Fix #6591. If a field with timezone isn't changed, we don't call will_change!.

1 files changed, 2 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
index c9b2edbd8c..7abe29c7d5 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -42,8 +42,9 @@ module ActiveRecord
                     time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
                   end
                   time = time.in_time_zone rescue nil if time
+                  changed = read_attribute(:#{attr_name}) != time
                   write_attribute(:#{attr_name}, original_time)
-                  #{attr_name}_will_change!
+                  #{attr_name}_will_change! if changed
                   @attributes_cache["#{attr_name}"] = time
                 end
               EOV