Bug #80184 [Opn->Ver]: Complex expression in while / if statements resolves to false incorrectly

Edit report at https://bugs.php.net/bug.php?id=80184&edit=1 ID: 80184 Updated by: nikic@php.net Reported by: jelly dot legend at gmail dot com Summary: Complex expression in while / if statements resolves to false incorrectly -Status: Open +Status: Verified Type: Bug Package: opcache Operating System: MacOS 10.15.6 PHP Version: 8.0.0rc1 Block user comment: N Private report: N New Comment: Also happens with opcache.jit=0, so generic optimization issue. Slightly reduced by Dharman: <?php $callbacks = [ function () { echo "First item!\n"; }, function () { echo "Second item!\n"; }, function () { echo "Third item!\n"; }, function () { echo "Fourth item!\n"; }, ]; while ($callback = array_shift($callbacks) and $callback() || true); This iterates once instead of multiple times. Previous Comments: ------------------------------------------------------------------------ [2020-10-04 12:58:24] jelly dot legend at gmail dot com Description: ------------ If a use a complex expression as an if condition or while condition, it incorrectly resolves to false. While it correctly evaluates it if passed to a variable and printed. PHP version: PHP 8.0.0rc1 (cli) (built: Oct 4 2020 13:58:56) ( NTS ) Copyright (c) The PHP Group Zend Engine v4.0.0-dev, Copyright (c) Zend Technologies with Zend OPcache v8.0.0rc1, Copyright (c), by Zend Technologies php.development-ini changes: zend_extension=opcache opcache.enable=1 opcache.enable_cli=1 opcache.memory_consumption=128 If I disable opcache I get the correct results. PHP was built from source. With following configuration. ./configure \ --prefix=.../php-8.0.0rc1 \ --with-config-file-path=.../php-8.0.0rc1/etc \ --enable-mbstring \ --enable-sockets \ --enable-opcache \ --with-openssl=/usr/local/openssl \ --with-curl \ --with-sodium \ --with-bz2 \ --with-zlib \ --with-zip I was first noticed the bug on beta-4 but decided to try it out in rc-1 instead. Test script: --------------- $factory = function (string $msg): Closure { return function () use ($msg): void { echo $msg; }; }; $callbacks = [ $factory('First item!'), $factory('Second item!'), $factory('Third item!'), $factory('Fourth item!'), ]; $nl = function (): void { echo PHP_EOL; }; while ((null !== $callback = array_shift($callbacks)) && ($callback() || $nl() || true)) /**/; // exists after first item, should iterate thought all // Full test at: https://pastebin.com/br54nGvM Expected result: ---------------- First item! Second item! Third item! Fourth item! Actual result: -------------- First item! ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80184&edit=1