ext/reflection: handle virtual+readonly in ReflectionProperty::isWritable().

Follow-up to review feedback from @iluuu1994 on GH-21769. Gate the
ZEND_ACC_VIRTUAL branch on prop->hooks being set, and short-circuit
virtual properties that also carry ZEND_ACC_READONLY to RETURN_FALSE
(no backing slot, treat as always initialized). Covers legitimate
virtual+readonly uses outside of DOM.

Author: devnexen

ext/reflection/php_reflection.c

@@ -6762,8 +6762,8 @@ ZEND_METHOD(ReflectionProperty, isReadable)
 		RETURN_FALSE;
 	}
 
-	if (prop->flags & ZEND_ACC_VIRTUAL) {
-		if (prop->hooks && !prop->hooks[ZEND_PROPERTY_HOOK_GET]) {
+	if ((prop->flags & ZEND_ACC_VIRTUAL) && prop->hooks) {
+		if (!prop->hooks[ZEND_PROPERTY_HOOK_GET]) {
 			RETURN_FALSE;
 		}
 	} else if (obj && (!prop->hooks || !prop->hooks[ZEND_PROPERTY_HOOK_GET])) {
@@ -6853,24 +6853,30 @@ ZEND_METHOD(ReflectionProperty, isWritable)
 		RETURN_FALSE;
 	}
 
-	if (prop->flags & ZEND_ACC_VIRTUAL) {
-		if (prop->hooks && !prop->hooks[ZEND_PROPERTY_HOOK_SET]) {
+	if ((prop->flags & ZEND_ACC_VIRTUAL) && prop->hooks) {
+		if (!prop->hooks[ZEND_PROPERTY_HOOK_SET]) {
+			RETURN_FALSE;
+		}
+	} else if (prop->flags & ZEND_ACC_VIRTUAL) {
+		if (prop->flags & ZEND_ACC_READONLY) {
 			RETURN_FALSE;
 		}
-	} else if (obj && (prop->flags & ZEND_ACC_READONLY)) {
+	} else if ((prop->flags & ZEND_ACC_READONLY)) {
+		if (obj) {
 retry:;
-		zval *prop_val = OBJ_PROP(obj, prop->offset);
-		if (Z_TYPE_P(prop_val) == IS_UNDEF
-		 && zend_lazy_object_must_init(obj)
-		 && (Z_PROP_FLAG_P(prop_val) & IS_PROP_LAZY)) {
-			obj = zend_lazy_object_init(obj);
-			if (!obj) {
-				RETURN_THROWS();
+			zval *prop_val = OBJ_PROP(obj, prop->offset);
+			if (Z_TYPE_P(prop_val) == IS_UNDEF
+		 	&& zend_lazy_object_must_init(obj)
+		 	&& (Z_PROP_FLAG_P(prop_val) & IS_PROP_LAZY)) {
+				obj = zend_lazy_object_init(obj);
+				if (!obj) {
+					RETURN_THROWS();
+				}
+				goto retry;
+			}
+			if (Z_TYPE_P(prop_val) != IS_UNDEF && !(Z_PROP_FLAG_P(prop_val) & IS_PROP_REINITABLE)) {
+				RETURN_FALSE;
 			}
-			goto retry;
-		}
-		if (Z_TYPE_P(prop_val) != IS_UNDEF && !(Z_PROP_FLAG_P(prop_val) & IS_PROP_REINITABLE)) {
-			RETURN_FALSE;
 		}
 	}