#41542 [NEW]: The '@' operator changes the behaviour of the code

From: linfo2003 at libero dot it Operating system: WindowsXP PHP version: 5.2.2 PHP Bug Type: Variables related Bug description: The '@' operator changes the behaviour of the code Description: ------------ The '@' operator to not only suppresses non-fatal errors, but it seems that it changes the behaviour of the code. I don't know if it's a bug or a normal behaviour. The fact is that if you pass by reference an undefined index of an array to a function, that index will be defined and set to NULL. While if you use the '@' operator, this won't happen. See the code. Reproduce code: --------------- error_reporting(E_ALL); print '<pre>'; function byVal( $v) {} function byRef(&$v) {} echo "byVal(first['undefined'])\n"; byVal ($first['undefined']); // gives a notice echo "var_dump(first)\n"; var_dump($first); // gives a notice print '<hr />'; echo "byRef(second['undefined'])\n"; byRef ($second['undefined']); // does NOT give a notice echo "var_dump(second)\n"; var_dump($second); // does NOT give a notice print '<hr />'; echo "byRef(@third['undefined'])\n"; byRef (@$third['undefined']); // does NOT give a notice echo "var_dump(third)\n"; var_dump($third); // gives a notice Expected result: ---------------- The $second or the $third case should be wrong, IMHO. AKAIK, the '@' operator should only suppress the notice, while it's changing the behaviour of the code, by not defining the $third array and not defining the 'undefined' index into the $third array. I don't know if the $second case is an expected behaviour, maybe it should NOT add the 'undefined' index into the (undefined) $third array. However, is a fact that the '@' operator makes something unexpected: it does NOT only suppress the notice. Actual result: -------------- byVal(first['undefined']) Notice: Undefined variable: first in ... on line 12 var_dump(first) Notice: Undefined variable: first in ... on line 14 NULL ----------------------------------------------------- byRef(second['undefined']) var_dump(second) array(1) { ["undefined"]=> NULL } ----------------------------------------------------- byRef(@third['undefined']) var_dump(third) Notice: Undefined variable: third in ... on line 28 NULL -- Edit bug report at http://bugs.php.net/?id=41542&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=41542&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=41542&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=41542&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=41542&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=41542&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=41542&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=41542&r=needscript Try newer version: http://bugs.php.net/fix.php?id=41542&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=41542&r=support Expected behavior: http://bugs.php.net/fix.php?id=41542&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=41542&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=41542&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=41542&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=41542&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=41542&r=dst IIS Stability: http://bugs.php.net/fix.php?id=41542&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=41542&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=41542&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=41542&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=41542&r=mysqlcfg