords %d %d %d %d",
                                lyr_a[lidx]->layer_mask.left,
                                lyr_a[lidx]->layer_mask.top,
                                lyr_a[lidx]->layer_mask.right,
                                lyr_a[lidx]->layer_mask.bottom);

              IFDBG(3) g_debug ("Default mask color %d, real color %d",
                                lyr_a[lidx]->layer_mask.def_color,
                                lyr_a[lidx]->layer_mask.extra_def_color);

              IFDBG(3) g_debug ("Mask flags %u, real flags %u, mask params %u",
                                lyr_a[lidx]->layer_mask.flags,
                                lyr_a[lidx]->layer_mask.extra_flags,
                                lyr_a[lidx]->layer_mask.mask_params);

              /* Rendered masks can have invalid dimensions: 0, 0, 0, -1 */
              if (! lyr_a[lidx]->layer_mask.mask_flags.rendered)
                {
                  /* sanity checks */
                  if (lyr_a[lidx]->layer_mask.bottom < lyr_a[lidx]->layer_mask.top ||
                      lyr_a[lidx]->layer_mask.bottom - lyr_a[lidx]->layer_mask.top > GIMP_MAX_IMAGE_SIZE)
                    {
                      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                                   _("Unsupported or invalid layer mask height: %d"),
                                   lyr_a[lidx]->layer_mask.bottom - lyr_a[lidx]->layer_mask.top);
                      return NULL;
                    }
                  if (lyr_a[lidx]->layer_mask.right < lyr_a[lidx]->layer_mask.left ||
                      lyr_a[lidx]->layer_mask.right - lyr_a[lidx]->layer_mask.left > GIMP_MAX_IMAGE_SIZE)
                    {
                      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                                   _("Unsupported or invalid layer mask width: %d"),
                                   lyr_a[lidx]->layer_mask.right - lyr_a[lidx]->layer_mask.left);
                      return NULL;
                    }

                  if ((lyr_a[lidx]->layer_mask.right - lyr_a[lidx]->layer_mask.left) >
                      G_MAXINT32 / MAX (lyr_a[lidx]->layer_mask.bottom - lyr_a[lidx]->layer_mask.top, 1))
                    {
                      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                                   _("Unsupported or invalid layer mask size: %dx%d"),
                                   lyr_a[lidx]->layer_mask.right - lyr_a[lidx]->layer_mask.left,
                                   lyr_a[lidx]->layer_mask.bottom - lyr_a[lidx]->layer_mask.top);
                      return NULL;
                    }
                }
            }

          /* Layer blending ranges */           /* FIXME  */
          if (fread (&block_len, 4, 1, f) < 1)
            {
              psd_set_error (feof (f), errno, error);
              return NULL;
            }

          block_len = GUINT32_FROM_BE (block_len);
          block_rem -= (block_len + 4);
          IFDBG(3) g_debug ("Remaining length %d", block_rem);

          if (block_len > 0)
            {
              if (fseek (f, block_len, SEEK_CUR) < 0)
                {
                  psd_set_error (feof (f), errno, error);
                  return NULL;
                }
            }

          lyr_a[lidx]->name = fread_pascal_string (&read_len, &write_len,
                                                   4, f, error);
          if (*error)
            return NULL;

          block_rem -= read_len;
          IFDBG(3) g_debug ("Remaining length %d", block_rem);

          /* Adjustment layer info */           /* FIXME */

          while (block_rem > 7)
            {
              if (get_layer_resource_header (&res_a, f, error) < 0)
                return NULL;

              block_rem -= 12;

              if (res_a.data_len % 2 != 0)
                {
                  /*  Warn the user about an invalid length value but
                   *  try to recover graciously. See bug #771558.
                   */
                  g_printerr ("psd-load: Layer extra data length should "
                              "be even, but it is %d.", res_a.data_len);
                }

              if (res_a.data_len > block_rem)
                {
                  IFDBG(1) g_debug ("Unexpected end of layer resource data");
                  g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                               _("The file is corrupt!"));
                  return NULL;
                }

              if (load_layer_resource (&res_a, lyr_a[lidx], f, error) < 0)
                return NULL;
              block_rem -= res_a.data_len;
            }
          if (block_rem > 0)
            {
              if (fseek (f, block_rem, SEEK_CUR) < 0)
                {
                  psd_set_error (feof (f), errno, error);
                  return NULL;
                }
            }
        }

      img_a->layer_data_start = ftell(f);
      if (fseek (f, img_a->layer_data_len, SEEK_CUR) < 0)
        {
          psd_set_error (feof (f), errno, error);
          return NULL;
        }

      IFDBG(1) g_debug ("Layer image data block size %d",
                        img_a->layer_data_len);
    }

  return lyr_a;
}


static PSDlayer **
read_layer_block (PSDimage  *img_a,
                  FILE      *f,
                  GError   **error)
{
  PSDlayer **lyr_a = NULL;
  guint32    block_len;
  guint32    block_end;

  if (fread (&block_len, 4, 1, f) < 1)
    {
      psd_set_error (feof (f), errno, error);
      img_a->num_layers = -1;
      return NULL;
    }

  img_a->mask_layer_len = GUINT32_FROM_BE (block_len);

  IFDBG(1) g_debug ("Layer and mask block size = %d", img_a->mask_layer_len);

  img_a->transparency = FALSE;
  img_a->layer_data_len = 0;

  if (!img_a->mask_layer_len)
    {
      img_a->num_layers = 0;
      return NULL;
    }
  else
    {
      guint32 total_len = img_a->mask_layer_len;

      img_a->mask_layer_start = ftell (f);
      block_end = img_a->mask_layer_start + img_a->mask_layer_len;

      /* Layer info */
      if (fread (&block_len, 4, 1, f) == 1 && block_len)
        {
          block_len = GUINT32_FROM_BE (block_len);
          IFDBG(1) g_debug ("Layer info size = %d", block_len);

          lyr_a = read_layer_info (img_a, f, error);

          total_len -= block_len;
        }
      else
        {
          img_a->num_layers = 0;
          lyr_a = NULL;
        }

      /* Global layer mask info */
      if (fread (&block_len, 4, 1, f) == 1 && block_len)
        {
          block_len = GUINT32_FROM_BE (block_len);
          IFDBG(1) g_debug ("Global layer mask info size = %d", block_len);

          /* read_global_layer_mask_info (img_a, f, error); */
          fseek (f, block_len, SEEK_CUR);

          total_len -= block_len;
        }

      /* Additional Layer Information */
      if (total_len > 12)
        {
          gchar signature_key[8];

          if (fread (&signature_key, 4, 2, f) == 2 &&
              (memcmp (signature_key, "8BIMLr16", 8) == 0 ||
               memcmp (signature_key, "8BIMLr32", 8) == 0) &&
              fread (&block_len, 4, 1, f) == 1 && block_len)
            lyr_a = read_layer_info (img_a, f, error);
        }

      /* Skip to end of block */
      if (fseek (f, block_end, SEEK_SET) < 0)
        {
          psd_set_error (feof (f), errno, error);
          return NULL;
        }
    }

  return lyr_a;
}

static gint
read_merged_image_block (PSDimage  *img_a,
                         FILE      *f,
                         GError   **error)
{
  img_a->merged_image_start = ftell(f);
  if (fseek (f, 0, SEEK_END) < 0)
    {
      psd_set_error (feof (f), errno, error);
      return -1;
    }

  img_a->merged_image_len = ftell(f) - img_a->merged_image_start;

