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authorJörg Frings-Fürst <debian@jff-webhosting.net>2015-05-01 16:13:57 +0200
committerJörg Frings-Fürst <debian@jff-webhosting.net>2015-05-01 16:13:57 +0200
commit094535c010320967639e8e86f974d878e80baa72 (patch)
treeefc3094b20355dcbeebb2c4ece4fcfc69bffedb5 /png/pngerror.c
parentc07d0c2d2f6f7b0eb6e92cc6204bf05037957e82 (diff)
Imported Upstream version 1.7.0upstream/1.7.0
Diffstat (limited to 'png/pngerror.c')
-rw-r--r--png/pngerror.c961
1 files changed, 961 insertions, 0 deletions
diff --git a/png/pngerror.c b/png/pngerror.c
new file mode 100644
index 0000000..f21f4dd
--- /dev/null
+++ b/png/pngerror.c
@@ -0,0 +1,961 @@
+
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * Last changed in libpng 1.6.11 [June 12, 2014]
+ * Copyright (c) 1998-2014 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 /* 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
+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))
+ {
+ 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_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 /* PNG_ERROR_TEXT_SUPPORTED */
+
+/* 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 || 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) if (count == 5) if (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))
+#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
+ * 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 /* PNG_WARNINGS_SUPPORTED */
+
+#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)
+ {
+# 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)
+ 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)
+ 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 */
+
+/* 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 196 /* Currently limited be profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+ (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
+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))
+ {
+ 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 /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
+
+#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 /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
+
+#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 /* PNG_WARNINGS_SUPPORTED */
+
+#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)
+ 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 /* PNG_READ_SUPPORTED */
+
+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)
+# 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))
+# 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 && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
+ 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 /* 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->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)
+ /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
+ * possible to implement without setjmp support just so long as there is some
+ * way to handle the error return here:
+ */
+PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
+png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+ const png_const_structrp png_ptr = png_nonconst_ptr;
+ png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+ /* An error is always logged here, overwriting anything (typically a warning)
+ * that is already there:
+ */
+ if (image != NULL)
+ {
+ png_safecat(image->message, (sizeof image->message), 0, error_message);
+ image->warning_or_error |= PNG_IMAGE_ERROR;
+
+ /* Retrieve the jmp_buf from within the png_control, making this work for
+ * C++ compilation too is pretty tricky: C++ wants a pointer to the first
+ * element of a jmp_buf, but C doesn't tell us the type of that.
+ */
+ if (image->opaque != NULL && image->opaque->error_buf != NULL)
+ longjmp(png_control_jmp_buf(image->opaque), 1);
+
+ /* Missing longjmp buffer, the following is to help debugging: */
+ {
+ size_t pos = png_safecat(image->message, (sizeof image->message), 0,
+ "bad longjmp: ");
+ png_safecat(image->message, (sizeof image->message), pos,
+ error_message);
+ }
+ }
+
+ /* Here on an internal programming error. */
+ abort();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void /* PRIVATE */ PNGCBAPI
+png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
+{
+ const png_const_structrp png_ptr = png_nonconst_ptr;
+ png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+ /* A warning is only logged if there is no prior warning or error. */
+ if (image->warning_or_error == 0)
+ {
+ png_safecat(image->message, (sizeof image->message), 0, warning_message);
+ image->warning_or_error |= PNG_IMAGE_WARNING;
+ }
+}
+#endif
+
+int /* PRIVATE */
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
+{
+ volatile png_imagep image = image_in;
+ volatile int result;
+ volatile png_voidp saved_error_buf;
+ jmp_buf safe_jmpbuf;
+
+ /* Safely execute function(arg) with png_error returning to this function. */
+ saved_error_buf = image->opaque->error_buf;
+ result = setjmp(safe_jmpbuf) == 0;
+
+ if (result != 0)
+ {
+
+ image->opaque->error_buf = safe_jmpbuf;
+ result = function(arg);
+ }
+
+ image->opaque->error_buf = saved_error_buf;
+
+ /* And do the cleanup prior to any failure return. */
+ if (result == 0)
+ png_image_free(image);
+
+ return result;
+}
+#endif /* SIMPLIFIED READ/WRITE */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */