tor-browser

pngset.c (62083B)

---

/* pngset.c - storage of image information into info struct
*
* Copyright (c) 2018-2025 Cosmin Truta
* Copyright (c) 1998-2018 Glenn Randers-Pehrson
* Copyright (c) 1996-1997 Andreas Dilger
* Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
* The functions here are used during reads to store data from the file
* into the info struct, and during writes to store application data
* into the info struct for writing into the file.  This abstracts the
* info struct and allows us to change the structure in the future.
*/

#include "pngpriv.h"

#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)

#ifdef PNG_bKGD_SUPPORTED
void PNGAPI
png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_color_16p background)
{
  png_debug1(1, "in %s storage function", "bKGD");

  if (png_ptr == NULL || info_ptr == NULL || background == NULL)
     return;

  info_ptr->background = *background;
  info_ptr->valid |= PNG_INFO_bKGD;
}
#endif

#ifdef PNG_cHRM_SUPPORTED
void PNGFAPI
png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
   png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
   png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
   png_fixed_point blue_x, png_fixed_point blue_y)
{
  png_debug1(1, "in %s storage function", "cHRM fixed");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  info_ptr->cHRM.redx = red_x;
  info_ptr->cHRM.redy = red_y;
  info_ptr->cHRM.greenx = green_x;
  info_ptr->cHRM.greeny = green_y;
  info_ptr->cHRM.bluex = blue_x;
  info_ptr->cHRM.bluey = blue_y;
  info_ptr->cHRM.whitex = white_x;
  info_ptr->cHRM.whitey = white_y;

  info_ptr->valid |= PNG_INFO_cHRM;
}

void PNGFAPI
png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
   png_fixed_point int_red_X, png_fixed_point int_red_Y,
   png_fixed_point int_red_Z, png_fixed_point int_green_X,
   png_fixed_point int_green_Y, png_fixed_point int_green_Z,
   png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
   png_fixed_point int_blue_Z)
{
  png_XYZ XYZ;
  png_xy xy;

  png_debug1(1, "in %s storage function", "cHRM XYZ fixed");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  XYZ.red_X = int_red_X;
  XYZ.red_Y = int_red_Y;
  XYZ.red_Z = int_red_Z;
  XYZ.green_X = int_green_X;
  XYZ.green_Y = int_green_Y;
  XYZ.green_Z = int_green_Z;
  XYZ.blue_X = int_blue_X;
  XYZ.blue_Y = int_blue_Y;
  XYZ.blue_Z = int_blue_Z;

  if (png_xy_from_XYZ(&xy, &XYZ) == 0)
  {
     info_ptr->cHRM = xy;
     info_ptr->valid |= PNG_INFO_cHRM;
  }

  else
     png_app_error(png_ptr, "invalid cHRM XYZ");
}

#  ifdef PNG_FLOATING_POINT_SUPPORTED
void PNGAPI
png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
   double white_x, double white_y, double red_x, double red_y,
   double green_x, double green_y, double blue_x, double blue_y)
{
  png_set_cHRM_fixed(png_ptr, info_ptr,
      png_fixed(png_ptr, white_x, "cHRM White X"),
      png_fixed(png_ptr, white_y, "cHRM White Y"),
      png_fixed(png_ptr, red_x, "cHRM Red X"),
      png_fixed(png_ptr, red_y, "cHRM Red Y"),
      png_fixed(png_ptr, green_x, "cHRM Green X"),
      png_fixed(png_ptr, green_y, "cHRM Green Y"),
      png_fixed(png_ptr, blue_x, "cHRM Blue X"),
      png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
}

void PNGAPI
png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
   double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
   double blue_X, double blue_Y, double blue_Z)
{
  png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
      png_fixed(png_ptr, red_X, "cHRM Red X"),
      png_fixed(png_ptr, red_Y, "cHRM Red Y"),
      png_fixed(png_ptr, red_Z, "cHRM Red Z"),
      png_fixed(png_ptr, green_X, "cHRM Green X"),
      png_fixed(png_ptr, green_Y, "cHRM Green Y"),
      png_fixed(png_ptr, green_Z, "cHRM Green Z"),
      png_fixed(png_ptr, blue_X, "cHRM Blue X"),
      png_fixed(png_ptr, blue_Y, "cHRM Blue Y"),
      png_fixed(png_ptr, blue_Z, "cHRM Blue Z"));
}
#  endif /* FLOATING_POINT */

#endif /* cHRM */

#ifdef PNG_cICP_SUPPORTED
void PNGAPI
png_set_cICP(png_const_structrp png_ptr, png_inforp info_ptr,
            png_byte colour_primaries, png_byte transfer_function,
            png_byte matrix_coefficients, png_byte video_full_range_flag)
{
  png_debug1(1, "in %s storage function", "cICP");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  info_ptr->cicp_colour_primaries = colour_primaries;
  info_ptr->cicp_transfer_function = transfer_function;
  info_ptr->cicp_matrix_coefficients = matrix_coefficients;
  info_ptr->cicp_video_full_range_flag = video_full_range_flag;

  if (info_ptr->cicp_matrix_coefficients != 0)
  {
     png_warning(png_ptr, "Invalid cICP matrix coefficients");
     return;
  }

  info_ptr->valid |= PNG_INFO_cICP;
}
#endif /* cICP */

#ifdef PNG_cLLI_SUPPORTED
void PNGFAPI
png_set_cLLI_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
   /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
    * 100,000 as in the case of png_fixed_point.
    */
   png_uint_32 maxCLL, png_uint_32 maxFALL)
{
  png_debug1(1, "in %s storage function", "cLLI");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  /* Check the light level range: */
  if (maxCLL > 0x7FFFFFFFU || maxFALL > 0x7FFFFFFFU)
  {
     /* The limit is 200kcd/m2; somewhat bright but not inconceivable because
      * human vision is said to run up to 100Mcd/m2.  The sun is about 2Gcd/m2.
      *
      * The reference sRGB monitor is 80cd/m2 and the limit of PQ encoding is
      * 2kcd/m2.
      */
     png_chunk_report(png_ptr, "cLLI light level exceeds PNG limit",
           PNG_CHUNK_WRITE_ERROR);
     return;
  }

  info_ptr->maxCLL = maxCLL;
  info_ptr->maxFALL = maxFALL;
  info_ptr->valid |= PNG_INFO_cLLI;
}

#  ifdef PNG_FLOATING_POINT_SUPPORTED
void PNGAPI
png_set_cLLI(png_const_structrp png_ptr, png_inforp info_ptr,
  double maxCLL, double maxFALL)
{
  png_set_cLLI_fixed(png_ptr, info_ptr,
      png_fixed_ITU(png_ptr, maxCLL, "png_set_cLLI(maxCLL)"),
      png_fixed_ITU(png_ptr, maxFALL, "png_set_cLLI(maxFALL)"));
}
#  endif /* FLOATING_POINT */
#endif /* cLLI */

