Rename method for consistency. Add compatibility check. Whitespace.

lib/paper_trail/version.rb

@@ -19,16 +19,6 @@ class Version < ActiveRecord::Base
     where(['created_at > ?', timestamp]).order("created_at ASC, #{self.primary_key} ASC")
   }
 
-  # In Rails 3.1+, calling reify on a previous version confuses the
-  # IdentityMap, if enabled. This prevents insertion into the map.
-  def with_identity_map_disabled(&block)
-    if defined?(ActiveRecord::IdentityMap)
-      ActiveRecord::IdentityMap.without(&block)
-    else
-      block.call
-    end 
-  end 
-      
   # Restore the item from this version.
   #
   # This will automatically restore all :has_one associations as they were "at the time",
@@ -41,12 +31,12 @@ class Version < ActiveRecord::Base
   #              set to a float to change the lookback time (check whether your db supports
   #              sub-second datetimes if you want them).
   def reify(options = {})
-    with_identity_map_disabled do 
+    without_identity_map do
       options.reverse_merge! :has_one => 3
-   
+
       unless object.nil?
         attrs = YAML::load object
-   
+
         # Normally a polymorphic belongs_to relationship allows us
         # to get the object we belong to by calling, in this case,
         # +item+.  However this returns nil if +item+ has been
@@ -59,7 +49,7 @@ class Version < ActiveRecord::Base
         # we belong to is using single table inheritance and the
         # +item_type+ will be the base class, not the actual subclass.
         # If +type+ is present but empty, the class is the base class.
-   
+
         if item
           model = item
         else
@@ -68,7 +58,7 @@ class Version < ActiveRecord::Base
           klass = class_name.constantize
           model = klass.new
         end
-   
+
         attrs.each do |k, v|
           begin
             model.send :write_attribute, k.to_sym , v
@@ -76,16 +66,16 @@ class Version < ActiveRecord::Base
             logger.warn "Attribute #{k} does not exist on #{item_type} (Version id: #{id})."
           end
         end
-   
+
         model.version = self
-   
+
         unless options[:has_one] == false
           reify_has_ones model, options[:has_one]
         end
-   
+
         model
       end
-    end 
+    end
   end
 
   # Returns who put the item into the state stored in this version.
@@ -117,6 +107,16 @@ class Version < ActiveRecord::Base
 
   private
 
+  # In Rails 3.1+, calling reify on a previous version confuses the
+  # IdentityMap, if enabled. This prevents insertion into the map.
+  def without_identity_map(&block)
+    if defined?(ActiveRecord::IdentityMap) && ActiveRecord::IdentityMap.respond_to?(:without)
+      ActiveRecord::IdentityMap.without(&block)
+    else
+      block.call
+    end
+  end
+
   # Restore the `model`'s has_one associations as they were when this version was
   # superseded by the next (because that's what the user was looking at when they
   # made the change).

test/unit/model_test.rb

@@ -96,19 +96,22 @@ class HasPaperTrailModelTest < ActiveSupport::TestCase
         should 'have versions that are not live' do
           assert @widget.versions.map(&:reify).compact.all? { |w| !w.live? }
         end
-        
-        should 'not clobber the IdentityMap when reifying' do
-          module ::ActiveRecord
-            class IdentityMap
-              def self.without(&block)
-                @unclobbered = true
-                block.call
-              end 
-            end
-          end
 
-          @widget.versions.last.reify
-          assert ActiveRecord::IdentityMap.instance_variable_get("@unclobbered")
+        if defined?(ActiveRecord::IdentityMap) && ActiveRecord::IdentityMap.respond_to?(:without)
+          should 'not clobber the IdentityMap when reifying' do
+            module ActiveRecord::IdentityMap
+              class << self
+                alias :__without :without
+                def without(&block)
+                  @unclobbered = true
+                  __without(&block)
+                end
+              end
+            end
+
+            @widget.versions.last.reify
+            assert ActiveRecord::IdentityMap.instance_variable_get("@unclobbered")
+          end
         end
 
         context 'and has one associated object' do