Merge branch 'master' into update_default_hsts_max_age

3 files changed, 4 insertions, 6 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/dirty.rb b/activerecord/lib/active_record/attribute_methods/dirty.rb
index 3de6fe566d..df4c79b0f6 100644
--- a/activerecord/lib/active_record/attribute_methods/dirty.rb
+++ b/activerecord/lib/active_record/attribute_methods/dirty.rb
@@ -32,9 +32,7 @@ module ActiveRecord
       # <tt>reload</tt> the record and clears changed attributes.
       def reload(*)
         super.tap do
-          @previously_changed = ActiveSupport::HashWithIndifferentAccess.new
           @mutations_before_last_save = nil
-          @attributes_changed_by_setter = ActiveSupport::HashWithIndifferentAccess.new
           @mutations_from_database = nil
         end
       end
@@ -114,12 +112,12 @@ module ActiveRecord
 
       # Alias for +changed+
       def changed_attribute_names_to_save
-        changes_to_save.keys
+        mutations_from_database.changed_attribute_names
       end
 
       # Alias for +changed_attributes+
       def attributes_in_database
-        changes_to_save.transform_values(&:first)
+        mutations_from_database.changed_values
       end
 
       private
diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index d8fc046e10..2907547634 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -131,7 +131,7 @@ module ActiveRecord
             def suppress_composite_primary_key(pk)
               return pk unless pk.is_a?(Array)
 
-              warn <<-WARNING.strip_heredoc
+              warn <<~WARNING
                 WARNING: Active Record does not support composite primary key.
 
                 #{table_name} has composite primary key. Composite primary key is ignored.
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index ebc2baed34..6e0e90f39c 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -7,7 +7,7 @@ module ActiveRecord
 
       class ColumnNotSerializableError < StandardError
         def initialize(name, type)
-          super <<-EOS.strip_heredoc
+          super <<~EOS
             Column `#{name}` of type #{type.class} does not support `serialize` feature.
             Usually it means that you are trying to use `serialize`
             on a column that already implements serialization natively.