XML::LibXML 1.89 + perl 5.14.2: segfault

Description: Ubuntu 12.04 LTS
Release: 12.04

# apt-cache policy libxml-libxml-perl
libxml-libxml-perl:
  Installed: 1.89+dfsg-1
  Candidate: 1.89+dfsg-1
  Version table:
 *** 1.89+dfsg-1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status

perl program testfail.pl:

#!/usr/bin/perl

use XML::LibXML;

my $elt = XML::LibXML::Element->new("top");
my @nodes = $elt->findnodes("/");
print @nodes . "\n";

should ouput '1' and a newline.

instead this will randomly either:

- work as expected or,
- emit something like "PmmREFCNT_dec: REFCNT decremented below 0 for 176c5b0!." and segfault

with roughly equal probability.

I have fixed this for myself by upgrading to the latest version of XML::LibXML (1.97 at time of writing):

# cpanm XML::LibXML

I thought it best to submit a bug report so this can be fixed in the distribution.

Anyone with the same problem reading this should note that you'll need a few things first before the above 'cpanm' command will work:

# apt-get install cpanminus, libxml2-dev, zlib1g-dev

EDIT (it was obviously too late at night for me to be reporting bugs):

1) I typo'd the new version of XML::LibXML I installed (1.97 instead of 1.92 as originally written).

2) The new version still doesn't work properly. The following script is enough to cause the original error to reappear:

#!/usr/bin/perl

use XML::LibXML;
my $elt = XML::LibXML::Element->new("top");
print $elt->toString . "\n";
my @nodes = $elt->findnodes("/");
print @nodes . "\n";

Given that the latest version of XML::LibXML still has problems, perhaps this is an upstream bug. It's still early here: I'll investigate later and maybe send a report to the XML::LibXML maintainers.