  IFDBG(1) g_debug ("Merged image data block: Start: %d, len: %d",
                     img_a->merged_image_start, img_a->merged_image_len);

  return 0;
}

static gint32
create_gimp_image (PSDimage    *img_a,
                   const gchar *filename)
{
  gint32 image_id = -1;
  GimpPrecision precision;

  switch (img_a->color_mode)
    {
    case PSD_MULTICHANNEL:
    case PSD_GRAYSCALE:
    case PSD_DUOTONE:
      img_a->base_type = GIMP_GRAY;
      break;

    case PSD_BITMAP:
    case PSD_INDEXED:
      img_a->base_type = GIMP_INDEXED;
      break;

    case PSD_CMYK:
    case PSD_RGB:
      img_a->base_type = GIMP_RGB;
      break;

    default:
      /* Color mode already validated - should not be here */
      g_warning ("Invalid color mode");
      return -1;
      break;
    }

    switch (img_a->bps)
      {
      case 32:
        precision = GIMP_PRECISION_U32_GAMMA;
        break;

      case 16:
        precision = GIMP_PRECISION_U16_GAMMA;
        break;

      case 8:
      case 1:
        if (img_a->color_mode == PSD_CMYK)
          precision = GIMP_PRECISION_FLOAT_GAMMA;
        else
          precision = GIMP_PRECISION_U8_GAMMA;
        break;

      default:
        /* Precision not supported */
        g_warning ("Invalid precision");
        return -1;
        break;
      }

  /* Create gimp image */
  IFDBG(2) g_debug ("Create image");
  image_id = gimp_image_new_with_precision (img_a->columns, img_a->rows,
                                            img_a->base_type, precision);
  gimp_image_set_filename (image_id, filename);
  gimp_image_undo_disable (image_id);

  return image_id;
}

static gint
add_color_map (gint32    image_id,
               PSDimage *img_a)
{
  GimpParasite *parasite;

  if (img_a->color_map_len)
    {
      if (img_a->color_mode != PSD_DUOTONE)
        {
          gimp_image_set_colormap (image_id, img_a->color_map,
                                   img_a->color_map_entries);
        }
      else
        {
           /* Add parasite for Duotone color data */
          IFDBG(2) g_debug ("Add Duotone color data parasite");
          parasite = gimp_parasite_new (PSD_PARASITE_DUOTONE_DATA, 0,
                                        img_a->color_map_len, img_a->color_map);
          gimp_image_attach_parasite (image_id, parasite);
          gimp_parasite_free (parasite);
        }
      g_free (img_a->color_map);
    }

  return 0;
}

static gint
add_image_resources (gint32     image_id,
                     PSDimage  *img_a,
                     FILE      *f,
                     gboolean  *resolution_loaded,
                     gboolean  *profile_loaded,
                     GError   **error)
{
  PSDimageres  res_a;

  if (fseek (f, img_a->image_res_start, SEEK_SET) < 0)
    {
      psd_set_error (feof (f), errno, error);
      return -1;
    }

  /* Initialise image resource variables */
  img_a->no_icc = FALSE;
  img_a->layer_state = 0;
  img_a->alpha_names = NULL;
  img_a->alpha_display_info = NULL;
  img_a->alpha_display_count = 0;
  img_a->alpha_id = NULL;
  img_a->alpha_id_count = 0;
  img_a->quick_mask_id = 0;

  while (ftell (f) < img_a->image_res_start + img_a->image_res_len)
    {
      if (get_image_resource_header (&res_a, f, error) < 0)
        return -1;

      if (res_a.data_start + res_a.data_len >
          img_a->image_res_start + img_a->image_res_len)
        {
          IFDBG(1) g_debug ("Unexpected end of image resource data");
          return 0;
        }

      if (load_image_resource (&res_a, image_id, img_a, f,
                               resolution_loaded, profile_loaded,
                               error) < 0)
        return -1;
    }

  return 0;
}

static guchar *
psd_convert_cmyk_to_srgb (PSDimage *img_a,
                          guchar   *dst,
                          guchar   *src,
                          gint      width,
                          gint      height,
                          gboolean  alpha)
{
  if (img_a->cmyk_profile)
    {
      if (alpha)
        {
          if (! img_a->cmyk_transform_alpha)
            {
              GimpColorProfile *srgb = gimp_color_profile_new_rgb_srgb ();

              img_a->cmyk_transform_alpha = gimp_color_transform_new (img_a->cmyk_profile, babl_format ("cmykA u8"),
                                                                      srgb, babl_format ("R'G'B'A float"),
                                                                      0, 0);

              g_object_unref (srgb);
            }

        gimp_color_transform_process_pixels (img_a->cmyk_transform_alpha,
                                             babl_format ("cmykA u8"),
                                             src,
                                             babl_format ("R'G'B'A float"),
                                             dst,
                                             width * height);
        }
      else
        {
          if (! img_a->cmyk_transform)
            {
              GimpColorProfile *srgb = gimp_color_profile_new_rgb_srgb ();

              img_a->cmyk_transform = gimp_color_transform_new (img_a->cmyk_profile, babl_format ("cmyk u8"),
                                                                      srgb, babl_format ("R'G'B' float"),
                                                                      0, 0);

              g_object_unref (srgb);
            }

          gimp_color_transform_process_pixels (img_a->cmyk_transform,
                                               babl_format ("cmyk u8"),
                                               src,
                                               babl_format ("R'G'B' float"),
                                               dst,
                                               width * height);
        }
    }
  else
    {
      const Babl *fish;

      if (alpha)
        fish = babl_fish ("cmykA u8", "R'G'B'A float");
      else
        fish = babl_fish ("cmyk u8", "R'G'B' float");

      babl_process (fish, src, dst, width * height);
    }

  return (guchar*) dst;
}

static gint
add_layers (gint32     image_id,
            PSDimage  *img_a,
            PSDlayer **lyr_a,
            FILE      *f,
            GError   **error)
{
  PSDchannel          **lyr_chn;
  GArray               *parent_group_stack;
  gint32                parent_group_id   = -1;
  gint32                clipping_group_id = -1;
  guint16               alpha_chn;
  guint16               user_mask_chn;
  guint16               layer_channels, base_channels;
  guint16               channel_idx[MAX_CHANNELS];
  guint16              *rle_pack_len;
  guint16               bps;
  gint32                l_x;                   /* Layer x */
  gint32                l_y;                   /* Layer y */
  gint32                l_w;                   /* Layer width */
  gint32                l_h;                   /* Layer height */
  gint32                lm_x;                  /* Layer mask x */
  gint32                lm_y;                  /* Layer mask y */
  gint32                lm_w;                  /* Layer mask width */
  gint32                lm_h;                  /* Layer mask height */
  gint32                layer_id = -1;
  gint32                mask_id = -1;
  gint32                active_layer_id = -1;
  gint                  lidx;                  /* Layer index */
  gint                  cidx;                  /* Channel index */
  gint                  gidx;                  /* Clipping group start index */
  gint                  rowi;                  /* Row index */
  gboolean              alpha;
  gboolean              user_mask;
  gboolean              empty;
  gboolean              empty_mask;
  gboolean              use_clipping_group;
  GeglBuffer           *buffer;
  GimpImageType         image_type;
  LayerModeInfo         mode_info;


  IFDBG(2) g_debug ("Number of layers: %d", img_a->num_layers);

  if (img_a->merged_image_only || img_a->num_layers == 0)
    {
      IFDBG(2) g_debug ("No layers to process");
      return 0;
    }

  /* Layered image - Photoshop 3 style */
  if (fseek (f, img_a->layer_data_start, SEEK_SET) < 0)
    {
      psd_set_error (feof (f), errno, error);
      return -1;
    }

  IFDBG(3) g_debug ("Pre process layers...");
  use_clipping_group = FALSE;
  gidx = -1;
  for (lidx = 0; lidx < img_a->num_layers; ++lidx)
    {
      if (lyr_a[lidx]->clipping == 1)
        {
          /* Photoshop handles layers with clipping differently than GIMP does.
           * To correctly show these layers we need to make a new group
           * starting with the first non-clipping layer and including all
           * the clipping layers above it.
           */
          if (lidx > 0)
            {
              if (gidx == -1)
                {
                  use_clipping_group = TRUE;