#ifdef PNG_mDCV_SUPPORTED
static png_uint_16
png_ITU_fixed_16(int *error, png_fixed_point v)
{
  /* Return a safe uint16_t value scaled according to the ITU H273 rules for
   * 16-bit display chromaticities.  Functions like the corresponding
   * png_fixed() internal function with regard to errors: it's an error on
   * write, a chunk_benign_error on read: See the definition of
   * png_chunk_report in pngpriv.h.
   */
  v /= 2; /* rounds to 0 in C: avoids insignificant arithmetic errors */
  if (v > 65535 || v < 0)
  {
     *error = 1;
     return 0;
  }

  return (png_uint_16)/*SAFE*/v;
}

void PNGAPI
png_set_mDCV_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
   png_fixed_point white_x, png_fixed_point white_y,
   png_fixed_point red_x, png_fixed_point red_y,
   png_fixed_point green_x, png_fixed_point green_y,
   png_fixed_point blue_x, png_fixed_point blue_y,
   png_uint_32 maxDL,
   png_uint_32 minDL)
{
  png_uint_16 rx, ry, gx, gy, bx, by, wx, wy;
  int error;

  png_debug1(1, "in %s storage function", "mDCV");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  /* Check the input values to ensure they are in the expected range: */
  error = 0;
  rx = png_ITU_fixed_16(&error, red_x);
  ry = png_ITU_fixed_16(&error, red_y);
  gx = png_ITU_fixed_16(&error, green_x);
  gy = png_ITU_fixed_16(&error, green_y);
  bx = png_ITU_fixed_16(&error, blue_x);
  by = png_ITU_fixed_16(&error, blue_y);
  wx = png_ITU_fixed_16(&error, white_x);
  wy = png_ITU_fixed_16(&error, white_y);

  if (error)
  {
     png_chunk_report(png_ptr,
        "mDCV chromaticities outside representable range",
        PNG_CHUNK_WRITE_ERROR);
     return;
  }

  /* Check the light level range: */
  if (maxDL > 0x7FFFFFFFU || minDL > 0x7FFFFFFFU)
  {
     /* The limit is 200kcd/m2; somewhat bright but not inconceivable because
      * human vision is said to run up to 100Mcd/m2.  The sun is about 2Gcd/m2.
      *
      * The reference sRGB monitor is 80cd/m2 and the limit of PQ encoding is
      * 2kcd/m2.
      */
     png_chunk_report(png_ptr, "mDCV display light level exceeds PNG limit",
           PNG_CHUNK_WRITE_ERROR);
     return;
  }

  /* All values are safe, the settings are accepted.
   *
   * IMPLEMENTATION NOTE: in practice the values can be checked and assigned
   * but the result is confusing if a writing app calls png_set_mDCV more than
   * once, the second time with an invalid value.  This approach is more
   * obviously correct at the cost of typing and a very slight machine
   * overhead.
   */
  info_ptr->mastering_red_x = rx;
  info_ptr->mastering_red_y = ry;
  info_ptr->mastering_green_x = gx;
  info_ptr->mastering_green_y = gy;
  info_ptr->mastering_blue_x = bx;
  info_ptr->mastering_blue_y = by;
  info_ptr->mastering_white_x = wx;
  info_ptr->mastering_white_y = wy;
  info_ptr->mastering_maxDL = maxDL;
  info_ptr->mastering_minDL = minDL;
  info_ptr->valid |= PNG_INFO_mDCV;
}

#  ifdef PNG_FLOATING_POINT_SUPPORTED
void PNGAPI
png_set_mDCV(png_const_structrp png_ptr, png_inforp info_ptr,
   double white_x, double white_y, double red_x, double red_y, double green_x,
   double green_y, double blue_x, double blue_y,
   double maxDL, double minDL)
{
  png_set_mDCV_fixed(png_ptr, info_ptr,
     png_fixed(png_ptr, white_x, "png_set_mDCV(white(x))"),
     png_fixed(png_ptr, white_y, "png_set_mDCV(white(y))"),
     png_fixed(png_ptr, red_x, "png_set_mDCV(red(x))"),
     png_fixed(png_ptr, red_y, "png_set_mDCV(red(y))"),
     png_fixed(png_ptr, green_x, "png_set_mDCV(green(x))"),
     png_fixed(png_ptr, green_y, "png_set_mDCV(green(y))"),
     png_fixed(png_ptr, blue_x, "png_set_mDCV(blue(x))"),
     png_fixed(png_ptr, blue_y, "png_set_mDCV(blue(y))"),
     png_fixed_ITU(png_ptr, maxDL, "png_set_mDCV(maxDL)"),
     png_fixed_ITU(png_ptr, minDL, "png_set_mDCV(minDL)"));
}
#  endif /* FLOATING_POINT */
#endif /* mDCV */

#ifdef PNG_eXIf_SUPPORTED
void PNGAPI
png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
   png_bytep exif)
{
 png_warning(png_ptr, "png_set_eXIf does not work; use png_set_eXIf_1");
 PNG_UNUSED(info_ptr)
 PNG_UNUSED(exif)
}

void PNGAPI
png_set_eXIf_1(png_const_structrp png_ptr, png_inforp info_ptr,
   png_uint_32 num_exif, png_bytep exif)
{
  png_bytep new_exif;

  png_debug1(1, "in %s storage function", "eXIf");

  if (png_ptr == NULL || info_ptr == NULL ||
      (png_ptr->mode & PNG_WROTE_eXIf) != 0)
     return;

  new_exif = png_voidcast(png_bytep, png_malloc_warn(png_ptr, num_exif));

  if (new_exif == NULL)
  {
     png_warning(png_ptr, "Insufficient memory for eXIf chunk data");
     return;
  }

  memcpy(new_exif, exif, (size_t)num_exif);

  png_free_data(png_ptr, info_ptr, PNG_FREE_EXIF, 0);

  info_ptr->num_exif = num_exif;
  info_ptr->exif = new_exif;
  info_ptr->free_me |= PNG_FREE_EXIF;
  info_ptr->valid |= PNG_INFO_eXIf;
}
#endif /* eXIf */

#ifdef PNG_gAMA_SUPPORTED
void PNGFAPI
png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
   png_fixed_point file_gamma)
{
  png_debug1(1, "in %s storage function", "gAMA");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  info_ptr->gamma = file_gamma;
  info_ptr->valid |= PNG_INFO_gAMA;
}

#  ifdef PNG_FLOATING_POINT_SUPPORTED
void PNGAPI
png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma)
{
  png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma,
      "png_set_gAMA"));
}
#  endif
#endif

#ifdef PNG_hIST_SUPPORTED
void PNGAPI
png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_uint_16p hist)
{
  int i;

  png_debug1(1, "in %s storage function", "hIST");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  if (info_ptr->num_palette == 0 || info_ptr->num_palette
      > PNG_MAX_PALETTE_LENGTH)
  {
     png_warning(png_ptr,
         "Invalid palette size, hIST allocation skipped");

     return;
  }

  png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);

  /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
   * version 1.2.1
   */
  info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
      PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));

  if (info_ptr->hist == NULL)
  {
     png_warning(png_ptr, "Insufficient memory for hIST chunk data");
     return;
  }

  for (i = 0; i < info_ptr->num_palette; i++)
     info_ptr->hist[i] = hist[i];

  info_ptr->free_me |= PNG_FREE_HIST;
  info_ptr->valid |= PNG_INFO_hIST;
}
#endif

void PNGAPI
png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
   png_uint_32 width, png_uint_32 height, int bit_depth,
   int color_type, int interlace_type, int compression_type,
   int filter_type)
{
  png_debug1(1, "in %s storage function", "IHDR");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  info_ptr->width = width;
  info_ptr->height = height;
  info_ptr->bit_depth = (png_byte)bit_depth;
  info_ptr->color_type = (png_byte)color_type;
  info_ptr->compression_type = (png_byte)compression_type;
  info_ptr->filter_type = (png_byte)filter_type;
  info_ptr->interlace_type = (png_byte)interlace_type;

  png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
      info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
      info_ptr->compression_type, info_ptr->filter_type);

  if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
     info_ptr->channels = 1;

  else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
     info_ptr->channels = 3;

  else
     info_ptr->channels = 1;

  if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
     info_ptr->channels++;

  info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);

  info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);

