Merge pull request #7371 from csmuc/fix_dup_validation_errors

Dup'ed ActiveRecord objects may not share the errors object
Conflicts:
	activerecord/CHANGELOG.md
	activerecord/test/cases/dup_test.rb

activerecord/CHANGELOG.md

@@ -1,5 +1,10 @@
 ## Rails 3.2.9 (unreleased)
 
+*   Fix AR#dup to nullify the validation errors in the dup'ed object. Previously the original
+    and the dup'ed object shared the same errors.
+
+    * Christian Seiler*
+
 *   Synchronize around deleting from the reserved connections hash.
     Fixes #7955
 

activerecord/lib/active_record/timestamp.rb

@@ -39,6 +39,7 @@ module ActiveRecord
 
     def initialize_dup(other)
       clear_timestamp_attributes
+      super
     end
 
   private

activerecord/test/cases/dup_test.rb

@@ -98,5 +98,20 @@ module ActiveRecord
       assert_not_nil new_topic.updated_at
       assert_not_nil new_topic.created_at
     end
+
+    def test_dup_validity_is_independent
+      Topic.validates_presence_of :title
+      topic = Topic.new("title" => "Litterature")
+      topic.valid?
+
+      duped = topic.dup
+      duped.title = nil
+      assert duped.invalid?
+
+      topic.title = nil
+      duped.title = 'Mathematics'
+      assert topic.invalid?
+      assert duped.valid?
+    end
   end
 end