Fix: Inability to reply to code comments in the MR view, if the MR comes from a fork

CHANGELOG

@@ -8,6 +8,7 @@ v 8.2.0 (unreleased)
   - Improved performance of sorting milestone issues
   - Allow users to select the Files view as default project view (Cristian Bica)
   - Show "Empty Repository Page" for repository without branches (Artem V. Navrotskiy)
+  - Fix: Inability to reply to code comments in the MR view, if the MR comes from a fork
 
 v 8.1.0
   - Ensure MySQL CI limits DB migrations occur after the fields have been created (Stan Hu)

app/controllers/projects/commits_controller.rb

@@ -12,7 +12,7 @@ class Projects::CommitsController < Projects::ApplicationController
     @limit, @offset = (params[:limit] || 40), (params[:offset] || 0)
 
     @commits = @repo.commits(@ref, @path, @limit, @offset)
-    @note_counts = Note.where(commit_id: @commits.map(&:id)).
+    @note_counts = project.notes.where(commit_id: @commits.map(&:id)).
       group(:commit_id).count
 
     respond_to do |format|

app/models/merge_request.rb

@@ -257,7 +257,7 @@ class MergeRequest < ActiveRecord::Base
 
     Note.where(
       "(project_id = :target_project_id AND noteable_type = 'MergeRequest' AND noteable_id = :mr_id) OR" +
-      "(project_id = :source_project_id AND noteable_type = 'Commit' AND commit_id IN (:commit_ids))",
+      "((project_id = :source_project_id OR project_id = :target_project_id) AND noteable_type = 'Commit' AND commit_id IN (:commit_ids))",
       mr_id: id,
       commit_ids: commit_ids,
       target_project_id: target_project_id,

spec/models/merge_request_spec.rb

@@ -79,6 +79,12 @@ describe MergeRequest do
       expect(merge_request.commits).not_to be_empty
       expect(merge_request.mr_and_commit_notes.count).to eq(2)
     end
+
+    it "should include notes for commits from target project as well" do
+      create(:note, commit_id: merge_request.commits.first.id, noteable_type: 'Commit', project: merge_request.target_project)
+      expect(merge_request.commits).not_to be_empty
+      expect(merge_request.mr_and_commit_notes.count).to eq(3)
+    end
   end
 
   describe '#is_being_reassigned?' do