reduce object allocation during AR instantiation

activerecord/lib/active_record/base.rb

@@ -2092,6 +2092,8 @@ def convert_number_column_value(value)
       end
 
       def populate_with_current_scope_attributes
+        return unless self.class.scope_attributes?
+
         self.class.scope_attributes.each do |att,value|
           send("#{att}=", value) if respond_to?("#{att}=")
         end

activerecord/lib/active_record/named_scope.rb

@@ -47,15 +47,18 @@ def scope_attributes # :nodoc:
         if current_scope
           current_scope.scope_for_create
         else
-          # Return an empty hash in the simple case
-          return {} unless default_scopes.any?
-
           scope = relation.clone
           scope.default_scoped = true
           scope.scope_for_create
         end
       end
 
+      ##
+      # Are there default attributes associated with this scope?
+      def scope_attributes? # :nodoc:
+        current_scope || default_scopes.any?
+      end
+
       # Adds a class method for retrieving and querying objects. A \scope represents a narrowing of a database query,
       # such as <tt>where(:color => :red).select('shirts.*').includes(:washing_instructions)</tt>.
       #