Fix phpGH-16384: cal_from_jd overflow on julian_day argument.

Author: devnexen

ext/calendar/gregor.c

@@ -160,6 +160,10 @@ void SdnToGregorian(
 	/* Calculate the century (year/100). */
 	century = temp / DAYS_PER_400_YEARS;
 
+	if (century > ((INT_MAX / 100) - (temp / DAYS_PER_4_YEARS))) {
+		goto fail;
+	}
+
 	/* Calculate the year and day of year (1 <= dayOfYear <= 366). */
 	temp = ((temp % DAYS_PER_400_YEARS) / 4) * 4 + 3;
 	year = (century * 100) + (temp / DAYS_PER_4_YEARS);

ext/calendar/tests/gh16834.phpt

@@ -0,0 +1,29 @@
+--TEST--
+GH-16834 (cal_from_jd from julian_day argument)
+--EXTENSIONS--
+calendar
+--FILE--
+<?php
+var_dump(cal_from_jd(076545676543223, CAL_GREGORIAN));
+?>
+--EXPECTF--
+array(9) {
+  ["date"]=>
+  string(5) "0/0/0"
+  ["month"]=>
+  int(0)
+  ["day"]=>
+  int(0)
+  ["year"]=>
+  int(0)
+  ["dow"]=>
+  int(%d)
+  ["abbrevdayname"]=>
+  string(3) "%s"
+  ["dayname"]=>
+  string(9) "%s"
+  ["abbrevmonth"]=>
+  string(0) ""
+  ["monthname"]=>
+  string(0) ""
+}