a few minor Rails 5 fixes

Change-Id: I6236c2bc4ce31fbcf501dcf16ad537e56a2a555a
Reviewed-on: https://gerrit.instructure.com/95674
Tested-by: Jenkins
Reviewed-by: Rob Orton <rob@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>

app/helpers/application_helper.rb

@@ -572,7 +572,7 @@ module ApplicationHelper
     parts.join(t('#title_separator', ': '))
   end
 
-  def cache(name = {}, options = nil, &block)
+  def cache(name = {}, options = {}, &block)
     unless options && options[:no_locale]
       name = name.cache_key if name.respond_to?(:cache_key)
       name = name + "/#{I18n.locale}" if name.is_a?(String)

config/initializers/strong_parameters.rb

@@ -48,7 +48,7 @@ end
 module ArbitraryStrongishParams
   ANYTHING = Object.new.freeze
 
-  def initialize(attributes = nil)
+  def initialize(attributes = (CANVAS_RAILS4_2 ? nil : {}))
     @anythings = {}.with_indifferent_access
     super
   end
@@ -107,7 +107,7 @@ module ArbitraryStrongishParams
     end
   end
 
-  def convert_hashes_to_parameters(key, value, assign_if_converted=true)
+  def convert_hashes_to_parameters(key, value, *args)
     return value if @anythings.key?(key)
     super
   end

lib/authentication_methods.rb

@@ -288,7 +288,7 @@ module AuthenticationMethods
       format.html {
         store_location
         flash[:warning] = I18n.t('lib.auth.errors.not_authenticated', "You must be logged in to access this page") unless request.path == '/'
-        redirect_to login_url(params.slice(:canvas_login, :authentication_provider))
+        redirect_to login_url(strong_params.permit(:canvas_login, :authentication_provider))
       }
       format.json { render_json_unauthorized }
     end

lib/canvas/request_forgery_protection.rb

@@ -5,7 +5,8 @@
 #
 module Canvas
   module RequestForgeryProtection
-    def form_authenticity_token
+    def form_authenticity_token(form_options: {})
+      # to implement per-form CSRF, see https://github.com/rails/rails/commit/3e98819e20bc113343d4d4c0df614865ad5a9d3a
       masked_authenticity_token
     end