michael@0: 
michael@0: /* pngerror.c - stub functions for i/o and memory allocation
michael@0:  *
michael@0:  * Last changed in libpng 1.6.10 [March 6, 2014]
michael@0:  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
michael@0:  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
michael@0:  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
michael@0:  *
michael@0:  * This code is released under the libpng license.
michael@0:  * For conditions of distribution and use, see the disclaimer
michael@0:  * and license in png.h
michael@0:  *
michael@0:  * This file provides a location for all error handling.  Users who
michael@0:  * need special error handling are expected to write replacement functions
michael@0:  * and use png_set_error_fn() to use those functions.  See the instructions
michael@0:  * at each function.
michael@0:  */
michael@0: 
michael@0: #include "pngpriv.h"
michael@0: 
michael@0: #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
michael@0: 
michael@0: static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
michael@0:     png_const_charp error_message)),PNG_NORETURN);
michael@0: 
michael@0: #ifdef PNG_WARNINGS_SUPPORTED
michael@0: static void /* PRIVATE */
michael@0: png_default_warning PNGARG((png_const_structrp png_ptr,
michael@0:    png_const_charp warning_message));
michael@0: #endif /* PNG_WARNINGS_SUPPORTED */
michael@0: 
michael@0: /* This function is called whenever there is a fatal error.  This function
michael@0:  * should not be changed.  If there is a need to handle errors differently,
michael@0:  * you should supply a replacement error function and use png_set_error_fn()
michael@0:  * to replace the error function at run-time.
michael@0:  */
michael@0: #ifdef PNG_ERROR_TEXT_SUPPORTED
michael@0: PNG_FUNCTION(void,PNGAPI
michael@0: png_error,(png_const_structrp png_ptr, png_const_charp error_message),
michael@0:    PNG_NORETURN)
michael@0: {
michael@0: #ifdef PNG_ERROR_NUMBERS_SUPPORTED
michael@0:    char msg[16];
michael@0:    if (png_ptr != NULL)
michael@0:    {
michael@0:       if (png_ptr->flags&
michael@0:          (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
michael@0:       {
michael@0:          if (*error_message == PNG_LITERAL_SHARP)
michael@0:          {
michael@0:             /* Strip "#nnnn " from beginning of error message. */
michael@0:             int offset;
michael@0:             for (offset = 1; offset<15; offset++)
michael@0:                if (error_message[offset] == ' ')
michael@0:                   break;
michael@0: 
michael@0:             if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
michael@0:             {
michael@0:                int i;
michael@0:                for (i = 0; i < offset - 1; i++)
michael@0:                   msg[i] = error_message[i + 1];
michael@0:                msg[i - 1] = '\0';
michael@0:                error_message = msg;
michael@0:             }
michael@0: 
michael@0:             else
michael@0:                error_message += offset;
michael@0:       }
michael@0: 
michael@0:       else
michael@0:       {
michael@0:          if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
michael@0:          {
michael@0:             msg[0] = '0';
michael@0:             msg[1] = '\0';
michael@0:             error_message = msg;
michael@0:          }
michael@0:        }
michael@0:      }
michael@0:    }
michael@0: #endif
michael@0:    if (png_ptr != NULL && png_ptr->error_fn != NULL)
michael@0:       (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
michael@0:           error_message);
michael@0: 
michael@0:    /* If the custom handler doesn't exist, or if it returns,
michael@0:       use the default handler, which will not return. */
michael@0:    png_default_error(png_ptr, error_message);
michael@0: }
michael@0: #else
michael@0: PNG_FUNCTION(void,PNGAPI
michael@0: png_err,(png_const_structrp png_ptr),PNG_NORETURN)
michael@0: {
michael@0:    /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
michael@0:     * erroneously as '\0', instead of the empty string "".  This was
michael@0:     * apparently an error, introduced in libpng-1.2.20, and png_default_error
michael@0:     * will crash in this case.
michael@0:     */
michael@0:    if (png_ptr != NULL && png_ptr->error_fn != NULL)
michael@0:       (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
michael@0: 
michael@0:    /* If the custom handler doesn't exist, or if it returns,
michael@0:       use the default handler, which will not return. */
michael@0:    png_default_error(png_ptr, "");
michael@0: }
michael@0: #endif /* PNG_ERROR_TEXT_SUPPORTED */
michael@0: 
michael@0: /* Utility to safely appends strings to a buffer.  This never errors out so
michael@0:  * error checking is not required in the caller.
michael@0:  */
michael@0: size_t
michael@0: png_safecat(png_charp buffer, size_t bufsize, size_t pos,
michael@0:    png_const_charp string)
michael@0: {
michael@0:    if (buffer != NULL && pos < bufsize)
michael@0:    {
michael@0:       if (string != NULL)
michael@0:          while (*string != '\0' && pos < bufsize-1)
michael@0:            buffer[pos++] = *string++;
michael@0: 
michael@0:       buffer[pos] = '\0';
michael@0:    }
michael@0: 
michael@0:    return pos;
michael@0: }
michael@0: 
michael@0: #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
michael@0: /* Utility to dump an unsigned value into a buffer, given a start pointer and
michael@0:  * and end pointer (which should point just *beyond* the end of the buffer!)
michael@0:  * Returns the pointer to the start of the formatted string.
michael@0:  */
michael@0: png_charp
michael@0: png_format_number(png_const_charp start, png_charp end, int format,
michael@0:    png_alloc_size_t number)
michael@0: {
michael@0:    int count = 0;    /* number of digits output */
michael@0:    int mincount = 1; /* minimum number required */
michael@0:    int output = 0;   /* digit output (for the fixed point format) */
michael@0: 
michael@0:    *--end = '\0';
michael@0: 
michael@0:    /* This is written so that the loop always runs at least once, even with
michael@0:     * number zero.
michael@0:     */
michael@0:    while (end > start && (number != 0 || count < mincount))
michael@0:    {
michael@0: 
michael@0:       static const char digits[] = "0123456789ABCDEF";
michael@0: 
michael@0:       switch (format)
michael@0:       {
michael@0:          case PNG_NUMBER_FORMAT_fixed:
michael@0:             /* Needs five digits (the fraction) */
michael@0:             mincount = 5;
michael@0:             if (output || number % 10 != 0)
michael@0:             {
michael@0:                *--end = digits[number % 10];
michael@0:                output = 1;
michael@0:             }
michael@0:             number /= 10;
michael@0:             break;
michael@0: 
michael@0:          case PNG_NUMBER_FORMAT_02u:
michael@0:             /* Expects at least 2 digits. */
michael@0:             mincount = 2;
michael@0:             /* FALL THROUGH */
michael@0: 
michael@0:          case PNG_NUMBER_FORMAT_u:
michael@0:             *--end = digits[number % 10];
michael@0:             number /= 10;
michael@0:             break;
michael@0: 
michael@0:          case PNG_NUMBER_FORMAT_02x:
michael@0:             /* This format expects at least two digits */
michael@0:             mincount = 2;
michael@0:             /* FALL THROUGH */
michael@0: 
michael@0:          case PNG_NUMBER_FORMAT_x:
michael@0:             *--end = digits[number & 0xf];
michael@0:             number >>= 4;
michael@0:             break;
michael@0: 
michael@0:          default: /* an error */
michael@0:             number = 0;
michael@0:             break;
michael@0:       }
michael@0: 
michael@0:       /* Keep track of the number of digits added */
michael@0:       ++count;
michael@0: 
michael@0:       /* Float a fixed number here: */
michael@0:       if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
michael@0:       {
michael@0:          /* End of the fraction, but maybe nothing was output?  In that case
michael@0:           * drop the decimal point.  If the number is a true zero handle that
michael@0:           * here.
michael@0:           */
michael@0:          if (output)
michael@0:             *--end = '.';
michael@0:          else if (number == 0) /* and !output */
michael@0:             *--end = '0';
michael@0:       }
michael@0:    }
michael@0: 
michael@0:    return end;
michael@0: }
michael@0: #endif
michael@0: 
michael@0: #ifdef PNG_WARNINGS_SUPPORTED
michael@0: /* This function is called whenever there is a non-fatal error.  This function
michael@0:  * should not be changed.  If there is a need to handle warnings differently,
michael@0:  * you should supply a replacement warning function and use
michael@0:  * png_set_error_fn() to replace the warning function at run-time.
michael@0:  */
michael@0: void PNGAPI
michael@0: png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
michael@0: {
michael@0:    int offset = 0;
michael@0:    if (png_ptr != NULL)
michael@0:    {
michael@0: #ifdef PNG_ERROR_NUMBERS_SUPPORTED
michael@0:    if (png_ptr->flags&
michael@0:        (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
michael@0: #endif
michael@0:       {
michael@0:          if (*warning_message == PNG_LITERAL_SHARP)
michael@0:          {
michael@0:             for (offset = 1; offset < 15; offset++)
michael@0:                if (warning_message[offset] == ' ')
michael@0:                   break;
michael@0:          }
michael@0:       }
michael@0:    }
michael@0:    if (png_ptr != NULL && png_ptr->warning_fn != NULL)
michael@0:       (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
michael@0:          warning_message + offset);
michael@0:    else
michael@0:       png_default_warning(png_ptr, warning_message + offset);
michael@0: }
michael@0: 
michael@0: /* These functions support 'formatted' warning messages with up to
michael@0:  * PNG_WARNING_PARAMETER_COUNT parameters.  In the format string the parameter
michael@0:  * is introduced by @<number>, where 'number' starts at 1.  This follows the
michael@0:  * standard established by X/Open for internationalizable error messages.
