#42477 [NEW]: round() returns negative zero

From: koen at genericmedia dot nl Operating system: Windows XP PHP version: 5.2.3 PHP Bug Type: Math related Bug description: round() returns negative zero Description: ------------ When rounding a small negative number, the function returns a negative zero. I suspect this has something to do with computing precision, so I suppose that the reason is not really a bug. I've seen the bug report at #31870 and I understand the answer. Strange thing is however that prior to 5.2.3 the result actually was float(0). Reproduce code: --------------- <?php var_dump( round(-0.26) ); ?> Expected result: ---------------- float(0) Actual result: -------------- PHP 4.3.10: float(0) PHP 4.4.6: float(0) PHP 5.1.6: float(0) PHP 5.2.3: float(-0) -- Edit bug report at http://bugs.php.net/?id=42477&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=42477&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=42477&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=42477&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=42477&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=42477&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=42477&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=42477&r=needscript Try newer version: http://bugs.php.net/fix.php?id=42477&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=42477&r=support Expected behavior: http://bugs.php.net/fix.php?id=42477&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=42477&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=42477&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=42477&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=42477&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=42477&r=dst IIS Stability: http://bugs.php.net/fix.php?id=42477&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=42477&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=42477&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=42477&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=42477&r=mysqlcfg