1 files changed, 8 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index a2ce620354..9a2f859fc7 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -130,7 +130,7 @@ module ActiveRecord
       end
 
       def arel_engine
-        @arel_engine ||= connection_handler.connection_pools[name] ? self : active_record_super.arel_engine
+        @arel_engine ||= connection_handler.retrieve_connection_pool(self) ? self : active_record_super.arel_engine
       end
 
       private
@@ -165,6 +165,7 @@ module ActiveRecord
     #   User.new({ :first_name => 'Jamie', :is_admin => true }, :without_protection => true)
     def initialize(attributes = nil, options = {})
       @attributes = self.class.initialize_attributes(self.class.column_defaults.dup)
+      @columns_hash = self.class.column_types.dup
 
       init_internals
 
@@ -175,7 +176,7 @@ module ActiveRecord
       assign_attributes(attributes, options) if attributes
 
       yield self if block_given?
-      run_callbacks :initialize
+      run_callbacks :initialize if _initialize_callbacks.any?
     end
 
     # Initialize an empty model object from +coder+. +coder+ must contain
@@ -190,6 +191,7 @@ module ActiveRecord
     #   post.title # => 'hello world'
     def init_with(coder)
       @attributes = self.class.initialize_attributes(coder['attributes'])
+      @columns_hash = self.class.column_types.merge(coder['column_types'] || {})
 
       init_internals
 
@@ -209,6 +211,8 @@ module ActiveRecord
     # The dup method does not preserve the timestamps (created|updated)_(at|on).
     def initialize_dup(other)
       cloned_attributes = other.clone_attributes(:read_attribute_before_type_cast)
+      self.class.initialize_attributes(cloned_attributes)
+
       cloned_attributes.delete(self.class.primary_key)
 
       @attributes = cloned_attributes
@@ -218,7 +222,7 @@ module ActiveRecord
 
       @changed_attributes = {}
       self.class.column_defaults.each do |attr, orig_value|
-        @changed_attributes[attr] = orig_value if field_changed?(attr, orig_value, @attributes[attr])
+        @changed_attributes[attr] = orig_value if _field_changed?(attr, orig_value, @attributes[attr])
       end
 
       @aggregation_cache = {}
@@ -243,7 +247,7 @@ module ActiveRecord
     #   end
     #   coder = {}
     #   Post.new.encode_with(coder)
-    #   coder # => { 'id' => nil, ... }
+    #   coder # => {"attributes" => {"id" => nil, ... }}
     def encode_with(coder)
       coder['attributes'] = attributes
     end