/* pngerror.c - stub functions for i/o and memory allocation

 *

 * Last changed in libpng 1.6.15 [November 20, 2014]

 * Copyright (c) 1998-2002,2004,2006-2014 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

 *

 * This file provides a location for all error handling.  Users who

 * need special error handling are expected to write replacement functions

 * and use png_set_error_fn() to use those functions.  See the instructions

 * at each function.

 */

#include "pngpriv.h"

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

static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,

    png_const_charp error_message)),PNG_NORETURN);

#ifdef PNG_WARNINGS_SUPPORTED

static void /* PRIVATE */

png_default_warning PNGARG((png_const_structrp png_ptr,

   png_const_charp warning_message));

#endif /* WARNINGS */

/* This function is called whenever there is a fatal error.  This function

 * should not be changed.  If there is a need to handle errors differently,

 * you should supply a replacement error function and use png_set_error_fn()

 * to replace the error function at run-time.

 */

#ifdef PNG_ERROR_TEXT_SUPPORTED

PNG_FUNCTION(void,PNGAPI

png_error,(png_const_structrp png_ptr, png_const_charp error_message),

   PNG_NORETURN)

{

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

   char msg[16];

   if (png_ptr != NULL)

   {

      if ((png_ptr->flags &

         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0

      {

         if (*error_message == PNG_LITERAL_SHARP)

         {

            /* Strip "#nnnn " from beginning of error message. */

            int offset;

            for (offset = 1; offset<15; offset++)

               if (error_message[offset] == ' ')

                  break;

            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)

            {

               int i;

               for (i = 0; i < offset - 1; i++)

                  msg[i] = error_message[i + 1];

               msg[i - 1] = '\0';

               error_message = msg;

            }

            else

               error_message += offset;

      }

      else

      {

         if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)

         {

            msg[0] = '0';

            msg[1] = '\0';

            error_message = msg;

         }

       }

     }

   }

#endif

   if (png_ptr != NULL && png_ptr->error_fn != NULL)

      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),

          error_message);

   /* If the custom handler doesn't exist, or if it returns,

      use the default handler, which will not return. */

   png_default_error(png_ptr, error_message);

}

#else

PNG_FUNCTION(void,PNGAPI

png_err,(png_const_structrp png_ptr),PNG_NORETURN)

{

   /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed

    * erroneously as '\0', instead of the empty string "".  This was

    * apparently an error, introduced in libpng-1.2.20, and png_default_error

    * will crash in this case.

    */

   if (png_ptr != NULL && png_ptr->error_fn != NULL)

      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");

   /* If the custom handler doesn't exist, or if it returns,

      use the default handler, which will not return. */

   png_default_error(png_ptr, "");

}

#endif /* ERROR_TEXT */

/* Utility to safely appends strings to a buffer.  This never errors out so

 * error checking is not required in the caller.

 */

size_t

png_safecat(png_charp buffer, size_t bufsize, size_t pos,

   png_const_charp string)

{

   if (buffer != NULL && pos < bufsize)

   {

      if (string != NULL)

         while (*string != '\0' && pos < bufsize-1)

           buffer[pos++] = *string++;

      buffer[pos] = '\0';

   }

   return pos;

}

#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)

/* Utility to dump an unsigned value into a buffer, given a start pointer and

 * and end pointer (which should point just *beyond* the end of the buffer!)

 * Returns the pointer to the start of the formatted string.

 */

png_charp

png_format_number(png_const_charp start, png_charp end, int format,

   png_alloc_size_t number)

{

   int count = 0;    /* number of digits output */

   int mincount = 1; /* minimum number required */

   int output = 0;   /* digit output (for the fixed point format) */

   *--end = '\0';

   /* This is written so that the loop always runs at least once, even with

    * number zero.

