Fix an additional problem

Author: nielsdos

ext/spl/spl_fixedarray.c

@@ -597,8 +597,8 @@ PHP_METHOD(SplFixedArray, __serialize)
 		RETURN_THROWS();
 	}
 
-	uint32_t num_properties =
-		intern->std.properties ? zend_hash_num_elements(intern->std.properties) : 0;
+	HashTable *ht = zend_std_get_properties(&intern->std);
+	uint32_t num_properties = zend_hash_num_elements(ht);
 	array_init_size(return_value, intern->array.size + num_properties);
 
 	/* elements */
@@ -609,17 +609,12 @@ PHP_METHOD(SplFixedArray, __serialize)
 	}
 
 	/* members */
-	if (intern->std.properties) {
-		ZEND_HASH_FOREACH_STR_KEY_VAL_IND(intern->std.properties, key, current) {
-			/* The properties hash table can also contain the array elements if the properties table was already rebuilt.
-			 * In this case we'd have a NULL key. We can't simply use the properties table in all cases because it's
-			 * potentially out of sync (missing elements, or containing removed elements) and might need a rebuild. */
-			if (key != NULL) {
-				zend_hash_add_new(Z_ARRVAL_P(return_value), key, current);
-				Z_TRY_ADDREF_P(current);
-			}
-		} ZEND_HASH_FOREACH_END();
-	}
+	ZEND_HASH_FOREACH_STR_KEY_VAL_IND(ht, key, current) {
+		if (key != NULL) {
+			zend_hash_add_new(Z_ARRVAL_P(return_value), key, current);
+			Z_TRY_ADDREF_P(current);
+		}
+	} ZEND_HASH_FOREACH_END();
 }
 
 PHP_METHOD(SplFixedArray, __unserialize)

ext/spl/tests/gh10925.phpt

@@ -0,0 +1,32 @@
+--TEST--
+Dynamic properties serialization for SplFixedArray should have updated properties
+--FILE--
+<?php
+#[AllowDynamicProperties]
+class MySplFixedArray extends SplFixedArray {
+    public $x;
+    public int $y = 3;
+}
+
+$x = new MySplFixedArray(2);
+var_dump($x->y);
+$x->y = 2;
+var_dump($x->y);
+$serialized = serialize($x);
+var_dump($serialized);
+var_dump(unserialize($serialized));
+?>
+--EXPECT--
+int(3)
+int(2)
+string(61) "O:15:"MySplFixedArray":4:{i:0;N;i:1;N;s:1:"x";N;s:1:"y";i:2;}"
+object(MySplFixedArray)#2 (4) {
+  ["x"]=>
+  NULL
+  ["y"]=>
+  int(2)
+  [0]=>
+  NULL
+  [1]=>
+  NULL
+}