Updated Ruby based on feedback

app/assets/javascripts/issuable.js.coffee

 issuable_created = false
 @Issuable =
   init: ->
-    if not issuable_created
+    unless issuable_created
       issuable_created = true
       Issuable.initTemplates()
       Issuable.initSearch()
@@ -28,7 +28,7 @@ issuable_created = false
           $input = $("input[name='#{$search.attr('name')}']", $form)
 
           if $input.length is 0
-            $form.append "<input type='hidden' name='#{$search.attr('name')}' value='#{$search.val()}'/>"
+            $form.append "<input type='hidden' name='#{$search.attr('name')}' value='#{_.escape($search.val())}'/>"
           else
             $input.val $search.val()
 

app/helpers/application_helper.rb

@@ -263,7 +263,8 @@ module ApplicationHelper
       assignee_id: params[:assignee_id],
       author_id: params[:author_id],
       sort: params[:sort],
-      issue_search: params[:issue_search]
+      issue_search: params[:issue_search],
+      label_name: params[:label_name]
     }
 
     options = exist_opts.merge(options)
@@ -276,19 +277,9 @@ module ApplicationHelper
 
     params = options.compact
 
-    path = request.path
+    params.delete(:label_name) unless add_label
 
-    if !params.nil?
-      path << "?#{params.to_param}"
-      if add_label
-        if params[:label_name].present? and params[:label_name].respond_to?('any?')
-          params[:label_name].each do |label|
-            path << "&label_name[]=#{label}"
-          end
-        end
-      end
-    end
-    path
+    "#{request.path}?#{params.to_param}"
   end
 
   def outdated_browser?

spec/features/issues/filter_issues_spec.rb

@@ -159,7 +159,7 @@ describe 'Filter issues', feature: true do
     before do
       create(:issue, title: "Bug", project: project)
 
-      create(:label, project: project, title: 'bug')
+      bug_label = create(:label, project: project, title: 'bug')
       milestone = create(:milestone, title: "8", project: project)
 
       issue = create(:issue,
@@ -168,7 +168,7 @@ describe 'Filter issues', feature: true do
         milestone: milestone,
         author: user,
         assignee: user)
-      issue.labels << project.labels.find_by(title: 'bug')
+      issue.labels << bug_label
 
       visit namespace_project_issues_path(project.namespace, project)
     end
@@ -264,12 +264,12 @@ describe 'Filter issues', feature: true do
 
   describe 'filter issues and sort', js: true do
     before do
-      create(:label, project: project, title: 'bug')
+      bug_label = create(:label, project: project, title: 'bug')
       bug_one = create(:issue, title: "Frontend", project: project)
       bug_two = create(:issue, title: "Bug 2", project: project)
 
-      bug_one.labels << project.labels.find_by(title: 'bug')
-      bug_two.labels << project.labels.find_by(title: 'bug')
+      bug_one.labels << bug_label
+      bug_two.labels << bug_label
 
       visit namespace_project_issues_path(project.namespace, project)
     end