#39579 [NEW]: Comparing zero & string values in boolean comparison has unexpected behaviour

From: iain at workingsoftware dot com dot au Operating system: FreeBSD 6.1 PHP version: 5.2.0 PHP Bug Type: Class/Object related Bug description: Comparing zero & string values in boolean comparison has unexpected behaviour Description: ------------ if you have a variable with the value 0 assigned to it and do a comparison with a non-integer then the non-integer value is cast to an int with unexpected results. it behaves differently when comparing a non-zero integer. Reproduce code: --------------- put this in test.php and run php -f test.php: <?php $zero = 0; $one = 1; if($zero == 'SOME STRING') echo("0 does equal 'SOME STRING'\n"); else echo("0 does not equal 'SOME STRING'\n"); if($one == 'SOME STRING') echo("1 does equal 'SOME STRING'\n"); else echo("1 does not equal 'SOME STRING'\n"); ?> Expected result: ---------------- 0 does not equal 'SOME STRING' 1 does not equal 'SOME STRING' Actual result: -------------- 0 does equal 'SOME STRING' 1 does not equal 'SOME STRING' -- Edit bug report at http://bugs.php.net/?id=39579&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=39579&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=39579&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=39579&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=39579&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=39579&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=39579&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=39579&r=needscript Try newer version: http://bugs.php.net/fix.php?id=39579&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=39579&r=support Expected behavior: http://bugs.php.net/fix.php?id=39579&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=39579&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=39579&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=39579&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=39579&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=39579&r=dst IIS Stability: http://bugs.php.net/fix.php?id=39579&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=39579&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=39579&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=39579&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=39579&r=mysqlcfg