1 files changed, 15 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index adba3f710c..a2ce620354 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -72,6 +72,16 @@ module ActiveRecord
       # The connection handler
       config_attribute :connection_handler
       self.connection_handler = ConnectionAdapters::ConnectionHandler.new
+
+      ##
+      # :singleton-method:
+      # Specifies wether or not has_many or has_one association option
+      # :dependent => :restrict raises an exception. If set to true, the
+      # ActiveRecord::DeleteRestrictionError exception will be raised
+      # along with a DEPRECATION WARNING. If set to false, an error would
+      # be added to the model instead.
+      config_attribute :dependent_restrict_raises, :global => true
+      self.dependent_restrict_raises = true
     end
 
     module ClassMethods
@@ -202,6 +212,7 @@ module ActiveRecord
       cloned_attributes.delete(self.class.primary_key)
 
       @attributes = cloned_attributes
+      @attributes[self.class.primary_key] = nil
 
       run_callbacks(:initialize) if _initialize_callbacks.any?
 
@@ -326,6 +337,10 @@ module ActiveRecord
     end
 
     def init_internals
+      pk = self.class.primary_key
+
+      @attributes[pk] = nil unless @attributes.key?(pk)
+
       @relation               = nil
       @aggregation_cache      = {}
       @association_cache      = {}