michael@0:  */
michael@0: void
michael@0: png_warning_parameter(png_warning_parameters p, int number,
michael@0:    png_const_charp string)
michael@0: {
michael@0:    if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
michael@0:       (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
michael@0: }
michael@0: 
michael@0: void
michael@0: png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
michael@0:    png_alloc_size_t value)
michael@0: {
michael@0:    char buffer[PNG_NUMBER_BUFFER_SIZE];
michael@0:    png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
michael@0: }
michael@0: 
michael@0: void
michael@0: png_warning_parameter_signed(png_warning_parameters p, int number, int format,
michael@0:    png_int_32 value)
michael@0: {
michael@0:    png_alloc_size_t u;
michael@0:    png_charp str;
michael@0:    char buffer[PNG_NUMBER_BUFFER_SIZE];
michael@0: 
michael@0:    /* Avoid overflow by doing the negate in a png_alloc_size_t: */
michael@0:    u = (png_alloc_size_t)value;
michael@0:    if (value < 0)
michael@0:       u = ~u + 1;
michael@0: 
michael@0:    str = PNG_FORMAT_NUMBER(buffer, format, u);
michael@0: 
michael@0:    if (value < 0 && str > buffer)
michael@0:       *--str = '-';
michael@0: 
michael@0:    png_warning_parameter(p, number, str);
michael@0: }
michael@0: 
michael@0: void
michael@0: png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
michael@0:    png_const_charp message)
michael@0: {
michael@0:    /* The internal buffer is just 192 bytes - enough for all our messages,
michael@0:     * overflow doesn't happen because this code checks!  If someone figures
michael@0:     * out how to send us a message longer than 192 bytes, all that will
michael@0:     * happen is that the message will be truncated appropriately.
michael@0:     */
michael@0:    size_t i = 0; /* Index in the msg[] buffer: */
michael@0:    char msg[192];
michael@0: 
michael@0:    /* Each iteration through the following loop writes at most one character
michael@0:     * to msg[i++] then returns here to validate that there is still space for
michael@0:     * the trailing '\0'.  It may (in the case of a parameter) read more than
michael@0:     * one character from message[]; it must check for '\0' and continue to the
michael@0:     * test if it finds the end of string.
michael@0:     */
michael@0:    while (i<(sizeof msg)-1 && *message != '\0')
michael@0:    {
michael@0:       /* '@' at end of string is now just printed (previously it was skipped);
michael@0:        * it is an error in the calling code to terminate the string with @.
michael@0:        */
michael@0:       if (p != NULL && *message == '@' && message[1] != '\0')
michael@0:       {
michael@0:          int parameter_char = *++message; /* Consume the '@' */
michael@0:          static const char valid_parameters[] = "123456789";
michael@0:          int parameter = 0;
michael@0: 
michael@0:          /* Search for the parameter digit, the index in the string is the
michael@0:           * parameter to use.
michael@0:           */
michael@0:          while (valid_parameters[parameter] != parameter_char &&
michael@0:             valid_parameters[parameter] != '\0')
michael@0:             ++parameter;
michael@0: 
michael@0:          /* If the parameter digit is out of range it will just get printed. */
michael@0:          if (parameter < PNG_WARNING_PARAMETER_COUNT)
michael@0:          {
michael@0:             /* Append this parameter */
michael@0:             png_const_charp parm = p[parameter];
michael@0:             png_const_charp pend = p[parameter] + (sizeof p[parameter]);
michael@0: 
michael@0:             /* No need to copy the trailing '\0' here, but there is no guarantee
michael@0:              * that parm[] has been initialized, so there is no guarantee of a
michael@0:              * trailing '\0':
michael@0:              */
michael@0:             while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
michael@0:                msg[i++] = *parm++;
michael@0: 
michael@0:             /* Consume the parameter digit too: */
michael@0:             ++message;
michael@0:             continue;
michael@0:          }
michael@0: 
michael@0:          /* else not a parameter and there is a character after the @ sign; just
michael@0:           * copy that.  This is known not to be '\0' because of the test above.
michael@0:           */
michael@0:       }
michael@0: 
michael@0:       /* At this point *message can't be '\0', even in the bad parameter case
michael@0:        * above where there is a lone '@' at the end of the message string.
michael@0:        */
michael@0:       msg[i++] = *message++;
michael@0:    }
michael@0: 
michael@0:    /* i is always less than (sizeof msg), so: */
michael@0:    msg[i] = '\0';
michael@0: 
michael@0:    /* And this is the formatted message. It may be larger than
michael@0:     * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
michael@0:     * are not (currently) formatted.
