Version

v18.18.2

Platform

Linux hostname 5.15.131-1-MANJARO #1 SMP PREEMPT Thu Sep 7 11:05:18 UTC 2023 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

fetch("https://postman-echo.com/get", {
    headers: {
        Test: 1234,
        Host: "foo.postman-echo.com",
    },
})
    .then((r) => {
        return r.text();
    })
    .then((text) => console.log(text))
    .catch((e) => {
        console.log(e);
    });

run this code

The test works successfullty with v18.18.0 & v18.18.0

How often does it reproduce? Is there a required condition?

ive run the tests numerous times
the only condition I know is to run with v18.18.2

What is the expected behavior? Why is that the expected behavior?

• should send a request topostman-echo.com but should override the Host to foo.postman-echo.com Header
• the reason: this is how a http client should behave
• see vor example: curl -H 'Host: foobar.com' https://postman-echo.com/get

What do you see instead?

• the host header has not been overidden by the headers config
• the initial set host in the request url is taken

Additional information

• this was also tested in several docker images
  • node:18-alpine (contains bug)
  • node:18.18.2-alpine (contains bug)
  • node:18.18.2-alpine (no bug)