Support plan

• is this issue currently blocking your project? (no):
• is this issue affecting a production system? (yes):

Context

• node version: 12.16.3
• module version with issue: 19.2.0
• last module version without issue: 19.1.1
• environment (e.g. node, browser, native): node
• used with (e.g. hapi application, another framework, standalone, ...): hapi application
• any other relevant information:
  After updating to v19.2.0 from v19.1.1 it was noticed that the headers of responses with no content now contain the content-type header with the value of null.
  Before v19.2.0, the content-type header was omitted for such responses.

What are you trying to achieve or the steps to reproduce?

The issue can be reproduced by returning an empty response from a route handler.
I suspect this may be due to changes here: ed0688c

  server.route({
      method: "GET",
      path: "/test",
      handler: (request, h) => {
         // response headers contain content-type as null on v19.2.0
         // response headers omit content-type  header on v19.1.1 and lower
        return h.response().code(204);
      },
  });

What was the result you got?

response headers containing content-type of null

What result did you expect?

response headers not containing content-type header