michael@0:     */
michael@0:    png_warning(png_ptr, msg);
michael@0: }
michael@0: #endif /* PNG_WARNINGS_SUPPORTED */
michael@0: 
michael@0: #ifdef PNG_BENIGN_ERRORS_SUPPORTED
michael@0: void PNGAPI
michael@0: png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
michael@0: {
michael@0:    if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
michael@0:    {
michael@0: #     ifdef PNG_READ_SUPPORTED
michael@0:          if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
michael@0:             png_ptr->chunk_name != 0)
michael@0:             png_chunk_warning(png_ptr, error_message);
michael@0:          else
michael@0: #     endif
michael@0:       png_warning(png_ptr, error_message);
michael@0:    }
michael@0: 
michael@0:    else
michael@0:    {
michael@0: #     ifdef PNG_READ_SUPPORTED
michael@0:          if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
michael@0:             png_ptr->chunk_name != 0)
michael@0:             png_chunk_error(png_ptr, error_message);
michael@0:          else
michael@0: #     endif
michael@0:       png_error(png_ptr, error_message);
michael@0:    }
michael@0: 
michael@0: #  ifndef PNG_ERROR_TEXT_SUPPORTED
michael@0:       PNG_UNUSED(error_message)
michael@0: #  endif
michael@0: }
michael@0: 
michael@0: void /* PRIVATE */
michael@0: png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
michael@0: {
michael@0:   if (png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN)
michael@0:      png_warning(png_ptr, error_message);
michael@0:   else
michael@0:      png_error(png_ptr, error_message);
michael@0: 
michael@0: #  ifndef PNG_ERROR_TEXT_SUPPORTED
michael@0:       PNG_UNUSED(error_message)
michael@0: #  endif
michael@0: }
michael@0: 
michael@0: void /* PRIVATE */
michael@0: png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
michael@0: {
michael@0:   if (png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN)
michael@0:      png_warning(png_ptr, error_message);
michael@0:   else
michael@0:      png_error(png_ptr, error_message);
michael@0: 
michael@0: #  ifndef PNG_ERROR_TEXT_SUPPORTED
michael@0:       PNG_UNUSED(error_message)
michael@0: #  endif
michael@0: }
michael@0: #endif /* BENIGN_ERRORS */
michael@0: 
michael@0: /* These utilities are used internally to build an error message that relates
michael@0:  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
michael@0:  * this is used to prefix the message.  The message is limited in length
michael@0:  * to 63 bytes, the name characters are output as hex digits wrapped in []
michael@0:  * if the character is invalid.
michael@0:  */
michael@0: #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
michael@0: static PNG_CONST char png_digit[16] = {
michael@0:    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
michael@0:    'A', 'B', 'C', 'D', 'E', 'F'
michael@0: };
michael@0: 
michael@0: #define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
michael@0: #if defined(PNG_WARNINGS_SUPPORTED) || \
michael@0:    (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
michael@0: static void /* PRIVATE */
michael@0: png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
michael@0:     error_message)
michael@0: {
michael@0:    png_uint_32 chunk_name = png_ptr->chunk_name;
michael@0:    int iout = 0, ishift = 24;
michael@0: 
michael@0:    while (ishift >= 0)
michael@0:    {
michael@0:       int c = (int)(chunk_name >> ishift) & 0xff;
michael@0: 
michael@0:       ishift -= 8;
michael@0:       if (isnonalpha(c))
michael@0:       {
michael@0:          buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
michael@0:          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
michael@0:          buffer[iout++] = png_digit[c & 0x0f];
michael@0:          buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
michael@0:       }
michael@0: 
michael@0:       else
michael@0:       {
michael@0:          buffer[iout++] = (char)c;
michael@0:       }
michael@0:    }
michael@0: 
michael@0:    if (error_message == NULL)
michael@0:       buffer[iout] = '\0';
michael@0: 
michael@0:    else
michael@0:    {
michael@0:       int iin = 0;
michael@0: 
michael@0:       buffer[iout++] = ':';
michael@0:       buffer[iout++] = ' ';
michael@0: 
michael@0:       while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
michael@0:          buffer[iout++] = error_message[iin++];
michael@0: 
michael@0:       /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
michael@0:       buffer[iout] = '\0';
michael@0:    }
michael@0: }
michael@0: #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
michael@0: 
michael@0: #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
michael@0: PNG_FUNCTION(void,PNGAPI
michael@0: png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
