cache the plural name on the reflection so we do not pay pluralize costs on joins

activerecord/lib/active_record/associations/join_helper.rb

@@ -32,7 +32,7 @@ def table_name_for(reflection)
       end
 
       def table_alias_for(reflection, join = false)
-        name = alias_tracker.pluralize(reflection.name, reflection.active_record)
+        name = reflection.plural_name.dup
         name << "_#{alias_suffix}"
         name << "_join" if join
         name

activerecord/lib/active_record/reflection.rb

@@ -80,12 +80,6 @@ def reflect_on_all_autosave_associations
     # Abstract base class for AggregateReflection and AssociationReflection. Objects of
     # AggregateReflection and AssociationReflection are returned by the Reflection::ClassMethods.
     class MacroReflection
-      attr_reader :active_record
-
-      def initialize(macro, name, options, active_record)
-        @macro, @name, @options, @active_record = macro, name, options, active_record
-      end
-
       # Returns the name of the macro.
       #
       # <tt>composed_of :balance, :class_name => 'Money'</tt> returns <tt>:balance</tt>
@@ -104,6 +98,19 @@ def initialize(macro, name, options, active_record)
       # <tt>has_many :clients</tt> returns +{}+
       attr_reader :options
 
+      attr_reader :active_record
+
+      attr_reader :plural_name # :nodoc:
+
+      def initialize(macro, name, options, active_record)
+        @macro         = macro
+        @name          = name
+        @options       = options
+        @active_record = active_record
+        @plural_name   = active_record.pluralize_table_names ?
+                            name.to_s.pluralize : name.to_s
+      end
+
       # Returns the class for the macro.
       #
       # <tt>composed_of :balance, :class_name => 'Money'</tt> returns the Money class

activerecord/test/cases/reflection_test.rb

@@ -76,7 +76,7 @@ def test_integer_columns
   end
 
   def test_reflection_klass_for_nested_class_name
-    reflection = MacroReflection.new(nil, nil, { :class_name => 'MyApplication::Business::Company' }, nil)
+    reflection = MacroReflection.new(:company, nil, { :class_name => 'MyApplication::Business::Company' }, ActiveRecord::Base)
     assert_nothing_raised do
       assert_equal MyApplication::Business::Company, reflection.klass
     end