Merge branch 'jej-use-issuable-finder-instead-of-access-check' into 'security'

Replace issue access checks with use of IssuableFinder

Split from !2024 to partially solve https://gitlab.com/gitlab-org/gitlab-ce/issues/23867

## Which fixes are in this MR?

:warning: - Potentially untested  
:bomb: - No test coverage  
:traffic_light: - Test coverage of some sort exists (a test failed when error raised)  
:vertical_traffic_light: - Test coverage of return value (a test failed when nil used)  
:white_check_mark: - Permissions check tested

### Issue lookup with access check

Using `visible_to_user` likely makes these security issues too. See [Code smells](#code-smells).

- [x] :vertical_traffic_light: app/finders/notes_finder.rb:15 [`visible_to_user`]
- [x] :traffic_light: app/views/layouts/nav/_project.html.haml:73 [`visible_to_user`] [`.count`]
- [x] :white_check_mark: app/services/merge_requests/build_service.rb:84 [`issue.try(:confidential?)`]
- [x] :white_check_mark: lib/api/issues.rb:112 [`visible_to_user`]
  - CHANGELOG: Prevented API returning issues set to 'Only team members' to everyone
- [x] :white_check_mark: lib/api/helpers.rb:126 [`can?(current_user, :read_issue, issue)`] Maybe here too?
- [x] :white_check_mark: lib/gitlab/search_results.rb:53 [`visible_to_user`]

### Previous discussions
- [ ] https://dev.gitlab.org/gitlab/gitlabhq/merge_requests/2024/diffs#b2ff264eddf9819d7693c14ae213d941494fe2b3_128_126
- [ ] https://dev.gitlab.org/gitlab/gitlabhq/merge_requests/2024/diffs#7b6375270d22f880bdcb085e47b519b426a5c6c7_87_87

See merge request !2031

1 files changed, 32 insertions, 19 deletions

diff --git a/spec/lib/gitlab/search_results_spec.rb b/spec/lib/gitlab/search_results_spec.rb
index dfbefad6367..f23e3522625 100644
--- a/spec/lib/gitlab/search_results_spec.rb
+++ b/spec/lib/gitlab/search_results_spec.rb
@@ -12,35 +12,48 @@ describe Gitlab::SearchResults do
   let!(:milestone) { create(:milestone, project: project, title: 'foo') }
   let(:results) { described_class.new(user, Project.all, 'foo') }
 
-  describe '#projects_count' do
-    it 'returns the total amount of projects' do
-      expect(results.projects_count).to eq(1)
+  context 'as a user with access' do
+    before do
+      project.team << [user, :developer]
     end
-  end
 
-  describe '#issues_count' do
-    it 'returns the total amount of issues' do
-      expect(results.issues_count).to eq(1)
+    describe '#projects_count' do
+      it 'returns the total amount of projects' do
+        expect(results.projects_count).to eq(1)
+      end
     end
-  end
 
-  describe '#merge_requests_count' do
-    it 'returns the total amount of merge requests' do
-      expect(results.merge_requests_count).to eq(1)
+    describe '#issues_count' do
+      it 'returns the total amount of issues' do
+        expect(results.issues_count).to eq(1)
+      end
+    end
+
+    describe '#merge_requests_count' do
+      it 'returns the total amount of merge requests' do
+        expect(results.merge_requests_count).to eq(1)
+      end
     end
-  end
 
-  describe '#milestones_count' do
-    it 'returns the total amount of milestones' do
-      expect(results.milestones_count).to eq(1)
+    describe '#milestones_count' do
+      it 'returns the total amount of milestones' do
+        expect(results.milestones_count).to eq(1)
+      end
     end
   end
 
+  it 'does not list issues on private projects' do
+    private_project = create(:empty_project, :private)
+    issue = create(:issue, project: private_project, title: 'foo')
+
+    expect(results.objects('issues')).not_to include issue
+  end
+
   describe 'confidential issues' do
-    let(:project_1) { create(:empty_project) }
-    let(:project_2) { create(:empty_project) }
-    let(:project_3) { create(:empty_project) }
-    let(:project_4) { create(:empty_project) }
+    let(:project_1) { create(:empty_project, :internal) }
+    let(:project_2) { create(:empty_project, :internal) }
+    let(:project_3) { create(:empty_project, :internal) }
+    let(:project_4) { create(:empty_project, :internal) }
     let(:query) { 'issue' }
     let(:limit_projects) { Project.where(id: [project_1.id, project_2.id, project_3.id]) }
     let(:author) { create(:user) }