michael@0:    PNG_NORETURN)
michael@0: {
michael@0:    char msg[18+PNG_MAX_ERROR_TEXT];
michael@0:    if (png_ptr == NULL)
michael@0:       png_error(png_ptr, error_message);
michael@0: 
michael@0:    else
michael@0:    {
michael@0:       png_format_buffer(png_ptr, msg, error_message);
michael@0:       png_error(png_ptr, msg);
michael@0:    }
michael@0: }
michael@0: #endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
michael@0: 
michael@0: #ifdef PNG_WARNINGS_SUPPORTED
michael@0: void PNGAPI
michael@0: png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
michael@0: {
michael@0:    char msg[18+PNG_MAX_ERROR_TEXT];
michael@0:    if (png_ptr == NULL)
michael@0:       png_warning(png_ptr, warning_message);
michael@0: 
michael@0:    else
michael@0:    {
michael@0:       png_format_buffer(png_ptr, msg, warning_message);
michael@0:       png_warning(png_ptr, msg);
michael@0:    }
michael@0: }
michael@0: #endif /* PNG_WARNINGS_SUPPORTED */
michael@0: 
michael@0: #ifdef PNG_READ_SUPPORTED
michael@0: #ifdef PNG_BENIGN_ERRORS_SUPPORTED
michael@0: void PNGAPI
michael@0: png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
michael@0:     error_message)
michael@0: {
michael@0:    if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
michael@0:       png_chunk_warning(png_ptr, error_message);
michael@0: 
michael@0:    else
michael@0:       png_chunk_error(png_ptr, error_message);
michael@0: 
michael@0: #  ifndef PNG_ERROR_TEXT_SUPPORTED
michael@0:       PNG_UNUSED(error_message)
michael@0: #  endif
michael@0: }
michael@0: #endif
michael@0: #endif /* PNG_READ_SUPPORTED */
michael@0: 
michael@0: void /* PRIVATE */
michael@0: png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
michael@0: {
michael@0: #  ifndef PNG_WARNINGS_SUPPORTED
michael@0:       PNG_UNUSED(message)
michael@0: #  endif
michael@0: 
michael@0:    /* This is always supported, but for just read or just write it
michael@0:     * unconditionally does the right thing.
michael@0:     */
michael@0: #  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
michael@0:       if (png_ptr->mode & PNG_IS_READ_STRUCT)
michael@0: #  endif
michael@0: 
michael@0: #  ifdef PNG_READ_SUPPORTED
michael@0:       {
michael@0:          if (error < PNG_CHUNK_ERROR)
michael@0:             png_chunk_warning(png_ptr, message);
michael@0: 
michael@0:          else
michael@0:             png_chunk_benign_error(png_ptr, message);
michael@0:       }
michael@0: #  endif
michael@0: 
michael@0: #  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
michael@0:       else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
michael@0: #  endif
michael@0: 
michael@0: #  ifdef PNG_WRITE_SUPPORTED
michael@0:       {
michael@0:          if (error < PNG_CHUNK_WRITE_ERROR)
michael@0:             png_app_warning(png_ptr, message);
michael@0: 
michael@0:          else
michael@0:             png_app_error(png_ptr, message);
michael@0:       }
michael@0: #  endif
michael@0: }
michael@0: 
michael@0: #ifdef PNG_ERROR_TEXT_SUPPORTED
michael@0: #ifdef PNG_FLOATING_POINT_SUPPORTED
michael@0: PNG_FUNCTION(void,
michael@0: png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
michael@0: {
michael@0: #  define fixed_message "fixed point overflow in "
michael@0: #  define fixed_message_ln ((sizeof fixed_message)-1)
michael@0:    int  iin;
michael@0:    char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
michael@0:    memcpy(msg, fixed_message, fixed_message_ln);
michael@0:    iin = 0;
michael@0:    if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
michael@0:    {
michael@0:       msg[fixed_message_ln + iin] = name[iin];
michael@0:       ++iin;
michael@0:    }
michael@0:    msg[fixed_message_ln + iin] = 0;
michael@0:    png_error(png_ptr, msg);
michael@0: }
michael@0: #endif
michael@0: #endif
michael@0: 
michael@0: #ifdef PNG_SETJMP_SUPPORTED
michael@0: /* This API only exists if ANSI-C style error handling is used,
michael@0:  * otherwise it is necessary for png_default_error to be overridden.
michael@0:  */
michael@0: jmp_buf* PNGAPI
michael@0: png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
michael@0:     size_t jmp_buf_size)
michael@0: {
michael@0:    /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
michael@0:     * and it must not change after that.  Libpng doesn't care how big the
michael@0:     * buffer is, just that it doesn't change.
michael@0:     *
michael@0:     * If the buffer size is no *larger* than the size of jmp_buf when libpng is
michael@0:     * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
michael@0:     * semantics that this call will not fail.  If the size is larger, however,
michael@0:     * the buffer is allocated and this may fail, causing the function to return
michael@0:     * NULL.
