Allow dumping any BasicObject that defines #marshal_dump or #marshal_load

Additionally, it is assumed that these objects will have implemented
`respond_to?` and `class`, (e.g. SimpleDelegator). These assumptions are
reasonably inline with the assumptions of `Marshal` in regards to
`BasicObject`s.

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/psych/visitors/yaml_tree.rb b/lib/psych/visitors/yaml_tree.rb
index 3f2427b..989e1f0 100644
--- a/lib/psych/visitors/yaml_tree.rb
+++ b/lib/psych/visitors/yaml_tree.rb
@@ -27,6 +27,8 @@ module Psych
 
         def key? target
           @obj_to_node.key? target.object_id
+        rescue NoMethodError
+          false
         end
 
         def id_for target
@@ -411,6 +413,18 @@ module Psych
         end
       end
 
+      def visit_BasicObject o
+        tag = Psych.dump_tags[o.class]
+        tag ||= "!ruby/marshalable:#{o.class.name}"
+
+        map = @emitter.start_mapping(nil, tag, false, Nodes::Mapping::BLOCK)
+        register(o, map)
+
+        o.marshal_dump.each(&method(:accept))
+
+        @emitter.end_mapping
+      end
+
       private
       # FIXME: Remove the index and count checks in Psych 3.0
       NULL         = "\x00"