Fixed paper trail inconsistent results for numeric values

There is a known issue in paper_trail that whenever we Query the
'versions.object' column it evaluates inconsistent results for numeric
values due to limitations of SQL wildcard matchers against the
serialized objects. So to fix this issue I have manually formed the where
query instead of using where_object and where_object_changes. I have
also added test for the same.
Fixes #1307

spec/controllers/admin/events_controller_spec.rb

@@ -0,0 +1,26 @@
+require 'spec_helper'
+
+describe Admin::EventsController do
+  let(:conference) { create(:conference) }
+  let(:organizer_role) { Role.find_by(name: 'organizer', resource: conference) }
+  let(:organizer) { create(:user, role_ids: organizer_role.id) }
+  let!(:event_without_commercial) { create(:event, program: conference.program) }
+  let!(:event_with_commercial) { create(:event, program: conference.program) }
+  let!(:event_commercial) { create(:event_commercial, commercialable: event_with_commercial, url: 'https://www.youtube.com/watch?v=M9bq_alk-sw') }
+
+  with_versioning do
+    describe 'GET #show' do
+      before :each do
+        sign_in(organizer)
+        get :show, id: event_without_commercial.id, conference_id: conference.short_title
+      end
+
+      it 'assigns versions' do
+        versions = event_without_commercial.versions
+        expect(event_without_commercial.id).to eq event_commercial.id
+        expect(event_commercial.id).not_to eq event_commercial.commercialable_id
+        expect(assigns(:versions)).to eq versions
+      end
+    end
+  end
+end