Allow readonly properties to be reinitialized once during cloning

Zend/tests/readonly_props/readonly_clone_error1.phpt

@@ -0,0 +1,36 @@
+--TEST--
+Readonly property cannot be reset twice during cloning
+--FILE--
+<?php
+
+class Foo {
+    public function __construct(
+        public readonly int $bar
+    ) {}
+
+    public function __clone()
+    {
+        $this->bar = 2;
+        var_dump($this);
+        $this->bar = 3;
+    }
+}
+
+$foo = new Foo(1);
+
+try {
+    clone $foo;
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+echo "done";
+
+?>
+--EXPECT--
+object(Foo)#2 (1) {
+  ["bar"]=>
+  int(2)
+}
+Cannot modify readonly property Foo::$bar
+done

Zend/tests/readonly_props/readonly_clone_error2.phpt

@@ -0,0 +1,42 @@
+--TEST--
+Readonly property cannot be reset after cloning when there is no custom clone handler
+--FILE--
+<?php
+
+class Foo {
+    public function __construct(
+        public readonly int $bar,
+        public readonly int $baz
+    ) {}
+
+    public function wrongCloneOld()
+    {
+        $instance = clone $this;
+        $this->bar++;
+    }
+
+    public function wrongCloneNew()
+    {
+        $instance = clone $this;
+        $instance->baz++;
+    }
+}
+
+$foo = new Foo(1, 1);
+
+try {
+    $foo->wrongCloneOld();
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+try {
+    $foo->wrongCloneNew();
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+?>
+--EXPECT--
+Cannot modify readonly property Foo::$bar
+Cannot modify readonly property Foo::$baz

Zend/tests/readonly_props/readonly_clone_error3.phpt

@@ -0,0 +1,44 @@
+--TEST--
+Readonly property cannot be reset after cloning when there is a custom clone handler
+--FILE--
+<?php
+
+class Foo {
+    public function __construct(
+        public readonly int $bar,
+        public readonly int $baz
+    ) {}
+
+    public function __clone() {}
+
+    public function wrongCloneOld()
+    {
+        $instance = clone $this;
+        $this->bar++;
+    }
+
+    public function wrongCloneNew()
+    {
+        $instance = clone $this;
+        $instance->baz++;
+    }
+}
+
+$foo = new Foo(1, 1);
+
+try {
+    $foo->wrongCloneOld();
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+try {
+    $foo->wrongCloneNew();
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+?>
+--EXPECT--
+Cannot modify readonly property Foo::$bar
+Cannot modify readonly property Foo::$baz

Zend/tests/readonly_props/readonly_clone_success1.phpt

@@ -0,0 +1,39 @@
+--TEST--
+Readonly property can be reset once during cloning
+--FILE--
+<?php
+
+class Foo {
+    public function __construct(
+        public readonly int $bar
+    ) {}
+
+    public function __clone()
+    {
+        $this->bar++;
+    }
+}
+
+$foo = new Foo(1);
+
+var_dump(clone $foo);
+
+$foo2 = clone $foo;
+var_dump($foo2);
+
+var_dump(clone $foo2);
+
+?>
+--EXPECTF--
+object(Foo)#%d (%d) {
+  ["bar"]=>
+  int(2)
+}
+object(Foo)#%d (%d) {
+  ["bar"]=>
+  int(2)
+}
+object(Foo)#%d (%d) {
+  ["bar"]=>
+  int(3)
+}

Zend/tests/readonly_props/readonly_clone_success2.phpt

@@ -0,0 +1,46 @@
+--TEST--
+Test that __clone() unset and reassign properties
+--FILE--
+<?php
+
+class Foo {
+    public function __construct(
+        public readonly stdClass $bar,
+    ) {}
+
+    public function __clone()
+    {
+        unset($this->bar);
+        var_dump($this);
+        $this->bar = new stdClass();
+    }
+}
+
+$foo = new Foo(new stdClass());
+var_dump($foo);
+$foo2 = clone $foo;
+
+var_dump($foo);
+var_dump($foo2);
+
+?>
+--EXPECTF--
+object(Foo)#1 (%d) {
+  ["bar"]=>
+  object(stdClass)#2 (%d) {
+  }
+}
+object(Foo)#3 (%d) {
+  ["bar"]=>
+  uninitialized(stdClass)
+}
+object(Foo)#1 (%d) {
+  ["bar"]=>
+  object(stdClass)#2 (%d) {
+  }
+}
+object(Foo)#3 (%d) {
+  ["bar"]=>
+  object(stdClass)#4 (%d) {
+  }
+}

Zend/tests/readonly_props/readonly_clone_success3.phpt

@@ -0,0 +1,37 @@
+--TEST--
+__clone() can indirectly modify unlocked readonly properties
+--FILE--
+<?php
+
+class Foo {
+    public function __construct(
+        public readonly array $bar
+    ) {}
+
+    public function __clone()
+    {
+        $this->bar['bar'] = 'bar';
+    }
+}
+
+$foo = new Foo([]);
+// First call fills the cache slot
+var_dump(clone $foo);
+var_dump(clone $foo);
+
+?>
+--EXPECTF--
+object(Foo)#2 (%d) {
+  ["bar"]=>
+  array(1) {
+    ["bar"]=>
+    string(3) "bar"
+  }
+}
+object(Foo)#2 (%d) {
+  ["bar"]=>
+  array(1) {
+    ["bar"]=>
+    string(3) "bar"
+  }
+}

