Add test case for bug #80483/#75035

Author: derickr

NEWS

@@ -7,6 +7,10 @@ PHP                                                                        NEWS
     different type). (Derick)
   . Fixed bug GH-8964 (DateTime object comparison after applying delta less
     than 1 second). (Derick)
+  . Fixed bug #75035 (Datetime fails to unserialize "extreme" dates).
+    (Derick)
+  . Fixed bug #80483 (DateTime Object with 5-digit year can't unserialized).
+    (Derick)
   . Fixed bug #81263 (Wrong result from DateTimeImmutable::diff). (Derick)
 
 - DBA:

ext/date/tests/bug80483.phpt

@@ -0,0 +1,35 @@
+--TEST--
+Bug #80483 (DateTime Object with 5-digit year can't unserialized)
+--INI--
+date.timezone=UTC
+--FILE--
+<?php
+
+$the_date = new DateTime();
+$the_date->SetTime(0, 0, 0);
+$the_date->SetDate(20201, 01, 01);
+
+var_dump($the_date);
+
+$serialized = serialize($the_date);
+var_dump($serialized);
+var_dump(unserialize($serialized));
+?>
+--EXPECTF--
+object(DateTime)#%d (%d) {
+  ["date"]=>
+  string(28) "+20201-01-01 00:00:00.000000"
+  ["timezone_type"]=>
+  int(3)
+  ["timezone"]=>
+  string(3) "UTC"
+}
+string(116) "O:8:"DateTime":3:{s:4:"date";s:28:"+20201-01-01 00:00:00.000000";s:13:"timezone_type";i:3;s:8:"timezone";s:3:"UTC";}"
+object(DateTime)#%d (%d) {
+  ["date"]=>
+  string(28) "+20201-01-01 00:00:00.000000"
+  ["timezone_type"]=>
+  int(3)
+  ["timezone"]=>
+  string(3) "UTC"
+}