Always allow user to revoke an authorized application

Even if User OAuth applications setting is disabled in admin settings.
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/controllers/oauth/applications_controller.rb

@@ -4,7 +4,7 @@ class Oauth::ApplicationsController < Doorkeeper::ApplicationsController
   include PageLayoutHelper
   include OauthApplications
 
-  before_action :verify_user_oauth_applications_enabled
+  before_action :verify_user_oauth_applications_enabled, except: :index
   before_action :authenticate_user!
   before_action :add_gon_variables
   before_action :load_scopes, only: [:index, :create, :edit]

app/views/layouts/nav/sidebar/_profile.html.haml

@@ -28,7 +28,6 @@
             = link_to profile_account_path do
               %strong.fly-out-top-item-name
                 = _('Account')
-      - if Gitlab::CurrentSettings.user_oauth_applications?
       = nav_link(controller: 'oauth/applications') do
         = link_to applications_profile_path do
           .nav-icon-container

changelogs/unreleased/47398-user-is-unable-revoke-a-authorized-application-unless-user-oauth-applications-is-checked-in-admin-settings.yml

+---
+title: Allow user to revoke an authorized application even if User OAuth applications
+  setting is disabled in admin settings
+merge_request: 21835
+author:
+type: changed

spec/controllers/oauth/applications_controller_spec.rb

@@ -16,13 +16,43 @@ describe Oauth::ApplicationsController do
       end
 
       it 'redirects back to profile page if OAuth applications are disabled' do
-        allow(Gitlab::CurrentSettings.current_application_settings).to receive(:user_oauth_applications?).and_return(false)
+        disable_user_oauth
 
         get :index
 
+        expect(response).to have_gitlab_http_status(200)
+      end
+    end
+
+    describe 'POST #create' do
+      it 'creates an application' do
+        post :create, oauth_params
+
+        expect(response).to have_gitlab_http_status(302)
+        expect(response).to redirect_to(oauth_application_path(Doorkeeper::Application.last))
+      end
+
+      it 'redirects back to profile page if OAuth applications are disabled' do
+        disable_user_oauth
+
+        post :create, oauth_params
+
         expect(response).to have_gitlab_http_status(302)
         expect(response).to redirect_to(profile_path)
       end
     end
   end
+
+  def disable_user_oauth
+    allow(Gitlab::CurrentSettings.current_application_settings).to receive(:user_oauth_applications?).and_return(false)
+  end
+
+  def oauth_params
+    {
+      doorkeeper_application: {
+        name: 'foo',
+        redirect_uri: 'http://example.org'
+      }
+    }
+  end
 end