+#else
+PNG_FUNCTION(void,PNGAPI
+png_err,(png_structp 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_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)
+ *--end = '.';
+ else if (number == 0) /* and !output */
+ *--end = '0';
+ }
+ }
+
+ return end;
+}
+#endif
projects / wxWidgets.git / blobdiff