#41690 [NEW]: Decrementing null is null

From: ian at ithomas dot name Operating system: Gentoo PHP version: 5.2.3 PHP Bug Type: Math related Bug description: Decrementing null is null Description: ------------ Incrementing null is 1. Decrementing null is null! I'm not sure which is the correct behaviour, but they should at least be consistent. I saw this on PHP 4.4.4 but have since duplicated it on 5.2.3. It was a problem for me because I had a "for ($i = null; $i > 0; $i--)" which results in an infinite loop (but would work fine if $i++ was used instead). Reproduce code: --------------- <?php echo '$i++: '; $i = null; var_dump($i); $i++; var_dump($i); echo '<br> <br> <br> $i--: '; $i = null; var_dump($i); $i--; var_dump($i); echo '<br> <br> <br> $i - 1: '; $i = null; var_dump($i); $i = $i - 1; var_dump($i); ?> Expected result: ---------------- null-- should be 1, so script should output: $i++: NULL int(1) $i--: NULL int(-1) $i - 1: NULL int(-1) Actual result: -------------- null-- is null, script output is: $i++: NULL int(1) $i--: NULL NULL $i - 1: NULL int(-1) -- Edit bug report at http://bugs.php.net/?id=41690&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=41690&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=41690&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=41690&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=41690&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=41690&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=41690&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=41690&r=needscript Try newer version: http://bugs.php.net/fix.php?id=41690&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=41690&r=support Expected behavior: http://bugs.php.net/fix.php?id=41690&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=41690&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=41690&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=41690&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=41690&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=41690&r=dst IIS Stability: http://bugs.php.net/fix.php?id=41690&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=41690&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=41690&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=41690&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=41690&r=mysqlcfg