strace perl -e 'msgget( 0xdeadbeef, 0 );'
...
msgget(0x80000000, 0)      = 655361

##</code><code>##

# A testcase exhibiting the issue
use IPC::SysV qw( IPC_CREAT IPC_RMID );
use Test::More tests => 1;
use strict;
use warnings;

my $last_key = 0x80000000;
my $i32b_key = 0xdeadbeef; # Anything > $last_key

cleanup();
test();
cleanup();

sub cleanup
{
    my $queue_id = msgget $last_key, 0;
    msgctl $queue_id, IPC_RMID, 0 if defined $queue_id;

    $queue_id = msgget $i32b_key, 0;
    msgctl $queue_id, IPC_RMID, 0 if defined $queue_id;

    return;
}

sub test
{
    my $queue1_id = msgget $i32b_key, IPC_CREAT;
    my $queue2_id = msgget $last_key, IPC_CREAT;

    my $msg = sprintf "Queues 0x%x and 0x%x have the same ID 0x%x", $last_key, $i32b_key, $queue1_id;
    isnt( $queue1_id, $queue2_id, $msg );

    return;
}

1;