                  /* Looking at the results we should ignore layer groups */
                  if (lyr_a[lidx-1]->group_type == 0)
                    gidx = lidx - 1;
                  else
                    gidx = lidx;

                  lyr_a[gidx]->clipping_group_type = 1; /* start clipping group */
                  IFDBG(3) g_debug ("Layer: %s - start of clipping group", lyr_a[gidx]->name);
                }
              else if (lidx + 1 == img_a->num_layers && use_clipping_group)
                {
                  /* end clipping group at the top of the layer stack */
                  lyr_a[lidx]->clipping_group_type = 2; /* end clipping group */
                  IFDBG(3) g_debug ("Layer: %s - end of clipping group", lyr_a[lidx]->name);

                  use_clipping_group = FALSE;
                  gidx = -1;
                }
              else
                {
                  lyr_a[lidx]->clipping_group_type = 0;
                }
            }
        }
      else if (use_clipping_group)
        {
          /* end clipping group */
          lyr_a[lidx-1]->clipping_group_type = 2;
          IFDBG(3) g_debug ("Layer: %s - end of clipping group", lyr_a[lidx-1]->name);

          use_clipping_group = FALSE;
          gidx = -1;
        }
      else
        {
          lyr_a[lidx]->clipping_group_type = 0;
        }
    }

  /* set the root of the group hierarchy */
  parent_group_stack = g_array_new (FALSE, FALSE, sizeof (gint32));
  g_array_append_val (parent_group_stack, parent_group_id);

  for (lidx = 0; lidx < img_a->num_layers; ++lidx)
    {
      IFDBG(2) g_debug ("Process Layer No %d (%s).", lidx, lyr_a[lidx]->name);

      if (lyr_a[lidx]->drop)
        {
          IFDBG(2) g_debug ("Drop layer %d", lidx);

          /* Step past layer data */
          for (cidx = 0; cidx < lyr_a[lidx]->num_channels; ++cidx)
            {
              if (fseek (f, lyr_a[lidx]->chn_info[cidx].data_len, SEEK_CUR) < 0)
                {
                  psd_set_error (feof (f), errno, error);
                  return -1;
                }
            }
        }
      else
        {
          /* Empty layer */
          if (lyr_a[lidx]->bottom - lyr_a[lidx]->top == 0
              || lyr_a[lidx]->right - lyr_a[lidx]->left == 0)
              empty = TRUE;
          else
              empty = FALSE;

          /* Empty mask */
          if (lyr_a[lidx]->layer_mask.bottom - lyr_a[lidx]->layer_mask.top == 0
              || lyr_a[lidx]->layer_mask.right - lyr_a[lidx]->layer_mask.left == 0)
              empty_mask = TRUE;
          else
              empty_mask = FALSE;

          IFDBG(3) g_debug ("Empty mask %d, size %d %d", empty_mask,
                            lyr_a[lidx]->layer_mask.bottom - lyr_a[lidx]->layer_mask.top,
                            lyr_a[lidx]->layer_mask.right - lyr_a[lidx]->layer_mask.left);

          /* Load layer channel data */
          IFDBG(2) g_debug ("Number of channels: %d", lyr_a[lidx]->num_channels);
          /* Create pointer array for the channel records */
          lyr_chn = g_new (PSDchannel *, lyr_a[lidx]->num_channels);
          for (cidx = 0; cidx < lyr_a[lidx]->num_channels; ++cidx)
            {
              guint16 comp_mode = PSD_COMP_RAW;

              /* Allocate channel record */
              lyr_chn[cidx] = g_malloc (sizeof (PSDchannel) );

              lyr_chn[cidx]->id = lyr_a[lidx]->chn_info[cidx].channel_id;
              lyr_chn[cidx]->rows = lyr_a[lidx]->bottom - lyr_a[lidx]->top;
              lyr_chn[cidx]->columns = lyr_a[lidx]->right - lyr_a[lidx]->left;
              lyr_chn[cidx]->data = NULL;

              if (lyr_chn[cidx]->id == PSD_CHANNEL_EXTRA_MASK)
                {
                  if (fseek (f, lyr_a[lidx]->chn_info[cidx].data_len, SEEK_CUR) != 0)
                    {
                      psd_set_error (feof (f), errno, error);
                      return -1;
                    }

                  continue;
                }
              else if (lyr_chn[cidx]->id == PSD_CHANNEL_MASK)
                {
                  /* Works around a bug in panotools psd files where the layer mask
                     size is given as 0 but data exists. Set mask size to layer size.
                  */
                  if (empty_mask && lyr_a[lidx]->chn_info[cidx].data_len - 2 > 0)
                    {
                      empty_mask = FALSE;
                      if (lyr_a[lidx]->layer_mask.top == lyr_a[lidx]->layer_mask.bottom)
                        {
                          lyr_a[lidx]->layer_mask.top = lyr_a[lidx]->top;
                          lyr_a[lidx]->layer_mask.bottom = lyr_a[lidx]->bottom;
                        }
                      if (lyr_a[lidx]->layer_mask.right == lyr_a[lidx]->layer_mask.left)
                        {
                          lyr_a[lidx]->layer_mask.right = lyr_a[lidx]->right;
                          lyr_a[lidx]->layer_mask.left = lyr_a[lidx]->left;
                        }
                    }
                  lyr_chn[cidx]->rows = (lyr_a[lidx]->layer_mask.bottom -
                                        lyr_a[lidx]->layer_mask.top);
                  lyr_chn[cidx]->columns = (lyr_a[lidx]->layer_mask.right -
                                           lyr_a[lidx]->layer_mask.left);
                }

              IFDBG(3) g_debug ("Channel id %d, %dx%d",
                                lyr_chn[cidx]->id,
                                lyr_chn[cidx]->columns,
                                lyr_chn[cidx]->rows);

              /* Only read channel data if there is any channel
               * data. Note that the channel data can contain a
               * compression method but no actual data.
               */
              if (lyr_a[lidx]->chn_info[cidx].data_len >= COMP_MODE_SIZE)
                {
                  if (fread (&comp_mode, COMP_MODE_SIZE, 1, f) < 1)
                    {
                      psd_set_error (feof (f), errno, error);
                      return -1;
                    }
                  comp_mode = GUINT16_FROM_BE (comp_mode);
                  IFDBG(3) g_debug ("Compression mode: %d", comp_mode);
                }
              if (lyr_a[lidx]->chn_info[cidx].data_len > COMP_MODE_SIZE)
                {
                  switch (comp_mode)
                    {
                      case PSD_COMP_RAW:        /* Planar raw data */
                        IFDBG(3) g_debug ("Raw data length: %d",
                                          lyr_a[lidx]->chn_info[cidx].data_len - 2);
                        if (read_channel_data (lyr_chn[cidx], img_a->bps,
                                               PSD_COMP_RAW, NULL, f, 0,
                                               error) < 1)
                          return -1;
                        break;

                      case PSD_COMP_RLE:        /* Packbits */
                        IFDBG(3) g_debug ("RLE channel length %d, RLE length data: %d, "
                                          "RLE data block: %d",
                                          lyr_a[lidx]->chn_info[cidx].data_len - 2,
                                          lyr_chn[cidx]->rows * 2,
                                          (lyr_a[lidx]->chn_info[cidx].data_len - 2 -
                                           lyr_chn[cidx]->rows * 2));
                        rle_pack_len = g_malloc (lyr_chn[cidx]->rows * 2);
                        for (rowi = 0; rowi < lyr_chn[cidx]->rows; ++rowi)
                          {
                            if (fread (&rle_pack_len[rowi], 2, 1, f) < 1)
                              {
                                psd_set_error (feof (f), errno, error);
                                g_free (rle_pack_len);
                                return -1;
                              }
                            rle_pack_len[rowi] = GUINT16_FROM_BE (rle_pack_len[rowi]);
                          }

