From 80a09caedc6fa67f95e78e45e7eb954f6b647b2c Mon Sep 17 00:00:00 2001 From: Eugene Kenny Date: Sun, 8 Apr 2018 23:06:48 +0100 Subject: Prevent changes_to_save from mutating attributes When an array of hashes is added to a `HashWithIndifferentAccess`, the hashes are replaced with HWIAs by mutating the array in place. If an attribute's value is an array of hashes, `changes_to_save` will convert it to an array of HWIAs as a side-effect of adding it to the changes hash. Using `merge!` instead of `[]=` fixes the problem, as `merge!` copies any array values in the provided hash instead of mutating them. --- activemodel/lib/active_model/attribute_mutation_tracker.rb | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'activemodel/lib') diff --git a/activemodel/lib/active_model/attribute_mutation_tracker.rb b/activemodel/lib/active_model/attribute_mutation_tracker.rb index 493be5bb88..1759f004a6 100644 --- a/activemodel/lib/active_model/attribute_mutation_tracker.rb +++ b/activemodel/lib/active_model/attribute_mutation_tracker.rb @@ -23,7 +23,7 @@ module ActiveModel attr_names.each_with_object({}.with_indifferent_access) do |attr_name, result| change = change_to_attribute(attr_name) if change - result[attr_name] = change + result.merge!(attr_name => change) end end end -- cgit v1.2.3