Improvements per code review.

* General style fixes.
* Add changes to configuration guide.
* Add missing tests.

1 files changed, 3 insertions, 1 deletions

diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index b14f8b6e7f..8bbe149a1c 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -311,6 +311,8 @@ The schema dumper adds one additional configuration option:
 
 * `config.action_controller.action_on_unpermitted_parameters` enables logging or raising an exception if parameters that are not explicitly permitted are found. Set to `:log` or `:raise` to enable. The default value is `:log` in development and test environments, and `false` in all other environments.
 
+* `config.action_controller.always_permitted_parameters` sets a list of whitelisted parameters that are permitted by default. The default values are `['controller', 'action']`.
+
 ### Configuring Action Dispatch
 
 * `config.action_dispatch.session_store` sets the name of the store for session data. The default is `:cookie_store`; other valid options include `:active_record_store`, `:mem_cache_store` or the name of your own custom class.
@@ -773,7 +775,7 @@ error similar to given below will be thrown.
 ActiveRecord::ConnectionTimeoutError - could not obtain a database connection within 5 seconds. The max pool size is currently 5; consider increasing it:
 ```
 
-If you get the above error, you might want to increase the size of connection 
+If you get the above error, you might want to increase the size of connection
 pool by incrementing the `pool` option in `database.yml`
 
 NOTE. If you have enabled `Rails.threadsafe!` mode then there could be a chance that several threads may be accessing multiple connections simultaneously. So depending on your current request load, you could very well have multiple threads contending for a limited amount of connections.