                        IFDBG(3) g_debug ("RLE decode - data");
                        if (read_channel_data (lyr_chn[cidx], img_a->bps,
                                               PSD_COMP_RLE, rle_pack_len, f, 0,
                                               error) < 1)
                          return -1;

                        g_free (rle_pack_len);
                        break;

                      case PSD_COMP_ZIP:                 /* ? */
                      case PSD_COMP_ZIP_PRED:
                        if (read_channel_data (lyr_chn[cidx], img_a->bps,
                                               comp_mode, NULL, f,
                                               lyr_a[lidx]->chn_info[cidx].data_len - 2,
                                               error) < 1)
                          return -1;
                        break;

                      default:
                        g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                                    _("Unsupported compression mode: %d"), comp_mode);
                        return -1;
                        break;
                    }
                }
            }

          /* Draw layer */

          alpha = FALSE;
          alpha_chn = -1;
          user_mask = FALSE;
          user_mask_chn = -1;
          layer_channels = 0;
          l_x = 0;
          l_y = 0;
          l_w = img_a->columns;
          l_h = img_a->rows;
          if (parent_group_stack->len > 0)
            parent_group_id = g_array_index (parent_group_stack, gint32,
                                             parent_group_stack->len - 1);
          else
            parent_group_id = -1; /* root */

          if (img_a->color_mode == PSD_CMYK)
            base_channels = 4;
          else if (img_a->color_mode == PSD_RGB || img_a->color_mode == PSD_LAB)
            base_channels = 3;
          else
            base_channels = 1;

          IFDBG(3) g_debug ("Re-hash channel indices");
          for (cidx = 0; cidx < lyr_a[lidx]->num_channels; ++cidx)
            {
              if (lyr_chn[cidx]->id == PSD_CHANNEL_MASK)
                {
                  user_mask = TRUE;
                  user_mask_chn = cidx;
                }
              else if (lyr_chn[cidx]->id == PSD_CHANNEL_ALPHA)
                {
                  alpha = TRUE;
                  alpha_chn = cidx;
                }
              else if (lyr_chn[cidx]->data)
                {
                  if (layer_channels < base_channels)
                    {
                      channel_idx[layer_channels] = cidx;   /* Assumes in sane order */
                      layer_channels++;                     /* RGB, Lab, CMYK etc.   */
                    }
                  else
                    {
                      /* channel_idx[base_channels] is reserved for alpha channel,
                       * but this layer apparently has extra channels.
                       * From the one example I have (see #8411) it looks like
                       * that channel is the same as the alpha channel. */
                      IFDBG(2) g_debug ("This layer has an extra channel (id: %d)", lyr_chn[cidx]->id);
                      channel_idx[layer_channels+1] = cidx;   /* Assumes in sane order */
                      layer_channels += 2;                    /* RGB, Lab, CMYK etc.   */
                    }
                }
              else
                {
                  IFDBG(4) g_debug ("Channel %d (id: %d) has no data", cidx, lyr_chn[cidx]->id);
                }
            }

          if (alpha)
            {
              if (layer_channels <= base_channels)
                {
                  channel_idx[layer_channels] = alpha_chn;
                  layer_channels++;
                }
              else
                {
                  channel_idx[base_channels] = alpha_chn;
                }
              base_channels++;
            }

          IFDBG(4) g_debug ("Create the layer (group type: %d, clipping group type: %d)",
                            lyr_a[lidx]->group_type, lyr_a[lidx]->clipping_group_type);

          /* Create the layer */
          if (lyr_a[lidx]->group_type != 0)
            {
              if (lyr_a[lidx]->group_type == 3)
                {
                  /* the </Layer group> marker layers are used to
                   * assemble the layer structure in a single pass
                   */
                  IFDBG(2) g_debug ("Create placeholder group layer");
                  layer_id = gimp_layer_group_new (image_id);
                  /* add this group layer as the new parent */
                  g_array_append_val (parent_group_stack, layer_id);
                }
              else /* group-type == 1 || group_type == 2 */
                {
                  if (parent_group_stack->len)
                    {
                      layer_id = g_array_index (parent_group_stack, gint32,
                                                parent_group_stack->len - 1);
                      IFDBG(2) g_debug ("End group layer id %d.", layer_id);
                      /* since the layers are stored in reverse, the group
                       * layer start marker actually means we're done with
                       * that layer group
                       */
                      g_array_remove_index (parent_group_stack,
                                            parent_group_stack->len - 1);

                      gimp_drawable_offsets (layer_id, &l_x, &l_y);

                      l_w = gimp_drawable_width  (layer_id);
                      l_h = gimp_drawable_height (layer_id);
                    }
                  else
                    {
                      IFDBG(1) g_debug ("WARNING: Unmatched group layer start marker.");
                      layer_id = -1;
                    }
                }
            }
          else
            {

              if (lyr_a[lidx]->clipping_group_type == 1)
                {
                  clipping_group_id = add_clipping_group (image_id, parent_group_id);
                }

              if (empty)
                {
                  IFDBG(2) g_debug ("Create blank layer");
                }
              else
                {
                  IFDBG(2) g_debug ("Create normal layer");
                  l_x = lyr_a[lidx]->left;
                  l_y = lyr_a[lidx]->top;
                  l_w = lyr_a[lidx]->right - lyr_a[lidx]->left;
                  l_h = lyr_a[lidx]->bottom - lyr_a[lidx]->top;
                }

              image_type = get_gimp_image_type (img_a->base_type, TRUE);
              IFDBG(3) g_debug ("Layer type %d", image_type);

              layer_id = gimp_layer_new (image_id, lyr_a[lidx]->name,
                                         l_w, l_h, image_type,
                                         100, GIMP_LAYER_MODE_NORMAL);
            }

          if (layer_id != -1)
            {
              /* Set the layer name.  Note that we do this even for group-end
               * markers, to avoid having the default group name collide with
               * subsequent layers; the real group name is set by the group
               * start marker.
               */
              gimp_item_set_name (layer_id, lyr_a[lidx]->name);

              /* Set the layer properties (skip this for layer group end
               * markers; we set their properties when processing the start
               * marker.)
               */
              if (lyr_a[lidx]->group_type != 3)
                {
                  /* Mode */
                  psd_to_gimp_blend_mode (lyr_a[lidx], &mode_info);
                  gimp_layer_set_mode (layer_id, mode_info.mode);
                  gimp_layer_set_blend_space (layer_id, mode_info.blend_space);
                  gimp_layer_set_composite_space (layer_id, mode_info.composite_space);
                  gimp_layer_set_composite_mode (layer_id, mode_info.composite_mode);

                  /* Opacity */
                  gimp_layer_set_opacity (layer_id,
                                          lyr_a[lidx]->opacity * 100.0 / 255.0);

                  /* Flags */
                  gimp_layer_set_lock_alpha  (layer_id, lyr_a[lidx]->layer_flags.trans_prot);
                  gimp_item_set_visible (layer_id, lyr_a[lidx]->layer_flags.visible);
#if 0
                  /* according to the spec, the 'irrelevant' flag indicates
                   * that the layer's "pixel data is irrelevant to the
                   * appearance of the document".  what this seems to mean is
                   * not that the layer doesn't contribute to the image, but
                   * rather that its appearance can be entirely derived from
                   * sources other than the pixel data, such as vector data.
                   * in particular, this doesn't mean that the layer is
                   * invisible. since we only support raster layers atm, we can
                   * just ignore this flag.
                   */
                  if (lyr_a[lidx]->layer_flags.irrelevant &&
                      lyr_a[lidx]->group_type == 0)
                    {
                      gimp_item_set_visible (layer_id, FALSE);
                    }
#endif

                  /* Position */
                  if (l_x != 0 || l_y != 0)
                    gimp_layer_set_offsets (layer_id, l_x, l_y);

