always need to specify netloc/realm to $ua->credentials ?

I can't check at this moment whether this is new in 5.15.7

make test for WWW-Mechanize-1.71
t/credentials-api.t ...... Use of uninitialized value in lc at /opt/perl/uq.is.perl.rhel6-5.15.7-20120121/lib/site_perl/5.15.7/LWP/UserAgent.pm line 580.

sub credentials  LWP::UserAgent
{
    my $self = shift;
    my $netloc = lc(shift);    <== line 580
    my $realm = shift || "";
    my $old = $self->{basic_authentication}{$netloc}{$realm};


but t/credentials-api.t says
my @ua = $ua->credentials;
isnt( "@ua", "mech2 mech2", 'LWP::UserAgent instance retains its old credentials' );


looks like that test is wrong as LWP::UserAgent pod
says you need to specify netloc & realm

just want to check before lodging a bug report

thanks
Danny