Display issue state in issue links section of merge request widget

app/presenters/merge_request_presenter.rb

@@ -110,12 +110,24 @@ class MergeRequestPresenter < Gitlab::View::Presenter::Delegated
   end
 
   def closing_issues_links
-    markdown issues_sentence(project, closing_issues), pipeline: :gfm, author: author, project: project
+    markdown(
+      issues_sentence(project, closing_issues),
+      pipeline: :gfm,
+      author: author,
+      project: project,
+      issuable_state_filter_enabled: true
+    )
   end
 
   def mentioned_issues_links
     mentioned_issues = issues_mentioned_but_not_closing(current_user)
-    markdown issues_sentence(project, mentioned_issues), pipeline: :gfm, author: author, project: project
+    markdown(
+      issues_sentence(project, mentioned_issues),
+      pipeline: :gfm,
+      author: author,
+      project: project,
+      issuable_state_filter_enabled: true
+    )
   end
 
   def assign_to_closing_issues_link

changelogs/unreleased/33381-display-issue-state-in-mr-widget-issue-links.yml

@@ -0,0 +1,4 @@
+---
+title: Display issue state in issue links section of merge request widget
+merge_request: 12021
+author:

spec/presenters/merge_request_presenter_spec.rb

@@ -132,6 +132,11 @@ describe MergeRequestPresenter do
       it 'does not present related issues links' do
         is_expected.not_to match("#{project.full_path}/issues/#{issue_b.iid}")
       end
+
+      it 'appends status when closing issue is already closed' do
+        issue_a.close
+        is_expected.to match('(closed)')
+      end
     end
 
     describe '#mentioned_issues_links' do
@@ -147,6 +152,11 @@ describe MergeRequestPresenter do
       it 'does not present closing issues links' do
         is_expected.not_to match("#{project.full_path}/issues/#{issue_a.iid}")
       end
+
+      it 'appends status when mentioned issue is already closed' do
+        issue_b.close
+        is_expected.to match('(closed)')
+      end
     end
 
     describe '#assign_to_closing_issues_link' do