Fix generation of property with class union type

The generated type was missing the UNION bit. Add a ZEND_TYPE_INIT_UNION
macro to hide the implementation details.

Author: nikic

Zend/zend_types.h

@@ -273,6 +273,9 @@ typedef struct {
 #define ZEND_TYPE_INIT_PTR_MASK(ptr, type_mask) \
 	{ (void *) (ptr), (type_mask) }
 
+#define ZEND_TYPE_INIT_UNION(ptr, extra_flags) \
+	{ (void *) (ptr), (_ZEND_TYPE_LIST_BIT|_ZEND_TYPE_UNION_BIT) | (extra_flags) }
+
 #define ZEND_TYPE_INIT_CLASS(class_name, allow_null, extra_flags) \
 	ZEND_TYPE_INIT_PTR(class_name, _ZEND_TYPE_NAME_BIT, allow_null, extra_flags)
 

build/gen_stub.php

@@ -1460,7 +1460,7 @@ public function getDeclaration(): string {
 
                     $typeMaskCode = $this->type->toArginfoType()->toTypeMask();
 
-                    $code .= "\tzend_type property_{$propertyName}_type = ZEND_TYPE_INIT_PTR(property_{$propertyName}_type_list, _ZEND_TYPE_LIST_BIT, 0, $typeMaskCode);\n";
+                    $code .= "\tzend_type property_{$propertyName}_type = ZEND_TYPE_INIT_UNION(property_{$propertyName}_type_list, $typeMaskCode);\n";
                     $typeCode = "property_{$propertyName}_type";
                 } else {
                     $escapedClassName = $arginfoType->classTypes[0]->toEscapedName();

ext/reflection/tests/internal_property_union_type.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Union type on internal property
+--EXTENSIONS--
+zend_test
+--FILE--
+<?php
+$rp = new ReflectionProperty(_ZendTestClass::class, 'classUnionProp');
+$rt = $rp->getType();
+echo $rt, "\n";
+?>
+--EXPECT--
+stdClass|Iterator|null

ext/zend_test/test_arginfo.h

@@ -252,7 +252,7 @@ static zend_class_entry *register_class__ZendTestClass(zend_class_entry *class_e
 	property_classUnionProp_type_list->num_types = 2;
 	property_classUnionProp_type_list->types[0] = (zend_type) ZEND_TYPE_INIT_CLASS(property_classUnionProp_class_stdClass, 0, 0);
 	property_classUnionProp_type_list->types[1] = (zend_type) ZEND_TYPE_INIT_CLASS(property_classUnionProp_class_Iterator, 0, 0);
-	zend_type property_classUnionProp_type = ZEND_TYPE_INIT_PTR(property_classUnionProp_type_list, _ZEND_TYPE_LIST_BIT, 0, MAY_BE_NULL);
+	zend_type property_classUnionProp_type = ZEND_TYPE_INIT_UNION(property_classUnionProp_type_list, MAY_BE_NULL);
 	zval property_classUnionProp_default_value;
 	ZVAL_NULL(&property_classUnionProp_default_value);
 	zend_string *property_classUnionProp_name = zend_string_init("classUnionProp", sizeof("classUnionProp") - 1, 1);