Bug #53989 [NEW]: Notice: Undefined variable/index with xor, but not with or

From: Operating system: Tested only with Windows PHP version: 5.3.5 Package: Scripting Engine problem Bug Type: Bug Bug description:Notice: Undefined variable/index with xor, but not with or Description: ------------ I want to check, if a variable is not set. If the variable is not set, i want to check, if this variable has a special value. There is no problem with "or", but with "xor" outputs a notice. Test script: --------------- <? session_start(); if(!isset($_SESSION['foo']) xor $_SESSION['foo'] == 1) echo "foo"; if(!isset($bar) xor $bar== 1) echo "bar"; if(!isset($_SESSION['foo']) or $_SESSION['foo'] == 1) echo "foo"; if(!isset($bar) or $bar== 1) echo "bar"; ?> Expected result: ---------------- foobarfoobar Actual result: -------------- Notice: Undefined index: foo in C:\xampp\htdocs\feredoras\testing.php on line 4 foo Notice: Undefined variable: bar in C:\xampp\htdocs\feredoras\testing.php on line 5 barfoobar -- Edit bug report at http://bugs.php.net/bug.php?id=53989&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=53989&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=53989&r=trysnapshot53 Try a snapshot (trunk): http://bugs.php.net/fix.php?id=53989&r=trysnapshottrunk Fixed in SVN: http://bugs.php.net/fix.php?id=53989&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=53989&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=53989&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=53989&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=53989&r=needscript Try newer version: http://bugs.php.net/fix.php?id=53989&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=53989&r=support Expected behavior: http://bugs.php.net/fix.php?id=53989&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=53989&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=53989&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=53989&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=53989&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=53989&r=dst IIS Stability: http://bugs.php.net/fix.php?id=53989&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=53989&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=53989&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=53989&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=53989&r=mysqlcfg