# IPC/Msg.pm lines 61-79
sub set {
my $self = shift;
my $ds;
if(@_ == 1) {
$ds = shift;
}
else {
croak 'Bad arg count' if @_ % 2;
my %arg = @_;
my $ds = $self->stat
or return undef;
my($key,$val);
$ds->$key($val)
while(($key,$val) = each %arg);
}
msgctl($$self,IPC_SET,$ds->pack);
}
There is a bug in this code: on line 11 (which is line 71 of the original file), my $ds creates a new $ds variable which goes out of scope at the end of the else block. That is why the final line has an undefined value for $ds when it tries to invoke $ds->pack.
Removing the redundant "my" will fix that problem by ensuring that (as intended) the outer $ds variable is the one used, and indeed in later perls you'll find that exactly this change has been made: replacing my $ds = $self->stat
with $ds = $self->stat
at line 71.
If you don't have permission to make this fix to the code directly, and you can't convince the system administrator to apply the fix for you, there are a couple of ways you can get around it. One way is subclassing to replace the buggy routine: {
package IPC::Msg::Bugfix;
our @ISA = qw/ IPC::Msg /;
sub set {
# corrected version of set here ...
}
}
# in your code
my $msg = new IPC::Msg::Bugfix('24h', IPC_CREAT);
# and continue as before
An alternative is to recode to avoid the path with the bug in it: # avoiding buggy multiple-arg set()
# $msg->set('qbytes' => 32768);
my $ds = $msg->stat or die "stat: $!";
$ds->qbytes(32768);
$msg->set($ds);
(Please note, I haven't tested any of this code.)
Hugo |