[perl #54802] extra positional arguments supplant named arguments

[via RT]

# New Ticket Created by  diakopter 
# Please include the string:  [perl #54802]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=54802 >


sub foo($w, $x?, $y?, :$z = 2){ say $w~"|"~$x~"|"~$y~"|"~$z};
foo(1,Undef,Undef,'something_extra',:z(3));

OUTPUT[1|Failure|Failure|something_extra␤]

the 'something_extra' should have been disregarded entirely.  I
expected: OUTPUT[1|Failure|Failure|3␤]

Note also that pugs gives: OUTPUT[*** No compatible multi variant
found: "&foo"␤    at /tmp/BwplDZyBLJ line 1, column 63-105␤]  (for the
same thing except with Undef in lowercase)