1 files changed, 38 insertions, 0 deletions
diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 29f06dc06a..3f62cea5f5 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -2,6 +2,44 @@
 
 * Associations with a :through option can now use *any* association as the through or source association, including other associations which have a :through option and has_and_belongs_to_many associations #1812 [Jon Leighton]
 
+* ActiveRecord::Base#dup and ActiveRecord::Base#clone semantics have changed
+to closer match normal Ruby dup and clone semantics.
+
+* Calling ActiveRecord::Base#clone will result in a shallow copy of the record,
+including copying the frozen state.  No callbacks will be called.
+
+* Calling ActiveRecord::Base#dup will duplicate the record, including calling
+after initialize hooks.  Frozen state will not be copied, and all associations
+will be cleared.  A duped record will return true for new_record?, have a nil
+id field, and is saveable.
+
+* Migrations can be defined as reversible, meaning that the migration system
+will figure out how to reverse your migration.  To use reversible migrations,
+just define the "change" method.  For example:
+
+    class MyMigration < ActiveRecord::Migration
+      def change
+        create_table(:horses) do
+          t.column :content, :text
+          t.column :remind_at, :datetime
+        end
+      end
+    end
+
+Some things cannot be automatically reversed for you.  If you know how to
+reverse those things, you should define 'up' and 'down' in your migration.  If
+you define something in `change` that cannot be reversed, an
+IrreversibleMigration exception will be raised when going down.
+
+* Migrations should use instance methods rather than class methods:
+    class FooMigration < ActiveRecord::Migration
+      def up
+        ...
+      end
+    end
+
+  [Aaron Patterson]
+
 * has_one maintains the association with separate after_create/after_update instead
   of a single after_save. [fxn]