HashWithIndifferentAccess better respects #to_hash

In particular, `.new`, `#update`, `#merge`, `#replace` all accept
objects which respond to `#to_hash`, even if those objects are not
Hashes directly.

1 files changed, 4 insertions, 3 deletions

diff --git a/activesupport/lib/active_support/hash_with_indifferent_access.rb b/activesupport/lib/active_support/hash_with_indifferent_access.rb
index 594a4ca938..a4ebdea598 100644
--- a/activesupport/lib/active_support/hash_with_indifferent_access.rb
+++ b/activesupport/lib/active_support/hash_with_indifferent_access.rb
@@ -55,9 +55,9 @@ module ActiveSupport
     end
 
     def initialize(constructor = {})
-      if constructor.is_a?(Hash)
+      if constructor.respond_to?(:to_hash)
         super()
-        update(constructor)
+        update(constructor.to_hash)
       else
         super(constructor)
       end
@@ -72,6 +72,7 @@ module ActiveSupport
     end
 
     def self.new_from_hash_copying_default(hash)
+      hash = hash.to_hash
       new(hash).tap do |new_hash|
         new_hash.default = hash.default
       end
@@ -125,7 +126,7 @@ module ActiveSupport
       if other_hash.is_a? HashWithIndifferentAccess
         super(other_hash)
       else
-        other_hash.each_pair do |key, value|
+        other_hash.to_hash.each_pair do |key, value|
           if block_given? && key?(key)
             value = yield(convert_key(key), self[key], value)
           end