render consent info in correct locale

app/helpers/user_consent_helper.rb

@@ -38,10 +38,18 @@ module ::UserConsentHelper
     Setting.consent_required? && consent_configured?
   end
 
-  def user_consent_instructions(user)
-    language = user.try(:language) || Setting.default_language
+  ##
+  # Gets consent instructions for the given user.
+  #
+  # @param user [User] The user to get instructions for.
+  # @param locale [String] ISO-639-1 code for the desired locale (e.g. de, en, fr).
+  #                        `I18n.locale` is set for each request individually depending
+  #                        among other things on the user's Accept-Language headers.
+  # @return [String] Instructions in the respective language.
+  def user_consent_instructions(user, locale: I18n.locale)
     all = Setting.consent_info
-    all.fetch(language) { all.values.first }
+
+    all.fetch(locale) { all.values.first }
   end
 
   def consent_configured?

app/views/account/_user_consent_check.html.erb

@@ -11,4 +11,3 @@
     <%= t('consent.checkbox_label') %>
   </label>
 </section>
-

spec/views/account/register.html.erb_spec.rb

@@ -114,4 +114,38 @@ describe 'account/register', type: :view do
       end
     end
   end
+
+  context "with consent required", with_settings: {
+    consent_required: true,
+    consent_info: {
+      en: "You must consent!",
+      de: "Du musst zustimmen!"
+    }
+  } do
+    let(:locale) { raise "you have to define the locale" }
+
+    before do
+      I18n.with_locale(locale) do
+        render
+      end
+    end
+
+    context "for English (locale: en) users" do
+      let(:locale) { :en }
+
+      it "shows the registration page and consent info in English" do
+        expect(rendered).to include "new account"
+        expect(rendered).to include "consent!"
+      end
+    end
+
+    context "for German (locale: de) users" do
+      let(:locale) { :de }
+
+      it "shows the registration page consent info in German" do
+        expect(rendered).to include "Neues Konto"
+        expect(rendered).to include "zustimmen!"
+      end
+    end
+  end
 end