1--TEST--
2ASSIGN_OP 002: Incorrect optimization of ASSIGN_OP may lead to incorrect result (sub assign -> pre dec conversion for null values)
3--INI--
4opcache.enable=1
5opcache.enable_cli=1
6opcache.optimization_level=-1
7--FILE--
8<?php
9function foo(?int $a = null) {
10    $a -= 1;
11    return $a;
12}
13var_dump(foo(2));
14var_dump(foo(null));
15?>
16--EXPECT--
17int(1)
18int(-1)
19