my @a = 1..3;
my @b = qw( a b c );

my @foo = orig_zip( \@a, \@b );
my @bar = fixed_zip( \@a, \@b );

print Data::Dumper->Dump( 
    [ \@foo,      \@bar   ], 
    [ 'original', 'fixed' ]
);

sub orig_zip {
    my( $r1, $r2 ) = @_;
    map {
        $r1->[ $_ ], $r2->[ $_ ]
    } 0 .. ( @$r1 > @$r2 ? @$r1 : @$r2 );
}

sub fixed_zip {
    my( $r1, $r2 ) = @_;
    map {
        $r1->[ $_ ], $r2->[ $_ ]
    } 0 .. ( $#$r1 > $#$r2 ? $#$r1 : $#$r2 );
}
__END__
$original = [
              1,
              'a',
              2,
              'b',
              3,
              'c',
              undef,
              undef
            ];
$fixed = [
           1,
           'a',
           2,
           'b',
           3,
           'c'
         ];