fixed some issues with JSON encoding

- as_json in ActiveModel should return a hash
  and handle :only/:except/:methods options
- Array and Hash should call as_json on their elements
- json methods should not modify options argument

[#5374 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/serialization.rb b/activerecord/lib/active_record/serialization.rb
index 6ec406316a..ad3f7afd6f 100644
--- a/activerecord/lib/active_record/serialization.rb
+++ b/activerecord/lib/active_record/serialization.rb
@@ -5,7 +5,7 @@ module ActiveRecord #:nodoc:
     include ActiveModel::Serializers::JSON
 
     def serializable_hash(options = nil)
-      options ||= {}
+      options = options.try(:clone) || {}
 
       options[:except] = Array.wrap(options[:except]).map { |n| n.to_s }
       options[:except] |= Array.wrap(self.class.inheritance_column)