[perl #129907] [BUG] interaction of class FALLBACK methods and safe method calls (.?)

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# New Ticket Created by  David Warring 
# Please include the string:  [perl #129907]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=129907 >


I'm adding a FALLBACK method to create method dynamically, the it receives
both '.' and '.?' invocations, and I can't distinguish between them.

This then breaks $obj.unknown vs $obj.?unknown handling in class objects.

Consider:

use Test;

class C {
    method foo { 42 }
    method FALLBACK($meth-name, |c) {
        warn "can $meth-name";
        if $meth-name eq 'bar' {
            self.^add_method($meth-name, method { 69 });
            self."$meth-name"(|c);
        }
        else {
            warn "dunno if this is a safe method call or not";
            Nil;
        }
    }
}

for C {
    my $obj = .new;
    is $obj.foo, 42, 'static method - direct call';
    is $obj.?foo, 42, 'static method - safe call';
    is $obj.bar, 69, 'dynamic method - direct call';
    is $obj.?bar, 69, 'dynamic method - safe call';
    todo "can't get both of these to pass!";
    dies-ok {$obj.unknown}, 'direct call - unknown method dies';
    lives-ok {$obj.?unknown}, 'safe call - unknown method lives';
}

I'm receiving both the safe and unsafe 'unknown' invocations, and can't
distinguish them.

I also tried overriding the classes 'can' method:

class C {
    method foo { 42 }
    method can($meth-name) {
        my $meths = callsame;
        if !$meths && $meth-name eq 'bar' {
            $meths = [method { 69 }, ];
            self.^add_method($meth-name, $meths[0]);
        }
        $meths;
    }
    method FALLBACK($meth-name, |c) {
        if self.can($meth-name) {
            self."$meth-name"(|c);
        }
        else {
            warn "dunno if this is a safe method call or not";
            Nil;
        }
    }
}

But the FALLBACK is still needed, and still has the same problem.

Any ideas?