Fix commits ordering when using PostgreSQL

CHANGELOG

 v8.0.0 (unreleased)
+v7.14.2
+  - Fix commits ordering when using PostgreSQL
+
 v7.14.1
   - Fix skipped svg
   - Fix commits ordering

app/models/project.rb

@@ -28,7 +28,7 @@
 class Project < ActiveRecord::Base
   include ProjectStatus
-  has_many :commits, ->() { order(:committed_at, :id) }, dependent: :destroy
+  has_many :commits, ->() { order('CASE WHEN commits.committed_at IS NULL THEN 0 ELSE 1 END', :committed_at, :id) }, dependent: :destroy
   has_many :builds, through: :commits, dependent: :destroy
   has_many :runner_projects, dependent: :destroy
   has_many :runners, through: :runner_projects

spec/models/project_spec.rb

@@ -61,6 +61,24 @@ describe Project do
     end
   end
+  describe 'ordered commits' do
+    let (:project) { FactoryGirl.create :project }
+
+    it 'returns ordered list of commits' do
+      commit1 = FactoryGirl.create :commit, committed_at: 1.hour.ago, project: project
+      commit2 = FactoryGirl.create :commit, committed_at: 2.hour.ago, project: project
+      project.commits.should == [commit2, commit1]
+    end
+
+    it 'returns commits ordered by committed_at and id, with nulls last' do
+      commit1 = FactoryGirl.create :commit, committed_at: 1.hour.ago, project: project
+      commit2 = FactoryGirl.create :commit, committed_at: nil, project: project
+      commit3 = FactoryGirl.create :commit, committed_at: 2.hour.ago, project: project
+      commit4 = FactoryGirl.create :commit, committed_at: nil, project: project
+      project.commits.should == [commit2, commit4, commit3, commit1]
+    end
+  end
+
   context :valid_project do
     let(:project) { FactoryGirl.create :project }