Bug #66040 [NEW]: Cloning an object while having reference to members results incorrect clone

From: bawolff+wn at gmail dot com Operating system: linux PHP version: 5.5Git-2013-11-07 (snap) Package: Scripting Engine problem Bug Type: Bug Bug description:Cloning an object while having reference to members results incorrect clone Description: ------------ The problem is easiest understood by looking at the test script. Basically, if you clone an object in a function that as one of its arguments (or one of its calling functions) has a reference to a member variable of this object, the clone of the object is not correct for the field that the reference is to. The fields of the two objects behave as if they are references to each other (To clarify I do not mean fields point to the same object as is expected, I mean the field itself is a reference to the other field.). If you assign something to that member variable, the change is reflected in both the cloned object and the original, where it should only be reflected in the object that the assignment was for. Tested on snapshot php5.5-201311070030 Also tested on earlier versions like 5.3.3-7 Originally discovered while investigating a bug in MediaWiki: https://bugzilla.wikimedia.org/show_bug.cgi?id=56226 Test script: --------------- <?php $originalObj = new A; class A { var $foo = 'default value'; } // Important note: If you remove the &, the bug disappears. function changeFooWithUnusedReference( &$unusedReferenceToFoo, $newValue ) { global $originalObj; $newObj = clone $originalObj; echo $originalObj->foo . "\n"; echo $newObj->foo . "\n"; $newObj->foo = $newValue; echo $originalObj->foo . "\n"; echo $newObj->foo . "\n"; } changeFooWithUnusedReference( $originalObj->foo, 'Some other value' ); Expected result: ---------------- I expect the following output: default value default value default value Some other value Actual result: -------------- Following output: default value default value Some other value Some other value -- Edit bug report at https://bugs.php.net/bug.php?id=66040&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=66040&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=66040&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=66040&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=66040&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=66040&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=66040&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=66040&r=needscript Try newer version: https://bugs.php.net/fix.php?id=66040&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=66040&r=support Expected behavior: https://bugs.php.net/fix.php?id=66040&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=66040&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=66040&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=66040&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=66040&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=66040&r=dst IIS Stability: https://bugs.php.net/fix.php?id=66040&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=66040&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=66040&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=66040&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=66040&r=mysqlcfg