Bug #77310 [Com]: Variable values incorrect when Opcache enabled

Edit report at https://bugs.php.net/bug.php?id=77310&edit=1 ID: 77310 Comment by: titansoftime at gmail dot com Reported by: taylor at laravel dot com Summary: Variable values incorrect when Opcache enabled Status: Open Type: Bug Package: opcache Operating System: Multiple PHP Version: 7.3.0 Block user comment: N Private report: N New Comment: I to have experienced this bug. Happens every time after first page load. Totally broke my games stat system. Code works ok on first attempt after ftp upload, get 0's every time afterwards. OpCache for php 7.2.13 has no issue, only php 7.3 has the issue. Disabling opcache solves the problem. Using Ubuntu 18. Test code: class itest{ function make_user_stats():array{ $stats = array( 'strength' => 0, 'stamina' => 0, 'intellect' => 0, 'spirit' => 0, 'agility' => 0, 'armor' => 0, 'resist' => 0 ); $item_stats = array( 'stam_x' => 0, 'str_x' => 0, 'int_x' => 0, 'agi_x' => 0, 'spirit_x' => 0, 'armor_inc' => 0, 'resist_inc' => 0 ); $count = count($rows = array( array( 'intellect' => 100, 'stamina' => 200, 'strength' => 30, 'spirit' => 300, 'agility' => 500, 'resist' => 5, 'armor' => 5, ), array( 'intellect' => 200, 'stamina' => 300, 'strength' => 330, 'spirit' => 40, 'agility' => 100, 'resist' => 10, 'armor' => 5, ), array( 'intellect' => 250, 'stamina' => 120, 'strength' => 330, 'spirit' => 30, 'agility' => 5, 'resist' => 10, 'armor' => 10, ), )); foreach( $rows as $row ){ $item_stats['stam_x'] += $row['stamina']; $item_stats['str_x'] += $row['strength']; $item_stats['int_x'] += $row['intellect']; $item_stats['agi_x'] += $row['agility']; $item_stats['spirit_x'] += $row['spirit']; $item_stats['armor_inc'] += $row['armor']; $item_stats['resist_inc'] += $row['resist']; //var_dump($item_stats); } $stats['stamina'] += ceil( ($stats['stamina'] * ($item_stats['stam_x']/100)) ) + $item_stats['stam_x']; $stats['intellect'] += ceil( ($stats['intellect'] * ($item_stats['int_x']/100)) ) + $item_stats['int_x']; $stats['strength'] += ceil( ($stats['strength'] * ($item_stats['str_x']/100)) ) + $item_stats['str_x']; $stats['agility'] += ceil( ($stats['agility'] * ($item_stats['agi_x']/100)) ) + $item_stats['agi_x']; $stats['spirit'] += ceil( ($stats['spirit'] * ($item_stats['spirit_x']/100)) ) + $item_stats['spirit_x']; $stats['armor'] += $item_stats['armor_inc']; $stats['resist'] += $item_stats['resist_inc']; return $stats; } } $itest = new itest; $stats = $itest->make_user_stats(); var_dump($stats); Previous Comments: ------------------------------------------------------------------------ [2019-01-07 02:44:03] syntax53 at gmail dot com I believe a problem I just ran across is related / same as this. This is with PHP 7.3 nts x64 (I tried 7.3.1RC1 and same problem) on Windows 2016. ---[begin] <?php $data[0][0] = 'zero'; $data[0][1] = 0; $data[1][0] = 'one'; $data[1][1] = 1; $data[2][0] = 'two'; $data[2][1] = 2; function breakit($op,$table,$data_arr,$qual="") { switch ($op) { case "go": $foo[0] = ""; $foo[1] = ""; $bar[0] = ""; $bar[1] = ""; for($i = 0; $i < count($data_arr); $i++) { if ($foo[0] != "") { $foo[0]=$foo[0].","; $foo[1]=$foo[1].","; } if ($bar[0] != "") { $bar[0]=$bar[0].","; $bar[1]=$bar[1].","; } $field = "".$data_arr[$i][0].""; $val = "'".$data_arr[$i][1]."'"; $foo[0] .= $field; $foo[1] .= $val; $bar[0] = $bar[0].$field; $bar[1] = $bar[1].$val; } echo "foo[0]: ".$foo[0]."<br>"; echo "foo[1]: ".$foo[1]."<br>"; echo "bar[0]: ".$bar[0]."<br>"; echo "bar[1]: ".$bar[1]."<br>"; break; } } breakit('go','table',$data); ?> ---[end] output-- foo[0]: foo[1]: bar[0]: zero,one,two bar[1]: '0','1','2' (edited) ... with opcache enabled the string concatenation of "var .= value" produces an empty string. But using "var = var . value" works fine. Disable opcache and output of foo and bar is identical. ------------------------------------------------------------------------ [2018-12-20 15:13:02] cmb@php.net Can you please check with the fix for that bug[1] applied? Instead of applying the fix yourself, you can also test with PHP 7.3.1RC1[2] (announcement including hashes and signatures will follow shortly). Anyhow, this issue might also be related to bug #76937. [1] <http://git.php.net/?p=php-src.git;a=commit;h=93aabf1533bd3af673bb59cf283e6599ced3ab9a> [2] <http://downloads.php.net/~cmb/> ------------------------------------------------------------------------ [2018-12-20 11:57:17] taylor at laravel dot com Might be duplicate / similar issue as: https://bugs.php.net/bug.php?id=77275 ------------------------------------------------------------------------ [2018-12-17 16:59:26] nikic@php.net Off-topic comment by spam2 at rhsoft dot net deleted. ------------------------------------------------------------------------ [2018-12-17 16:50:43] taylor at laravel dot com We have temporarily worked around this by referencing $this->app within the Closure which is set to the same value that $app was previously. So, Laravel >= 5.7.18 should not be affected by this; however, I am worried the bug could affect other areas of code we haven't discovered yet. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=77310 -- Edit this bug report at https://bugs.php.net/bug.php?id=77310&edit=1