JIT if condition optimization leads to flipped result: true is false and false is true

[paulmhh]

Description

The following code:

<?php declare(strict_types=1);

$a = new stdClass();
$a->a = 'a';

if (!empty($a?->a)) {
    echo 'OK';
} else {
    echo 'ERROR';
}
echo PHP_EOL;

run with:
php -dopcache.enable=1 -dopcache.enable_cli=1 -dopcache.jit=1205 ./file.php
will result in
ERROR

while plain
php ./file.php
will result in
OK

tested with:

docker run --rm -ti -v ./jitIssue.php:/jitIssue.php php:8.5 php -dopcache.enable=1 -dopcache.enable_cli=1 -dopcache.jit=1205 /jitIssue.php
docker run --rm -ti -v ./jitIssue.php:/jitIssue.php php:8.4 php -dopcache.enable=1 -dopcache.enable_cli=1 -dopcache.jit=1205 /jitIssue.php

(it seems php8.3 is not affected)

The issue seems to be a negated empty with a null-safe operator inside, only in an if condition.
if (!empty($a?->a)) => fails
if (empty($a?->a)) => works
if (!empty($a->a)) => works
$result = !empty($a?->a) => works

PHP Version

PHP 8.4.19 (cli) (built: Mar 16 2026 22:25:56) (NTS)
Copyright (c) The PHP Group
Built by https://github.com/docker-library/php
Zend Engine v4.4.19, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.19, Copyright (c), by Zend Technologies

and

PHP 8.5.4 (cli) (built: Mar 16 2026 22:25:19) (NTS)
Copyright (c) The PHP Group
Built by https://github.com/docker-library/php
Zend Engine v4.5.4, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.4, Copyright (c), by Zend Technologies

Operating System

No response

[iluuu1994]

Nice reproducer, thanks!

[paulmhh]

thank you for the very quick fix and the credits, much appreciated