Merge branch 'label-filter' into 'master'

Fixed not being able to filter by any or no labels

Brings back the options to filter by any or no label

Closes #15008 

![Screen_Shot_2016-04-07_at_11.26.41](/uploads/20d949b19f537d830118532e1d44feb7/Screen_Shot_2016-04-07_at_11.26.41.png)

See merge request !3589

app/assets/javascripts/labels_select.js.coffee

@@ -218,7 +218,7 @@ class @LabelsSelect
         selectable: true
 
         toggleLabel: (selected) ->
-          if selected and selected.title isnt 'Any Label'
+          if selected and selected.title?
             selected.title
           else
             defaultLabel

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

 - if params[:label_name].present?
   = hidden_field_tag(:label_name, params[:label_name])
 .dropdown
-  %button.dropdown-menu-toggle.js-label-select.js-filter-submit{type: "button", data: {toggle: "dropdown", field_name: "label_name", show_no: "true", show_any: "true", selected: params[:label_name], project_id: @project.try(:id), labels: labels_filter_path, default_label: "Label"}}
+  %button.dropdown-menu-toggle.js-label-select.js-filter-submit.js-extra-options{type: "button", data: {toggle: "dropdown", field_name: "label_name", show_no: "true", show_any: "true", selected: params[:label_name], project_id: @project.try(:id), labels: labels_filter_path, default_label: "Label"}}
     %span.dropdown-toggle-text
       = h(params[:label_name].presence || "Label")
     = icon('chevron-down')

spec/features/issues/filter_issues_spec.rb

@@ -76,6 +76,37 @@ describe 'Filter issues', feature: true do
     end
   end
 
+  describe 'Filter issues for label from issues#index', js: true do
+    before do
+      visit namespace_project_issues_path(project.namespace, project)
+      find('.js-label-select').click
+    end
+
+    it 'should filter by any label' do
+      find('.dropdown-menu-labels a', text: 'Any Label').click
+      page.within '.labels-filter' do
+        expect(page).to have_content 'Any Label'
+      end
+      expect(find('.js-label-select .dropdown-toggle-text')).to have_content('Label')
+    end
+
+    it 'should filter by no label' do
+      find('.dropdown-menu-labels a', text: 'No Label').click
+      page.within '.labels-filter' do
+        expect(page).to have_content 'No Label'
+      end
+      expect(find('.js-label-select .dropdown-toggle-text')).to have_content('No Label')
+    end
+
+    it 'should filter by no label' do
+      find('.dropdown-menu-labels a', text: label.title).click
+      page.within '.labels-filter' do
+        expect(page).to have_content label.title
+      end
+      expect(find('.js-label-select .dropdown-toggle-text')).to have_content(label.title)
+    end
+  end
+
   describe 'Filter issues for assignee and label from issues#index' do
 
     before do