dup is working better

activerecord/lib/active_record/base.rb

@@ -1420,7 +1420,7 @@ MSG
         @attributes = coder['attributes']
         @attributes_cache, @previously_changed, @changed_attributes = {}, {}, {}
         @readonly = @destroyed = @marked_for_destruction = false
-        @persisted = true
+        @persisted = false
         _run_find_callbacks
         _run_initialize_callbacks
       end
@@ -1615,11 +1615,15 @@ MSG
         @attributes.frozen?
       end
 
+      def initialize_dup(other)
+        super
+        init_with 'attributes' => other.attributes
+        self
+      end
+
       # Returns duplicated record with unfreezed attributes.
       def dup
-        obj = super
-        obj.instance_variable_set('@attributes', @attributes.dup)
-        obj
+        super
       end
 
       # Returns +true+ if the record is read only. Records loaded through joins with piggy-back

activerecord/test/cases/base_test.rb

@@ -1443,10 +1443,6 @@ class BasicsTest < ActiveRecord::TestCase
     ActiveRecord::Base.logger = original_logger
   end
 
-  def test_dup
-    assert !Minimalistic.new.freeze.dup.frozen?
-  end
-
   def test_compute_type_success
     assert_equal Author, ActiveRecord::Base.send(:compute_type, 'Author')
   end

activerecord/test/cases/duplication_test.rb

@@ -0,0 +1,43 @@
+require "cases/helper"
+require 'models/topic'
+
+module ActiveRecord
+  class DuplicationTest < ActiveRecord::TestCase
+    fixtures :topics
+
+    def test_dup
+      assert !Minimalistic.new.freeze.dup.frozen?
+    end
+
+    def test_dup_not_persisted
+      topic = Topic.first
+      duped = topic.dup
+
+      assert !duped.persisted?, 'topic not persisted'
+      assert duped.new_record?, 'topic is new'
+    end
+
+    def test_dup_has_no_id
+      topic = Topic.first
+      duped = topic.dup
+      assert_nil duped.id
+    end
+
+    def test_clone_persisted
+      topic = Topic.first
+      cloned = topic.clone
+      assert cloned.persisted?, 'topic persisted'
+      assert !cloned.new_record?, 'topic is not new'
+    end
+
+    def test_clone_keeps_frozen
+      topic = Topic.first
+      topic.freeze
+
+      cloned = topic.clone
+      assert cloned.persisted?, 'topic persisted'
+      assert !cloned.new_record?, 'topic is not new'
+      assert cloned.frozen?, 'topic is frozen'
+    end
+  end
+end