Address a few review comments

Author: kocsismate

Zend/tests/readonly_props/readonly_clone_success2.phpt

@@ -0,0 +1,74 @@
+--TEST--
+Test that __clone() can write to readonly properties
+--FILE--
+<?php
+
+class Counter
+{
+    private static int $counter = 0;
+
+    public readonly int $count;
+    private readonly int $foo;
+
+    public function __construct()
+    {
+        $this->count = ++self::$counter;
+        $this->foo = 0;
+    }
+
+    public function count(?int $count = null): static
+    {
+        $new = clone $this;
+        $new->count = $count ?? ++self::$counter;
+
+        return $new;
+    }
+
+    public function __clone()
+    {
+        if (is_a(debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2)[1]['class'] ?? '', self::class, true)) {
+            unset($this->count);
+        } else {
+            $this->count = ++self::$counter;
+        }
+        $this->foo = 1;
+    }
+}
+
+$a = new Counter();
+var_dump($a);
+
+var_dump(clone $a);
+
+$b = $a->count();
+var_dump($b);
+
+$c = $a->count(123);
+var_dump($c);
+
+?>
+--EXPECTF--
+object(Counter)#%d (2) {
+  ["count"]=>
+  int(1)
+  ["foo":"Counter":private]=>
+  int(0)
+}
+object(Counter)#%d (2) {
+  ["count"]=>
+  int(2)
+  ["foo":"Counter":private]=>
+  int(1)
+}
+object(Counter)#%d (2) {
+  ["count"]=>
+  int(3)
+  ["foo":"Counter":private]=>
+  int(1)
+}
+object(Counter)#%d (2) {
+  ["count"]=>
+  int(123)
+  ["foo":"Counter":private]=>
+  int(1)
+}

Zend/zend_API.c

@@ -1703,7 +1703,6 @@ static zend_always_inline zend_result _object_and_properties_init(zval *arg, zen
 	} else {
 		ZVAL_OBJ(arg, class_type->create_object(class_type));
 	}
-
 	return SUCCESS;
 }
 /* }}} */

Zend/zend_execute.c

@@ -983,8 +983,12 @@ static zend_never_inline zval* zend_assign_to_typed_prop(zend_property_info *inf
 	zval tmp;
 
 	if (UNEXPECTED(info->flags & ZEND_ACC_READONLY)) {
-		zend_readonly_property_modification_error(info);
-		return &EG(uninitialized_zval);
+		if (Z_PROP_FLAG_P(property_val) & IS_PROP_REINITABLE) {
+			Z_PROP_FLAG_P(property_val) &= ~IS_PROP_REINITABLE;
+		} else {
+			zend_readonly_property_modification_error(info);
+			return &EG(uninitialized_zval);
+		}
 	}
 
 	ZVAL_DEREF(value);
@@ -3116,6 +3120,9 @@ static zend_always_inline void zend_fetch_property_address(zval *result, zval *c
 						ZEND_ASSERT(type == BP_VAR_W || type == BP_VAR_RW || type == BP_VAR_UNSET);
 						if (Z_TYPE_P(ptr) == IS_OBJECT) {
 							ZVAL_COPY(result, ptr);
+						} else if (Z_PROP_FLAG_P(ptr) & IS_PROP_REINITABLE) {
+							Z_PROP_FLAG_P(ptr) &= ~IS_PROP_REINITABLE;
+							ZVAL_COPY(result, ptr);
 						} else {
 							zend_readonly_property_modification_error(prop_info);
 							ZVAL_ERROR(result);

Zend/zend_objects.c

@@ -263,15 +263,16 @@ ZEND_API void ZEND_FASTCALL zend_objects_clone_members(zend_object *new_object,
 	}
 
 	if (has_clone_method) {
-		zval *prop;
-
 		GC_ADDREF(new_object);
 		zend_call_known_instance_method_with_0_params(new_object->ce->clone, new_object, NULL);
 
-		rebuild_object_properties(new_object);
-		ZEND_HASH_FOREACH_PTR(new_object->properties, prop) {
-			Z_PROP_FLAG_P(prop) &= ~IS_PROP_REINITABLE;
-		} ZEND_HASH_FOREACH_END();
+		for (uint32_t i = 0; i < new_object->ce->default_properties_count; i++) {
+			zend_property_info *prop_info = new_object->ce->properties_info_table[i];
+			if (prop_info && (prop_info->flags & (~ZEND_ACC_STATIC|ZEND_ACC_READONLY)) && ZEND_TYPE_IS_SET(prop_info->type)) {
+				zval *prop = OBJ_PROP_NUM(new_object, i);
+				Z_PROP_FLAG_P(prop) &= ~IS_PROP_REINITABLE;
+			}
+		}
 
 		OBJ_RELEASE(new_object);
 	}