Merge branch 'master' into add_roles_via_LTI

# Conflicts:
#	app/views/application/_breadcrumbs.html.slim
#	app/views/application/welcome.html.slim
#	app/views/exercise_collections/show.html.slim
#	app/views/external_users/index.html.slim
#	app/views/layouts/application.html.slim
#	app/views/proxy_exercises/index.html.slim
#	app/views/user_exercise_feedbacks/index.html.slim
#	app/views/user_mailer/send_thank_you_note.slim

app/controllers/concerns/lti.rb

@@ -22,6 +22,7 @@ module Lti
     if (exercise_id.nil?)
       session.delete(:consumer_id)
       session.delete(:external_user_id)
+      session.delete(:embed_options)
     else
       LtiParameter.where(consumers_id: consumer_id,
                          external_users_id: user_id,
@@ -148,6 +149,26 @@ module Lti
   end
   private :set_current_user
 
+  def set_embedding_options
+    @embed_options = {}
+    [:hide_navbar,
+     :hide_exercise_description,
+     :disable_run,
+     :disable_score,
+     :disable_rfc,
+     :disable_interventions,
+     :hide_sidebar,
+     :read_only,
+     :hide_test_results,
+     :disable_hints].each do |option|
+      value = params["custom_embed_options_#{option}".to_sym] == 'true'
+      # Optimize storage and save only those that are true, the session cookie is limited to 4KB
+      @embed_options[option] = value if value.present?
+    end
+    session[:embed_options] = @embed_options
+  end
+  private :set_embedding_options
+
   def store_lti_session_data(options = {})
     lti_parameters = LtiParameter.find_or_create_by(consumers_id: options[:consumer].id,
                                                     external_users_id: @current_user.id,