michael@0:     */
michael@0:    if (png_ptr == NULL)
michael@0:       return NULL;
michael@0: 
michael@0:    if (png_ptr->jmp_buf_ptr == NULL)
michael@0:    {
michael@0:       png_ptr->jmp_buf_size = 0; /* not allocated */
michael@0: 
michael@0:       if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
michael@0:          png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
michael@0: 
michael@0:       else
michael@0:       {
michael@0:          png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
michael@0:             png_malloc_warn(png_ptr, jmp_buf_size));
michael@0: 
michael@0:          if (png_ptr->jmp_buf_ptr == NULL)
michael@0:             return NULL; /* new NULL return on OOM */
michael@0: 
michael@0:          png_ptr->jmp_buf_size = jmp_buf_size;
michael@0:       }
michael@0:    }
michael@0: 
michael@0:    else /* Already allocated: check the size */
michael@0:    {
michael@0:       size_t size = png_ptr->jmp_buf_size;
michael@0: 
michael@0:       if (size == 0)
michael@0:       {
michael@0:          size = (sizeof png_ptr->jmp_buf_local);
michael@0:          if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
michael@0:          {
michael@0:             /* This is an internal error in libpng: somehow we have been left
michael@0:              * with a stack allocated jmp_buf when the application regained
michael@0:              * control.  It's always possible to fix this up, but for the moment
michael@0:              * this is a png_error because that makes it easy to detect.
michael@0:              */
michael@0:             png_error(png_ptr, "Libpng jmp_buf still allocated");
michael@0:             /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
michael@0:          }
michael@0:       }
michael@0: 
michael@0:       if (size != jmp_buf_size)
michael@0:       {
michael@0:          png_warning(png_ptr, "Application jmp_buf size changed");
michael@0:          return NULL; /* caller will probably crash: no choice here */
michael@0:       }
michael@0:    }
michael@0: 
michael@0:    /* Finally fill in the function, now we have a satisfactory buffer. It is
michael@0:     * valid to change the function on every call.
michael@0:     */
michael@0:    png_ptr->longjmp_fn = longjmp_fn;
michael@0:    return png_ptr->jmp_buf_ptr;
michael@0: }
michael@0: 
michael@0: void /* PRIVATE */
michael@0: png_free_jmpbuf(png_structrp png_ptr)
michael@0: {
michael@0:    if (png_ptr != NULL)
michael@0:    {
michael@0:       jmp_buf *jb = png_ptr->jmp_buf_ptr;
michael@0: 
michael@0:       /* A size of 0 is used to indicate a local, stack, allocation of the
michael@0:        * pointer; used here and in png.c
michael@0:        */
michael@0:       if (jb != NULL && png_ptr->jmp_buf_size > 0)
michael@0:       {
michael@0: 
michael@0:          /* This stuff is so that a failure to free the error control structure
michael@0:           * does not leave libpng in a state with no valid error handling: the
michael@0:           * free always succeeds, if there is an error it gets ignored.
michael@0:           */
michael@0:          if (jb != &png_ptr->jmp_buf_local)
michael@0:          {
michael@0:             /* Make an internal, libpng, jmp_buf to return here */
michael@0:             jmp_buf free_jmp_buf;
michael@0: 
michael@0:             if (!setjmp(free_jmp_buf))
michael@0:             {
michael@0:                png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
michael@0:                png_ptr->jmp_buf_size = 0; /* stack allocation */
michael@0:                png_ptr->longjmp_fn = longjmp;
michael@0:                png_free(png_ptr, jb); /* Return to setjmp on error */
michael@0:             }
michael@0:          }
michael@0:       }
michael@0: 
michael@0:       /* *Always* cancel everything out: */
michael@0:       png_ptr->jmp_buf_size = 0;
michael@0:       png_ptr->jmp_buf_ptr = NULL;
michael@0:       png_ptr->longjmp_fn = 0;
michael@0:    }
michael@0: }
michael@0: #endif
michael@0: 
michael@0: /* This is the default error handling function.  Note that replacements for
michael@0:  * this function MUST NOT RETURN, or the program will likely crash.  This
michael@0:  * function is used by default, or if the program supplies NULL for the
michael@0:  * error function pointer in png_set_error_fn().
