Bug #80649 [Opn]: Incorrect type checking behaviour

Edit report at https://bugs.php.net/bug.php?id=80649&edit=1 ID: 80649 Updated by: cmb@php.net Reported by: graham at alt-three dot com Summary: Incorrect type checking behaviour Status: Open Type: Bug Package: *General Issues Operating System: Linux PHP Version: 8.0.1 Block user comment: N Private report: N New Comment: Indeed, null is coerced to an empty string when passed to an internal function, even in strict type mode. I can't find respective documentation in the manual. Previous Comments: ------------------------------------------------------------------------ [2021-01-20 08:29:27] nicolasgrekas@php.net Check https://wiki.php.net/rfc/deprecate_null_to_scalar_internal_arg ------------------------------------------------------------------------ [2021-01-20 00:21:38] graham at alt-three dot com Description: ------------ Many mb_ functions are not throwing type errors when the provided input does not match the type signature, on PHP 8. Test script: --------------- <?php function f(string $x) {} var_dump((new ReflectionFunction('mb_strpos'))->getParameters()[0]->getType()->getName()); var_dump((new ReflectionFunction('f'))->getParameters()[0]->getType()->getName()); mb_strpos(null, 'a'); f(null); Expected result: ---------------- string(6) "string" string(6) "string" Fatal error: Uncaught TypeError: mb_strpos(): Argument #1 ($haystack) must be of type string Actual result: -------------- string(6) "string" string(6) "string" Fatal error: Uncaught TypeError: f(): Argument #1 ($x) must be of type string ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80649&edit=1