Merge branch 'pr#440_clear_after_rollback'; closes #440

CHANGELOG.md

@@ -5,6 +5,7 @@
 PaperTrail::Rails::Engine.eager_load!
 ```
 
+  - [#440](https://github.com/airblade/paper_trail/pull/440) - `versions` association should clear/reload after a transaction rollback.
   - [#438](https://github.com/airblade/paper_trail/issues/438) - `Model.paper_trail_enabled_for_model?` should return `false` if
     `has_paper_trail` has not been declared on the class.
   - [#427](https://github.com/airblade/paper_trail/pull/427) - Fix `reify` method in context of model where a column has been removed.

lib/paper_trail/has_paper_trail.rb

@@ -78,6 +78,7 @@ module PaperTrail
           after_update  :clear_version_instance!
         end
         after_destroy :record_destroy, :if => :save_version? if options_on.empty? || options_on.include?(:destroy)
+        after_rollback :clear_rolled_back_versions
       end
 
       # Switches PaperTrail off for this class.
@@ -180,6 +181,12 @@ module PaperTrail
         (source_version || send(self.class.versions_association_name).last).try(:whodunnit)
       end
 
+      # Invoked after rollbacks to ensure versions records are not created
+      # for changes that never actually took place
+      def clear_rolled_back_versions
+        send(self.class.versions_association_name).reload
+      end
+
       # Returns the object (not a Version) as it was at the given timestamp.
       def version_at(timestamp, reify_options={})
         # Because a version stores how its object looked *before* the change,

spec/models/widget_spec.rb

@@ -85,6 +85,29 @@ describe Widget, :type => :model do
         expect(widget.version).to eq(widget.versions.last)
       end
     end
+
+    describe :after_rollback do
+      let(:rolled_back_name) { 'Big Moo' }
+
+      before do
+        begin
+          widget.transaction do
+            widget.update_attributes!(:name => rolled_back_name)
+            widget.update_attributes!(:name => Widget::EXCLUDED_NAME)
+          end
+        rescue ActiveRecord::RecordInvalid
+          widget.reload
+          widget.name = nil
+          widget.save
+        end
+      end
+
+      it 'does not create an event for changes that did not happen' do
+        widget.versions.map(&:changeset).each do |changeset|
+          expect(changeset.fetch('name', [])).to_not include(rolled_back_name)
+        end
+      end
+    end
   end
 
   describe "Association", :versioning => true do

test/dummy/app/models/widget.rb

@@ -2,6 +2,10 @@ class Widget < ActiveRecord::Base
   has_paper_trail
   has_one :wotsit
 
+  EXCLUDED_NAME = 'Biglet'
+
+  validates :name, :exclusion => { :in => [EXCLUDED_NAME] }
+
   if ::ActiveRecord::VERSION::MAJOR >= 4 # `has_many` syntax for specifying order uses a lambda in Rails 4
     has_many :fluxors, lambda { order(:name) }
   else