Ruby 1.8.7 compat: detect and alias non-superclass DateTime#to_s

activesupport/lib/active_support/core_ext/date_time/conversions.rb

@@ -3,17 +3,22 @@ module CoreExtensions #:nodoc:
     module DateTime #:nodoc:
       # Converting datetimes to formatted strings, dates, and times.
       module Conversions
-        def self.included(base) #:nodoc:
+        def self.append_features(base) #:nodoc:
           base.class_eval do
-            alias_method :to_default_s, :to_s if instance_methods.include?(:to_s)
-            alias_method :to_s, :to_formatted_s
             alias_method :default_inspect, :inspect
-            alias_method :inspect, :readable_inspect
+            alias_method :to_default_s, :to_s unless (instance_methods(false) & [:to_s, 'to_s']).empty?
 
             # Ruby 1.9 has DateTime#to_time which internally relies on Time. We define our own #to_time which allows
             # DateTimes outside the range of what can be created with Time.
             remove_method :to_time if instance_methods.include?(:to_time)
           end
+
+          super
+
+          base.class_eval do
+            alias_method :to_s, :to_formatted_s
+            alias_method :inspect, :readable_inspect
+          end
         end
 
         # Convert to a formatted string. See Time::DATE_FORMATS for predefined formats.