Make createDocument() $namespace nullable

According to the DOM specification, this argument should be
nullable. It's also supposed to be a required argument, but
not changing that at this point.

Author: nikic

ext/dom/domimplementation.c

@@ -127,7 +127,7 @@ PHP_METHOD(DOMImplementation, createDocument)
 	char *prefix = NULL, *localname = NULL;
 	dom_object *doctobj;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|ssO!", &uri, &uri_len, &name, &name_len, &node, dom_documenttype_class_entry) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|s!sO!", &uri, &uri_len, &name, &name_len, &node, dom_documenttype_class_entry) == FAILURE) {
 		RETURN_THROWS();
 	}
 

ext/dom/php_dom.stub.php

@@ -105,7 +105,7 @@ public function hasFeature(string $feature, string $version) {}
     public function createDocumentType(string $qualifiedName, string $publicId = "", string $systemId = "") {}
 
     /** @return DOMDocument|false */
-    public function createDocument(string $namespace = "", string $qualifiedName = "", ?DOMDocumentType $doctype = null) {}
+    public function createDocument(?string $namespace = null, string $qualifiedName = "", ?DOMDocumentType $doctype = null) {}
 }
 
 class DOMDocumentFragment implements DOMParentNode

ext/dom/php_dom_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 72c2add8db9af8f90e84997a2a5ca6743268fae8 */
+ * Stub hash: f4f6923a713a51d2944a21a123967343320be15c */
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_dom_import_simplexml, 0, 1, DOMElement, 1)
 	ZEND_ARG_TYPE_INFO(0, node, IS_OBJECT, 0)
@@ -106,7 +106,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_DOMImplementation_createDocumentType, 0, 0,
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_DOMImplementation_createDocument, 0, 0, 0)
-	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, namespace, IS_STRING, 0, "\"\"")
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, namespace, IS_STRING, 1, "null")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, qualifiedName, IS_STRING, 0, "\"\"")
 	ZEND_ARG_OBJ_INFO_WITH_DEFAULT_VALUE(0, doctype, DOMDocumentType, 1, "null")
 ZEND_END_ARG_INFO()

ext/dom/tests/DOMImplementation_createDocument_basic.phpt

@@ -6,6 +6,7 @@ include('skipif.inc');
 ?>
 --FILE--
 <?php
+declare(strict_types=1);
 $x = new DOMImplementation();
 $doc = $x->createDocument(null, 'html');
 echo $doc->saveHTML();