Revert "Merge pull request #6986 from kennyj/fix_6975"

This reverts commit 8905c1fb496641c3cdb7b3b816ae6d3d4b2c2b73.

Closes #8460

Conflicts:
	activerecord/test/cases/dirty_test.rb

1 files changed, 5 insertions, 14 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 39d81cf6ef..45810322de 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -42,14 +42,11 @@ module ActiveRecord
                   unless time.acts_like?(:time)
                     time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
                   end
-                  zoned_time   = time && time.in_time_zone rescue nil
-                  rounded_time = round_usec(zoned_time)
-                  rounded_value = round_usec(read_attribute("#{attr_name}"))
-                  if (rounded_value != rounded_time) || (!rounded_value && original_time)
-                    write_attribute("#{attr_name}", original_time)
-                    #{attr_name}_will_change!
-                    @attributes_cache["#{attr_name}"] = zoned_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! if changed
+                  @attributes_cache["#{attr_name}"] = time
                 end
               EOV
               generated_attribute_methods.module_eval(method_body, __FILE__, line)
@@ -63,12 +60,6 @@ module ActiveRecord
             time_zone_aware_attributes && !self.skip_time_zone_conversion_for_attributes.include?(name.to_sym) && column.type.in?([:datetime, :timestamp])
           end
       end
-
-      private
-      def round_usec(value)
-        return unless value
-        value.change(:usec => 0)
-      end
     end
   end
 end