Wrong result when updateing already existing items with timezone naive values.

[petschki]

Scenario

I have a JSON export with Events. The start and end values do not have a timezone info.

Frist import

The event is created with the correct (=same) start/end values as in the JSON export. ✅

Second import

Importing the same JSON the second time with the setting Update existing item does the following:

• DatetimeFieldDeserializer checks for existing value and its timezone (which is set on the first import)
• the timezone naive JSON value is assumed as UTC and gets converted to the current timezone. In my case +01:00 and all the events have a wrong time value plus 1h.

I'm not sure if this is a plone.restapi bug or if it should be handled here.