remove some kludge-caching of :nil

that was only needed in rails 2

Change-Id: I1e2a00f65237d45ac82daa19eaecf5c589171718
Reviewed-on: https://gerrit.instructure.com/61025
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/models/plugin_setting.rb

@@ -101,9 +101,8 @@ class PluginSetting < ActiveRecord::Base
 
   def self.cached_plugin_setting(name)
     plugin_setting = MultiCache.fetch(settings_cache_key(name)) do
-      PluginSetting.find_by_name(name.to_s) || :nil
+      PluginSetting.find_by_name(name.to_s)
     end
-    plugin_setting = nil if plugin_setting == :nil
     plugin_setting
   end
 
@@ -121,7 +120,7 @@ class PluginSetting < ActiveRecord::Base
   end
 
   def self.settings_cache_key(name)
-    ["settings_for_plugin2", name].cache_key
+    ["settings_for_plugin3", name].cache_key
   end
 
   def clear_cache

lib/feature_flags.rb

@@ -60,7 +60,7 @@ module FeatureFlags
   end
 
   def feature_flag_cache_key(feature)
-    ['feature_flag', self.class.name, self.global_id, feature.to_s].cache_key
+    ['feature_flag2', self.class.name, self.global_id, feature.to_s].cache_key
   end
 
   # return the feature flag for the given feature that is defined on this object, if any.
@@ -68,9 +68,8 @@ module FeatureFlags
   def feature_flag(feature)
     self.shard.activate do
       result = MultiCache.fetch(feature_flag_cache_key(feature)) do
-        self.feature_flags.where(feature: feature.to_s).first || :nil
+        self.feature_flags.where(feature: feature.to_s).first
       end
-      result = nil if result == :nil
       result
     end
   end

spec/apis/v1/feature_flags_api_spec.rb

@@ -304,7 +304,7 @@ describe "Feature Flags API", type: :request do
       enable_cache do
         flag = t_root_account.feature_flags.create! feature: 'course_feature', state: 'on'
         # try to trick the controller into inserting (and violating a unique constraint) instead of updating
-        MultiCache.fetch(cache_key) { :nil }
+        MultiCache.fetch(cache_key) { nil }
         api_call_as_user(t_root_admin, :put, "/api/v1/accounts/#{t_root_account.id}/features/flags/course_feature?state=off",
                          { controller: 'feature_flags', action: 'update', format: 'json', account_id: t_root_account.to_param, feature: 'course_feature', state: 'off' })
       end