Merge branch 'master' into nested_has_many_through

Conflicts:
	activerecord/CHANGELOG
	activerecord/lib/active_record/association_preload.rb
	activerecord/lib/active_record/associations.rb
	activerecord/lib/active_record/associations/class_methods/join_dependency.rb
	activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
	activerecord/lib/active_record/associations/has_many_association.rb
	activerecord/lib/active_record/associations/has_many_through_association.rb
	activerecord/lib/active_record/associations/has_one_association.rb
	activerecord/lib/active_record/associations/has_one_through_association.rb
	activerecord/lib/active_record/associations/through_association_scope.rb
	activerecord/lib/active_record/reflection.rb
	activerecord/test/cases/associations/has_many_through_associations_test.rb
	activerecord/test/cases/associations/has_one_through_associations_test.rb
	activerecord/test/cases/reflection_test.rb
	activerecord/test/cases/relations_test.rb
	activerecord/test/fixtures/memberships.yml
	activerecord/test/models/categorization.rb
	activerecord/test/models/category.rb
	activerecord/test/models/member.rb
	activerecord/test/models/reference.rb
	activerecord/test/models/tagging.rb

1 files changed, 20 insertions, 1 deletions

diff --git a/activesupport/lib/active_support/ordered_hash.rb b/activesupport/lib/active_support/ordered_hash.rb
index 8e157d3af4..fbc40d1b69 100644
--- a/activesupport/lib/active_support/ordered_hash.rb
+++ b/activesupport/lib/active_support/ordered_hash.rb
@@ -1,3 +1,8 @@
+begin
+  require 'psych'
+rescue LoadError
+end
+
 require 'yaml'
 
 YAML.add_builtin_type("omap") do |type, val|
@@ -20,9 +25,17 @@ module ActiveSupport
       "!tag:yaml.org,2002:omap"
     end
 
+    def encode_with(coder)
+      coder.represent_seq '!omap', map { |k,v| { k => v } }
+    end
+
     def to_yaml(opts = {})
+      if YAML.const_defined?(:ENGINE) && !YAML::ENGINE.syck?
+        return super
+      end
+
       YAML.quick_emit(self, opts) do |out|
-        out.seq(taguri, to_yaml_style) do |seq|
+        out.seq(taguri) do |seq|
           each do |k, v|
             seq.add(k => v)
           end
@@ -124,15 +137,21 @@ module ActiveSupport
       end
 
       def each_key
+        return to_enum(:each_key) unless block_given?
         @keys.each { |key| yield key }
+        self
       end
 
       def each_value
+        return to_enum(:each_value) unless block_given?
         @keys.each { |key| yield self[key]}
+        self
       end
 
       def each
+        return to_enum(:each) unless block_given?
         @keys.each {|key| yield [key, self[key]]}
+        self
       end
 
       alias_method :each_pair, :each