URI decode Page-Title header to preserve UTF-8 characters

3 files changed, 16 insertions, 2 deletions

diff --git a/app/assets/javascripts/repo/helpers/repo_helper.js b/app/assets/javascripts/repo/helpers/repo_helper.js
index dfaf9caaee7..19425cedc90 100644
--- a/app/assets/javascripts/repo/helpers/repo_helper.js
+++ b/app/assets/javascripts/repo/helpers/repo_helper.js
@@ -95,7 +95,7 @@ const RepoHelper = {
     return Service.getContent()
     .then((response) => {
       const data = response.data;
-      if (response.headers && response.headers['page-title']) data.pageTitle = response.headers['page-title'];
+      if (response.headers && response.headers['page-title']) data.pageTitle = decodeURI(response.headers['page-title']);
       if (response.headers && response.headers['is-root'] && !Store.isInitialRoot) {
         Store.isRoot = convertPermissionToBoolean(response.headers['is-root']);
         Store.isInitialRoot = Store.isRoot;
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 967fe39256a..391a0519195 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -349,6 +349,6 @@ class ApplicationController < ActionController::Base
 
   def set_page_title_header
     # Per https://tools.ietf.org/html/rfc5987, headers need to be ISO-8859-1, not UTF-8
-    response.headers['Page-Title'] = page_title('GitLab').encode('ISO-8859-1')
+    response.headers['Page-Title'] = URI.escape(page_title('GitLab'))
   end
 end
diff --git a/spec/controllers/application_controller_spec.rb b/spec/controllers/application_controller_spec.rb
index 59a6cfbf4f5..0a3a0f7da18 100644
--- a/spec/controllers/application_controller_spec.rb
+++ b/spec/controllers/application_controller_spec.rb
@@ -221,6 +221,20 @@ describe ApplicationController do
     end
   end
 
+  describe '#set_page_title_header' do
+    let(:controller) { described_class.new }
+
+    it 'URI encodes UTF-8 characters in the title' do
+      response = double(headers: {})
+      allow_any_instance_of(PageLayoutHelper).to receive(:page_title).and_return('€100 · GitLab')
+      allow(controller).to receive(:response).and_return(response)
+
+      controller.send(:set_page_title_header)
+
+      expect(response.headers['Page-Title']).to eq('%E2%82%AC100%20%C2%B7%20GitLab')
+    end
+  end
+
   context 'two-factor authentication' do
     let(:controller) { described_class.new }