Use :write_attribute everywhere. Add tests.

lib/paper_trail/has_paper_trail.rb

@@ -126,7 +126,7 @@ module PaperTrail
         previous = self.clone
         previous.id = id
         changes.each do |attr, ary|
-          previous.send "#{attr}=", ary.first
+          previous.send :write_attribute, attr.to_sym, ary.first
         end
         previous
       end

lib/paper_trail/version.rb

@@ -102,7 +102,7 @@ class Version < ActiveRecord::Base
         # and therefore impossible to know when "just before" was.
         if (child_as_it_was = child.version_at(created_at - lookback.seconds))
           child_as_it_was.attributes.each do |k,v|
-            model.send(assoc.name).send "#{k}=", v rescue nil
+            model.send(assoc.name).send :write_attribute, k.to_sym, v rescue nil
           end
         else
           model.send "#{assoc.name}=", nil

test/paper_trail_model_test.rb

@@ -43,6 +43,19 @@ class Person < ActiveRecord::Base
   has_paper_trail
 end
 
+# Example from 'Overwriting default accessors' in ActiveRecord::Base.
+class Song < ActiveRecord::Base
+  has_paper_trail
+
+  # Uses an integer of seconds to hold the length of the song
+  def length=(minutes)
+    write_attribute(:length, minutes.to_i * 60)
+  end
+  def length
+    read_attribute(:length) / 60
+  end
+end
+
 
 class HasPaperTrailModelTest < Test::Unit::TestCase
   load_schema
@@ -740,6 +753,22 @@ class HasPaperTrailModelTest < Test::Unit::TestCase
     end
   end
 
+
+  context 'An overwritten default accessor' do
+    setup do
+      @song = Song.create :length => 4
+      @song.update_attributes :length => 5
+    end
+
+    should 'return "overwritten" value on live instance' do
+      assert_equal 5, @song.length
+    end
+    should 'return "overwritten" value on reified instance' do
+      assert_equal 4, @song.versions.last.reify.length
+    end
+  end
+
+
   private
 
   # Updates `model`'s last version so it looks like the version was

test/schema.rb

@@ -63,4 +63,8 @@ ActiveRecord::Schema.define(:version => 0) do
     t.string :name
   end
 
+  create_table :songs, :force => true do |t|
+    t.integer :length
+  end
+
 end