Bug #76051 [NEW]: Inconsistent behavior with overriding constants in interfaces

From: korikulum at net dot hr Operating system: PHP version: 7.1.15 Package: Class/Object related Bug Type: Bug Bug description:Inconsistent behavior with overriding constants in interfaces Description: ------------ Overriding constants defined in interfaces isn't allowed in classes that implement the interface, but is in classes that extend classes that implement the interface. Test script: --------------- <?php interface FooInterface { const BAR = ''; } class Foo implements FooInterface { const BAR = 'BAR'; } $baz = new Foo; var_dump($baz::BAR); https://3v4l.org/qVreY <?php interface FooInterface { const BAR = ''; } abstract class AbstractFoo implements FooInterface { } class Foo extends AbstractFoo { const BAR = 'BAR'; } $baz = new Foo; var_dump($baz::BAR); https://3v4l.org/9S53j Expected result: ---------------- Either both cases work or both result in the error "Fatal error: Cannot inherit previously-inherited or override constant SOME_CONST from interface MyInterface". Actual result: -------------- The first case gives the error "Fatal error: Cannot inherit previously-inherited or override constant SOME_CONST from interface MyInterface". The second case works normally. -- Edit bug report at https://bugs.php.net/bug.php?id=76051&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=76051&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=76051&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=76051&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=76051&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=76051&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=76051&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=76051&r=needscript Try newer version: https://bugs.php.net/fix.php?id=76051&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=76051&r=support Expected behavior: https://bugs.php.net/fix.php?id=76051&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=76051&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=76051&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=76051&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=76051&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=76051&r=dst IIS Stability: https://bugs.php.net/fix.php?id=76051&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=76051&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=76051&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=76051&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=76051&r=mysqlcfg