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 /* pngset.c - storage of image information into info struct

  *

  * Last changed in libpng 1.6.8 [December 19, 2013]

  * Copyright (c) 1998-2013 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*/))

       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))

       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 Red X"),

       png_fixed(png_ptr, green_Y, "cHRM Red Y"),

       png_fixed(png_ptr, green_Z, "cHRM Red Z"),

       png_fixed(png_ptr, blue_X, "cHRM Red X"),

       png_fixed(png_ptr, blue_Y, "cHRM Red Y"),

       png_fixed(png_ptr, blue_Z, "cHRM Red Z"));

 }

 #  endif /* PNG_FLOATING_POINT_SUPPORTED */

 #endif /* PNG_cHRM_SUPPORTED */

 #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)

       info_ptr->channels = 3;

    else

       info_ptr->channels = 1;

    if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)

       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_debug1(1, "in %s storage function", "PLTE");

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

       return;

    if (num_palette < 0 || num_palette > PNG_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");

       return;

    }

    /* 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 that has

     * 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))

    {

       /* 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)

          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)

       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 ? "unexpected" :

       (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 /* PNG_iTXt_SUPPORTED */

       {

          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)

          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))

       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)

    {

       int sample_max = (1 << info_ptr->bit_depth);

       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");

       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 even 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);

          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 /* PNG_sPLT_SUPPORTED */

 #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) &&

             !(png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))

         {

           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)

         png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;

     else

         png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN;

     PNG_UNUSED(info_ptr)

     return 1;

 }

 #endif /* PNG_APNG_SUPPORTED */

 #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))

    {

       /* 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)

       {

          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))

       {

          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)) /* undocumented! */

             location = PNG_AFTER_IDAT;

          else

             location = PNG_HAVE_IHDR; /* also undocumented */

       }

       info_ptr->unknown_chunks[chunk].location =

          check_location(png_ptr, location);

    }

 }

 #endif

 #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 = (sizeof chunks_to_ignore)/5;

    }

    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)

    {

       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 && (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)

       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)

       {

          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))

       {

          if (png_ptr->zowner != 0)

          {

             png_warning(png_ptr,

               "Compression buffer size cannot be changed because it is in use");

             return;

          }

          if (size > ZLIB_IO_MAX)

          {

             png_warning(png_ptr,

                "Compression buffer size limited to system maximum");

             size = ZLIB_IO_MAX; /* must fit */

          }

          else 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 && info_ptr)

       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 0x7ffffffL.

     */

    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)

        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)

       png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;

 }

 #endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */

 #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)

       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 /* PNG_BENIGN_ERRORS_SUPPORTED */

 #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 zeroes

     * (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

 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */