Fix another memory leak

Author: bobtfish

CHANGES

@@ -1,7 +1,7 @@
 Revision history for Perl module Git::PurePerl:
 
      - Add config file handling via Config::GitLike
-     - Fix a memory leak due to unweakened circular references.
+     - Fix a couple of memory leaks due to unweakened circular references.
 
 0.45 Mon 21st Dec 12:36:29 GMT 2009
      - Be Win32 compatible (RT#52677), patch contributed by kmx.

lib/Git/PurePerl/DirectoryEntry.pm

@@ -7,7 +7,7 @@ use namespace::autoclean;
 has 'mode'     => ( is => 'ro', isa => 'Str',           required => 1 );
 has 'filename' => ( is => 'ro', isa => 'Str',           required => 1 );
 has 'sha1'     => ( is => 'ro', isa => 'Str',           required => 1 );
-has 'git'      => ( is => 'ro', isa => 'Git::PurePerl', required => 1 );
+has 'git'      => ( is => 'ro', isa => 'Git::PurePerl', required => 1, weak_ref => 1 );
 
 sub object {
     my $self = shift;