Be aware when using Hash or Array as default value for unknown Hash keys.

If you're using `Hash.new([])` or `Hash#default=` then it's the same object that is assigned to each unknown key, so you'll be adding to the same array when e.g. adding multiple AX attributes.

Author: Tobias Haagen Michaelsen

lib/openid/extensions/ax.rb

@@ -275,8 +275,7 @@ class KeyValueMessage < AXMessage
       def initialize
         super()
         @mode = nil
-        @data = {}
-        @data.default = []
+        @data = Hash.new { |hash, key| hash[key] = [] }
       end
 
       # Add a single value for the given attribute type to the

lib/openid/store/memory.rb

@@ -9,8 +9,7 @@ module Store
     class Memory < Interface
 
       def initialize
-        @associations = {}
-        @associations.default = {}
+        @associations = Hash.new { |hash, key| hash[key] = {} }
         @nonces = {}
       end