Bug #74020 [NEW]: Foreach-by-reference may create unexpected key references

From: icarpenter at leadid dot com Operating system: PHP version: 7.0.15 Package: Arrays related Bug Type: Bug Bug description:Foreach-by-reference may create unexpected key references Description: ------------ After a foreach-by-reference, an array may create references to keys if you create a copy of the original variable (either directly or indirectly via foreach) and then on that new variable, create a copy of a key to another key. The original key in that variable will then become a reference to the same key in the original array. In PHP 5.6 and 7.1, this can be avoided by either having the foreach run in a different scope, or unsetting the reference variable after the loop. PHP 7.0 exhibits this behavior regardless. Test script: --------------- https://3v4l.org/mHX7B (Triggers the bug in PHP 7.0) https://3v4l.org/VLuhn (Triggers the bug in PHP 5.6, 7.0, and 7.1) Expected result: ---------------- string(3) "foo" Actual result: -------------- string(3) "bar" -- Edit bug report at https://bugs.php.net/bug.php?id=74020&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=74020&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=74020&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=74020&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=74020&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=74020&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=74020&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=74020&r=needscript Try newer version: https://bugs.php.net/fix.php?id=74020&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=74020&r=support Expected behavior: https://bugs.php.net/fix.php?id=74020&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=74020&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=74020&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=74020&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=74020&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=74020&r=dst IIS Stability: https://bugs.php.net/fix.php?id=74020&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=74020&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=74020&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=74020&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=74020&r=mysqlcfg