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

 *

 * (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 "png.h"

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

static void /* PRIVATE */

png_default_error PNGARG((png_structp png_ptr,

static void /* PRIVATE */

png_default_warning PNGARG((png_structp png_ptr,

  png_const_charp warning_message));

/* 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.

 */

void PNGAPI

png_error(png_structp png_ptr, png_const_charp error_message)

{

#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))

     {

       {

           /* 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)

           {

              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)

           {

              msg[0] = '0';

              msg[1] = '\0';

              error_message = msg;

           }

       }

     }

   }

#endif

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

      (*(png_ptr->error_fn))(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

void PNGAPI

png_err(png_structp png_ptr)

{

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

      (*(png_ptr->error_fn))(png_ptr, '\0');

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

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

   png_default_error(png_ptr, '\0');

}

/* 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_structp 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))

#endif

     {

       {

           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_ptr, warning_message + offset);

   else

      png_default_warning(png_ptr, warning_message + offset);

}

/* 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,

 * this 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'

};

#define PNG_MAX_ERROR_TEXT 64

static void /* PRIVATE */

png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp

   error_message)

{

   int iout = 0, iin = 0;

   while (iin < 4)

   {

      int c = png_ptr->chunk_name[iin++];

      if (isnonalpha(c))

      {

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

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

      }

      else

      {

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

      }

   }

   if (error_message == NULL)

      buffer[iout] = '\0';

   else

   {

      buffer[iout++] = ':';

      buffer[iout++] = ' ';

      png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);

      buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';

   }

}

#ifdef PNG_READ_SUPPORTED

void PNGAPI

png_chunk_error(png_structp png_ptr, png_const_charp error_message)

{

   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 /* PNG_READ_SUPPORTED */

void PNGAPI

png_chunk_warning(png_structp 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);

   }

}

/* 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 void /* PRIVATE */

png_default_error(png_structp png_ptr, png_const_charp error_message)

{

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

   {

     /* 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);

      fprintf(stderr, PNG_STRING_NEWLINE);

   }

#endif

#ifdef PNG_SETJMP_SUPPORTED

   {

#  ifdef USE_FAR_KEYWORD

   {

      jmp_buf jmpbuf;

      png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));

   }

#  else

#  endif

   }

   PNG_ABORT();

   error_message = error_message; /* Make compiler happy */

#endif

}

/* 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_structp png_ptr, png_const_charp warning_message)

{

#  ifdef PNG_ERROR_NUMBERS_SUPPORTED

   {

     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

   warning_message = warning_message; /* Make compiler happy */

#endif

   png_ptr = png_ptr; /* Make compiler happy */

}

/* 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->jmpbuf, 1)

 */

void PNGAPI

png_set_error_fn(png_structp 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;

   png_ptr->warning_fn = warning_fn;

}

/* 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_structp 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_structp 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

#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */