Fix socket_write() default value

Author: nikic

ext/sockets/sockets.stub.php

@@ -26,7 +26,7 @@ function socket_listen($socket, int $backlog = 0): bool {}
 function socket_close($socket): void {}
 
 /** @param resource $socket */
-function socket_write($socket, string $buf, int $length = 0): int|false {}
+function socket_write($socket, string $buf, int $length = UNKNOWN): int|false {}
 
 /** @param resource $socket */
 function socket_read($socket, int $length, int $type = PHP_BINARY_READ): string|false {}

ext/sockets/sockets_arginfo.h

@@ -35,7 +35,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_socket_write, 0, 2, MAY_BE_LONG|MAY_BE_FALSE)
 	ZEND_ARG_INFO(0, socket)
 	ZEND_ARG_TYPE_INFO(0, buf, IS_STRING, 0)
-	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, length, IS_LONG, 0, "0")
+	ZEND_ARG_TYPE_INFO(0, length, IS_LONG, 0)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_socket_read, 0, 2, MAY_BE_STRING|MAY_BE_FALSE)