    */

   while (end > start && (number != 0 || count < mincount))

   {

      static const char digits[] = "0123456789ABCDEF";

      switch (format)

      {

         case PNG_NUMBER_FORMAT_fixed:

            /* Needs five digits (the fraction) */

            mincount = 5;

            if (output != 0 || number % 10 != 0)

            {

               *--end = digits[number % 10];

               output = 1;

            }

            number /= 10;

            break;

         case PNG_NUMBER_FORMAT_02u:

            /* Expects at least 2 digits. */

            mincount = 2;

            /* FALL THROUGH */

         case PNG_NUMBER_FORMAT_u:

            *--end = digits[number % 10];

            number /= 10;

            break;

         case PNG_NUMBER_FORMAT_02x:

            /* This format expects at least two digits */

            mincount = 2;

            /* FALL THROUGH */

         case PNG_NUMBER_FORMAT_x:

            *--end = digits[number & 0xf];

            number >>= 4;

            break;

         default: /* an error */

            number = 0;

            break;

      }

      /* Keep track of the number of digits added */

      ++count;

      /* Float a fixed number here: */

      if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))

      {

         /* End of the fraction, but maybe nothing was output?  In that case

          * drop the decimal point.  If the number is a true zero handle that

          * here.

          */

         if (output != 0)

            *--end = '.';

         else if (number == 0) /* and !output */

            *--end = '0';

      }

   }

   return end;

}

#endif

#ifdef PNG_WARNINGS_SUPPORTED

/* This function is called whenever there is a non-fatal error.  This function

 * should not be changed.  If there is a need to handle warnings differently,

 * you should supply a replacement warning function and use

 * png_set_error_fn() to replace the warning function at run-time.

 */

void PNGAPI

png_warning(png_const_structrp png_ptr, png_const_charp warning_message)

{

   int offset = 0;

   if (png_ptr != NULL)

   {

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

   if ((png_ptr->flags &

       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)

#endif

      {

         if (*warning_message == PNG_LITERAL_SHARP)

         {

            for (offset = 1; offset < 15; offset++)

               if (warning_message[offset] == ' ')

                  break;

         }

      }

   }

   if (png_ptr != NULL && png_ptr->warning_fn != NULL)

      (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),

         warning_message + offset);

   else

      png_default_warning(png_ptr, warning_message + offset);

}

/* These functions support 'formatted' warning messages with up to

 * PNG_WARNING_PARAMETER_COUNT parameters.  In the format string the parameter

 * is introduced by @<number>, where 'number' starts at 1.  This follows the</number>

 * standard established by X/Open for internationalizable error messages.

 */

void

png_warning_parameter(png_warning_parameters p, int number,

   png_const_charp string)

{

   if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)

      (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);

}

void

png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,

   png_alloc_size_t value)

{

   char buffer[PNG_NUMBER_BUFFER_SIZE];

   png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));

}

void

png_warning_parameter_signed(png_warning_parameters p, int number, int format,

   png_int_32 value)

{

   png_alloc_size_t u;

   png_charp str;

   char buffer[PNG_NUMBER_BUFFER_SIZE];

   /* Avoid overflow by doing the negate in a png_alloc_size_t: */

   u = (png_alloc_size_t)value;

   if (value < 0)

      u = ~u + 1;

   str = PNG_FORMAT_NUMBER(buffer, format, u);

   if (value < 0 && str > buffer)

      *--str = '-';

   png_warning_parameter(p, number, str);

}

void

png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,

   png_const_charp message)

{

   /* The internal buffer is just 192 bytes - enough for all our messages,

    * overflow doesn't happen because this code checks!  If someone figures

    * out how to send us a message longer than 192 bytes, all that will

    * happen is that the message will be truncated appropriately.

    */

   size_t i = 0; /* Index in the msg[] buffer: */

   char msg[192];

   /* Each iteration through the following loop writes at most one character

    * to msg[i++] then returns here to validate that there is still space for

    * the trailing '\0'.  It may (in the case of a parameter) read more than

    * one character from message[]; it must check for '\0' and continue to the

    * test if it finds the end of string.

