Improve uniqueness of field names on the signup form

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/15075

app/controllers/registrations_controller.rb

@@ -8,6 +8,13 @@ class RegistrationsController < Devise::RegistrationsController
   def create
     if !Gitlab::Recaptcha.load_configurations! || verify_recaptcha
+      # To avoid duplicate form fields on the login page, the registration form
+      # names fields using `new_user`, but Devise still wants the params in
+      # `user`.
+      if params["new_#{resource_name}"].present? && params[resource_name].blank?
+        params[resource_name] = params.delete(:"new_#{resource_name}")
+      end
+
       super
     else
       flash[:alert] = "There was an error with the reCAPTCHA code below. Please re-enter the code."

app/views/devise/shared/_signup_box.html.haml

@@ -6,7 +6,7 @@
     .login-heading
       %h3 Create an account
   .login-body
-    = form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f|
+    = form_for(resource, as: "new_#{resource_name}", url: registration_path(resource_name)) do |f|
       .devise-errors
         = devise_error_messages!
       %div
@@ -16,7 +16,7 @@
       %div
         = f.email_field :email, class: "form-control middle", placeholder: "Email", required: true
       .form-group.append-bottom-20#password-strength
-        = f.password_field :password, class: "form-control bottom", id: "user_password_sign_up", placeholder: "Password", required: true
+        = f.password_field :password, class: "form-control bottom", placeholder: "Password", required: true
       %div
       - if current_application_settings.recaptcha_enabled
         = recaptcha_tags

spec/features/signup_spec.rb

@@ -7,10 +7,10 @@ feature 'Signup', feature: true do
       visit root_path
-      fill_in 'user_name',                with: user.name
-      fill_in 'user_username',            with: user.username
-      fill_in 'user_email',               with: user.email
-      fill_in 'user_password_sign_up',    with: user.password
+      fill_in 'new_user_name',     with: user.name
+      fill_in 'new_user_username', with: user.username
+      fill_in 'new_user_email',    with: user.email
+      fill_in 'new_user_password', with: user.password
       click_button "Sign up"
       expect(current_path).to eq user_session_path
@@ -25,10 +25,10 @@ feature 'Signup', feature: true do
       visit root_path
-      fill_in 'user_name',                with: user.name
-      fill_in 'user_username',            with: user.username
-      fill_in 'user_email',               with: existing_user.email
-      fill_in 'user_password_sign_up',    with: user.password
+      fill_in 'new_user_name',     with: user.name
+      fill_in 'new_user_username', with: user.username
+      fill_in 'new_user_email',    with: existing_user.email
+      fill_in 'new_user_password', with: user.password
       click_button "Sign up"
       expect(current_path).to eq user_registration_path
@@ -42,10 +42,10 @@ feature 'Signup', feature: true do
       visit root_path
-      fill_in 'user_name',                with: user.name
-      fill_in 'user_username',            with: user.username
-      fill_in 'user_email',               with: existing_user.email
-      fill_in 'user_password_sign_up',    with: user.password
+      fill_in 'new_user_name',     with: user.name
+      fill_in 'new_user_username', with: user.username
+      fill_in 'new_user_email',    with: existing_user.email
+      fill_in 'new_user_password', with: user.password
       click_button "Sign up"
       expect(current_path).to eq user_registration_path

spec/features/users_spec.rb

@@ -5,10 +5,10 @@ feature 'Users', feature: true do
   scenario 'GET /users/sign_in creates a new user account' do
     visit new_user_session_path
-    fill_in 'user_name', with: 'Name Surname'
-    fill_in 'user_username', with: 'Great'
-    fill_in 'user_email', with: 'name@mail.com'
-    fill_in 'user_password_sign_up', with: 'password1234'
+    fill_in 'new_user_name',     with: 'Name Surname'
+    fill_in 'new_user_username', with: 'Great'
+    fill_in 'new_user_email',    with: 'name@mail.com'
+    fill_in 'new_user_password', with: 'password1234'
     expect { click_button 'Sign up' }.to change { User.count }.by(1)
   end
@@ -31,10 +31,10 @@ feature 'Users', feature: true do
   scenario 'Should show one error if email is already taken' do
     visit new_user_session_path
-    fill_in 'user_name', with: 'Another user name'
-    fill_in 'user_username', with: 'anotheruser'
-    fill_in 'user_email', with: user.email
-    fill_in 'user_password_sign_up', with: '12341234'
+    fill_in 'new_user_name',     with: 'Another user name'
+    fill_in 'new_user_username', with: 'anotheruser'
+    fill_in 'new_user_email',    with: user.email
+    fill_in 'new_user_password', with: '12341234'
     expect { click_button 'Sign up' }.to change { User.count }.by(0)
     expect(page).to have_text('Email has already been taken')
     expect(number_of_errors_on_page(page)).to be(1), 'errors on page:\n #{errors_on_page page}'