                  /* Color tag */
                  gimp_item_set_color_tag (layer_id,
                                           psd_to_gimp_layer_color_tag (lyr_a[lidx]->color_tag[0]));

                  /* Tattoo */
                  if (lyr_a[lidx]->id)
                    gimp_item_set_tattoo (layer_id, lyr_a[lidx]->id);

                  /* For layer groups, expand or collapse the group */
                  if (lyr_a[lidx]->group_type != 0)
                    {
                      gimp_item_set_expanded (layer_id,
                                              lyr_a[lidx]->group_type == 1);
                    }
                }

              /* Remember the active layer ID */
              if (lidx == img_a->layer_state)
                {
                  active_layer_id = layer_id;
                }

              /* Set the layer data */
              if (lyr_a[lidx]->group_type == 0)
                {
                  IFDBG(3) g_debug ("Draw layer");

                  if (empty)
                    {
                      gimp_drawable_fill (layer_id, GIMP_FILL_TRANSPARENT);
                    }
                  else
                    {
                      GeglBufferIterator *iter;

                      bps = img_a->bps / 8;
                      if (bps == 0)
                        bps++;

                      buffer = gimp_drawable_get_buffer (layer_id);

                      iter = gegl_buffer_iterator_new (
                        buffer, NULL, 0, get_layer_format (img_a, alpha),
                        GEGL_ACCESS_WRITE, GEGL_ABYSS_NONE, 1);

                      while (gegl_buffer_iterator_next (iter))
                        {
                          const GeglRectangle *roi      = &iter->items[0].roi;
                          guint8              *dst0     = iter->items[0].data;
                          gint                 src_step = bps;
                          gint                 dst_step = bps * base_channels;

                          if (img_a->color_mode == PSD_CMYK)
                            {
                              dst0 = gegl_scratch_alloc (base_channels *
                                                         iter->length);
                            }

                          for (cidx = 0; cidx < base_channels; ++cidx)
                            {
                              gint b;

                              if (roi->x == 0 && roi->y == 0)
                                IFDBG(3) g_debug ("Start channel %d", channel_idx[cidx]);

                              for (b = 0; b < bps; ++b)
                                {
                                  guint8 *dst;
                                  gint    y;

                                  dst = &dst0[cidx * bps + b];

                                  for (y = 0; y < roi->height; y++)
                                    {
                                      const guint8 *src;
                                      gint          x;

                                      src = (const guint8 *)
                                        &lyr_chn[channel_idx[cidx]]->data[
                                          ((roi->y + y) * l_w +
                                           roi->x)      * bps +
                                          b];

                                      for (x = 0; x < roi->width; ++x)
                                        {
                                          *dst = *src;

                                          src += src_step;
                                          dst += dst_step;
                                        }
                                    }
                                }
                            }

                          if (img_a->color_mode == PSD_CMYK)
                            {
                              psd_convert_cmyk_to_srgb (
                                img_a,
                                iter->items[0].data, dst0,
                                roi->width, roi->height,
                                alpha);

                              gegl_scratch_free (dst0);
                            }
                        }

                      for (cidx = 0; cidx < layer_channels; ++cidx)
                        g_free (lyr_chn[channel_idx[cidx]]->data);

                      g_object_unref (buffer);
                    }
                }

              /* Layer mask */
              if (user_mask && lyr_a[lidx]->group_type != 3)
                {
                  if (empty_mask)
                    {
                      IFDBG(3) g_debug ("Create empty mask");
                      if (lyr_a[lidx]->layer_mask.def_color == 255)
                        mask_id = gimp_layer_create_mask (layer_id,
                                                          GIMP_ADD_MASK_WHITE);
                      else
                        mask_id = gimp_layer_create_mask (layer_id,
                                                          GIMP_ADD_MASK_BLACK);
                      gimp_layer_add_mask (layer_id, mask_id);
                      gimp_layer_set_apply_mask (layer_id,
                        ! lyr_a[lidx]->layer_mask.mask_flags.disabled);
                    }
                  else
                    {
                      GeglRectangle mask_rect;

                      /* Load layer mask data */
                      lm_x = lyr_a[lidx]->layer_mask.left - l_x;
                      lm_y = lyr_a[lidx]->layer_mask.top - l_y;
                      lm_w = lyr_a[lidx]->layer_mask.right - lyr_a[lidx]->layer_mask.left;
                      lm_h = lyr_a[lidx]->layer_mask.bottom - lyr_a[lidx]->layer_mask.top;
                      IFDBG(3) g_debug ("Mask channel index %d", user_mask_chn);
                      IFDBG(3) g_debug ("Original Mask %d %d %d %d", lm_x, lm_y, lm_w, lm_h);
                      /* Crop mask at layer boundary, and draw layer mask data,
                       * if any
                       */
                      if (gegl_rectangle_intersect (
                            &mask_rect,
                            GEGL_RECTANGLE (0, 0, l_w, l_h),
                            GEGL_RECTANGLE (lm_x, lm_y, lm_w, lm_h)))
                        {
                          IFDBG(3) g_debug ("Layer %d %d %d %d", l_x, l_y, l_w, l_h);
                          IFDBG(3) g_debug ("Mask %d %d %d %d",
                                            mask_rect.x,     mask_rect.y,
                                            mask_rect.width, mask_rect.height);

                          if (lyr_a[lidx]->layer_mask.def_color == 255)
                            mask_id = gimp_layer_create_mask (layer_id,
                                                              GIMP_ADD_MASK_WHITE);
                          else
                            mask_id = gimp_layer_create_mask (layer_id,
                                                              GIMP_ADD_MASK_BLACK);

                          bps = img_a->bps / 8;
                          if (bps == 0)
                            bps++;

                          IFDBG(3) g_debug ("New layer mask %d", mask_id);
                          gimp_layer_add_mask (layer_id, mask_id);
                          buffer = gimp_drawable_get_buffer (mask_id);
                          gegl_buffer_set (buffer,
                                           &mask_rect,
                                           0, get_mask_format (img_a),
                                           lyr_chn[user_mask_chn]->data + (
                                             (mask_rect.y - lm_y)  * lm_w +
                                             (mask_rect.x - lm_x)) * bps,
                                           lm_w * bps);
                          g_object_unref (buffer);
                          gimp_layer_set_apply_mask (layer_id,
                                                     ! lyr_a[lidx]->layer_mask.mask_flags.disabled);
                        }
                      g_free (lyr_chn[user_mask_chn]->data);
                    }
                }

                /* Insert the layer */
                if (lyr_a[lidx]->group_type == 0 || /* normal layer */
                    lyr_a[lidx]->group_type == 3    /* group layer end marker */)
                  {
                     if (clipping_group_id != -1)
                      {
                        gimp_image_insert_layer (image_id, layer_id, clipping_group_id, 0);

                        if (lyr_a[lidx]->clipping_group_type == 2)
                          {
                            /* End of our clipping group. */
                            clipping_group_id = -1;
                          }
                      }
                    else
                      {
                        gimp_image_insert_layer (image_id, layer_id, parent_group_id, 0);
                      }

                  }
            }

          for (cidx = 0; cidx < lyr_a[lidx]->num_channels; ++cidx)
            if (lyr_chn[cidx])
              g_free (lyr_chn[cidx]);
          g_free (lyr_chn);
        }
      g_free (lyr_a[lidx]->chn_info);
      g_free (lyr_a[lidx]->name);
      g_free (lyr_a[lidx]);
    }
  g_free (lyr_a);
  g_array_free (parent_group_stack, FALSE);

