List issues with another milestone that has a matching board list label

app/services/boards/issues/list_service.rb

@@ -51,10 +51,14 @@ module Boards
       def without_board_labels(issues)
         return issues unless board_label_ids.any?
 
-        issues.where.not(
-          LabelLink.where("label_links.target_type = 'Issue' AND label_links.target_id = issues.id")
-                   .where(label_id: board_label_ids).limit(1).arel.exists
-        )
+        label_links = LabelLink.where("label_links.target_type = 'Issue' AND label_links.target_id = issues.id")
+                               .where(label_id: board_label_ids)
+
+        if board.milestone.present?
+          label_links = label_links.where("issues.milestone_id = ?", board.milestone_id)
+        end
+
+        issues.where.not(label_links.limit(1).arel.exists)
       end
 
       def with_list_label(issues)

spec/services/boards/issues/list_service_spec.rb

@@ -6,6 +6,9 @@ describe Boards::Issues::ListService, services: true do
     let(:project) { create(:empty_project) }
     let(:board)   { create(:board, project: project) }
 
+    let(:m1) { create(:milestone, project: project) }
+    let(:m2) { create(:milestone, project: project) }
+
     let(:bug) { create(:label, project: project, name: 'Bug') }
     let(:development) { create(:label, project: project, name: 'Development') }
     let(:testing)  { create(:label, project: project, name: 'Testing') }
@@ -17,14 +20,14 @@ describe Boards::Issues::ListService, services: true do
     let!(:list2)   { create(:list, board: board, label: testing, position: 1) }
     let!(:done)    { board.done_list }
 
-    let!(:opened_issue1) { create(:labeled_issue, project: project, labels: [bug]) }
-    let!(:opened_issue2) { create(:labeled_issue, project: project, labels: [p2]) }
-    let!(:reopened_issue1) { create(:issue, :reopened, project: project) }
+    let!(:opened_issue1) { create(:labeled_issue, project: project, milestone: m1, title: 'Issue 1', labels: [bug]) }
+    let!(:opened_issue2) { create(:labeled_issue, project: project, milestone: m2, title: 'Issue 2', labels: [p2]) }
+    let!(:reopened_issue1) { create(:issue, :reopened, project: project, title: 'Issue 3', ) }
 
-    let!(:list1_issue1) { create(:labeled_issue, project: project, labels: [p2, development]) }
-    let!(:list1_issue2) { create(:labeled_issue, project: project, labels: [development]) }
-    let!(:list1_issue3) { create(:labeled_issue, project: project, labels: [development, p1]) }
-    let!(:list2_issue1) { create(:labeled_issue, project: project, labels: [testing]) }
+    let!(:list1_issue1) { create(:labeled_issue, project: project, milestone: m1, labels: [p2, development]) }
+    let!(:list1_issue2) { create(:labeled_issue, project: project, milestone: m2, labels: [development]) }
+    let!(:list1_issue3) { create(:labeled_issue, project: project, milestone: m1, labels: [development, p1]) }
+    let!(:list2_issue1) { create(:labeled_issue, project: project, milestone: m1, labels: [testing]) }
 
     let!(:closed_issue1) { create(:labeled_issue, :closed, project: project, labels: [bug]) }
     let!(:closed_issue2) { create(:labeled_issue, :closed, project: project, labels: [p3]) }
@@ -43,14 +46,28 @@ describe Boards::Issues::ListService, services: true do
       described_class.new(project, user, params).execute
     end
 
-    context 'issues are ordered by priority' do
-      it 'returns opened issues when list_id is missing' do
+    context 'when list_id is missing' do
+      context 'when board does not have a milestone' do
+        it 'returns opened issues without board labels applied' do
           params = { board_id: board.id }
 
           issues = described_class.new(project, user, params).execute
 
           expect(issues).to eq [opened_issue2, reopened_issue1, opened_issue1]
         end
+      end
+
+      context 'when board have a milestone' do
+        it 'returns opened issues without board labels and milestone applied' do
+          params = { board_id: board.id }
+          board.update_attribute(:milestone, m1)
+
+          issues = described_class.new(project, user, params).execute
+
+          expect(issues).to eq [opened_issue2, list1_issue2, reopened_issue1, opened_issue1]
+        end
+      end
+    end
 
     it 'returns closed issues when listing issues from Done' do
       params = { board_id: board.id, id: done.id }
@@ -67,7 +84,6 @@ describe Boards::Issues::ListService, services: true do
 
       expect(issues).to eq [list1_issue3, list1_issue1, list1_issue2]
     end
-    end
 
     context 'with list that does not belong to the board' do
       it 'raises an error' do