Fixed group label in issuable sidebar

Group label link was pointing to group#issues rather than the projects issues. This fixes that by sending the correct subject to the link_to_label helper method.

Closes #27253

app/views/shared/issuable/_sidebar.html.haml

@@ -130,7 +130,7 @@
           .value.issuable-show-labels.hide-collapsed{ class: ("has-labels" if selected_labels.any?) }
             - if selected_labels.any?
               - selected_labels.each do |label|
-                = link_to_label(label, type: issuable.to_ability_name)
+                = link_to_label(label, subject: issuable.project, type: issuable.to_ability_name)
             - else
               %span.no-value None
           .selectbox.hide-collapsed

changelogs/unreleased/group-label-sidebar-link.yml

+---
+title: Fixed group label links in issue/merge request sidebar
+merge_request:
+author:

spec/features/issues/group_label_sidebar_spec.rb

+require 'rails_helper'
+
+describe 'Group label on issue', :feature do
+  it 'renders link to the project issues page' do
+    group = create(:group)
+    project = create(:empty_project, :public, namespace: group)
+    feature = create(:group_label, group: group, title: 'feature')
+    issue = create(:labeled_issue, project: project, labels: [feature])
+    label_link = namespace_project_issues_path(
+      project.namespace,
+      project,
+      label_name: [feature.name]
+    )
+
+    visit namespace_project_issue_path(project.namespace, project, issue)
+
+    link = find('.issuable-show-labels a')
+
+    expect(link[:href]).to eq(label_link)
+  end
+end