Fix sorting issues/mrs by votes on the groups page

The `non_archived` scope applied here
https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/controllers/conc
erns/issues_action.rb#L5 overrides the previous `ORDER BY` applied
inside the IssuesFinder, with the default scope of the Project model,
resulting in SQL errors.

CHANGELOG

@@ -62,6 +62,7 @@ v 8.6.0 (unreleased)
   - Canceled builds are now ignored in compound build status if marked as `allowed to fail`
   - Trigger a todo for mentions on commits page
   - Let project owners and admins soft delete issues and merge requests
+  - Fix sorting issues by votes on the groups issues page results in SQL errors
 
 v 8.5.8
   - Bump Git version requirement to 2.7.4

app/models/concerns/issuable.rb

@@ -41,7 +41,7 @@ module Issuable
 
     scope :join_project, -> { joins(:project) }
     scope :references_project, -> { references(:project) }
-    scope :non_archived, -> { join_project.merge(Project.non_archived) }
+    scope :non_archived, -> { join_project.merge(Project.non_archived.only(:where)) }
 
     delegate :name,
              :email,

spec/controllers/groups_controller_spec.rb

 require 'rails_helper'
 
 describe GroupsController do
-  describe 'GET index' do
+  let(:user) { create(:user) }
+  let(:group) { create(:group) }
+  let(:project) { create(:project, namespace: group) }
+  let!(:group_member) { create(:group_member, group: group, user: user) }
+
+  describe 'GET #index' do
     context 'as a user' do
       it 'redirects to Groups Dashboard' do
-        sign_in(create(:user))
+        sign_in(user)
 
         get :index
 
@@ -20,4 +25,54 @@ describe GroupsController do
       end
     end
   end
+
+  describe 'GET #issues' do
+    let(:issue_1) { create(:issue, project: project) }
+    let(:issue_2) { create(:issue, project: project) }
+
+    before do
+      create_list(:upvote_note, 3, project: project, noteable: issue_2)
+      create_list(:upvote_note, 2, project: project, noteable: issue_1)
+      create_list(:downvote_note, 2, project: project, noteable: issue_2)
+
+      sign_in(user)
+    end
+
+    context 'sorting by votes' do
+      it 'sorts most popular issues' do
+        get :issues, id: group.to_param, sort: 'upvotes_desc'
+        expect(assigns(:issues)).to eq [issue_2, issue_1]
+      end
+
+      it 'sorts least popular issues' do
+        get :issues, id: group.to_param, sort: 'downvotes_desc'
+        expect(assigns(:issues)).to eq [issue_2, issue_1]
+      end
+    end
+  end
+
+  describe 'GET #merge_requests' do
+    let(:merge_request_1) { create(:merge_request, source_project: project) }
+    let(:merge_request_2) { create(:merge_request, :simple, source_project: project) }
+
+    before do
+      create_list(:upvote_note, 3, project: project, noteable: merge_request_2)
+      create_list(:upvote_note, 2, project: project, noteable: merge_request_1)
+      create_list(:downvote_note, 2, project: project, noteable: merge_request_2)
+
+      sign_in(user)
+    end
+
+    context 'sorting by votes' do
+      it 'sorts most popular merge requests' do
+        get :merge_requests, id: group.to_param, sort: 'upvotes_desc'
+        expect(assigns(:merge_requests)).to eq [merge_request_2, merge_request_1]
+      end
+
+      it 'sorts least popular merge requests' do
+        get :merge_requests, id: group.to_param, sort: 'downvotes_desc'
+        expect(assigns(:merge_requests)).to eq [merge_request_2, merge_request_1]
+      end
+    end
+  end
 end