  /* Set the active layer */
  if (active_layer_id >= 0)
    gimp_image_set_active_layer (image_id, active_layer_id);

  return 0;
}

static gint
add_merged_image (gint32     image_id,
                  PSDimage  *img_a,
                  FILE      *f,
                  GError   **error)
{
  PSDchannel            chn_a[MAX_CHANNELS];
  gchar                *alpha_name;
  guchar               *pixels;
  guint16               comp_mode;
  guint16               base_channels;
  guint16               extra_channels;
  guint16               total_channels;
  guint16               bps;
  guint16              *rle_pack_len[MAX_CHANNELS];
  guint32               alpha_id;
  gint32                layer_size;
  gint32                layer_id = -1;
  gint32                channel_id = -1;
  gint16                alpha_opacity;
  gint                  cidx;                  /* Channel index */
  gint                  rowi;                  /* Row index */
  gint                  offset;
  gint                  i;
  gboolean              alpha_visible;
  gboolean              alpha_channel = FALSE;
  GeglBuffer           *buffer;
  GimpImageType         image_type;
  GimpRGB               alpha_rgb;

  total_channels = img_a->channels;
  extra_channels = 0;
  bps = img_a->bps / 8;
  if (bps == 0)
    bps++;

  if (img_a->num_layers > 0 && img_a->color_mode == PSD_CMYK)
    {
      /* In this case there is no conversion. Merged image is RGB. */
      img_a->color_mode = PSD_RGB;
      if (! img_a->transparency)
        total_channels--;
    }

  if ((img_a->color_mode == PSD_BITMAP ||
       img_a->color_mode == PSD_MULTICHANNEL ||
       img_a->color_mode == PSD_GRAYSCALE ||
       img_a->color_mode == PSD_DUOTONE ||
       img_a->color_mode == PSD_INDEXED) &&
       total_channels > 1)
    {
      extra_channels = total_channels - 1;
    }
  else if ((img_a->color_mode == PSD_RGB ||
            img_a->color_mode == PSD_LAB) &&
            total_channels > 3)
    {
      extra_channels = total_channels - 3;
    }
  else if ((img_a->color_mode == PSD_CMYK) &&
            total_channels > 4)
    {
      extra_channels = total_channels - 4;
    }
  if (img_a->transparency && extra_channels > 0)
    extra_channels--;
  base_channels = total_channels - extra_channels;

  if (img_a->merged_image_only)
    {
      if (! img_a->transparency && extra_channels > 0)
        {
          alpha_channel = TRUE;
          base_channels += 1;
        }
      extra_channels = 0;
      total_channels = base_channels;
    }

  /* ----- Read merged image & extra channel pixel data ----- */
  if (img_a->merged_image_only ||
      img_a->num_layers == 0   ||
      extra_channels > 0)
    {
      guint32 block_len;
      guint32 block_start;

      block_start = img_a->merged_image_start;
      block_len = img_a->merged_image_len;

      fseek (f, block_start, SEEK_SET);

      if (fread (&comp_mode, COMP_MODE_SIZE, 1, f) < 1)
        {
          psd_set_error (feof (f), errno, error);
          return -1;
        }
      comp_mode = GUINT16_FROM_BE (comp_mode);

      switch (comp_mode)
        {
          case PSD_COMP_RAW:        /* Planar raw data */
            IFDBG(3) g_debug ("Raw data length: %d", block_len);
            for (cidx = 0; cidx < total_channels; ++cidx)
              {
                chn_a[cidx].columns = img_a->columns;
                chn_a[cidx].rows = img_a->rows;
                if (read_channel_data (&chn_a[cidx], img_a->bps,
                                       PSD_COMP_RAW, NULL, f, 0,
                                       error) < 1)
                  return -1;
              }
            break;

          case PSD_COMP_RLE:        /* Packbits */
            /* Image data is stored as packed scanlines in planar order
               with all compressed length counters stored first */
            IFDBG(3) g_debug ("RLE length data: %d, RLE data block: %d",
                               total_channels * img_a->rows * 2,
                               block_len - (total_channels * img_a->rows * 2));
            for (cidx = 0; cidx < total_channels; ++cidx)
              {
                chn_a[cidx].columns = img_a->columns;
                chn_a[cidx].rows = img_a->rows;
                rle_pack_len[cidx] = g_malloc (img_a->rows * 2);
                for (rowi = 0; rowi < img_a->rows; ++rowi)
                  {
                    if (fread (&rle_pack_len[cidx][rowi], 2, 1, f) < 1)
                      {
                        psd_set_error (feof (f), errno, error);
                        return -1;
                      }
                    rle_pack_len[cidx][rowi] = GUINT16_FROM_BE (rle_pack_len[cidx][rowi]);
                  }
              }

            /* Skip channel length data for unloaded channels */
            if (fseek (f, (img_a->channels - total_channels) * img_a->rows * 2,
                       SEEK_CUR) < 0)
              {
                psd_set_error (feof (f), errno, error);
                return -1;
              }

            IFDBG(3) g_debug ("RLE decode - data");
            for (cidx = 0; cidx < total_channels; ++cidx)
              {
                if (read_channel_data (&chn_a[cidx], img_a->bps,
                                       PSD_COMP_RLE, rle_pack_len[cidx], f, 0,
                                       error) < 1)
                  return -1;
                g_free (rle_pack_len[cidx]);
              }
            break;

          case PSD_COMP_ZIP:                 /* ? */
          case PSD_COMP_ZIP_PRED:
          default:
            g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                        _("Unsupported compression mode: %d"), comp_mode);
            return -1;
            break;
        }
    }

  /* ----- Draw merged image ----- */
  if (img_a->merged_image_only ||
      img_a->num_layers == 0)            /* Merged image - Photoshop 2 style */
    {
      image_type = get_gimp_image_type (img_a->base_type,
                                        img_a->transparency || alpha_channel);

      layer_size = img_a->columns * img_a->rows;
      pixels = g_malloc (layer_size * base_channels * bps);
      for (cidx = 0; cidx < base_channels; ++cidx)
        {
          for (i = 0; i < layer_size; ++i)
            {
              memcpy (&pixels[((i * base_channels) + cidx) * bps],
                      &chn_a[cidx].data[i * bps], bps);
            }
          g_free (chn_a[cidx].data);
        }

      /* Add background layer */
      IFDBG(2) g_debug ("Draw merged image");
      layer_id = gimp_layer_new (image_id, _("Background"),
                                 img_a->columns, img_a->rows,
                                 image_type,
                                 100,
                                 gimp_image_get_default_new_layer_mode (image_id));
      gimp_image_insert_layer (image_id, layer_id, -1, 0);

      buffer = gimp_drawable_get_buffer (layer_id);
      if (img_a->color_mode == PSD_CMYK)
        {
          guchar *dst0;

          dst0 = g_malloc (base_channels * layer_size * sizeof(float));
          psd_convert_cmyk_to_srgb ( img_a,
                                     dst0, pixels,
                                     img_a->columns, img_a->rows,
                                     alpha_channel);
          g_free (pixels);
          pixels = dst0;
       }

      gegl_buffer_set (buffer,
                       GEGL_RECTANGLE (0, 0,
                                       gegl_buffer_get_width (buffer),
                                       gegl_buffer_get_height (buffer)),
                       0, get_layer_format (img_a,
                                            img_a->transparency ||
                                            alpha_channel),
                       pixels, GEGL_AUTO_ROWSTRIDE);

      if (img_a->color_mode == PSD_CMYK)
        img_a->color_mode = PSD_RGB;

      /* Merged image data is blended against white.  Unblend it. */
      if (img_a->transparency)
        {
          GeglBufferIterator *iter;

          iter = gegl_buffer_iterator_new (buffer, NULL, 0,
                                           babl_format ("R'G'B'A float"),
                                           GEGL_ACCESS_READWRITE,
                                           GEGL_ABYSS_NONE, 1);

          while (gegl_buffer_iterator_next (iter))
            {
              gfloat *data = iter->items[0].data;

              for (i = 0; i < iter->length; i++)
                {
                  gint c;

                  if (data[3])
                    {
                      for (c = 0; c < 3; c++)
                        data[c] = (data[c] + data[3] - 1.0f) / data[3];
                    }

                  data += 4;
                }
            }
        }

      g_object_unref (buffer);
      g_free (pixels);
    }
  else
    {
      /* Free merged image data for layered image */
      if (extra_channels)
        for (cidx = 0; cidx < base_channels; ++cidx)
          g_free (chn_a[cidx].data);
    }

  if (img_a->transparency)
    {
      /* Free "Transparency" channel name */
      if (img_a->alpha_names)
        {
          alpha_name = g_ptr_array_index (img_a->alpha_names, 0);
          if (alpha_name)
            g_free (alpha_name);
        }
    }

  /* ----- Draw extra alpha channels ----- */
  if (extra_channels                   /* Extra alpha channels */
      && image_id > -1)
    {
      IFDBG(2) g_debug ("Add extra channels");
      pixels = g_malloc(0);

      /* Get channel resource data */
      if (img_a->transparency)
        offset = 1;
      else
        offset = 0;

      /* Draw channels */
      IFDBG(2) g_debug ("Number of channels: %d", extra_channels);
      for (i = 0; i < extra_channels; ++i)
        {
          /* Alpha channel name */
          alpha_name = NULL;
          alpha_visible = FALSE;
          /* Quick mask channel*/
          if (img_a->quick_mask_id)
            if (i == img_a->quick_mask_id - base_channels + offset)
              {
                /* Free "Quick Mask" channel name */
                alpha_name = g_ptr_array_index (img_a->alpha_names, i + offset);
                if (alpha_name)
                  g_free (alpha_name);
                alpha_name = g_strdup (GIMP_IMAGE_QUICK_MASK_NAME);
                alpha_visible = TRUE;
              }
          if (! alpha_name && img_a->alpha_names)
            if (offset < img_a->alpha_names->len
                && i + offset <= img_a->alpha_names->len)
              alpha_name = g_ptr_array_index (img_a->alpha_names, i + offset);
          if (! alpha_name)
            alpha_name = g_strdup (_("Extra"));

          if (offset < img_a->alpha_id_count &&
              offset + i <= img_a->alpha_id_count)
            alpha_id = img_a->alpha_id[i + offset];
          else
            alpha_id = 0;
          if (offset < img_a->alpha_display_count &&
              i + offset <= img_a->alpha_display_count)
            {
              alpha_rgb = img_a->alpha_display_info[i + offset]->gimp_color;
              alpha_opacity = img_a->alpha_display_info[i + offset]->opacity;
            }
          else
            {
              gimp_rgba_set (&alpha_rgb, 1.0, 0.0, 0.0, 1.0);
              alpha_opacity = 50;
            }

          cidx = base_channels + i;
          pixels = g_realloc (pixels, chn_a[cidx].columns * chn_a[cidx].rows * bps);
          memcpy (pixels, chn_a[cidx].data, chn_a[cidx].columns * chn_a[cidx].rows * bps);
          channel_id = gimp_channel_new (image_id, alpha_name,
                                         chn_a[cidx].columns, chn_a[cidx].rows,
                                         alpha_opacity, &alpha_rgb);
          gimp_image_insert_channel (image_id, channel_id, -1, i);
          g_free (alpha_name);
          buffer = gimp_drawable_get_buffer (channel_id);
          if (alpha_id)
            gimp_item_set_tattoo (channel_id, alpha_id);
          gimp_item_set_visible (channel_id, alpha_visible);
          gegl_buffer_set (buffer,
                           GEGL_RECTANGLE (0, 0,
                                           gegl_buffer_get_width (buffer),
                                           gegl_buffer_get_height (buffer)),
                           0, get_channel_format (img_a),
                           pixels, GEGL_AUTO_ROWSTRIDE);
          g_object_unref (buffer);
          g_free (chn_a[cidx].data);
        }

      g_free (pixels);
      if (img_a->alpha_names)
        g_ptr_array_free (img_a->alpha_names, TRUE);

      if (img_a->alpha_id)
        g_free (img_a->alpha_id);

      if (img_a->alpha_display_info)
        {
          for (cidx = 0; cidx < img_a->alpha_display_count; ++cidx)
            g_free (img_a->alpha_display_info[cidx]);
          g_free (img_a->alpha_display_info);
        }
    }

  /* FIXME gimp image tattoo state */

  return 0;
}


/* Local utility functions */
static gint32
add_clipping_group (gint32 image_id,
                    gint32 parent_id)
{
  gint32 clipping_group_id = -1;

  /* We need to create a group because GIMP handles clipping and
   * composition mode in a different manner than PS. */
  IFDBG(2) g_debug ("Creating a layer group to handle PS transparency clipping correctly.");

  clipping_group_id = gimp_layer_group_new (image_id);

  gimp_item_set_name (clipping_group_id, "Group added by GIMP");
  gimp_layer_set_blend_space (clipping_group_id, GIMP_LAYER_COLOR_SPACE_RGB_PERCEPTUAL);
  gimp_layer_set_composite_space (clipping_group_id, GIMP_LAYER_COLOR_SPACE_RGB_PERCEPTUAL);
  gimp_layer_set_composite_mode (clipping_group_id, GIMP_LAYER_COMPOSITE_UNION);

  gimp_image_insert_layer (image_id, clipping_group_id, parent_id, 0);

  return clipping_group_id;
}

static gchar *
get_psd_color_mode_name (PSDColorMode mode)
{
  static gchar * const psd_color_mode_names[] =
  {
    "BITMAP",
    "GRAYSCALE",
    "INDEXED",
    "RGB",
    "CMYK",
    "UNKNOWN (5)",
    "UNKNOWN (6)",
    "MULTICHANNEL",
    "DUOTONE",
    "LAB"
  };

  static gchar *err_name = NULL;

  if (mode >= PSD_BITMAP && mode <= PSD_LAB)
    return psd_color_mode_names[mode];

  g_free (err_name);
  err_name = g_strdup_printf ("UNKNOWN (%d)", mode);

  return err_name;
}

static void
psd_to_gimp_color_map (guchar *map256)
{
  guchar *tmpmap;
  gint    i;

  tmpmap = g_malloc (3 * 256);

  for (i = 0; i < 256; ++i)
    {
      tmpmap[i*3  ] = map256[i];
      tmpmap[i*3+1] = map256[i+256];
      tmpmap[i*3+2] = map256[i+512];
    }

  memcpy (map256, tmpmap, 3 * 256);
  g_free (tmpmap);
}

static GimpImageType
get_gimp_image_type (GimpImageBaseType image_base_type,
                     gboolean          alpha)
{
  GimpImageType image_type;

  switch (image_base_type)
    {
    case GIMP_GRAY:
      image_type = (alpha) ? GIMP_GRAYA_IMAGE : GIMP_GRAY_IMAGE;
      break;

    case GIMP_INDEXED:
      image_type = (alpha) ? GIMP_INDEXEDA_IMAGE : GIMP_INDEXED_IMAGE;
      break;

    case GIMP_RGB:
      image_type = (alpha) ? GIMP_RGBA_IMAGE : GIMP_RGB_IMAGE;
      break;

    default:
      image_type = -1;
      break;
    }

  return image_type;
}

static voidpf
zzalloc (voidpf opaque, uInt items, uInt size)
{
  /* overflow check missing */
  return g_malloc (items * size);
}

static void
zzfree (voidpf opaque, voidpf address)
{
  g_free (address);
}

static gint
read_channel_data (PSDchannel     *channel,
                   guint16         bps,
                   guint16         compression,
                   const guint16  *rle_pack_len,
                   FILE           *f,
                   guint32         comp_len,
                   GError        **error)
{
  gchar    *raw_data;
  gchar    *src;
  guint32   readline_len;
  gint      i, j;

  if (bps == 1)
    readline_len = ((channel->columns + 7) / 8);
  else
    readline_len = (channel->columns * bps / 8);

  IFDBG(3) g_debug ("raw data size %d x %d = %d", readline_len,
                    channel->rows, readline_len * channel->rows);

  /* sanity check, int overflow check (avoid divisions by zero) */
  if ((channel->rows == 0) || (channel->columns == 0) ||
      (channel->rows > G_MAXINT32 / channel->columns / MAX (bps / 8, 1)))
    {
      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                   _("Unsupported or invalid channel size"));
      return -1;
    }

  raw_data = g_malloc (readline_len * channel->rows);
  switch (compression)
    {
      case PSD_COMP_RAW:
        if (fread (raw_data, readline_len, channel->rows, f) < 1)
          {
            psd_set_error (feof (f), errno, error);
            return -1;
          }
        break;

      case PSD_COMP_RLE:
        for (i = 0; i < channel->rows; ++i)
          {
            src = gegl_scratch_alloc (rle_pack_len[i]);
/*      FIXME check for over-run
            if (ftell (f) + rle_pack_len[i] > block_end)
              {
                psd_set_error (TRUE, errno, error);
                return -1;
              }
*/
            if (fread (src, rle_pack_len[i], 1, f) < 1)
              {
                psd_set_error (feof (f), errno, error);
                gegl_scratch_free (src);
                return -1;
              }
            /* FIXME check for errors returned from decode packbits */
            decode_packbits (src, raw_data + i * readline_len,
                             rle_pack_len[i], readline_len);
            gegl_scratch_free (src);
          }
        break;
      case PSD_COMP_ZIP:
      case PSD_COMP_ZIP_PRED:
        {
          z_stream zs;

          src = g_malloc (comp_len);
          if (fread (src, comp_len, 1, f) < 1)
            {
              psd_set_error (feof (f), errno, error);
              g_free (src);
              return -1;
            }

          zs.next_in = (guchar*) src;
          zs.avail_in = comp_len;
          zs.next_out = (guchar*) raw_data;
          zs.avail_out = readline_len * channel->rows;
          zs.zalloc = zzalloc;
          zs.zfree = zzfree;

          if (inflateInit (&zs) == Z_OK &&
              inflate (&zs, Z_FINISH) == Z_STREAM_END)
            {
              inflateEnd (&zs);
            }
          else
            {
              g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                           _("Failed to decompress data"));
              g_free (src);
              return -1;
            }

          g_free (src);
          break;
        }
    }

  /* Convert channel data to GIMP format */
  switch (bps)
    {
    case 32:
      {
        guint32 *data = (guint32*) raw_data;

        channel->data = raw_data;
        raw_data      = NULL;

        for (i = 0; i < channel->rows * channel->columns; ++i)
          data[i] = GUINT32_FROM_BE (data[i]);

        if (compression == PSD_COMP_ZIP_PRED)
          {
            for (i = 0; i < channel->rows; ++i)
              for (j = 1; j < channel->columns; ++j)
                data[i * channel->columns + j] += data[i * channel->columns + j - 1];
          }
        break;
      }

    case 16:
      {
        guint16 *data = (guint16*) raw_data;

        channel->data = raw_data;
        raw_data      = NULL;

        for (i = 0; i < channel->rows * channel->columns; ++i)
          data[i] = GUINT16_FROM_BE (data[i]);

        if (compression == PSD_COMP_ZIP_PRED)
          {
            for (i = 0; i < channel->rows; ++i)
              for (j = 1; j < channel->columns; ++j)
                data[i * channel->columns + j] += data[i * channel->columns + j - 1];
          }
        break;
      }

      case 8:
        channel->data = raw_data;
        raw_data      = NULL;

        if (compression == PSD_COMP_ZIP_PRED)
          {
            for (i = 0; i < channel->rows; ++i)
              for (j = 1; j < channel->columns; ++j)
                channel->data[i * channel->columns + j] += channel->data[i * channel->columns + j - 1];
          }
        break;

      case 1:
        channel->data = (gchar *) g_malloc (channel->rows * channel->columns);
        convert_1_bit (raw_data, channel->data, channel->rows, channel->columns);
        break;

      default:
        return -1;
        break;
    }

  g_free (raw_data);

  return 1;
}

static void
convert_1_bit (const gchar *src,
               gchar       *dst,
               guint32      rows,
               guint32      columns)
{
/* Convert bits to bytes left to right by row.
   Rows are padded out to a byte boundary.
*/
  guint32 row_pos = 0;
  gint    i, j;

  IFDBG(3)  g_debug ("Start 1 bit conversion");

  for (i = 0; i < rows * ((columns + 7) / 8); ++i)
    {
      guchar    mask = 0x80;
      for (j = 0; j < 8 && row_pos < columns; ++j)
        {
          *dst = (*src & mask) ? 0 : 1;
          IFDBG(3) g_debug ("byte %d, bit %d, offset %d, src %d, dst %d",
            i , j, row_pos, *src, *dst);
          dst++;
          mask >>= 1;
          row_pos++;
        }
      if (row_pos >= columns)
        row_pos = 0;
      src++;
    }
  IFDBG(3)  g_debug ("End 1 bit conversion");
}

static const Babl*
get_layer_format (PSDimage *img_a,
                  gboolean  alpha)
{
  const Babl *format = NULL;

  switch (get_gimp_image_type (img_a->base_type, alpha))
    {
    case GIMP_GRAY_IMAGE:
      switch (img_a->bps)
        {
        case 32:
          format = babl_format ("Y' u32");
          break;

        case 16:
          format = babl_format ("Y' u16");
          break;

        case 8:
        case 1:
          format = babl_format ("Y' u8");
          break;

        default:
          return NULL;
          break;
        }
      break;

    case GIMP_GRAYA_IMAGE:
      switch (img_a->bps)
        {
        case 32:
          format = babl_format ("Y'A u32");
          break;

        case 16:
          format = babl_format ("Y'A u16");
          break;

        case 8:
        case 1:
          format = babl_format ("Y'A u8");
          break;

        default:
          return NULL;
          break;
        }
      break;

    case GIMP_RGB_IMAGE:
      switch (img_a->bps)
        {
        case 32:
          format = babl_format ("R'G'B' u32");
          break;

        case 16:
          format = babl_format ("R'G'B' u16");
          break;

        case 8:
        case 1:
          format = babl_format (img_a->color_mode == PSD_CMYK ? "R'G'B' float" : "R'G'B' u8");
          break;

        default:
          return NULL;
          break;
        }
      break;

    case GIMP_RGBA_IMAGE:
      switch (img_a->bps)
        {
        case 32:
          format = babl_format ("R'G'B'A u32");
          break;

        case 16:
          format = babl_format ("R'G'B'A u16");
          break;

        case 8:
        case 1:
          format = babl_format (img_a->color_mode == PSD_CMYK ? "R'G'B'A float" : "R'G'B'A u8");
          break;

        default:
          return NULL;
          break;
        }
      break;

    default:
      return NULL;
      break;
    }

  return format;
}

static const Babl*
get_channel_format (PSDimage *img_a)
{
  const Babl *format = NULL;

  switch (img_a->bps)
    {
    case 32:
      format = babl_format ("Y u32");
      break;

    case 16:
      format = babl_format ("Y u16");
      break;

    case 8:
    case 1:
      /* see gimp_image_get_channel_format() */
      format = babl_format ("Y' u8");
      break;

    default:
      break;
    }

  return format;
}

static const Babl*
get_mask_format (PSDimage *img_a)
{
  const Babl *format = NULL;

  switch (img_a->bps)
    {
    case 32:
      format = babl_format ("Y u32");
      break;

    case 16:
      format = babl_format ("Y u16");
      break;

    case 8:
    case 1:
      format = babl_format ("Y u8");
      break;

    default:
      break;
    }

  return format;
}
