Bug#343656: libyaml-perl: Bug in "load" OO method

[Gilles]

Package: libyaml-perl
Version: 0.39-1
Severity: important

Hi.

You'll find here attached 3 files providing a stripped-down version
of a program that uncovered some strange behaviour of the YAML module
when using the "load" method.
In "TY.pm", when using the "Load" function (commented out line), the
behaviour is as expected, but not so with "load" for which the script
produces:
---CUT---
The input is correctly read from file, as you can see:

--- !perl/TY
key: some value

Something wrong happens in the "load" OO method:
Use of uninitialized value in substitution (s///) at /usr/share/perl5/YAML.pm 
line 670.
Use of uninitialized value in substitution (s///) at /usr/share/perl5/YAML.pm 
line 671.
Use of uninitialized value in pattern match (m//) at /usr/share/perl5/YAML.pm 
line 673.
Use of uninitialized value in length at /usr/share/perl5/YAML.pm line 675.
Use of uninitialized value in split at /usr/share/perl5/YAML.pm line 678.
And the "dump" shows that the input was not correctly loaded:

--- !perl/TY
key: ~

---CUT---

In the full program I was working on, the side-effect was even stranger: I 
didn't
get any of the above error messages from inside YAML.pm *but* on return from the
"load" method, my variable didn't contain the unserialized "TY" object but the
enclosing data (the equivalent of "$config" in the script provided here)!
[Obviously that doesn't happen with the reduced script, but why, I don't 
know...]


Regards,
Gilles

-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable')
Architecture: amd64 (x86_64)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.14-vs2.1.0-rc5+g3
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)

Versions of packages libyaml-perl depends on:
ii  perl                          5.8.7-7    Larry Wall's Practical Extraction 

libyaml-perl recommends no packages.

-- no debconf information

package TY ;

use strict ;
use YAML ;

sub load {
    my $proto = shift ;
    my $input = shift ;
    my $class = ref( $proto ) || $proto ;

    print
	'The input is correctly read from file, as you can see:',
	"\n\n",
	$input,
	"\n" ;
    print
	'Something wrong happens in the "load" OO method:',
	"\n" ;

    my $self = YAML->new->load( $input ) ;
#    my $self = Load( $input ) ;

    return __PACKAGE__->new( $self->{'key'} ) ;
}

sub new {
    my $proto = shift ;
    my $class = ref( $proto ) || $proto ;

    my $arg = shift ;
    my $self = { key => $arg } ;

    bless( $self, $class ) ;

    return $self ;
}


sub dump {
    my $self = shift ;
    return YAML->new->dump( $self ) ;
}


1 ;

--- !perl/TY
key: some value

#!/usr/bin/perl -w

use strict ;
use TY ;
use IO::File ;

my $config = { 'input' => [ { 'ty' => 'ty.yaml' } ] } ;

my @input = @{$config->{'input'}} ;
for ( my $i = 0 ; $i < @input ; $i++ ) {

    my $ty = TY->load( join( '', &readTY( $input[$i]->{'ty'} ) ) ) ;
    print
	'And the "dump" shows that the input was not correctly loaded:',
	"\n\n",
	$ty->dump,
	"\n" ;
}


sub readTY {
    my $file = shift ;

    my $io = IO::File->new( $file, "r" ) ;
    my @text = $io->getlines ;
    $io->close ;

    return @text ;
}