Zend's zend_do_perform_implementation_check does not compare variadic-ness
per position. Its rules are:
- a variadic parent requires a variadic child (unbounded contract);
- a trailing child variadic stands in for every remaining parent
position (decorator pattern), with the variadic's type checked for
contravariance against each covered parent parameter and by-ref-ness
matched per position;
- when the parent is variadic, extra child parameters are validated
against the parent's variadic slot.
validateMethodOverrideSignature required an exact per-position variadic
match, rejecting valid programs such as parent f(int $a, int $b)
overridden by f(int ...$args). Rework the position loop per the Zend
rules; the required-argument-count and extra-optional-parameter checks
are unchanged.
The pre-existing testVariadicMismatch expectation (untyped f($x)
overridden by f(...$x) must fail) contradicts Zend 8.4, which accepts
it; the test now asserts the program compiles.
Alessio Giacobbe