media/libpng/pngset.c
author Bryce Van Dyk <bvandyk@mozilla.com>
Tue, 19 Jan 2016 11:43:49 +1300
changeset 288503 4261e08ba51aa5241a05d5a6da8c7557e870ef47
parent 285731 be199e2f9e395d870a48d6e5bdc20bb12372e6a5
child 302129 7f9d9dfa09d2d3b27bd3f3cc45aae160cf52fb5d
permissions -rw-r--r--
Bug 657791 - Update WebM demuxer to consider cue-less WebMs seekable. r=jya It appears that the work to seek in WebMs that do not have cues has already been done, however this functionality was gated by the IsSeekable() function still returning that such WebMs were not seekable. This updates that function so that WebMs without cues are now considered seekable. Tests are also updated to reflect this.


/* pngset.c - storage of image information into info struct
 *
 * Last changed in libpng 1.6.21 [January 15, 2016]
 * Copyright (c) 1998-2015 Glenn Randers-Pehrson
 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
 * (Version 0.88 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_xy xy;

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

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

   xy.redx = red_x;
   xy.redy = red_y;
   xy.greenx = green_x;
   xy.greeny = green_y;
   xy.bluex = blue_x;
   xy.bluey = blue_y;
   xy.whitex = white_x;
   xy.whitey = white_y;

   if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy,
       2/* override with app values*/) != 0)
      info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;

   png_colorspace_sync_info(png_ptr, info_ptr);
}

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_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_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace,
       &XYZ, 2) != 0)
      info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;

   png_colorspace_sync_info(png_ptr, info_ptr);
}

#  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_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;

   png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma);
   png_colorspace_sync_info(png_ptr, info_ptr);
}

#  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;
   }

   info_ptr->free_me |= PNG_FREE_HIST;

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

   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)
{
   png_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_error(png_ptr, "Invalid pCAL equation type");

   if (nparams < 0 || nparams > 255)
      png_error(png_ptr, "Invalid pCAL parameter count");

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

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

   if (info_ptr->pcal_purpose == NULL)
   {
      png_warning(png_ptr, "Insufficient memory for pCAL purpose");

      return;
   }

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

   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,
       (png_size_t)((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, (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;
   info_ptr->free_me |= PNG_FREE_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)
{
   png_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->valid |= PNG_INFO_sCAL;
   info_ptr->free_me |= PNG_FREE_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, 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;

   (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent);
   png_colorspace_sync_info(png_ptr, info_ptr);
}

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;

   if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace,
       srgb_intent) != 0)
   {
      /* This causes the gAMA and cHRM to be written too */
      info_ptr->colorspace.flags |=
         PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
   }

   png_colorspace_sync_info(png_ptr, info_ptr);
}
#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;
   png_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");

   /* Set the colorspace first because this validates the profile; do not
    * override previously set app cHRM or gAMA here (because likely as not the
    * application knows better than libpng what the correct values are.)  Pass
    * the info_ptr color_type field to png_colorspace_set_ICC because in the
    * write case it has not yet been stored in png_ptr.
    */
   {
      int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
         proflen, profile, info_ptr->color_type);

      png_colorspace_sync_info(png_ptr, info_ptr);

      /* Don't do any of the copying if the profile was bad, or inconsistent. */
      if (result == 0)
         return;

      /* But do write the gAMA and cHRM chunks from the profile. */
      info_ptr->colorspace.flags |=
         PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
   }

   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 %lx storage function", png_ptr == NULL ? 0xabadca11U :
      (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);

       /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
       png_ptr->trans_alpha = info_ptr->trans_alpha = png_voidcast(png_bytep,
         png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));

       if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
          memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
   }

   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->valid |= PNG_INFO_tRNS;
      info_ptr->free_me |= PNG_FREE_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;

   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
   {
      png_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,
         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;
   }
   while (++entries, --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 > PNG_UINT_31_MAX)
        png_error(png_ptr, "invalid width in fcTL (> 2^31-1)");
    if (height > PNG_UINT_31_MAX)
        png_error(png_ptr, "invalid height in fcTL (> 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 ((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 PNG_CONST png_byte chunks_to_ignore[] = {
         98,  75,  71,  68, '\0',  /* bKGD */
         99,  72,  82,  77, '\0',  /* cHRM */
        103,  65,  77,  65, '\0',  /* gAMA */
        104,  73,  83,  84, '\0',  /* hIST */
        105,  67,  67,  80, '\0',  /* iCCP */
        105,  84,  88, 116, '\0',  /* iTXt */
        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 = 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_debug1(1, "in %s storage function", "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, png_size_t 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 &= ~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)
{
   /* 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)
{
   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)
{
   if (png_ptr != NULL)
      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)
{
   png_const_charp orig_key = key;
   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'");
   }
#endif /* WARNINGS */

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