Merge branch 'exceptions' with the following features:

* A Railtie API for registering new exceptions and their respective status code (check Active Record railtie for an example)

* Extraction of ShowExceptions middleware logging and debugging features into a middleware called DebugExceptions

Conflicts:
	actionpack/CHANGELOG.md

1 files changed, 7 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb
index 47133e77e8..c2e31579a4 100644
--- a/activerecord/lib/active_record/railtie.rb
+++ b/activerecord/lib/active_record/railtie.rb
@@ -22,6 +22,13 @@ module ActiveRecord
     config.app_middleware.insert_after "::ActionDispatch::Callbacks",
       "ActiveRecord::ConnectionAdapters::ConnectionManagement"
 
+    config.action_dispatch.rescue_responses.merge!(
+      'ActiveRecord::RecordNotFound'   => :not_found,
+      'ActiveRecord::StaleObjectError' => :conflict,
+      'ActiveRecord::RecordInvalid'    => :unprocessable_entity,
+      'ActiveRecord::RecordNotSaved'   => :unprocessable_entity
+    )
+
     rake_tasks do
       load "active_record/railties/databases.rake"
     end