* ext/psych/lib/psych.rb: Syck api compatibility [ruby-core:29157]

* ext/psych/lib/psych/nodes/node.rb: ditto
* test/psych/test_psych.rb: ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27134 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 7 insertions, 2 deletions

diff --git a/ext/psych/lib/psych.rb b/ext/psych/lib/psych.rb
index 59307e3d99..9b4b215b67 100644
--- a/ext/psych/lib/psych.rb
+++ b/ext/psych/lib/psych.rb
@@ -153,10 +153,15 @@ module Psych
   # Example:
   #
   #   Psych.dump(['a', 'b'])  # => "---\n- a\n- b\n"
-  def self.dump o, options = {}
+  def self.dump o, io = nil, options = {}
+    if Hash === io
+      options = io
+      io      = nil
+    end
+
     visitor = Psych::Visitors::YAMLTree.new options
     visitor << o
-    visitor.tree.to_yaml
+    visitor.tree.to_yaml io
   end
 
   ###