jas_stream_t *jas_stream_freopen(const char *path, const char *mode, FILE *fp)
{
	jas_stream_t *stream;
	int openflags;

	/* Eliminate compiler warning about unused variable. */
	path = 0;

	/* Allocate a stream object. */
	if (!(stream = jas_stream_create())) {
		return 0;
	}

	/* Parse the mode string. */
	stream->openmode_ = jas_strtoopenmode(mode);

	/* Determine the correct flags to use for opening the file. */
	if ((stream->openmode_ & JAS_STREAM_READ) &&
	  (stream->openmode_ & JAS_STREAM_WRITE)) {
		openflags = O_RDWR;
	} else if (stream->openmode_ & JAS_STREAM_READ) {
		openflags = O_RDONLY;
	} else if (stream->openmode_ & JAS_STREAM_WRITE) {
		openflags = O_WRONLY;
	} else {
		openflags = 0;
	}
	if (stream->openmode_ & JAS_STREAM_APPEND) {
		openflags |= O_APPEND;
	}
	if (stream->openmode_ & JAS_STREAM_BINARY) {
		openflags |= O_BINARY;
	}
	if (stream->openmode_ & JAS_STREAM_CREATE) {
		openflags |= O_CREAT | O_TRUNC;
	}

	stream->obj_ = JAS_CAST(void *, fp);

	/* Select the operations for a file stream object. */
	stream->ops_ = &jas_stream_sfileops;

	/* By default, use full buffering for this type of stream. */
	jas_stream_initbuf(stream, JAS_STREAM_FULLBUF, 0, 0);

	return stream;
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.