    */

   while (i<(sizeof msg)-1 && *message != '\0')

   {

      /* '@' at end of string is now just printed (previously it was skipped);

       * it is an error in the calling code to terminate the string with @.

       */

      if (p != NULL && *message == '@' && message[1] != '\0')

      {

         int parameter_char = *++message; /* Consume the '@' */

         static const char valid_parameters[] = "123456789";

         int parameter = 0;

         /* Search for the parameter digit, the index in the string is the

          * parameter to use.

          */

         while (valid_parameters[parameter] != parameter_char &&

            valid_parameters[parameter] != '\0')

            ++parameter;

         /* If the parameter digit is out of range it will just get printed. */

         if (parameter < PNG_WARNING_PARAMETER_COUNT)

         {

            /* Append this parameter */

            png_const_charp parm = p[parameter];

            png_const_charp pend = p[parameter] + (sizeof p[parameter]);

            /* No need to copy the trailing '\0' here, but there is no guarantee

             * that parm[] has been initialized, so there is no guarantee of a

             * trailing '\0':

             */

            while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)

               msg[i++] = *parm++;

            /* Consume the parameter digit too: */

            ++message;

            continue;

         }

         /* else not a parameter and there is a character after the @ sign; just

          * copy that.  This is known not to be '\0' because of the test above.

          */

      }

      /* At this point *message can't be '\0', even in the bad parameter case

       * above where there is a lone '@' at the end of the message string.

       */

      msg[i++] = *message++;

   }

   /* i is always less than (sizeof msg), so: */

   msg[i] = '\0';

   /* And this is the formatted message. It may be larger than

    * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these

    * are not (currently) formatted.

    */

   png_warning(png_ptr, msg);

}

#endif /* WARNINGS */

#ifdef PNG_BENIGN_ERRORS_SUPPORTED

void PNGAPI

png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)

{

   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)

   {

#     ifdef PNG_READ_SUPPORTED

         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&

            png_ptr->chunk_name != 0)

            png_chunk_warning(png_ptr, error_message);

         else

#     endif

      png_warning(png_ptr, error_message);

   }

   else

   {

#     ifdef PNG_READ_SUPPORTED

         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&

            png_ptr->chunk_name != 0)

            png_chunk_error(png_ptr, error_message);

         else

#     endif

      png_error(png_ptr, error_message);

   }

#  ifndef PNG_ERROR_TEXT_SUPPORTED

      PNG_UNUSED(error_message)

#  endif

}

void /* PRIVATE */

png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)

{

  if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)

     png_warning(png_ptr, error_message);

  else

     png_error(png_ptr, error_message);

#  ifndef PNG_ERROR_TEXT_SUPPORTED

      PNG_UNUSED(error_message)

#  endif

}

void /* PRIVATE */

png_app_error(png_const_structrp png_ptr, png_const_charp error_message)

{

  if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)

     png_warning(png_ptr, error_message);

  else

     png_error(png_ptr, error_message);

#  ifndef PNG_ERROR_TEXT_SUPPORTED

      PNG_UNUSED(error_message)

#  endif

}

#endif /* BENIGN_ERRORS */

#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */

#if defined(PNG_WARNINGS_SUPPORTED) || \

   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))

/* These utilities are used internally to build an error message that relates

 * to the current chunk.  The chunk name comes from png_ptr->chunk_name,

 * which is used to prefix the message.  The message is limited in length

 * to 63 bytes. The name characters are output as hex digits wrapped in []

 * if the character is invalid.

 */

#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))

static PNG_CONST char png_digit[16] = {

   '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',

   'A', 'B', 'C', 'D', 'E', 'F'

};

static void /* PRIVATE */

png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp

    error_message)

{

   png_uint_32 chunk_name = png_ptr->chunk_name;

   int iout = 0, ishift = 24;

   while (ishift >= 0)

   {

      int c = (int)(chunk_name >> ishift) & 0xff;

      ishift -= 8;

      if (isnonalpha(c) != 0)

      {

         buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;

         buffer[iout++] = png_digit[(c & 0xf0) >> 4];

         buffer[iout++] = png_digit[c & 0x0f];

         buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;

      }

      else

      {

         buffer[iout++] = (char)c;

      }

   }

   if (error_message == NULL)

      buffer[iout] = '\0';

   else

   {

      int iin = 0;

      buffer[iout++] = ':';

      buffer[iout++] = ' ';

      while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')

         buffer[iout++] = error_message[iin++];

      /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */

      buffer[iout] = '\0';

   }

}

#endif /* WARNINGS || ERROR_TEXT */

#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)

PNG_FUNCTION(void,PNGAPI

png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),

   PNG_NORETURN)

{

   char msg[18+PNG_MAX_ERROR_TEXT];

   if (png_ptr == NULL)

      png_error(png_ptr, error_message);

   else

   {

      png_format_buffer(png_ptr, msg, error_message);

      png_error(png_ptr, msg);

   }

}

#endif /* READ && ERROR_TEXT */

#ifdef PNG_WARNINGS_SUPPORTED

void PNGAPI

png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)

{

   char msg[18+PNG_MAX_ERROR_TEXT];

   if (png_ptr == NULL)

      png_warning(png_ptr, warning_message);

   else

   {

      png_format_buffer(png_ptr, msg, warning_message);

      png_warning(png_ptr, msg);

   }

}

#endif /* WARNINGS */

#ifdef PNG_READ_SUPPORTED

#ifdef PNG_BENIGN_ERRORS_SUPPORTED

void PNGAPI

png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp

    error_message)

{

   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)

      png_chunk_warning(png_ptr, error_message);

   else

      png_chunk_error(png_ptr, error_message);

#  ifndef PNG_ERROR_TEXT_SUPPORTED

      PNG_UNUSED(error_message)

#  endif

}

#endif

#endif /* READ */

void /* PRIVATE */

png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)

{

#  ifndef PNG_WARNINGS_SUPPORTED

      PNG_UNUSED(message)

#  endif

   /* This is always supported, but for just read or just write it

    * unconditionally does the right thing.

    */

#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)

      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)

#  endif

#  ifdef PNG_READ_SUPPORTED

      {

         if (error < PNG_CHUNK_ERROR)

            png_chunk_warning(png_ptr, message);

         else

            png_chunk_benign_error(png_ptr, message);

      }

#  endif

#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)

      else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)

#  endif

#  ifdef PNG_WRITE_SUPPORTED

      {

         if (error < PNG_CHUNK_WRITE_ERROR)

            png_app_warning(png_ptr, message);

         else

            png_app_error(png_ptr, message);

      }

#  endif

}

#ifdef PNG_ERROR_TEXT_SUPPORTED

#ifdef PNG_FLOATING_POINT_SUPPORTED

PNG_FUNCTION(void,

png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)

{

#  define fixed_message "fixed point overflow in "

#  define fixed_message_ln ((sizeof fixed_message)-1)

   int  iin;

   char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];

   memcpy(msg, fixed_message, fixed_message_ln);

   iin = 0;

   if (name != NULL)

      while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)

      {

         msg[fixed_message_ln + iin] = name[iin];

         ++iin;

      }

   msg[fixed_message_ln + iin] = 0;

   png_error(png_ptr, msg);

}

#endif

#endif

#ifdef PNG_SETJMP_SUPPORTED

/* This API only exists if ANSI-C style error handling is used,

 * otherwise it is necessary for png_default_error to be overridden.

 */

jmp_buf* PNGAPI

png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,

    size_t jmp_buf_size)

{

   /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value

    * and it must not change after that.  Libpng doesn't care how big the

    * buffer is, just that it doesn't change.

    *

    * If the buffer size is no *larger* than the size of jmp_buf when libpng is

    * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0

    * semantics that this call will not fail.  If the size is larger, however,

    * the buffer is allocated and this may fail, causing the function to return

    * NULL.

    */

   if (png_ptr == NULL)

      return NULL;

   if (png_ptr->jmp_buf_ptr == NULL)

   {

      png_ptr->jmp_buf_size = 0; /* not allocated */

      if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))

         png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;

      else

      {

         png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,

            png_malloc_warn(png_ptr, jmp_buf_size));

         if (png_ptr->jmp_buf_ptr == NULL)

            return NULL; /* new NULL return on OOM */

         png_ptr->jmp_buf_size = jmp_buf_size;

      }

   }

   else /* Already allocated: check the size */

   {

      size_t size = png_ptr->jmp_buf_size;

      if (size == 0)

      {

         size = (sizeof png_ptr->jmp_buf_local);

         if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)

         {

            /* This is an internal error in libpng: somehow we have been left

             * with a stack allocated jmp_buf when the application regained

             * control.  It's always possible to fix this up, but for the moment

             * this is a png_error because that makes it easy to detect.

             */

            png_error(png_ptr, "Libpng jmp_buf still allocated");

            /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */

         }

      }

      if (size != jmp_buf_size)

      {

         png_warning(png_ptr, "Application jmp_buf size changed");

         return NULL; /* caller will probably crash: no choice here */

      }

   }

   /* Finally fill in the function, now we have a satisfactory buffer. It is

    * valid to change the function on every call.

    */

   png_ptr->longjmp_fn = longjmp_fn;

   return png_ptr->jmp_buf_ptr;

}

void /* PRIVATE */

png_free_jmpbuf(png_structrp png_ptr)

{

   if (png_ptr != NULL)

   {

      jmp_buf *jb = png_ptr->jmp_buf_ptr;

      /* A size of 0 is used to indicate a local, stack, allocation of the

       * pointer; used here and in png.c

       */

      if (jb != NULL && png_ptr->jmp_buf_size > 0)

      {

         /* This stuff is so that a failure to free the error control structure

          * does not leave libpng in a state with no valid error handling: the

          * free always succeeds, if there is an error it gets ignored.

          */

         if (jb != &png_ptr->jmp_buf_local)

         {

            /* Make an internal, libpng, jmp_buf to return here */

            jmp_buf free_jmp_buf;

            if (!setjmp(free_jmp_buf))

            {

               png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */

               png_ptr->jmp_buf_size = 0; /* stack allocation */

               png_ptr->longjmp_fn = longjmp;

               png_free(png_ptr, jb); /* Return to setjmp on error */

            }

         }

      }

      /* *Always* cancel everything out: */

      png_ptr->jmp_buf_size = 0;

      png_ptr->jmp_buf_ptr = NULL;

      png_ptr->longjmp_fn = 0;

   }

}

#endif

/* This is the default error handling function.  Note that replacements for

 * this function MUST NOT RETURN, or the program will likely crash.  This

 * function is used by default, or if the program supplies NULL for the

 * error function pointer in png_set_error_fn().

 */

static PNG_FUNCTION(void /* PRIVATE */,

png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),

   PNG_NORETURN)

{

#ifdef PNG_CONSOLE_IO_SUPPORTED

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

   /* Check on NULL only added in 1.5.4 */

   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)

   {

      /* Strip "#nnnn " from beginning of error message. */

      int offset;

      char error_number[16];

      for (offset = 0; offset<15; offset++)

      {

         error_number[offset] = error_message[offset + 1];

         if (error_message[offset] == ' ')

            break;

      }

      if ((offset > 1) && (offset < 15))

      {

         error_number[offset - 1] = '\0';

         fprintf(stderr, "libpng error no. %s: %s",

             error_number, error_message + offset + 1);

         fprintf(stderr, PNG_STRING_NEWLINE);

      }

      else

      {

         fprintf(stderr, "libpng error: %s, offset=%d",

             error_message, offset);

         fprintf(stderr, PNG_STRING_NEWLINE);

      }

   }

   else

#endif

   {

      fprintf(stderr, "libpng error: %s", error_message ? error_message :

         "undefined");

      fprintf(stderr, PNG_STRING_NEWLINE);

   }

#else

   PNG_UNUSED(error_message) /* Make compiler happy */

#endif

   png_longjmp(png_ptr, 1);

}

PNG_FUNCTION(void,PNGAPI

png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)

{

#ifdef PNG_SETJMP_SUPPORTED

   if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&

       png_ptr->jmp_buf_ptr != NULL)

      png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);

#else

   PNG_UNUSED(png_ptr)

   PNG_UNUSED(val)

#endif

   /* If control reaches this point, png_longjmp() must not return. The only

    * choice is to terminate the whole process (or maybe the thread); to do

    * this the ANSI-C abort() function is used unless a different method is

    * implemented by overriding the default configuration setting for

    * PNG_ABORT().

    */

   PNG_ABORT();

}

#ifdef PNG_WARNINGS_SUPPORTED

/* This function is called when there is a warning, but the library thinks

 * it can continue anyway.  Replacement functions don't have to do anything

 * here if you don't want them to.  In the default configuration, png_ptr is

 * not used, but it is passed in case it may be useful.

 */

static void /* PRIVATE */

png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)

{

#ifdef PNG_CONSOLE_IO_SUPPORTED

#  ifdef PNG_ERROR_NUMBERS_SUPPORTED

   if (*warning_message == PNG_LITERAL_SHARP)

   {

      int offset;

      char warning_number[16];

      for (offset = 0; offset < 15; offset++)

      {

         warning_number[offset] = warning_message[offset + 1];

         if (warning_message[offset] == ' ')

            break;

      }

      if ((offset > 1) && (offset < 15))

      {

         warning_number[offset + 1] = '\0';

         fprintf(stderr, "libpng warning no. %s: %s",

             warning_number, warning_message + offset);

         fprintf(stderr, PNG_STRING_NEWLINE);

      }

      else

      {

         fprintf(stderr, "libpng warning: %s",

             warning_message);

         fprintf(stderr, PNG_STRING_NEWLINE);

      }

   }

   else

#  endif

   {

      fprintf(stderr, "libpng warning: %s", warning_message);

      fprintf(stderr, PNG_STRING_NEWLINE);

   }

#else

   PNG_UNUSED(warning_message) /* Make compiler happy */

#endif

   PNG_UNUSED(png_ptr) /* Make compiler happy */

}

#endif /* WARNINGS */

/* This function is called when the application wants to use another method

 * of handling errors and warnings.  Note that the error function MUST NOT

 * return to the calling routine or serious problems will occur.  The return

 * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)

 */

void PNGAPI

png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,

    png_error_ptr error_fn, png_error_ptr warning_fn)

{

   if (png_ptr == NULL)

      return;

   png_ptr->error_ptr = error_ptr;

   png_ptr->error_fn = error_fn;

#ifdef PNG_WARNINGS_SUPPORTED

   png_ptr->warning_fn = warning_fn;

#else

   PNG_UNUSED(warning_fn)

#endif

}

/* This function returns a pointer to the error_ptr associated with the user

 * functions.  The application should free any memory associated with this

 * pointer before png_write_destroy and png_read_destroy are called.

 */

png_voidp PNGAPI

png_get_error_ptr(png_const_structrp png_ptr)

{

   if (png_ptr == NULL)

      return NULL;

   return ((png_voidp)png_ptr->error_ptr);

}

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

void PNGAPI

png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)

{

   if (png_ptr != NULL)

   {

      png_ptr->flags &=

         ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |

         PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);

   }

}

#endif

#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\

   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)