Description:
------------
*cut*
void SdnToJulian(
					long int sdn,
					int *pYear,
					int *pMonth,
					int *pDay)
{
	int year;
	int month;
	int day;
	long int temp;
	int dayOfYear;

	if (sdn <= 0) {
		*pYear = 0;
		*pMonth = 0;
		*pDay = 0;
		return;
	}

	temp = (sdn + JULIAN_SDN_OFFSET) * 4 - 1;
*cut*

temp could here be less then 0 due to integer overflow (when sdn is large enough).

Test script:
---------------
<?php
for(;;) {
    $x = rand(0, 2147483640);
    echo "$x\n";
    $dummy = cal_from_jd($x,0);
    $dummy = cal_from_jd($x,1);
}
?>


Expected result:
----------------
Sigsegv:

$ php core1.php 
758413092
1698116908
42935006
988939165
101976420
1332880082
882858043
Naruszenie ochrony pamięci (SIGSEGV)