Arthur Gavlyukovskiy opened SPR-16367 and commented
According to HttpInputMessage documentation body can never be null, although this is not true when you create mock response using MockRestResponseCreators without body, e.g. withBadRequest() or withSuccess().
Looks like changes should be done in MockHttpInputMessage to set ByteArrayInputStream with empty byte array if passed content is null. As well null check before closing stream in MockClientHttpResponse may be removed.
Affects: 4.3.12