Bug #47623 [Ver->Nab]: array_shift() fails with @ operator

Edit report at https://bugs.php.net/bug.php?id=47623&edit=1 ID: 47623 Updated by: nikic@php.net Reported by: Henry at huis-stijl dot nl Summary: array_shift() fails with @ operator -Status: Verified +Status: Not a bug Type: Bug Package: Scripting Engine problem Operating System: * PHP Version: 5.*, 6CVS (2009-04-30) Block user comment: N Private report: N New Comment: As array_shift() uses by-reference argument passing and an error suppression expression is not a variable, this behavior is correct. Note that it throws the usual "only variables can be passed by reference" notice. Previous Comments: ------------------------------------------------------------------------ [2010-06-01 04:05:20] laruence at yahoo dot com dot cn errata: //then in zend_do_pass_param: ZEND_SEND_VAR gen opcode:"SEND_REF", ZEND_SEND_VAL gen opcode:"SEND_VAR_NO_REF" ------------------------------------------------------------------------ [2010-05-28 16:35:20] laruence at yahoo dot com dot cn Hi, I found the same bug in php 5.2.8(linux) and I also find out why: in php complie phase, @$var -> expr_without_variable; //code expr_without_variable: ... | '@' { zend_do_begin_silence(&$1 TSRMLS_CC); } expr { zend_do_end_silence(&$1 TSRMLS_CC); $$ = $3; } while: $var -> variable then this different cause the znode's difference // non_empty_function_call_parameter_list: expr_without_variable { Z_LVAL($$.u.constant) = 1; zend_do_pass_param(&$1, ZEND_SEND_VAL, Z_LVAL($$.u.constant) TSRMLS_CC); } | variable { Z_LVAL($$.u.constant) = 1; zend_do_pass_param(&$1, ZEND_SEND_VAR, Z_LVAL($$.u.constant) TSRMLS_CC); } then in zend_so_pass_param: ZEND_SEND_VAR gen opcode:"SEND_REF", ZEND_SEND_VAR gen opcode:"SEND_VAR_NO_REF" so when use @, cause param send without ref. you can find more info on : http://www.laruence.com/2010/05/28/1565.html ------------------------------------------------------------------------ [2010-05-05 20:56:31] whatrevolution at yahoo dot com <?php $_SESSION['villas'] = array ( 1 => array(1,2,3), 2 => array(2,3,4), 3 => array(3,4,5), 4 => array(4,5,6), ); /* * ONE: */ /* While(@$_SESSION['villas'] != array()) { $row = array_shift(@$_SESSION['villas']); print_r($row); }// einde while */ /* * TWO: */ /* while($foo['villas'] != array()) { $row = array_shift(@$foo['villas']); // Removing @ makes it work.. var_dump($foo); } */ /* * THREE: */ //I cann bypass this failure by using: $arr_temp = @$_SESSION['villas']; $row = array_shift($arr_temp); $_SESSION['villas'] = $arr_temp; unset($arr_temp); var_dump($_SESSION['villas']); ?> Result: One and Two, same as described before. Three: array 0 => array 0 => int 2 1 => int 3 2 => int 4 1 => array 0 => int 3 1 => int 4 2 => int 5 2 => array 0 => int 4 1 => int 5 2 => int 6 PHP Version 5.2.10-2ubuntu6.4 System Linux 2.6.31-20-generic x86_64 Build Date Jan 6 2010 22:36:47 Server API Apache 2.0 Handler PHP API 20041225 PHP Extension 20060613 Zend Extension 220060519 Debug Build no Thread Safety disabled Zend Memory Manager enabled Apache/2.2.12 (Ubuntu) ------------------------------------------------------------------------ [2009-04-13 18:23:01] jani@php.net This has nothing to do with sessions. Simplified script: <?php $foo['villas'] = array('a','b','c'); while($foo['villas'] != array()) { $row = array_shift(@$foo['villas']); // Removing @ makes it work.. var_dump($foo); } ?> ------------------------------------------------------------------------ [2009-03-16 22:11:28] Henry at huis-stijl dot nl Tried with and without the @ same output. ------------------------------------------------------------------------ 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=47623 -- Edit this bug report at https://bugs.php.net/bug.php?id=47623&edit=1