Serialize uninitialized nullable typed properties with a default value to null

Author: nicolas-grekas

ext/standard/tests/serialize/sleep_uninitialized_typed_prop.phpt

@@ -4,12 +4,13 @@ Referencing an uninitialized typed property in __sleep() should be skipped
 <?php
 
 class Test {
+    public ?int $w = 123;
     public int $x;
     protected int $y;
     private int $z;
 
     public function __sleep() {
-        return ['x', 'y', 'z'];
+        return ['w', 'x', 'y', 'z'];
     }
 
     public function __set($name, $val) {
@@ -30,15 +31,23 @@ var_dump(unserialize(serialize($t)) == $t);
 $t->z = 3;
 var_dump(unserialize(serialize($t)) == $t);
 
+unset($t->w);
+$s = serialize($t);
+$t->w = null;
+var_dump(unserialize($s) == $t);
+
 var_dump($t);
 ?>
---EXPECT--
-string(15) "O:4:"Test":0:{}"
+--EXPECTF--
+string(29) "O:4:"Test":1:{s:1:"w";i:123;}"
+bool(true)
 bool(true)
 bool(true)
 bool(true)
 bool(true)
-object(Test)#1 (3) {
+object(Test)#1 (4) {
+  ["w"]=>
+  NULL
   ["x"]=>
   int(1)
   ["y":protected]=>

ext/standard/var.c

@@ -782,11 +782,20 @@ static int php_var_serialize_try_add_sleep_prop(
 	if (Z_TYPE_P(val) == IS_INDIRECT) {
 		val = Z_INDIRECT_P(val);
 		if (Z_TYPE_P(val) == IS_UNDEF) {
-			zend_property_info *info = zend_get_typed_property_info_for_slot(Z_OBJ_P(struc), val);
-			if (info) {
+			zend_property_info *prop_info = zend_get_typed_property_info_for_slot(Z_OBJ_P(struc), val);
+			if (!prop_info) {
+				return FAILURE;
+			}
+			zval *prop;
+			if ((prop_info->flags & ZEND_ACC_STATIC) != 0) {
+				prop = &prop_info->ce->default_static_members_table[prop_info->offset];
+			} else {
+				prop = &prop_info->ce->default_properties_table[OBJ_PROP_TO_NUM(prop_info->offset)];
+			}
+			if (Z_ISUNDEF_P(prop) || !ZEND_TYPE_ALLOW_NULL(prop_info->type)) {
 				return SUCCESS;
 			}
-			return FAILURE;
+			val = &EG(uninitialized_zval);
 		}
 	}