`HashWithIndifferentAccess.new` respects the default value or proc on objects that respond to `#to_hash`.

Builds on the work of #12550 where `.new` will convert the object (that respond to `#to_hash`) to a hash and
add that hash's keys and values to itself.

This change will also make `.new` respect the default value or proc of objects that respond to `#to_hash`.
In other words, this `.new` behaves exactly like `.new_from_hash_copying_default`.

`.new_from_hash_copying_default` now simply invokes `.new` and any references to `.new_from_hash_copying_default`
are replaced with `.new`.

Added tests confirm behavior.

1 files changed, 18 insertions, 0 deletions

diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index dbbb2d77da..b71206d2e3 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -996,6 +996,24 @@ class HashExtTest < ActiveSupport::TestCase
     assert hash.key?('a')
     assert_equal 1, hash[:a]
   end
+
+  def test_new_with_to_hash_conversion_copies_default
+    normal_hash = Hash.new(3)
+    normal_hash[:a] = 1
+
+    hash = HashWithIndifferentAccess.new(HashByConversion.new(normal_hash))
+    assert_equal 1, hash[:a]
+    assert_equal 3, hash[:b]
+  end
+
+  def test_new_with_to_hash_conversion_copies_default_proc
+    normal_hash = Hash.new { 1 + 2 }
+    normal_hash[:a] = 1
+
+    hash = HashWithIndifferentAccess.new(HashByConversion.new(normal_hash))
+    assert_equal 1, hash[:a]
+    assert_equal 3, hash[:b]
+  end
 end
 
 class IWriteMyOwnXML