Zend/tests/readonly_props/readonly_clone_success4.phpt

@@ -0,0 +1,39 @@
+--TEST--
+Readonly property can be reset once during cloning even after a type error
+--FILE--
+<?php
+
+class Foo {
+    public function __construct(
+        public readonly int $bar
+    ) {}
+
+    public function __clone()
+    {
+        try {
+            $this->bar = "foo";
+        } catch (Error $e) {
+            echo $e->getMessage() . "\n";
+        }
+
+        $this->bar = 2;
+    }
+}
+
+$foo = new Foo(1);
+
+var_dump(clone $foo);
+var_dump(clone $foo);
+
+?>
+--EXPECTF--
+Cannot assign string to property Foo::$bar of type int
+object(Foo)#%d (%d) {
+  ["bar"]=>
+  int(2)
+}
+Cannot assign string to property Foo::$bar of type int
+object(Foo)#%d (%d) {
+  ["bar"]=>
+  int(2)
+}

Zend/tests/readonly_props/readonly_coercion_type_error.phpt

@@ -0,0 +1,23 @@
+--TEST--
+Test failing readonly assignment with coercion
+--FILE--
+<?php
+
+class Foo {
+    public readonly string $bar;
+
+    public function __construct() {
+        $this->bar = 'bar';
+        try {
+            $this->bar = 42;
+        } catch (Error $e) {
+            echo $e->getMessage(), "\n";
+        }
+    }
+}
+
+new Foo();
+
+?>
+--EXPECTF--
+Cannot modify readonly property Foo::$bar

Zend/zend_API.c

@@ -4224,6 +4224,10 @@ ZEND_API zend_property_info *zend_declare_typed_property(zend_class_entry *ce, z
 		ce->ce_flags |= ZEND_ACC_HAS_TYPE_HINTS;
 	}
 
+	if (access_type & ZEND_ACC_READONLY) {
+		ce->ce_flags |= ZEND_ACC_HAS_READONLY_PROPS;
+	}
+
 	if (ce->type == ZEND_INTERNAL_CLASS) {
 		property_info = pemalloc(sizeof(zend_property_info), 1);
 	} else {

Zend/zend_compile.h

@@ -241,7 +241,7 @@ typedef struct _zend_oparray_context {
 /* or IS_CONSTANT_VISITED_MARK                            |     |     |     */
 #define ZEND_CLASS_CONST_IS_CASE         (1 << 6)  /*     |     |     |  X  */
 /*                                                        |     |     |     */
-/* Class Flags (unused: 21,30,31)                         |     |     |     */
+/* Class Flags (unused: 30,31)                            |     |     |     */
 /* ===========                                            |     |     |     */
 /*                                                        |     |     |     */
 /* Special class types                                    |     |     |     */
@@ -288,6 +288,8 @@ typedef struct _zend_oparray_context {
 /*                                                        |     |     |     */
 /* Class is linked apart from variance obligations.       |     |     |     */
 #define ZEND_ACC_NEARLY_LINKED           (1 << 20) /*  X  |     |     |     */
+/* Class has readonly props                               |     |     |     */
+#define ZEND_ACC_HAS_READONLY_PROPS      (1 << 21) /*  X  |     |     |     */
 /*                                                        |     |     |     */
 /* stored in opcache (may be partially)                   |     |     |     */
 #define ZEND_ACC_CACHED                  (1 << 22) /*  X  |     |     |     */

Zend/zend_enum.c

@@ -41,9 +41,17 @@ zend_object *zend_enum_new(zval *result, zend_class_entry *ce, zend_string *case
 	zend_object *zobj = zend_objects_new(ce);
 	ZVAL_OBJ(result, zobj);
 
-	ZVAL_STR_COPY(OBJ_PROP_NUM(zobj, 0), case_name);
+	zval *zname = OBJ_PROP_NUM(zobj, 0);
+	ZVAL_STR_COPY(zname, case_name);
+	/* ZVAL_COPY does not set Z_PROP_FLAG, this needs to be cleared to avoid leaving IS_PROP_REINITABLE set */
+	Z_PROP_FLAG_P(zname) = 0;
+
 	if (backing_value_zv != NULL) {
-		ZVAL_COPY(OBJ_PROP_NUM(zobj, 1), backing_value_zv);
+		zval *prop = OBJ_PROP_NUM(zobj, 1);
+
+		ZVAL_COPY(prop, backing_value_zv);
+		/* ZVAL_COPY does not set Z_PROP_FLAG, this needs to be cleared to avoid leaving IS_PROP_REINITABLE set */
+		Z_PROP_FLAG_P(prop) = 0;
 	}
 
 	return zobj;
@@ -179,7 +187,7 @@ void zend_enum_add_interfaces(zend_class_entry *ce)
 
 	if (ce->enum_backing_type != IS_UNDEF) {
 		ce->interface_names[num_interfaces_before + 1].name = zend_string_copy(zend_ce_backed_enum->name);
-		ce->interface_names[num_interfaces_before + 1].lc_name = zend_string_init("backedenum", sizeof("backedenum") - 1, 0);	
+		ce->interface_names[num_interfaces_before + 1].lc_name = zend_string_init("backedenum", sizeof("backedenum") - 1, 0);
 	}
 
 	ce->default_object_handlers = &zend_enum_object_handlers;