src/png/pngerror.c


/* pngerror.c - stub functions for i/o and memory allocation
 *
 * Last changed in libpng 1.4.0 [January 3, 2010]
 * Copyright (c) 1998-2010 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.
 */

#define PNG_NO_PEDANTIC_WARNINGS
#include "png.h"
#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
#include "pngpriv.h"

static void /* PRIVATE */
png_default_error PNGARG((png_structp png_ptr,
  png_const_charp error_message)) PNG_NORETURN;
#ifdef PNG_WARNINGS_SUPPORTED
static void /* PRIVATE */
png_default_warning PNGARG((png_structp png_ptr,
  png_const_charp warning_message));
#endif /* PNG_WARNINGS_SUPPORTED */

/* 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
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))
     {
       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)
           {
              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');
}
#endif /* PNG_ERROR_TEXT_SUPPORTED */

#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_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
     {
       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_ptr, warning_message + offset);
   else
      png_default_warning(png_ptr, warning_message + offset);
}
#endif /* PNG_WARNINGS_SUPPORTED */

#ifdef PNG_BENIGN_ERRORS_SUPPORTED
void PNGAPI
png_benign_error(png_structp png_ptr, png_const_charp error_message)
{
  if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
    png_warning(png_ptr, error_message);
  else
    png_error(png_ptr, error_message);
}
#endif

/* 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
#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
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_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++] = (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 */
#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */

#ifdef PNG_WARNINGS_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);
   }
}
#endif /* PNG_WARNINGS_SUPPORTED */

#ifdef PNG_READ_SUPPORTED
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
void PNGAPI
png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
{
  if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
    png_chunk_warning(png_ptr, error_message);
  else
    png_chunk_error(png_ptr, error_message);
}
#endif
#endif /* PNG_READ_SUPPORTED */

#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_structp png_ptr, png_longjmp_ptr longjmp_fn,
    size_t jmp_buf_size)
{
   if (png_ptr == NULL || jmp_buf_size != png_sizeof(jmp_buf))
      return NULL;

   png_ptr->longjmp_fn = longjmp_fn;
   return &png_ptr->jmpbuf;
}
#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 void /* PRIVATE */
png_default_error(png_structp png_ptr, png_const_charp error_message)
{
#ifdef PNG_CONSOLE_IO_SUPPORTED
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
   if (*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);
      fprintf(stderr, PNG_STRING_NEWLINE);
   }
#endif

#ifdef PNG_SETJMP_SUPPORTED
   if (png_ptr && png_ptr->longjmp_fn)
   {
#  ifdef USE_FAR_KEYWORD
   {
      jmp_buf jmpbuf;
      png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
     png_ptr->longjmp_fn(jmpbuf, 1);
   }
#  else
   png_ptr->longjmp_fn(png_ptr->jmpbuf, 1);
#  endif
   }
#endif
   /* Here if not setjmp support or if png_ptr is null. */
   PNG_ABORT();
#ifndef PNG_CONSOLE_IO_SUPPORTED
   error_message = error_message; /* Make compiler happy */
#endif
}

#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_structp 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
   warning_message = warning_message; /* Make compiler happy */
#endif
   png_ptr = png_ptr; /* Make compiler happy */
}
#endif /* PNG_WARNINGS_SUPPORTED */

/* 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 */
Commit	Line	Data
	1
	2	/* pngerror.c - stub functions for i/o and memory allocation
	3	*
	4	* Last changed in libpng 1.4.0 [January 3, 2010]
	5	* Copyright (c) 1998-2010 Glenn Randers-Pehrson
	6	* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
	7	* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
	8	*
	9	* This code is released under the libpng license.
	10	* For conditions of distribution and use, see the disclaimer
	11	* and license in png.h
	12	*
	13	* This file provides a location for all error handling. Users who
	14	* need special error handling are expected to write replacement functions
	15	* and use png_set_error_fn() to use those functions. See the instructions
	16	* at each function.
	17	*/
	18
	19	#define PNG_NO_PEDANTIC_WARNINGS
	20	#include "png.h"
	21	#if defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED)
	22	#include "pngpriv.h"
	23
	24	static void /* PRIVATE */
	25	png_default_error PNGARG((png_structp png_ptr,
	26	png_const_charp error_message)) PNG_NORETURN;
	27	#ifdef PNG_WARNINGS_SUPPORTED
	28	static void /* PRIVATE */
	29	png_default_warning PNGARG((png_structp png_ptr,
	30	png_const_charp warning_message));
	31	#endif /* PNG_WARNINGS_SUPPORTED */
	32
	33	/* This function is called whenever there is a fatal error. This function
	34	* should not be changed. If there is a need to handle errors differently,
	35	* you should supply a replacement error function and use png_set_error_fn()
	36	* to replace the error function at run-time.
	37	*/
	38	#ifdef PNG_ERROR_TEXT_SUPPORTED
	39	void PNGAPI
	40	png_error(png_structp png_ptr, png_const_charp error_message)
	41	{
	42	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
	43	char msg[16];
	44	if (png_ptr != NULL)
	45	{
	46	if (png_ptr->flags&
	47	(PNG_FLAG_STRIP_ERROR_NUMBERS\|PNG_FLAG_STRIP_ERROR_TEXT))
	48	{
	49	if (*error_message == PNG_LITERAL_SHARP)
	50	{
	51	/* Strip "#nnnn " from beginning of error message. */
	52	int offset;
	53	for (offset = 1; offset<15; offset++)
	54	if (error_message[offset] == ' ')
	55	break;
	56	if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
	57	{
	58	int i;
	59	for (i = 0; i < offset - 1; i++)
	60	msg[i] = error_message[i + 1];
	61	msg[i - 1] = '\0';
	62	error_message = msg;
	63	}
	64	else
	65	error_message += offset;
	66	}
	67	else
	68	{
	69	if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
	70	{
	71	msg[0] = '0';
	72	msg[1] = '\0';
	73	error_message = msg;
	74	}
	75	}
	76	}
	77	}
	78	#endif
	79	if (png_ptr != NULL && png_ptr->error_fn != NULL)
	80	(*(png_ptr->error_fn))(png_ptr, error_message);
	81
	82	/* If the custom handler doesn't exist, or if it returns,
	83	use the default handler, which will not return. */
	84	png_default_error(png_ptr, error_message);
	85	}
	86	#else
	87	void PNGAPI
	88	png_err(png_structp png_ptr)
	89	{
	90	if (png_ptr != NULL && png_ptr->error_fn != NULL)
	91	(*(png_ptr->error_fn))(png_ptr, '\0');
	92
	93	/* If the custom handler doesn't exist, or if it returns,
	94	use the default handler, which will not return. */
	95	png_default_error(png_ptr, '\0');
	96	}
	97	#endif /* PNG_ERROR_TEXT_SUPPORTED */
	98
	99	#ifdef PNG_WARNINGS_SUPPORTED
	100	/* This function is called whenever there is a non-fatal error. This function
	101	* should not be changed. If there is a need to handle warnings differently,
	102	* you should supply a replacement warning function and use
	103	* png_set_error_fn() to replace the warning function at run-time.
	104	*/
	105	void PNGAPI
	106	png_warning(png_structp png_ptr, png_const_charp warning_message)
	107	{
	108	int offset = 0;
	109	if (png_ptr != NULL)
	110	{
	111	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
	112	if (png_ptr->flags&
	113	(PNG_FLAG_STRIP_ERROR_NUMBERS\|PNG_FLAG_STRIP_ERROR_TEXT))
	114	#endif
	115	{
	116	if (*warning_message == PNG_LITERAL_SHARP)
	117	{
	118	for (offset = 1; offset < 15; offset++)
	119	if (warning_message[offset] == ' ')
	120	break;
	121	}
	122	}
	123	}
	124	if (png_ptr != NULL && png_ptr->warning_fn != NULL)
	125	(*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
	126	else
	127	png_default_warning(png_ptr, warning_message + offset);
	128	}
	129	#endif /* PNG_WARNINGS_SUPPORTED */
	130
	131	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
	132	void PNGAPI
	133	png_benign_error(png_structp png_ptr, png_const_charp error_message)
	134	{
	135	if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
	136	png_warning(png_ptr, error_message);
	137	else
	138	png_error(png_ptr, error_message);
	139	}
	140	#endif
	141
	142	/* These utilities are used internally to build an error message that relates
	143	* to the current chunk. The chunk name comes from png_ptr->chunk_name,
	144	* this is used to prefix the message. The message is limited in length
	145	* to 63 bytes, the name characters are output as hex digits wrapped in []
	146	* if the character is invalid.
	147	*/
	148	#define isnonalpha(c) ((c) < 65 \|\| (c) > 122 \|\| ((c) > 90 && (c) < 97))
	149	static PNG_CONST char png_digit[16] = {
	150	'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
	151	'A', 'B', 'C', 'D', 'E', 'F'
	152	};
	153
	154	#define PNG_MAX_ERROR_TEXT 64
	155	#if defined(PNG_WARNINGS_SUPPORTED) \|\| defined(PNG_ERROR_TEXT_SUPPORTED)
	156	static void /* PRIVATE */
	157	png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
	158	error_message)
	159	{
	160	int iout = 0, iin = 0;
	161
	162	while (iin < 4)
	163	{
	164	int c = png_ptr->chunk_name[iin++];
	165	if (isnonalpha(c))
	166	{
	167	buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
	168	buffer[iout++] = png_digit[(c & 0xf0) >> 4];
	169	buffer[iout++] = png_digit[c & 0x0f];
	170	buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
	171	}
	172	else
	173	{
	174	buffer[iout++] = (png_byte)c;
	175	}
	176	}
	177
	178	if (error_message == NULL)
	179	buffer[iout] = '\0';
	180	else
	181	{
	182	buffer[iout++] = ':';
	183	buffer[iout++] = ' ';
	184	png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
	185	buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
	186	}
	187	}
	188
	189	#ifdef PNG_READ_SUPPORTED
	190	void PNGAPI
	191	png_chunk_error(png_structp png_ptr, png_const_charp error_message)
	192	{
	193	char msg[18+PNG_MAX_ERROR_TEXT];
	194	if (png_ptr == NULL)
	195	png_error(png_ptr, error_message);
	196	else
	197	{
	198	png_format_buffer(png_ptr, msg, error_message);
	199	png_error(png_ptr, msg);
	200	}
	201	}
	202	#endif /* PNG_READ_SUPPORTED */
	203	#endif /* PNG_WARNINGS_SUPPORTED \|\| PNG_ERROR_TEXT_SUPPORTED */
	204
	205	#ifdef PNG_WARNINGS_SUPPORTED
	206	void PNGAPI
	207	png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
	208	{
	209	char msg[18+PNG_MAX_ERROR_TEXT];
	210	if (png_ptr == NULL)
	211	png_warning(png_ptr, warning_message);
	212	else
	213	{
	214	png_format_buffer(png_ptr, msg, warning_message);
	215	png_warning(png_ptr, msg);
	216	}
	217	}
	218	#endif /* PNG_WARNINGS_SUPPORTED */
	219
	220	#ifdef PNG_READ_SUPPORTED
	221	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
	222	void PNGAPI
	223	png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
	224	{
	225	if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
	226	png_chunk_warning(png_ptr, error_message);
	227	else
	228	png_chunk_error(png_ptr, error_message);
	229	}
	230	#endif
	231	#endif /* PNG_READ_SUPPORTED */
	232
	233	#ifdef PNG_SETJMP_SUPPORTED
	234	/* This API only exists if ANSI-C style error handling is used,
	235	* otherwise it is necessary for png_default_error to be overridden.
	236	*/
	237	jmp_buf* PNGAPI
	238	png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
	239	size_t jmp_buf_size)
	240	{
	241	if (png_ptr == NULL \|\| jmp_buf_size != png_sizeof(jmp_buf))
	242	return NULL;
	243
	244	png_ptr->longjmp_fn = longjmp_fn;
	245	return &png_ptr->jmpbuf;
	246	}
	247	#endif
	248
	249	/* This is the default error handling function. Note that replacements for
	250	* this function MUST NOT RETURN, or the program will likely crash. This
	251	* function is used by default, or if the program supplies NULL for the
	252	* error function pointer in png_set_error_fn().
	253	*/
	254	static void /* PRIVATE */
	255	png_default_error(png_structp png_ptr, png_const_charp error_message)
	256	{
	257	#ifdef PNG_CONSOLE_IO_SUPPORTED
	258	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
	259	if (*error_message == PNG_LITERAL_SHARP)
	260	{
	261	/* Strip "#nnnn " from beginning of error message. */
	262	int offset;
	263	char error_number[16];
	264	for (offset = 0; offset<15; offset++)
	265	{
	266	error_number[offset] = error_message[offset + 1];
	267	if (error_message[offset] == ' ')
	268	break;
	269	}
	270	if ((offset > 1) && (offset < 15))
	271	{
	272	error_number[offset - 1] = '\0';
	273	fprintf(stderr, "libpng error no. %s: %s",
	274	error_number, error_message + offset + 1);
	275	fprintf(stderr, PNG_STRING_NEWLINE);
	276	}
	277	else
	278	{
	279	fprintf(stderr, "libpng error: %s, offset=%d",
	280	error_message, offset);
	281	fprintf(stderr, PNG_STRING_NEWLINE);
	282	}
	283	}
	284	else
	285	#endif
	286	{
	287	fprintf(stderr, "libpng error: %s", error_message);
	288	fprintf(stderr, PNG_STRING_NEWLINE);
	289	}
	290	#endif
	291
	292	#ifdef PNG_SETJMP_SUPPORTED
	293	if (png_ptr && png_ptr->longjmp_fn)
	294	{
	295	# ifdef USE_FAR_KEYWORD
	296	{
	297	jmp_buf jmpbuf;
	298	png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
	299	png_ptr->longjmp_fn(jmpbuf, 1);
	300	}
	301	# else
	302	png_ptr->longjmp_fn(png_ptr->jmpbuf, 1);
	303	# endif
	304	}
	305	#endif
	306	/* Here if not setjmp support or if png_ptr is null. */
	307	PNG_ABORT();
	308	#ifndef PNG_CONSOLE_IO_SUPPORTED
	309	error_message = error_message; /* Make compiler happy */
	310	#endif
	311	}
	312
	313	#ifdef PNG_WARNINGS_SUPPORTED
	314	/* This function is called when there is a warning, but the library thinks
	315	* it can continue anyway. Replacement functions don't have to do anything
	316	* here if you don't want them to. In the default configuration, png_ptr is
	317	* not used, but it is passed in case it may be useful.
	318	*/
	319	static void /* PRIVATE */
	320	png_default_warning(png_structp png_ptr, png_const_charp warning_message)
	321	{
	322	#ifdef PNG_CONSOLE_IO_SUPPORTED
	323	# ifdef PNG_ERROR_NUMBERS_SUPPORTED
	324	if (*warning_message == PNG_LITERAL_SHARP)
	325	{
	326	int offset;
	327	char warning_number[16];
	328	for (offset = 0; offset < 15; offset++)
	329	{
	330	warning_number[offset] = warning_message[offset + 1];
	331	if (warning_message[offset] == ' ')
	332	break;
	333	}
	334	if ((offset > 1) && (offset < 15))
	335	{
	336	warning_number[offset + 1] = '\0';
	337	fprintf(stderr, "libpng warning no. %s: %s",
	338	warning_number, warning_message + offset);
	339	fprintf(stderr, PNG_STRING_NEWLINE);
	340	}
	341	else
	342	{
	343	fprintf(stderr, "libpng warning: %s",
	344	warning_message);
	345	fprintf(stderr, PNG_STRING_NEWLINE);
	346	}
	347	}
	348	else
	349	# endif
	350	{
	351	fprintf(stderr, "libpng warning: %s", warning_message);
	352	fprintf(stderr, PNG_STRING_NEWLINE);
	353	}
	354	#else
	355	warning_message = warning_message; /* Make compiler happy */
	356	#endif
	357	png_ptr = png_ptr; /* Make compiler happy */
	358	}
	359	#endif /* PNG_WARNINGS_SUPPORTED */
	360
	361	/* This function is called when the application wants to use another method
	362	* of handling errors and warnings. Note that the error function MUST NOT
	363	* return to the calling routine or serious problems will occur. The return
	364	* method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
	365	*/
	366	void PNGAPI
	367	png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
	368	png_error_ptr error_fn, png_error_ptr warning_fn)
	369	{
	370	if (png_ptr == NULL)
	371	return;
	372	png_ptr->error_ptr = error_ptr;
	373	png_ptr->error_fn = error_fn;
	374	png_ptr->warning_fn = warning_fn;
	375	}
	376
	377
	378	/* This function returns a pointer to the error_ptr associated with the user
	379	* functions. The application should free any memory associated with this
	380	* pointer before png_write_destroy and png_read_destroy are called.
	381	*/
	382	png_voidp PNGAPI
	383	png_get_error_ptr(png_structp png_ptr)
	384	{
	385	if (png_ptr == NULL)
	386	return NULL;
	387	return ((png_voidp)png_ptr->error_ptr);
	388	}
	389
	390
	391	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
	392	void PNGAPI
	393	png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
	394	{
	395	if (png_ptr != NULL)
	396	{
	397	png_ptr->flags &=
	398	((~(PNG_FLAG_STRIP_ERROR_NUMBERS\|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
	399	}
	400	}
	401	#endif
	402	#endif /* PNG_READ_SUPPORTED \|\| PNG_WRITE_SUPPORTED */