1 files changed, 23 insertions, 20 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index fe0e01db28..c7521422bb 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module AttributeMethods
     module Write
@@ -7,17 +9,19 @@ module ActiveRecord
         attribute_method_suffix "="
       end
 
-      module ClassMethods
+      module ClassMethods # :nodoc:
         private
 
           def define_method_attribute=(name)
-            safe_name = name.unpack("h*".freeze).first
+            safe_name = name.unpack1("h*".freeze)
             ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
+            sync_with_transaction_state = "sync_with_transaction_state" if name == primary_key
 
             generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
               def __temp__#{safe_name}=(value)
                 name = ::ActiveRecord::AttributeMethods::AttrNames::ATTR_#{safe_name}
-                write_attribute(name, value)
+                #{sync_with_transaction_state}
+                _write_attribute(name, value)
               end
               alias_method #{(name + '=').inspect}, :__temp__#{safe_name}=
               undef_method :__temp__#{safe_name}=
@@ -35,30 +39,29 @@ module ActiveRecord
           attr_name.to_s
         end
 
-        write_attribute_with_type_cast(name, value, true)
+        primary_key = self.class.primary_key
+        name = primary_key if name == "id".freeze && primary_key
+        sync_with_transaction_state if name == primary_key
+        _write_attribute(name, value)
       end
 
-      def raw_write_attribute(attr_name, value) # :nodoc:
-        write_attribute_with_type_cast(attr_name, value, false)
+      # This method exists to avoid the expensive primary_key check internally, without
+      # breaking compatibility with the write_attribute API
+      def _write_attribute(attr_name, value) # :nodoc:
+        @attributes.write_from_user(attr_name.to_s, value)
+        value
       end
 
       private
-        # Handle *= for method_missing.
-        def attribute=(attribute_name, value)
-          write_attribute(attribute_name, value)
+        def write_attribute_without_type_cast(attr_name, value)
+          name = attr_name.to_s
+          @attributes.write_cast_value(name, value)
+          value
         end
 
-        def write_attribute_with_type_cast(attr_name, value, should_type_cast)
-          attr_name = attr_name.to_s
-          attr_name = self.class.primary_key if attr_name == "id" && self.class.primary_key
-
-          if should_type_cast
-            @attributes.write_from_user(attr_name, value)
-          else
-            @attributes.write_cast_value(attr_name, value)
-          end
-
-          value
+        # Handle *= for method_missing.
+        def attribute=(attribute_name, value)
+          _write_attribute(attribute_name, value)
         end
     end
   end