Fix LabelsHelper#link_to_label to use the subject argument

app/helpers/labels_helper.rb

@@ -31,7 +31,13 @@ module LabelsHelper
   #
   # Returns a String
   def link_to_label(label, subject: nil, type: :issue, tooltip: true, css_class: nil, &block)
-    link = label_filter_path(label, type: type)
+    subject ||=
+      case label
+      when GroupLabel then label.group
+      when ProjectLabel then label.project
+      end
+
+    link = label_filter_path(subject, label, type: type)
 
     if block_given?
       link_to link, class: css_class, &block
@@ -40,16 +46,16 @@ module LabelsHelper
     end
   end
 
-  def label_filter_path(label, type: issue)
-    case label
-    when GroupLabel
+  def label_filter_path(subject, label, type: issue)
+    case subject
+    when Group
       send("#{type.to_s.pluralize}_group_path",
-                  label.group,
+                  subject,
                   label_name: [label.name])
-    else
+    when Project
       send("namespace_project_#{type.to_s.pluralize}_path",
-                  label.project.namespace,
-                  label.project,
+                  subject.namespace,
+                  subject,
                   label_name: [label.name])
     end
   end

app/views/shared/_label.html.haml

@@ -12,10 +12,10 @@
     .dropdown-menu.dropdown-menu-align-right
       %ul
         %li
-          = link_to_label(label, type: :merge_request) do
+          = link_to_label(label, subject: @project, type: :merge_request) do
             = pluralize open_merge_requests_count, 'merge request'
         %li
-          = link_to_label(label) do
+          = link_to_label(label, subject: @project) do
             = pluralize open_issues_count, 'open issue'
         - if current_user
           %li.label-subscription{ data: { url: toggle_subscription_label_path(label) } }
@@ -28,9 +28,9 @@
             = link_to 'Delete', destroy_label_path(label), title: 'Delete', method: :delete, remote: true, data: {confirm: 'Remove this label? Are you sure?'}
 
   .pull-right.hidden-xs.hidden-sm.hidden-md
-    = link_to_label(label, type: :merge_request, css_class: 'btn btn-transparent btn-action') do
+    = link_to_label(label, subject: @project, type: :merge_request, css_class: 'btn btn-transparent btn-action') do
       = pluralize open_merge_requests_count, 'merge request'
-    = link_to_label(label, css_class: 'btn btn-transparent btn-action') do
+    = link_to_label(label, subject: @project, css_class: 'btn btn-transparent btn-action') do
       = pluralize open_issues_count, 'open issue'
 
     - if current_user

app/views/shared/_label_row.html.haml

@@ -9,7 +9,7 @@
       %button.remove-priority.btn.has-tooltip{ title: 'Remove priority', :'data-placement' => 'top' }
         = icon('star')
   %span.label-name
-    = link_to_label(label, tooltip: false)
+    = link_to_label(label, subject: @project, tooltip: false)
     - if can?(current_user, :admin_label, @project)
       = label_type_icon(label, hidden: label.priority.blank?)
   - if label.description

app/views/shared/_labels_row.html.haml

@@ -1,5 +1,5 @@
 - labels.each do |label|
   %span.label-row.btn-group{ role: "group", aria: { label: label.name }, style: "color: #{text_color_for_bg(label.color)}" }
-    = link_to_label(label, css_class: 'btn btn-transparent')
+    = link_to_label(label, subject: @project, css_class: 'btn btn-transparent')
     %button.btn.btn-transparent.label-remove.js-label-filter-remove{ type: "button", style: "background-color: #{label.color};", data: { label: label.title } }
       = icon("times")

spec/helpers/labels_helper_spec.rb

@@ -5,27 +5,26 @@ describe LabelsHelper do
     let(:project) { create(:empty_project) }
     let(:label) { create(:label, project: project) }
 
-    context 'with @project set' do
-      before do
-        @project = project
-      end
-
-      it 'uses the instance variable' do
-        expect(link_to_label(label)).to match %r{<a href="/#{@project.to_reference}/issues\?label_name%5B%5D=#{label.name}"><span class="[\w\s\-]*has-tooltip".*</span></a>}
-      end
-    end
-
-    context 'without @project set' do
+    context 'without subject' do
       it "uses the label's project" do
         expect(link_to_label(label)).to match %r{<a href="/#{label.project.to_reference}/issues\?label_name%5B%5D=#{label.name}">.*</a>}
       end
     end
 
-    context 'with a project argument' do
-      let(:another_project) { double('project', namespace: 'foo3', to_param: 'bar3') }
+    context 'with a project as subject' do
+      let(:namespace) { build(:namespace, name: 'foo3') }
+      let(:another_project) { build(:empty_project, namespace: namespace, name: 'bar3') }
 
-      it 'links to merge requests page' do
-        expect(link_to_label(label, project: another_project)).to match %r{<a href="/foo3/bar3/issues\?label_name%5B%5D=#{label.name}">.*</a>}
+      it 'links to project issues page' do
+        expect(link_to_label(label, subject: another_project)).to match %r{<a href="/foo3/bar3/issues\?label_name%5B%5D=#{label.name}">.*</a>}
+      end
+    end
+
+    context 'with a group as subject' do
+      let(:group) { build(:group, name: 'bar') }
+
+      it 'links to group issues page' do
+        expect(link_to_label(label, subject: group)).to match %r{<a href="/groups/bar/issues\?label_name%5B%5D=#{label.name}">.*</a>}
       end
     end