Re: after upgrade: glibc detected *** /usr/bin/perl: double free or corruption

Graham Barr wrote:
[...]
In your first statement

   ($self->{prog_name}= $0) =~ s|^.*/([^/]+)$|$1|;

you are calling s/// on the hash element. In the second

   $self->{prog_name}= (my $_p= $0) =~ s|^.*/([^/]+)$|$1|;

you are just setting the hash element, actually to the value "1" not the prog name.

oops ;)

> Anyway, I suspect the issue is todo with calling s/// on the element of 
> a tied hash.
> 
> See if this reproduces the issue.
> 
> {
>     package Foo;
>     use Tie::Hash;
>     use base qw(Tie::StdHash);
> 
>     sub new {
>         my $proto = shift;
>         my $inner = bless {};
>         my %outer;
>         tie %outer, __PACKAGE__, $inner;
>         bless \%outer;
>     }
> }
> 
> $self = Foo->new;
> ($self->{prog_name} = $0) =~ s|^.*/([^/]+)$|$1|;

That's it: Same thing - the program is aborted with a stack trace!
(Btw: this is happening with glibc-2.7 on Debian "lenny")

So: what's the big difference between just assigning a value and calling s/// ?
Is there anything else that shouldn't be done on a tied hash?

Regards,
                         Peter