Redeclaring protected properties on children creates a liskov violation #19406
Description
Description
The following code:
<?php
class P {
protected $v;
}
class C extends P {
public function test(P $i) {
return $i->v;
}
}
class C2 extends P {
protected $v;
}
$c = new C;
$c2 = new C2;
$c->test($c2);Resulted in this output:
PHP Fatal error: Uncaught Error: Cannot access protected property C2::$v
But I expected this output instead:
After a discussion on the mailing list everyone seemed to agree it's a bug, and I believe fixing it wouldn't break any pre-existing code. Properties were invariant up to 8.4, and property hook variance is well defined.
PHP Version
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