fixing cyclic object reference handling. Thanks to @CvX for the test. fixes #19

3 files changed, 24 insertions, 1 deletions

diff --git a/CHANGELOG.rdoc b/CHANGELOG.rdoc
index 8d92124..babac95 100644
--- a/CHANGELOG.rdoc
+++ b/CHANGELOG.rdoc
@@ -1,3 +1,9 @@
+Wed Jun 22 03:20:52 2011  Aaron Patterson <aaron@tenderlovemaking.com>
+
+	* ext/psych/lib/psych/visitors/to_ruby.rb: Fix cyclic references of
+	  objects.  Thanks to CvX for reporting the bug and a test case.
+	* test/psych/test_object.rb: test for cyclic object references.
+
 Thu Jun  9 10:57:03 2011  Aaron Patterson <aaron@tenderlovemaking.com>
 
 	* ext/psych/lib/psych/visitors/to_ruby.rb: Hash subclasses can be read
diff --git a/lib/psych/visitors/to_ruby.rb b/lib/psych/visitors/to_ruby.rb
index 2562816..b8eb698 100644
--- a/lib/psych/visitors/to_ruby.rb
+++ b/lib/psych/visitors/to_ruby.rb
@@ -182,7 +182,6 @@ module Psych
         when /^!ruby\/object:?(.*)?$/
           name = $1 || 'Object'
           obj = revive((resolve_class(name) || Object), o)
-          @st[o.anchor] = obj if o.anchor
           obj
 
         when /^!map:(.*)$/, /^!ruby\/hash:(.*)$/
@@ -233,6 +232,7 @@ module Psych
 
       def revive klass, node
         s = klass.allocate
+        @st[node.anchor] = s if node.anchor
         h = Hash[*node.children.map { |c| accept c }]
         init_with(s, h, node)
       end
diff --git a/test/psych/test_object.rb b/test/psych/test_object.rb
index 9890d50..6145bb6 100644
--- a/test/psych/test_object.rb
+++ b/test/psych/test_object.rb
@@ -11,6 +11,14 @@ module Psych
     end
   end
 
+  class Foo
+    attr_accessor :parent
+
+    def initialize parent
+      @parent = parent
+    end
+  end
+
   class TestObject < TestCase
     def test_dump_with_tag
       tag = Tagged.new
@@ -23,5 +31,14 @@ module Psych
       assert_equal tag.baz, tag2.baz
       assert_instance_of(Tagged, tag2)
     end
+
+    def test_cyclic_references
+      foo = Foo.new(nil)
+      foo.parent = foo
+      loaded = Psych.load Psych.dump foo
+
+      assert_instance_of(Foo, loaded)
+      assert_equal loaded, loaded.parent
+    end
   end
 end