Fix GH-16235 jdtogregorian overflow

Author: devnexen

ext/calendar/gregor.c

@@ -153,6 +153,10 @@ void SdnToGregorian(
 	}
 	temp = (sdn + GREGOR_SDN_OFFSET) * 4 - 1;
 
+	if (temp < 0 || (temp / DAYS_PER_400_YEARS) > INT_MAX) {
+		goto fail;
+	}
+
 	/* Calculate the century (year/100). */
 	century = temp / DAYS_PER_400_YEARS;
 

ext/calendar/tests/gh16235.phpt

@@ -0,0 +1,11 @@
+--TEST--
+GH-16235 (jdtogregorian overflow on argument)
+--EXTENSIONS--
+calendar
+--FILE--
+<?php
+jdtogregorian(92233658792494800);
+echo "DONE";
+?>
+--EXPECT--
+DONE