#ifdef PNG_APNG_SUPPORTED
  /* for non-animated png. this may be overwritten from an acTL chunk later */
  info_ptr->num_frames = 1;
#endif
}

#ifdef PNG_oFFs_SUPPORTED
void PNGAPI
png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr,
   png_int_32 offset_x, png_int_32 offset_y, int unit_type)
{
  png_debug1(1, "in %s storage function", "oFFs");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  info_ptr->x_offset = offset_x;
  info_ptr->y_offset = offset_y;
  info_ptr->offset_unit_type = (png_byte)unit_type;
  info_ptr->valid |= PNG_INFO_oFFs;
}
#endif

#ifdef PNG_pCAL_SUPPORTED
void PNGAPI
png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
   int nparams, png_const_charp units, png_charpp params)
{
  size_t length;
  int i;

  png_debug1(1, "in %s storage function", "pCAL");

  if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
      || (nparams > 0 && params == NULL))
     return;

  length = strlen(purpose) + 1;
  png_debug1(3, "allocating purpose for info (%lu bytes)",
      (unsigned long)length);

  /* TODO: validate format of calibration name and unit name */

  /* Check that the type matches the specification. */
  if (type < 0 || type > 3)
  {
     png_chunk_report(png_ptr, "Invalid pCAL equation type",
           PNG_CHUNK_WRITE_ERROR);
     return;
  }

  if (nparams < 0 || nparams > 255)
  {
     png_chunk_report(png_ptr, "Invalid pCAL parameter count",
           PNG_CHUNK_WRITE_ERROR);
     return;
  }

  /* Validate params[nparams] */
  for (i=0; i<nparams; ++i)
  {
     if (params[i] == NULL ||
         !png_check_fp_string(params[i], strlen(params[i])))
     {
        png_chunk_report(png_ptr, "Invalid format for pCAL parameter",
              PNG_CHUNK_WRITE_ERROR);
        return;
     }
  }

  info_ptr->pcal_purpose = png_voidcast(png_charp,
      png_malloc_warn(png_ptr, length));

  if (info_ptr->pcal_purpose == NULL)
  {
     png_chunk_report(png_ptr, "Insufficient memory for pCAL purpose",
           PNG_CHUNK_WRITE_ERROR);
     return;
  }

  memcpy(info_ptr->pcal_purpose, purpose, length);

  info_ptr->free_me |= PNG_FREE_PCAL;

  png_debug(3, "storing X0, X1, type, and nparams in info");
  info_ptr->pcal_X0 = X0;
  info_ptr->pcal_X1 = X1;
  info_ptr->pcal_type = (png_byte)type;
  info_ptr->pcal_nparams = (png_byte)nparams;

  length = strlen(units) + 1;
  png_debug1(3, "allocating units for info (%lu bytes)",
      (unsigned long)length);

  info_ptr->pcal_units = png_voidcast(png_charp,
      png_malloc_warn(png_ptr, length));

  if (info_ptr->pcal_units == NULL)
  {
     png_warning(png_ptr, "Insufficient memory for pCAL units");
     return;
  }

  memcpy(info_ptr->pcal_units, units, length);

  info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
      (size_t)(((unsigned int)nparams + 1) * (sizeof (png_charp)))));

  if (info_ptr->pcal_params == NULL)
  {
     png_warning(png_ptr, "Insufficient memory for pCAL params");
     return;
  }

  memset(info_ptr->pcal_params, 0, ((unsigned int)nparams + 1) *
      (sizeof (png_charp)));

  for (i = 0; i < nparams; i++)
  {
     length = strlen(params[i]) + 1;
     png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
         (unsigned long)length);

     info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);

     if (info_ptr->pcal_params[i] == NULL)
     {
        png_warning(png_ptr, "Insufficient memory for pCAL parameter");
        return;
     }

     memcpy(info_ptr->pcal_params[i], params[i], length);
  }

  info_ptr->valid |= PNG_INFO_pCAL;
}
#endif

#ifdef PNG_sCAL_SUPPORTED
void PNGAPI
png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
   int unit, png_const_charp swidth, png_const_charp sheight)
{
  size_t lengthw = 0, lengthh = 0;

  png_debug1(1, "in %s storage function", "sCAL");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  /* Double check the unit (should never get here with an invalid
   * unit unless this is an API call.)
   */
  if (unit != 1 && unit != 2)
     png_error(png_ptr, "Invalid sCAL unit");

  if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
      swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
     png_error(png_ptr, "Invalid sCAL width");

  if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
      sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
     png_error(png_ptr, "Invalid sCAL height");

  info_ptr->scal_unit = (png_byte)unit;

  ++lengthw;

  png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);

  info_ptr->scal_s_width = png_voidcast(png_charp,
      png_malloc_warn(png_ptr, lengthw));

  if (info_ptr->scal_s_width == NULL)
  {
     png_warning(png_ptr, "Memory allocation failed while processing sCAL");

     return;
  }

  memcpy(info_ptr->scal_s_width, swidth, lengthw);

  ++lengthh;

  png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);

  info_ptr->scal_s_height = png_voidcast(png_charp,
      png_malloc_warn(png_ptr, lengthh));

  if (info_ptr->scal_s_height == NULL)
  {
     png_free(png_ptr, info_ptr->scal_s_width);
     info_ptr->scal_s_width = NULL;

     png_warning(png_ptr, "Memory allocation failed while processing sCAL");
     return;
  }

  memcpy(info_ptr->scal_s_height, sheight, lengthh);

  info_ptr->free_me |= PNG_FREE_SCAL;
  info_ptr->valid |= PNG_INFO_sCAL;
}

#  ifdef PNG_FLOATING_POINT_SUPPORTED
void PNGAPI
png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
   double width, double height)
{
  png_debug1(1, "in %s storage function", "sCAL");

  /* Check the arguments. */
  if (width <= 0)
     png_warning(png_ptr, "Invalid sCAL width ignored");

  else if (height <= 0)
     png_warning(png_ptr, "Invalid sCAL height ignored");

  else
  {
     /* Convert 'width' and 'height' to ASCII. */
     char swidth[PNG_sCAL_MAX_DIGITS+1];
     char sheight[PNG_sCAL_MAX_DIGITS+1];

     png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
         PNG_sCAL_PRECISION);
     png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
         PNG_sCAL_PRECISION);

     png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
  }
}
#  endif

#  ifdef PNG_FIXED_POINT_SUPPORTED
void PNGAPI
png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
   png_fixed_point width, png_fixed_point height)
{
  png_debug1(1, "in %s storage function", "sCAL");

  /* Check the arguments. */
  if (width <= 0)
     png_warning(png_ptr, "Invalid sCAL width ignored");

  else if (height <= 0)
     png_warning(png_ptr, "Invalid sCAL height ignored");

  else
  {
     /* Convert 'width' and 'height' to ASCII. */
     char swidth[PNG_sCAL_MAX_DIGITS+1];
     char sheight[PNG_sCAL_MAX_DIGITS+1];

     png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
     png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);

     png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
  }
}
#  endif
#endif

#ifdef PNG_pHYs_SUPPORTED
void PNGAPI
png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr,
   png_uint_32 res_x, png_uint_32 res_y, int unit_type)
{
  png_debug1(1, "in %s storage function", "pHYs");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  info_ptr->x_pixels_per_unit = res_x;
  info_ptr->y_pixels_per_unit = res_y;
  info_ptr->phys_unit_type = (png_byte)unit_type;
  info_ptr->valid |= PNG_INFO_pHYs;
}
#endif

void PNGAPI
png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
   png_const_colorp palette, int num_palette)
{

  png_uint_32 max_palette_length;

  png_debug1(1, "in %s storage function", "PLTE");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
     (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;

  if (num_palette < 0 || num_palette > (int) max_palette_length)
  {
     if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
        png_error(png_ptr, "Invalid palette length");

     else
     {
        png_warning(png_ptr, "Invalid palette length");

        return;
     }
  }

  if ((num_palette > 0 && palette == NULL) ||
     (num_palette == 0
#        ifdef PNG_MNG_FEATURES_SUPPORTED
           && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
#        endif
     ))
  {
     png_error(png_ptr, "Invalid palette");
  }

  /* It may not actually be necessary to set png_ptr->palette here;
   * we do it for backward compatibility with the way the png_handle_tRNS
   * function used to do the allocation.
   *
   * 1.6.0: the above statement appears to be incorrect; something has to set
   * the palette inside png_struct on read.
   */
  png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);

  /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
   * of num_palette entries, in case of an invalid PNG file or incorrect
   * call to png_set_PLTE() with too-large sample values.
   */
  png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
      PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));

  if (num_palette > 0)
     memcpy(png_ptr->palette, palette, (unsigned int)num_palette *
         (sizeof (png_color)));

  info_ptr->palette = png_ptr->palette;
  info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
  info_ptr->free_me |= PNG_FREE_PLTE;
  info_ptr->valid |= PNG_INFO_PLTE;
}

#ifdef PNG_sBIT_SUPPORTED
void PNGAPI
png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_color_8p sig_bit)
{
  png_debug1(1, "in %s storage function", "sBIT");

  if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL)
     return;

  info_ptr->sig_bit = *sig_bit;
  info_ptr->valid |= PNG_INFO_sBIT;
}
#endif

#ifdef PNG_sRGB_SUPPORTED
void PNGAPI
png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
{
  png_debug1(1, "in %s storage function", "sRGB");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  info_ptr->rendering_intent = srgb_intent;
  info_ptr->valid |= PNG_INFO_sRGB;
}

void PNGAPI
png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
   int srgb_intent)
{
  png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  png_set_sRGB(png_ptr, info_ptr, srgb_intent);

#  ifdef PNG_gAMA_SUPPORTED
     png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
#  endif /* gAMA */

#  ifdef PNG_cHRM_SUPPORTED
     png_set_cHRM_fixed(png_ptr, info_ptr,
        /* color      x       y */
        /* white */ 31270, 32900,
        /* red   */ 64000, 33000,
        /* green */ 30000, 60000,
        /* blue  */ 15000,  6000);
#  endif /* cHRM */
}
#endif /* sRGB */


#ifdef PNG_iCCP_SUPPORTED
void PNGAPI
png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_charp name, int compression_type,
   png_const_bytep profile, png_uint_32 proflen)
{
  png_charp new_iccp_name;
  png_bytep new_iccp_profile;
  size_t length;

  png_debug1(1, "in %s storage function", "iCCP");

  if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
     return;

  if (compression_type != PNG_COMPRESSION_TYPE_BASE)
     png_app_error(png_ptr, "Invalid iCCP compression method");

  length = strlen(name)+1;
  new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));

  if (new_iccp_name == NULL)
  {
     png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");

     return;
  }

  memcpy(new_iccp_name, name, length);
  new_iccp_profile = png_voidcast(png_bytep,
      png_malloc_warn(png_ptr, proflen));

  if (new_iccp_profile == NULL)
  {
     png_free(png_ptr, new_iccp_name);
     png_benign_error(png_ptr,
         "Insufficient memory to process iCCP profile");

     return;
  }

  memcpy(new_iccp_profile, profile, proflen);

  png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);

  info_ptr->iccp_proflen = proflen;
  info_ptr->iccp_name = new_iccp_name;
  info_ptr->iccp_profile = new_iccp_profile;
  info_ptr->free_me |= PNG_FREE_ICCP;
  info_ptr->valid |= PNG_INFO_iCCP;
}
#endif

#ifdef PNG_TEXT_SUPPORTED
void PNGAPI
png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_textp text_ptr, int num_text)
{
  int ret;
  ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);

  if (ret != 0)
     png_error(png_ptr, "Insufficient memory to store text");
}

int /* PRIVATE */
png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_textp text_ptr, int num_text)
{
  int i;

  png_debug1(1, "in text storage function, chunk typeid = 0x%lx",
     png_ptr == NULL ? 0xabadca11UL : (unsigned long)png_ptr->chunk_name);

  if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
     return 0;

  /* Make sure we have enough space in the "text" array in info_struct
   * to hold all of the incoming text_ptr objects.  This compare can't overflow
   * because max_text >= num_text (anyway, subtract of two positive integers
   * can't overflow in any case.)
   */
  if (num_text > info_ptr->max_text - info_ptr->num_text)
  {
     int old_num_text = info_ptr->num_text;
     int max_text;
     png_textp new_text = NULL;

     /* Calculate an appropriate max_text, checking for overflow. */
     max_text = old_num_text;
     if (num_text <= INT_MAX - max_text)
     {
        max_text += num_text;

        /* Round up to a multiple of 8 */
        if (max_text < INT_MAX-8)
           max_text = (max_text + 8) & ~0x7;

        else
           max_text = INT_MAX;

        /* Now allocate a new array and copy the old members in; this does all
         * the overflow checks.
         */
        new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
            info_ptr->text, old_num_text, max_text-old_num_text,
            sizeof *new_text));
     }

     if (new_text == NULL)
     {
        png_chunk_report(png_ptr, "too many text chunks",
            PNG_CHUNK_WRITE_ERROR);

        return 1;
     }

     png_free(png_ptr, info_ptr->text);

     info_ptr->text = new_text;
     info_ptr->free_me |= PNG_FREE_TEXT;
     info_ptr->max_text = max_text;
     /* num_text is adjusted below as the entries are copied in */

     png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
  }

  for (i = 0; i < num_text; i++)
  {
     size_t text_length, key_len;
     size_t lang_len, lang_key_len;
     png_textp textp = &(info_ptr->text[info_ptr->num_text]);

     if (text_ptr[i].key == NULL)
         continue;

     if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
         text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
     {
        png_chunk_report(png_ptr, "text compression mode is out of range",
            PNG_CHUNK_WRITE_ERROR);
        continue;
     }

     key_len = strlen(text_ptr[i].key);

     if (text_ptr[i].compression <= 0)
     {
        lang_len = 0;
        lang_key_len = 0;
     }

     else
#  ifdef PNG_iTXt_SUPPORTED
     {
        /* Set iTXt data */

        if (text_ptr[i].lang != NULL)
           lang_len = strlen(text_ptr[i].lang);

        else
           lang_len = 0;

        if (text_ptr[i].lang_key != NULL)
           lang_key_len = strlen(text_ptr[i].lang_key);

        else
           lang_key_len = 0;
     }
#  else /* iTXt */
     {
        png_chunk_report(png_ptr, "iTXt chunk not supported",
            PNG_CHUNK_WRITE_ERROR);
        continue;
     }
#  endif

     if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
     {
        text_length = 0;
#  ifdef PNG_iTXt_SUPPORTED
        if (text_ptr[i].compression > 0)
           textp->compression = PNG_ITXT_COMPRESSION_NONE;

        else
#  endif
           textp->compression = PNG_TEXT_COMPRESSION_NONE;
     }

     else
     {
        text_length = strlen(text_ptr[i].text);
        textp->compression = text_ptr[i].compression;
     }

     textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
         key_len + text_length + lang_len + lang_key_len + 4));

     if (textp->key == NULL)
     {
        png_chunk_report(png_ptr, "text chunk: out of memory",
            PNG_CHUNK_WRITE_ERROR);

        return 1;
     }

     png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
         (unsigned long)(png_uint_32)
         (key_len + lang_len + lang_key_len + text_length + 4),
         textp->key);

     memcpy(textp->key, text_ptr[i].key, key_len);
     *(textp->key + key_len) = '\0';

     if (text_ptr[i].compression > 0)
     {
        textp->lang = textp->key + key_len + 1;
        memcpy(textp->lang, text_ptr[i].lang, lang_len);
        *(textp->lang + lang_len) = '\0';
        textp->lang_key = textp->lang + lang_len + 1;
        memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
        *(textp->lang_key + lang_key_len) = '\0';
        textp->text = textp->lang_key + lang_key_len + 1;
     }

     else
     {
        textp->lang=NULL;
        textp->lang_key=NULL;
        textp->text = textp->key + key_len + 1;
     }

     if (text_length != 0)
        memcpy(textp->text, text_ptr[i].text, text_length);

     *(textp->text + text_length) = '\0';

#  ifdef PNG_iTXt_SUPPORTED
     if (textp->compression > 0)
     {
        textp->text_length = 0;
        textp->itxt_length = text_length;
     }

     else
#  endif
     {
        textp->text_length = text_length;
        textp->itxt_length = 0;
     }

     info_ptr->num_text++;
     png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
  }

  return 0;
}
#endif

#ifdef PNG_tIME_SUPPORTED
void PNGAPI
png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
   png_const_timep mod_time)
{
  png_debug1(1, "in %s storage function", "tIME");

  if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
      (png_ptr->mode & PNG_WROTE_tIME) != 0)
     return;

  if (mod_time->month == 0   || mod_time->month > 12  ||
      mod_time->day   == 0   || mod_time->day   > 31  ||
      mod_time->hour  > 23   || mod_time->minute > 59 ||
      mod_time->second > 60)
  {
     png_warning(png_ptr, "Ignoring invalid time value");

     return;
  }

  info_ptr->mod_time = *mod_time;
  info_ptr->valid |= PNG_INFO_tIME;
}
#endif

#ifdef PNG_tRNS_SUPPORTED
void PNGAPI
png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
   png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
{
  png_debug1(1, "in %s storage function", "tRNS");

  if (png_ptr == NULL || info_ptr == NULL)

     return;

  if (trans_alpha != NULL)
  {
      /* It may not actually be necessary to set png_ptr->trans_alpha here;
       * we do it for backward compatibility with the way the png_handle_tRNS
       * function used to do the allocation.
       *
       * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
       * relies on png_set_tRNS storing the information in png_struct
       * (otherwise it won't be there for the code in pngrtran.c).
       */

      png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);

      if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
      {
        /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
         info_ptr->trans_alpha = png_voidcast(png_bytep,
             png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
         memcpy(info_ptr->trans_alpha, trans_alpha, (size_t)num_trans);

         info_ptr->free_me |= PNG_FREE_TRNS;
         info_ptr->valid |= PNG_INFO_tRNS;
      }
      png_ptr->trans_alpha = info_ptr->trans_alpha;
  }

  if (trans_color != NULL)
  {
#ifdef PNG_WARNINGS_SUPPORTED
     if (info_ptr->bit_depth < 16)
     {
        int sample_max = (1 << info_ptr->bit_depth) - 1;

        if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
            trans_color->gray > sample_max) ||
            (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
            (trans_color->red > sample_max ||
            trans_color->green > sample_max ||
            trans_color->blue > sample_max)))
           png_warning(png_ptr,
               "tRNS chunk has out-of-range samples for bit_depth");
     }
#endif

     info_ptr->trans_color = *trans_color;

     if (num_trans == 0)
        num_trans = 1;
  }

  info_ptr->num_trans = (png_uint_16)num_trans;

  if (num_trans != 0)
  {
     info_ptr->free_me |= PNG_FREE_TRNS;
     info_ptr->valid |= PNG_INFO_tRNS;
  }
}
#endif

#ifdef PNG_sPLT_SUPPORTED
void PNGAPI
png_set_sPLT(png_const_structrp png_ptr,
   png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
/*
*  entries        - array of png_sPLT_t structures
*                   to be added to the list of palettes
*                   in the info structure.
*
*  nentries       - number of palette structures to be
*                   added.
*/
{
  png_sPLT_tp np;

  png_debug1(1, "in %s storage function", "sPLT");

  if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
     return;

  /* Use the internal realloc function, which checks for all the possible
   * overflows.  Notice that the parameters are (int) and (size_t)
   */
  np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
      info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
      sizeof *np));

  if (np == NULL)
  {
     /* Out of memory or too many chunks */
     png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
     return;
  }

  png_free(png_ptr, info_ptr->splt_palettes);

  info_ptr->splt_palettes = np;
  info_ptr->free_me |= PNG_FREE_SPLT;

  np += info_ptr->splt_palettes_num;

  do
  {
     size_t length;

     /* Skip invalid input entries */
     if (entries->name == NULL || entries->entries == NULL)
     {
        /* png_handle_sPLT doesn't do this, so this is an app error */
        png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
        /* Just skip the invalid entry */
        continue;
     }

     np->depth = entries->depth;

     /* In the event of out-of-memory just return - there's no point keeping
      * on trying to add sPLT chunks.
      */
     length = strlen(entries->name) + 1;
     np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));

     if (np->name == NULL)
        break;

     memcpy(np->name, entries->name, length);

     /* IMPORTANT: we have memory now that won't get freed if something else
      * goes wrong; this code must free it.  png_malloc_array produces no
      * warnings; use a png_chunk_report (below) if there is an error.
      */
     np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
         entries->nentries, sizeof (png_sPLT_entry)));

     if (np->entries == NULL)
     {
        png_free(png_ptr, np->name);
        np->name = NULL;
        break;
     }

     np->nentries = entries->nentries;
     /* This multiply can't overflow because png_malloc_array has already
      * checked it when doing the allocation.
      */
     memcpy(np->entries, entries->entries,
         (unsigned int)entries->nentries * sizeof (png_sPLT_entry));

     /* Note that 'continue' skips the advance of the out pointer and out
      * count, so an invalid entry is not added.
      */
     info_ptr->valid |= PNG_INFO_sPLT;
     ++(info_ptr->splt_palettes_num);
     ++np;
     ++entries;
  }
  while (--nentries);

  if (nentries > 0)
     png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
}
#endif /* sPLT */

#ifdef PNG_APNG_SUPPORTED
png_uint_32 PNGAPI
png_set_acTL(png_structp png_ptr, png_infop info_ptr,
   png_uint_32 num_frames, png_uint_32 num_plays)
{
   png_debug1(1, "in %s storage function", "acTL");

   if (png_ptr == NULL || info_ptr == NULL)
   {
       png_warning(png_ptr,
                   "Call to png_set_acTL() with NULL png_ptr "
                   "or info_ptr ignored");
       return (0);
   }
   if (num_frames == 0)
   {
       png_warning(png_ptr,
                   "Ignoring attempt to set acTL with num_frames zero");
       return (0);
   }
   if (num_frames > PNG_UINT_31_MAX)
   {
       png_warning(png_ptr,
                   "Ignoring attempt to set acTL with num_frames > 2^31-1");
       return (0);
   }
   if (num_plays > PNG_UINT_31_MAX)
   {
       png_warning(png_ptr,
                   "Ignoring attempt to set acTL with num_plays > 2^31-1");
       return (0);
   }

   info_ptr->num_frames = num_frames;
   info_ptr->num_plays = num_plays;

   info_ptr->valid |= PNG_INFO_acTL;

   return (1);
}

/* delay_num and delay_den can hold any 16-bit values including zero */
png_uint_32 PNGAPI
png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
   png_uint_32 width, png_uint_32 height,
   png_uint_32 x_offset, png_uint_32 y_offset,
   png_uint_16 delay_num, png_uint_16 delay_den,
   png_byte dispose_op, png_byte blend_op)
{
   png_debug1(1, "in %s storage function", "fcTL");

   if (png_ptr == NULL || info_ptr == NULL)
   {
       png_warning(png_ptr,
                   "Call to png_set_fcTL() with NULL png_ptr or info_ptr "
                   "ignored");
       return (0);
   }

   png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset,
                            delay_num, delay_den, dispose_op, blend_op);

   if (blend_op == PNG_BLEND_OP_OVER)
   {
       if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0 &&
           png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) == 0)
       {
         png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless "
                              "and wasteful for opaque images, ignored");
         blend_op = PNG_BLEND_OP_SOURCE;
       }
   }

   info_ptr->next_frame_width = width;
   info_ptr->next_frame_height = height;
   info_ptr->next_frame_x_offset = x_offset;
   info_ptr->next_frame_y_offset = y_offset;
   info_ptr->next_frame_delay_num = delay_num;
   info_ptr->next_frame_delay_den = delay_den;
   info_ptr->next_frame_dispose_op = dispose_op;
   info_ptr->next_frame_blend_op = blend_op;

   info_ptr->valid |= PNG_INFO_fcTL;

   return (1);
}

void /* PRIVATE */
png_ensure_fcTL_is_valid(png_structp png_ptr,
   png_uint_32 width, png_uint_32 height,
   png_uint_32 x_offset, png_uint_32 y_offset,
   png_uint_16 delay_num, png_uint_16 delay_den,
   png_byte dispose_op, png_byte blend_op)
{
   if (width == 0 || width > PNG_UINT_31_MAX)
       png_error(png_ptr, "invalid width in fcTL (0 or > 2^31-1)");
   if (height == 0 || height > PNG_UINT_31_MAX)
       png_error(png_ptr, "invalid height in fcTL (0 or > 2^31-1)");
   if (x_offset > PNG_UINT_31_MAX)
       png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)");
   if (y_offset > PNG_UINT_31_MAX)
       png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)");
   if (width + x_offset > png_ptr->first_frame_width ||
       height + y_offset > png_ptr->first_frame_height)
       png_error(png_ptr, "dimensions of a frame are greater than "
                          "the ones in IHDR");

   if (dispose_op != PNG_DISPOSE_OP_NONE &&
       dispose_op != PNG_DISPOSE_OP_BACKGROUND &&
       dispose_op != PNG_DISPOSE_OP_PREVIOUS)
       png_error(png_ptr, "invalid dispose_op in fcTL");

   if (blend_op != PNG_BLEND_OP_SOURCE &&
       blend_op != PNG_BLEND_OP_OVER)
       png_error(png_ptr, "invalid blend_op in fcTL");

   PNG_UNUSED(delay_num)
   PNG_UNUSED(delay_den)
}

png_uint_32 PNGAPI
png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr,
                             png_byte is_hidden)
{
   png_debug(1, "in png_first_frame_is_hidden()");

   if (png_ptr == NULL)
       return 0;

   if (is_hidden != 0)
       png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
   else
       png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN;

   PNG_UNUSED(info_ptr)

   return 1;
}
#endif /* APNG */

#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
static png_byte
check_location(png_const_structrp png_ptr, int location)
{
  location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);

  /* New in 1.6.0; copy the location and check it.  This is an API
   * change; previously the app had to use the
   * png_set_unknown_chunk_location API below for each chunk.
   */
  if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
  {
     /* Write struct, so unknown chunks come from the app */
     png_app_warning(png_ptr,
         "png_set_unknown_chunks now expects a valid location");
     /* Use the old behavior */
     location = (png_byte)(png_ptr->mode &
         (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
  }

  /* This need not be an internal error - if the app calls
   * png_set_unknown_chunks on a read pointer it must get the location right.
   */
  if (location == 0)
     png_error(png_ptr, "invalid location in png_set_unknown_chunks");

  /* Now reduce the location to the top-most set bit by removing each least
   * significant bit in turn.
   */
  while (location != (location & -location))
     location &= ~(location & -location);

  /* The cast is safe because 'location' is a bit mask and only the low four
   * bits are significant.
   */
  return (png_byte)location;
}

void PNGAPI
png_set_unknown_chunks(png_const_structrp png_ptr,
   png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
{
  png_unknown_chunkp np;

  if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
      unknowns == NULL)
     return;

  /* Check for the failure cases where support has been disabled at compile
   * time.  This code is hardly ever compiled - it's here because
   * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
   * code) but may be meaningless if the read or write handling of unknown
   * chunks is not compiled in.
   */
#  if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
     defined(PNG_READ_SUPPORTED)
     if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
     {
        png_app_error(png_ptr, "no unknown chunk support on read");

        return;
     }
#  endif
#  if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
     defined(PNG_WRITE_SUPPORTED)
     if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
     {
        png_app_error(png_ptr, "no unknown chunk support on write");

        return;
     }
#  endif

  /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
   * unknown critical chunks could be lost with just a warning resulting in
   * undefined behavior.  Now png_chunk_report is used to provide behavior
   * appropriate to read or write.
   */
  np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
      info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
      sizeof *np));

  if (np == NULL)
  {
     png_chunk_report(png_ptr, "too many unknown chunks",
         PNG_CHUNK_WRITE_ERROR);
     return;
  }

  png_free(png_ptr, info_ptr->unknown_chunks);

  info_ptr->unknown_chunks = np; /* safe because it is initialized */
  info_ptr->free_me |= PNG_FREE_UNKN;

  np += info_ptr->unknown_chunks_num;