michael@0:  */
michael@0: static PNG_FUNCTION(void /* PRIVATE */,
michael@0: png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
michael@0:    PNG_NORETURN)
michael@0: {
michael@0: #ifdef PNG_CONSOLE_IO_SUPPORTED
michael@0: #ifdef PNG_ERROR_NUMBERS_SUPPORTED
michael@0:    /* Check on NULL only added in 1.5.4 */
michael@0:    if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
michael@0:    {
michael@0:       /* Strip "#nnnn " from beginning of error message. */
michael@0:       int offset;
michael@0:       char error_number[16];
michael@0:       for (offset = 0; offset<15; offset++)
michael@0:       {
michael@0:          error_number[offset] = error_message[offset + 1];
michael@0:          if (error_message[offset] == ' ')
michael@0:             break;
michael@0:       }
michael@0: 
michael@0:       if ((offset > 1) && (offset < 15))
michael@0:       {
michael@0:          error_number[offset - 1] = '\0';
michael@0:          fprintf(stderr, "libpng error no. %s: %s",
michael@0:              error_number, error_message + offset + 1);
michael@0:          fprintf(stderr, PNG_STRING_NEWLINE);
michael@0:       }
michael@0: 
michael@0:       else
michael@0:       {
michael@0:          fprintf(stderr, "libpng error: %s, offset=%d",
michael@0:              error_message, offset);
michael@0:          fprintf(stderr, PNG_STRING_NEWLINE);
michael@0:       }
michael@0:    }
michael@0:    else
michael@0: #endif
michael@0:    {
michael@0:       fprintf(stderr, "libpng error: %s", error_message ? error_message :
michael@0:          "undefined");
michael@0:       fprintf(stderr, PNG_STRING_NEWLINE);
michael@0:    }
michael@0: #else
michael@0:    PNG_UNUSED(error_message) /* Make compiler happy */
michael@0: #endif
michael@0:    png_longjmp(png_ptr, 1);
michael@0: }
michael@0: 
michael@0: PNG_FUNCTION(void,PNGAPI
michael@0: png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
michael@0: {
michael@0: #ifdef PNG_SETJMP_SUPPORTED
michael@0:    if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
michael@0:       png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
michael@0: #endif
michael@0: 
michael@0:    /* If control reaches this point, png_longjmp() must not return. The only
michael@0:     * choice is to terminate the whole process (or maybe the thread); to do
michael@0:     * this the ANSI-C abort() function is used unless a different method is 
michael@0:     * implemented by overriding the default configuration setting for
michael@0:     * PNG_ABORT().
michael@0:     */
michael@0:    PNG_ABORT();
michael@0: }
michael@0: 
michael@0: #ifdef PNG_WARNINGS_SUPPORTED
michael@0: /* This function is called when there is a warning, but the library thinks
michael@0:  * it can continue anyway.  Replacement functions don't have to do anything
michael@0:  * here if you don't want them to.  In the default configuration, png_ptr is
michael@0:  * not used, but it is passed in case it may be useful.
michael@0:  */
michael@0: static void /* PRIVATE */
michael@0: png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
michael@0: {
michael@0: #ifdef PNG_CONSOLE_IO_SUPPORTED
michael@0: #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
michael@0:    if (*warning_message == PNG_LITERAL_SHARP)
michael@0:    {
michael@0:       int offset;
michael@0:       char warning_number[16];
michael@0:       for (offset = 0; offset < 15; offset++)
michael@0:       {
michael@0:          warning_number[offset] = warning_message[offset + 1];
michael@0:          if (warning_message[offset] == ' ')
michael@0:             break;
michael@0:       }
michael@0: 
michael@0:       if ((offset > 1) && (offset < 15))
michael@0:       {
michael@0:          warning_number[offset + 1] = '\0';
michael@0:          fprintf(stderr, "libpng warning no. %s: %s",
michael@0:              warning_number, warning_message + offset);
michael@0:          fprintf(stderr, PNG_STRING_NEWLINE);
michael@0:       }
michael@0: 
michael@0:       else
michael@0:       {
michael@0:          fprintf(stderr, "libpng warning: %s",
michael@0:              warning_message);
michael@0:          fprintf(stderr, PNG_STRING_NEWLINE);
michael@0:       }
michael@0:    }
michael@0:    else
michael@0: #  endif
michael@0: 
michael@0:    {
michael@0:       fprintf(stderr, "libpng warning: %s", warning_message);
michael@0:       fprintf(stderr, PNG_STRING_NEWLINE);
michael@0:    }
michael@0: #else
michael@0:    PNG_UNUSED(warning_message) /* Make compiler happy */
michael@0: #endif
michael@0:    PNG_UNUSED(png_ptr) /* Make compiler happy */
michael@0: }
michael@0: #endif /* PNG_WARNINGS_SUPPORTED */
michael@0: 
michael@0: /* This function is called when the application wants to use another method
michael@0:  * of handling errors and warnings.  Note that the error function MUST NOT
michael@0:  * return to the calling routine or serious problems will occur.  The return
michael@0:  * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
michael@0:  */
michael@0: void PNGAPI
michael@0: png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
michael@0:     png_error_ptr error_fn, png_error_ptr warning_fn)
michael@0: {
michael@0:    if (png_ptr == NULL)
michael@0:       return;
michael@0: 
michael@0:    png_ptr->error_ptr = error_ptr;
michael@0:    png_ptr->error_fn = error_fn;
michael@0: #ifdef PNG_WARNINGS_SUPPORTED
michael@0:    png_ptr->warning_fn = warning_fn;
michael@0: #else
michael@0:    PNG_UNUSED(warning_fn)
michael@0: #endif
michael@0: }
michael@0: 
michael@0: 
michael@0: /* This function returns a pointer to the error_ptr associated with the user
michael@0:  * functions.  The application should free any memory associated with this
michael@0:  * pointer before png_write_destroy and png_read_destroy are called.
