SplFileObject::fwrite $length param nullable (#17242)

UPGRADING

@@ -57,6 +57,8 @@ PHP 8.5 UPGRADE NOTES
 - SPL:
   . ArrayObject no longer accepts enums, as modifying the $name or $value
     properties can break engine assumptions.
+  . SplFileObject::fwrite's parameter $length is now nullable. The default
+    value changed from 0 to null.
 
 ========================================
 2. New Features
@@ -99,7 +101,7 @@ PHP 8.5 UPGRADE NOTES
 ========================================
 
 - Zlib:
-  . The "use_include_path" argument for the 
+  . The "use_include_path" argument for the
     gzfile, gzopen and readgzfile functions had been changed
     from int to boolean.
 

ext/spl/spl_directory.c

@@ -2606,15 +2606,18 @@ PHP_METHOD(SplFileObject, fwrite)
 	char *str;
 	size_t str_len;
 	zend_long length = 0;
+	bool length_is_null = true;
 	ssize_t written;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "s|l", &str, &str_len, &length) == FAILURE) {
-		RETURN_THROWS();
-	}
+	ZEND_PARSE_PARAMETERS_START(1, 2)
+		Z_PARAM_STRING(str, str_len)
+		Z_PARAM_OPTIONAL
+		Z_PARAM_LONG_OR_NULL(length, length_is_null)
+	ZEND_PARSE_PARAMETERS_END();
 
 	CHECK_SPL_FILE_OBJECT_IS_INITIALIZED(intern);
 
-	if (ZEND_NUM_ARGS() > 1) {
+	if (!length_is_null) {
 		if (length >= 0) {
 			str_len = MIN((size_t)length, str_len);
 		} else {

ext/spl/spl_directory.stub.php

@@ -283,7 +283,7 @@ public function fpassthru(): int {}
     public function fscanf(string $format, mixed &...$vars): array|int|null {}
 
     /** @tentative-return-type */
-    public function fwrite(string $data, int $length = 0): int|false {}
+    public function fwrite(string $data, ?int $length = null): int|false {}
 
     /** @tentative-return-type */
     public function fstat(): array {}