  /* Increment unknown_chunks_num each time round the loop to protect the
   * just-allocated chunk data.
   */
  for (; num_unknowns > 0; --num_unknowns, ++unknowns)
  {
     memcpy(np->name, unknowns->name, (sizeof np->name));
     np->name[(sizeof np->name)-1] = '\0';
     np->location = check_location(png_ptr, unknowns->location);

     if (unknowns->size == 0)
     {
        np->data = NULL;
        np->size = 0;
     }

     else
     {
        np->data = png_voidcast(png_bytep,
            png_malloc_base(png_ptr, unknowns->size));

        if (np->data == NULL)
        {
           png_chunk_report(png_ptr, "unknown chunk: out of memory",
               PNG_CHUNK_WRITE_ERROR);
           /* But just skip storing the unknown chunk */
           continue;
        }

        memcpy(np->data, unknowns->data, unknowns->size);
        np->size = unknowns->size;
     }

     /* These increments are skipped on out-of-memory for the data - the
      * unknown chunk entry gets overwritten if the png_chunk_report returns.
      * This is correct in the read case (the chunk is just dropped.)
      */
     ++np;
     ++(info_ptr->unknown_chunks_num);
  }
}

void PNGAPI
png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
   int chunk, int location)
{
  /* This API is pretty pointless in 1.6.0 because the location can be set
   * before the call to png_set_unknown_chunks.
   *
   * TODO: add a png_app_warning in 1.7
   */
  if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
     chunk < info_ptr->unknown_chunks_num)
  {
     if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
     {
        png_app_error(png_ptr, "invalid unknown chunk location");
        /* Fake out the pre 1.6.0 behavior: */
        if (((unsigned int)location & PNG_HAVE_IDAT) != 0) /* undocumented! */
           location = PNG_AFTER_IDAT;

        else
           location = PNG_HAVE_IHDR; /* also undocumented */
     }

     info_ptr->unknown_chunks[chunk].location =
        check_location(png_ptr, location);
  }
}
#endif /* STORE_UNKNOWN_CHUNKS */

#ifdef PNG_MNG_FEATURES_SUPPORTED
png_uint_32 PNGAPI
png_permit_mng_features(png_structrp png_ptr, png_uint_32 mng_features)
{
  png_debug(1, "in png_permit_mng_features");

  if (png_ptr == NULL)
     return 0;

  png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES;

  return png_ptr->mng_features_permitted;
}
#endif

#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
static unsigned int
add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
{
  unsigned int i;

  /* Utility function: update the 'keep' state of a chunk if it is already in
   * the list, otherwise add it to the list.
   */
  for (i=0; i<count; ++i, list += 5)
  {
     if (memcmp(list, add, 4) == 0)
     {
        list[4] = (png_byte)keep;

        return count;
     }
  }

  if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
  {
     ++count;
     memcpy(list, add, 4);
     list[4] = (png_byte)keep;
  }

  return count;
}

void PNGAPI
png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
   png_const_bytep chunk_list, int num_chunks_in)
{
  png_bytep new_list;
  unsigned int num_chunks, old_num_chunks;

  if (png_ptr == NULL)
     return;

  if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
  {
     png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");

     return;
  }

  if (num_chunks_in <= 0)
  {
     png_ptr->unknown_default = keep;

     /* '0' means just set the flags, so stop here */
     if (num_chunks_in == 0)
       return;
  }

  if (num_chunks_in < 0)
  {
     /* Ignore all unknown chunks and all chunks recognized by
      * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
      */
     static const png_byte chunks_to_ignore[] = {
        98,  75,  71,  68, '\0',  /* bKGD */
        99,  72,  82,  77, '\0',  /* cHRM */
        99,  73,  67,  80, '\0',  /* cICP */
        99,  76,  76,  73, '\0',  /* cLLI */
       101,  88,  73, 102, '\0',  /* eXIf */
       103,  65,  77,  65, '\0',  /* gAMA */
       104,  73,  83,  84, '\0',  /* hIST */
       105,  67,  67,  80, '\0',  /* iCCP */
       105,  84,  88, 116, '\0',  /* iTXt */
       109,  68,  67,  86, '\0',  /* mDCV */
       111,  70,  70, 115, '\0',  /* oFFs */
       112,  67,  65,  76, '\0',  /* pCAL */
       112,  72,  89, 115, '\0',  /* pHYs */
       115,  66,  73,  84, '\0',  /* sBIT */
       115,  67,  65,  76, '\0',  /* sCAL */
       115,  80,  76,  84, '\0',  /* sPLT */
       115,  84,  69,  82, '\0',  /* sTER */
       115,  82,  71,  66, '\0',  /* sRGB */
       116,  69,  88, 116, '\0',  /* tEXt */
       116,  73,  77,  69, '\0',  /* tIME */
       122,  84,  88, 116, '\0'   /* zTXt */
     };

     chunk_list = chunks_to_ignore;
     num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
  }

  else /* num_chunks_in > 0 */
  {
     if (chunk_list == NULL)
     {
        /* Prior to 1.6.0 this was silently ignored, now it is an app_error
         * which can be switched off.
         */
        png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");

        return;
     }

     num_chunks = (unsigned int)num_chunks_in;
  }

  old_num_chunks = png_ptr->num_chunk_list;
  if (png_ptr->chunk_list == NULL)
     old_num_chunks = 0;

  /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
   */
  if (num_chunks + old_num_chunks > UINT_MAX/5)
  {
     png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");

     return;
  }

  /* If these chunks are being reset to the default then no more memory is
   * required because add_one_chunk above doesn't extend the list if the 'keep'
   * parameter is the default.
   */
  if (keep != 0)
  {
     new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
         5 * (num_chunks + old_num_chunks)));

     if (old_num_chunks > 0)
        memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
  }

  else if (old_num_chunks > 0)
     new_list = png_ptr->chunk_list;

  else
     new_list = NULL;

  /* Add the new chunks together with each one's handling code.  If the chunk
   * already exists the code is updated, otherwise the chunk is added to the
   * end.  (In libpng 1.6.0 order no longer matters because this code enforces
   * the earlier convention that the last setting is the one that is used.)
   */
  if (new_list != NULL)
  {
     png_const_bytep inlist;
     png_bytep outlist;
     unsigned int i;

     for (i=0; i<num_chunks; ++i)
     {
        old_num_chunks = add_one_chunk(new_list, old_num_chunks,
            chunk_list+5*i, keep);
     }

     /* Now remove any spurious 'default' entries. */
     num_chunks = 0;
     for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
     {
        if (inlist[4])
        {
           if (outlist != inlist)
              memcpy(outlist, inlist, 5);
           outlist += 5;
           ++num_chunks;
        }
     }

     /* This means the application has removed all the specialized handling. */
     if (num_chunks == 0)
     {
        if (png_ptr->chunk_list != new_list)
           png_free(png_ptr, new_list);

        new_list = NULL;
     }
  }

  else
     num_chunks = 0;

  png_ptr->num_chunk_list = num_chunks;

  if (png_ptr->chunk_list != new_list)
  {
     if (png_ptr->chunk_list != NULL)
        png_free(png_ptr, png_ptr->chunk_list);

     png_ptr->chunk_list = new_list;
  }
}
#endif

#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
void PNGAPI
png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr,
   png_user_chunk_ptr read_user_chunk_fn)
{
  png_debug(1, "in png_set_read_user_chunk_fn");

  if (png_ptr == NULL)
     return;

  png_ptr->read_user_chunk_fn = read_user_chunk_fn;
  png_ptr->user_chunk_ptr = user_chunk_ptr;
}
#endif

#ifdef PNG_INFO_IMAGE_SUPPORTED
void PNGAPI
png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
   png_bytepp row_pointers)
{
  png_debug(1, "in png_set_rows");

  if (png_ptr == NULL || info_ptr == NULL)
     return;

  if (info_ptr->row_pointers != NULL &&
      (info_ptr->row_pointers != row_pointers))
     png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);

  info_ptr->row_pointers = row_pointers;

  if (row_pointers != NULL)
     info_ptr->valid |= PNG_INFO_IDAT;
}
#endif

void PNGAPI
png_set_compression_buffer_size(png_structrp png_ptr, size_t size)
{
  png_debug(1, "in png_set_compression_buffer_size");

  if (png_ptr == NULL)
     return;

  if (size == 0 || size > PNG_UINT_31_MAX)
     png_error(png_ptr, "invalid compression buffer size");

#  ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
  {
     png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
     return;
  }
#  endif

#  ifdef PNG_WRITE_SUPPORTED
  if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
  {
     if (png_ptr->zowner != 0)
     {
        png_warning(png_ptr,
            "Compression buffer size cannot be changed because it is in use");

        return;
     }

#ifndef __COVERITY__
     /* Some compilers complain that this is always false.  However, it
      * can be true when integer overflow happens.
      */
     if (size > ZLIB_IO_MAX)
     {
        png_warning(png_ptr,
            "Compression buffer size limited to system maximum");
        size = ZLIB_IO_MAX; /* must fit */
     }
#endif

     if (size < 6)
     {
        /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
         * if this is permitted.
         */
        png_warning(png_ptr,
            "Compression buffer size cannot be reduced below 6");

        return;
     }

     if (png_ptr->zbuffer_size != size)
     {
        png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
        png_ptr->zbuffer_size = (uInt)size;
     }
  }
#  endif
}

void PNGAPI
png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
{
  if (png_ptr != NULL && info_ptr != NULL)
     info_ptr->valid &= (unsigned int)(~mask);
}


#ifdef PNG_SET_USER_LIMITS_SUPPORTED
/* This function was added to libpng 1.2.6 */
void PNGAPI
png_set_user_limits(png_structrp png_ptr, png_uint_32 user_width_max,
   png_uint_32 user_height_max)
{
  png_debug(1, "in png_set_user_limits");

  /* Images with dimensions larger than these limits will be
   * rejected by png_set_IHDR().  To accept any PNG datastream
   * regardless of dimensions, set both limits to 0x7fffffff.
   */
  if (png_ptr == NULL)
     return;

  png_ptr->user_width_max = user_width_max;
  png_ptr->user_height_max = user_height_max;
}

/* This function was added to libpng 1.4.0 */
void PNGAPI
png_set_chunk_cache_max(png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
{
  png_debug(1, "in png_set_chunk_cache_max");

  if (png_ptr != NULL)
     png_ptr->user_chunk_cache_max = user_chunk_cache_max;
}

/* This function was added to libpng 1.4.1 */
void PNGAPI
png_set_chunk_malloc_max(png_structrp png_ptr,
   png_alloc_size_t user_chunk_malloc_max)
{
  png_debug(1, "in png_set_chunk_malloc_max");

  /* pngstruct::user_chunk_malloc_max is initialized to a non-zero value in
   * png.c.  This API supports '0' for unlimited, make sure the correct
   * (unlimited) value is set here to avoid a need to check for 0 everywhere
   * the parameter is used.
   */
  if (png_ptr != NULL)
  {
     if (user_chunk_malloc_max == 0U) /* unlimited */
     {
#        ifdef PNG_MAX_MALLOC_64K
           png_ptr->user_chunk_malloc_max = 65536U;
#        else
           png_ptr->user_chunk_malloc_max = PNG_SIZE_MAX;
#        endif
     }
     else
        png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
  }
}
#endif /* ?SET_USER_LIMITS */


#ifdef PNG_BENIGN_ERRORS_SUPPORTED
void PNGAPI
png_set_benign_errors(png_structrp png_ptr, int allowed)
{
  png_debug(1, "in png_set_benign_errors");

  /* If allowed is 1, png_benign_error() is treated as a warning.
   *
   * If allowed is 0, png_benign_error() is treated as an error (which
   * is the default behavior if png_set_benign_errors() is not called).
   */

  if (allowed != 0)
     png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
        PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;

  else
     png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
        PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
}
#endif /* BENIGN_ERRORS */

#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
  /* Whether to report invalid palette index; added at libng-1.5.10.
   * It is possible for an indexed (color-type==3) PNG file to contain
   * pixels with invalid (out-of-range) indexes if the PLTE chunk has
   * fewer entries than the image's bit-depth would allow. We recover
   * from this gracefully by filling any incomplete palette with zeros
   * (opaque black).  By default, when this occurs libpng will issue
   * a benign error.  This API can be used to override that behavior.
   */
void PNGAPI
png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
{
  png_debug(1, "in png_set_check_for_invalid_index");

  if (allowed > 0)
     png_ptr->num_palette_max = 0;

  else
     png_ptr->num_palette_max = -1;
}
#endif

#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \
   defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
* and if invalid, correct the keyword rather than discarding the entire
* chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
* length, forbids leading or trailing whitespace, multiple internal spaces,
* and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
*
* The 'new_key' buffer must be 80 characters in size (for the keyword plus a
* trailing '\0').  If this routine returns 0 then there was no keyword, or a
* valid one could not be generated, and the caller must png_error.
*/
png_uint_32 /* PRIVATE */
png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
{
#ifdef PNG_WARNINGS_SUPPORTED
  png_const_charp orig_key = key;
#endif
  png_uint_32 key_len = 0;
  int bad_character = 0;
  int space = 1;

  png_debug(1, "in png_check_keyword");

  if (key == NULL)
  {
     *new_key = 0;
     return 0;
  }

  while (*key && key_len < 79)
  {
     png_byte ch = (png_byte)*key++;

     if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
     {
        *new_key++ = ch; ++key_len; space = 0;
     }

     else if (space == 0)
     {
        /* A space or an invalid character when one wasn't seen immediately
         * before; output just a space.
         */
        *new_key++ = 32; ++key_len; space = 1;

        /* If the character was not a space then it is invalid. */
        if (ch != 32)
           bad_character = ch;
     }

     else if (bad_character == 0)
        bad_character = ch; /* just skip it, record the first error */
  }

  if (key_len > 0 && space != 0) /* trailing space */
  {
     --key_len; --new_key;
     if (bad_character == 0)
        bad_character = 32;
  }

  /* Terminate the keyword */
  *new_key = 0;

  if (key_len == 0)
     return 0;

#ifdef PNG_WARNINGS_SUPPORTED
  /* Try to only output one warning per keyword: */
  if (*key != 0) /* keyword too long */
     png_warning(png_ptr, "keyword truncated");

  else if (bad_character != 0)
  {
     PNG_WARNING_PARAMETERS(p)

     png_warning_parameter(p, 1, orig_key);
     png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);

     png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
  }
#else /* !WARNINGS */
  PNG_UNUSED(png_ptr)
#endif /* !WARNINGS */

  return key_len;
}
#endif /* TEXT || pCAL || iCCP || sPLT */
#endif /* READ || WRITE */