michael@0:  */
michael@0: png_voidp PNGAPI
michael@0: png_get_error_ptr(png_const_structrp png_ptr)
michael@0: {
michael@0:    if (png_ptr == NULL)
michael@0:       return NULL;
michael@0: 
michael@0:    return ((png_voidp)png_ptr->error_ptr);
michael@0: }
michael@0: 
michael@0: 
michael@0: #ifdef PNG_ERROR_NUMBERS_SUPPORTED
michael@0: void PNGAPI
michael@0: png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
michael@0: {
michael@0:    if (png_ptr != NULL)
michael@0:    {
michael@0:       png_ptr->flags &=
michael@0:          ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
michael@0:          PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
michael@0:    }
michael@0: }
michael@0: #endif
michael@0: 
michael@0: #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
michael@0:    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
michael@0:    /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
michael@0:     * possible to implement without setjmp support just so long as there is some
michael@0:     * way to handle the error return here:
michael@0:     */
michael@0: PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
michael@0: png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
michael@0:    PNG_NORETURN)
michael@0: {
michael@0:    const png_const_structrp png_ptr = png_nonconst_ptr;
michael@0:    png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
michael@0: 
michael@0:    /* An error is always logged here, overwriting anything (typically a warning)
michael@0:     * that is already there:
michael@0:     */
michael@0:    if (image != NULL)
michael@0:    {
michael@0:       png_safecat(image->message, (sizeof image->message), 0, error_message);
michael@0:       image->warning_or_error |= PNG_IMAGE_ERROR;
michael@0: 
michael@0:       /* Retrieve the jmp_buf from within the png_control, making this work for
michael@0:        * C++ compilation too is pretty tricky: C++ wants a pointer to the first
michael@0:        * element of a jmp_buf, but C doesn't tell us the type of that.
michael@0:        */
michael@0:       if (image->opaque != NULL && image->opaque->error_buf != NULL)
michael@0:          longjmp(png_control_jmp_buf(image->opaque), 1);
michael@0: 
michael@0:       /* Missing longjmp buffer, the following is to help debugging: */
michael@0:       {
michael@0:          size_t pos = png_safecat(image->message, (sizeof image->message), 0,
michael@0:             "bad longjmp: ");
michael@0:          png_safecat(image->message, (sizeof image->message), pos,
michael@0:              error_message);
michael@0:       }
michael@0:    }
michael@0: 
michael@0:    /* Here on an internal programming error. */
michael@0:    abort();
michael@0: }
michael@0: 
michael@0: #ifdef PNG_WARNINGS_SUPPORTED
michael@0: void /* PRIVATE */ PNGCBAPI
michael@0: png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
michael@0: {
michael@0:    const png_const_structrp png_ptr = png_nonconst_ptr;
michael@0:    png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
michael@0: 
michael@0:    /* A warning is only logged if there is no prior warning or error. */
michael@0:    if (image->warning_or_error == 0)
michael@0:    {
michael@0:       png_safecat(image->message, (sizeof image->message), 0, warning_message);
michael@0:       image->warning_or_error |= PNG_IMAGE_WARNING;
michael@0:    }
michael@0: }
michael@0: #endif
michael@0: 
michael@0: int /* PRIVATE */
michael@0: png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
michael@0: {
michael@0:    volatile png_imagep image = image_in;
michael@0:    volatile int result;
michael@0:    volatile png_voidp saved_error_buf;
michael@0:    jmp_buf safe_jmpbuf;
michael@0: 
michael@0:    /* Safely execute function(arg) with png_error returning to this function. */
michael@0:    saved_error_buf = image->opaque->error_buf;
michael@0:    result = setjmp(safe_jmpbuf) == 0;
michael@0: 
michael@0:    if (result)
michael@0:    {
michael@0: 
michael@0:       image->opaque->error_buf = safe_jmpbuf;
michael@0:       result = function(arg);
michael@0:    }
michael@0: 
michael@0:    image->opaque->error_buf = saved_error_buf;
michael@0: 
michael@0:    /* And do the cleanup prior to any failure return. */
michael@0:    if (!result)
michael@0:       png_image_free(image);
michael@0: 
michael@0:    return result;
michael@0: }
michael@0: #endif /* SIMPLIFIED READ/WRITE */
michael@0: #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */