use 5.010;

package Foo;

use vars '$i';
use strict;
use warnings;

sub bar
{
    for $i (1 .. 10)
    {
        main::baz( $i );
    }
}

package main;

use strict;
use warnings;
use Test::More tests => 12;

$Foo::i = 100;

sub baz
{
    my $expect = shift;
    is( $Foo::i, $expect );
}

baz(100);
Foo::bar();
baz(100);