Fix search results for notes without commits

CHANGELOG

@@ -31,6 +31,7 @@ v 8.11.0 (unreleased)
   - Check for Ci::Build artifacts at database level on pipeline partial
   - Make "New issue" button in Issue page less obtrusive !5457 (winniehell)
   - Gitlab::Metrics.current_transaction needs to be public for RailsQueueDuration
+  - Fix search for notes which belongs to deleted objects
   - Add GitLab Workhorse version to admin dashboard (Katarzyna Kobierska Ula Budziszewska)
   - Add the `sprockets-es6` gem
   - Multiple trigger variables show in separate lines (Katarzyna Kobierska Ula Budziszewska)

app/views/search/results/_note.html.haml

 - project = note.project
 - note_url = Gitlab::UrlBuilder.build(note)
-- noteable_identifier = note.noteable.try(:iid) || note.noteable.id
+- noteable_identifier = note.noteable.try(:iid) || note.noteable.try(:id)
+
 .search-result-row
   %h5.note-search-caption.str-truncated
     %i.fa.fa-comment
@@ -10,7 +11,10 @@
     ·
 
     - if note.for_commit?
-      = link_to "Commit #{truncate_sha(note.commit_id)}", note_url
+      = link_to_if(noteable_identifier, "Commit #{truncate_sha(note.commit_id)}", note_url) do
+        = truncate_sha(note.commit_id)
+        %span.light Commit deleted
+
     - else
       %span #{note.noteable_type.titleize} ##{noteable_identifier}
       ·

spec/features/search_spec.rb

@@ -28,6 +28,26 @@ describe "Search", feature: true  do
   end
 
   context 'search for comments' do
+    context 'when comment belongs to a invalid commit' do
+      let(:note) { create(:note_on_commit, author: user, project: project, commit_id: project.repository.commit.id, note: 'Bug here') }
+
+      before { note.update_attributes(commit_id: 12345678) }
+
+      it 'finds comment' do
+        visit namespace_project_path(project.namespace, project)
+
+        page.within '.search' do
+          fill_in 'search', with: note.note
+          click_button 'Go'
+        end
+
+        click_link 'Comments'
+
+        expect(page).to have_text("Commit deleted")
+        expect(page).to have_text("12345678")
+      end
+    end
+
     it 'finds a snippet' do
       snippet = create(:project_snippet, :private, project: project, author: user, title: 'Some title')
       note = create(:note,