Fetch request class headers from cloned request are not copied over which is inconsistent with browser

[calebmer]

Version

20.9.0

Platform

Darwin Calebs-MBP-2 21.4.0 Darwin Kernel Version 21.4.0: Mon Feb 21 20:35:58 PST 2022; root:xnu-8020.101.4~2/RELEASE_ARM64_T6000 arm64

Subsystem

undici

What steps will reproduce the bug?

const request1 = new Request('localhost:3000', {method: 'POST', headers: {a: 'b'}});
request1.headers.get('a'); // Ok: 'b'

const request2 = new Request(request1, {method: 'GET'});
request2.headers.get('a'); // Node.js returns null, Chrome returns 'b'

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

Reproduces 100% of the time

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

Expected behavior is request2.headers.get('a') returns 'b' like the browser.

What do you see instead?

request2.headers.get('a') returns null.

Additional information

No response

[KhafraDev]

duplicate of #50263