ESP8266HTTPClient sets Content-Length even on empty GET-requests

[dakhnod]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• I have tested that the issue is present in current master branch (aka latest git).
• I have searched the issue tracker for a similar issue.
• If there is a stack dump, I have decoded it.
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Platform

• Hardware: ESP8266
• Core Version:
• Development Env: Any
• Operating System: Any

Settings in IDE

Problem Description

Due to this line, the HTTP client always sets the Content-Length header.
I think this header should be omitted for GET-requests with a length of 0.

[mcspr]

Yup, RFC seems to imply we should not include it
https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.2
https://datatracker.ietf.org/doc/html/rfc7230#section-3.3

I would guess our client has a similar problem that Dart's one had at some point
dart-lang/sdk@6c254fa

Do you have an example of a server that breaks with current behavior?