The problem is that you are using a reference as index in an array.

I admit that this appears to be whats going on, But I do not understand how. I see no lookup of an array in that code.

Heres some toying I did with the problem.

#!perl -l
use strict;
use warnings;

my $a = {child1 => [ {child2 => [ {child3 => [ {child4 => [1]} ]} ]} ]
+};
print $a->{child1}{child2}{child3}; #cut off {child3} and no problem.

print '$a:',ref $a;
print '$a->{child1}:',ref $a->{child1};
print '$a->{child1}{child2}:',ref $a->{child1}{child2};
print '@{$a->{child1}}:',scalar @{$a->{child1}};
__END__
$a:HASH
$a->{child1}:ARRAY
$a->{child1}{child2}:HASH
@{$a->{child1}}:28004977
[download]

So it would appear that somehow $a->{child1}{child2} is being treated as an array lookup. But how? There is no array lookup involved.

Id be interested to hear an explanation as to why this isnt a bug in perl.

---
demerphq

First they ignore you, then they laugh at you, then they fight you, then you win.
-- Gandhi